Patent Publication Number: US-8117764-B2

Title: Control system for particulate material drying apparatus and process

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. Ser. No. 11/199,744 filed on Aug. 8, 2005, granted on Aug. 2, 2011 as U.S. Pat. No. 7,987,613, which is a continuation-in-part of U.S. Ser. No. 11/107,152 filed on Apr. 15, 2005, which claims the benefit of U.S. provisional application Ser. No. 60/618,379 filed on Oct. 12, 2004, which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a control system for controlling a dryer apparatus. More specifically, the invention utilizes a general programmable computer system in communication with at least one continuous throughput dryer, such as a fluidized bed dryer, of an industrial processing plant. Additionally, the system is in communication with other functions or operations of the industrial processing plant that are operatively coupled to the throughput dryer. While this system may be utilized in many varied industries in an efficient and economical manner, it is particularly well-suited for use in electric power generation plants for controlling the reduction of moisture content in coal before it is fired. 
     BACKGROUND OF THE INVENTION 
     Throughout the last century electric power plants have been servicing an increasing number of customers. To be able to successfully provide power to these customers, the electric power plants have had to grow. As the power plants grew they became more complex requiring new control systems to monitor their operations. 
     Older power plants typically utilize several remote operators to control its operations. For instance, auxiliary operators work in the plant operating and monitoring various valves, switches, and gauges of boilers, turbines and generators to produce the electric power. Once the electricity is generated, switchboard operators control the flow of the electricity out of the electric power plant. Power distributors and dispatchers control the flow of the electricity through transmission lines to industrial plants and substations that supply residential and commercial customers with electricity. 
     In modern electric power plants, the duties of the traditional auxiliary operators, switch operators and distributors and dispatchers are combined in a central control room. The control room operator(s) control an automated control system consisting of a central computer in communication with various peripheral devices that monitor and/or control different parts of the electric power plant. 
     The following is a general discussion of the operation of an electrical power plant to provide a better understanding of what is being controlled by the conventional automated control system. Large electric power plants producing electricity from any electric generator that is turned by a turbine shaft in response to some energy source. While some electric power plants are operated by hydroelectric or nuclear energy sources, about 63% of the world&#39;s electric power and 70% of the electric power produced in the United States is generated from the burning of fossil fuels like coal, oil, or natural gas. The burning of fossil fuels in power plants need to be monitored very closely. Close monitoring is very important when a power plant burns coal. 
     Mined coal is burned in a combustion chamber at the power plant to produce heat used to convert water in a boiler to steam. This steam is then superheated and introduced to huge steam turbines whereupon it pushes against fanlike blades of the turbine to rotate a shaft. This spinning shaft, in turn, rotates the rotor of an electric generator to produce electricity. 
     Once the steam has passed through the turbine, it enters a condenser where it passes around pipes carrying cooling water, which absorbs heat from the steam. As the steam cools, it condenses into water which can then be pumped back to the boiler to repeat the process of heating it into steam once again. In many power plants, the water in the condenser pipes that has absorbed the heat from the steam is pumped to a spray pond or cooling tower to be cooled. The cooled water can then be recycled through the condenser or discharged into lakes, rivers, or other water bodies. Conventional control systems can monitor the above steps in the production of electricity from fossil fuels. Eighty-nine percent of the coal mined in the United States is used as the heat source for electric power plants. Unlike petroleum and natural gas, the available supplies of coal that can be economically extracted from the earth are plentiful. 
     There are four primary types of coal: anthracite, bituminous, subbituminous, and lignite. While all four types of these coals principally contain carbon, hydrogen, nitrogen, oxygen, and sulfur, as well as moisture, the specific amounts of these solid elements and moisture contained in coal varies widely. For example, the highest ranking anthracite coals contain about 98% wt carbon, while the lowest ranking lignite coals (also called “brown coal”) may only contain about 30% wt carbon. At the same time, the amount of moisture may be less than 1% in anthracite and bituminous coals, but 25-30% wt for subbituminous coals like Powder River Basin (“PRB”), and 35-40% wt for North American lignites. For Australia and Russia, these lignite moisture levels may be as high as 50% and 60%, respectively. These high-moisture subbituminous and lignite coals have lower heating values compared with bituminous and anthracite coals because they produce a smaller amount of heat when they are burned. Moreover, high fuel moisture affects all aspects of electric power unit operation including performance and emissions. High fuel moisture results in significantly lower boiler efficiencies and higher unit heat rates than is the case for higher-rank coals. The high moisture content can also lead to problems in areas such as fuel handling, fuel grinding, fan capacity, and high flue gas flow rates. 
     Bituminous coals therefore have been the most widely used rank of coal for electric power production because of their abundance and relatively high heating values. However, they also contain medium to high levels of sulfur. As a result of increasingly stringent environmental regulations like the Clean Air Act in the U.S., electric power plants have had to install costly scrubber devices upstream of the chimneys of these plants to prevent the sulfur dioxide (“SO 2 ”), nitrous oxides (“NO x ”), mercury compounds, and fly ash that result from burning these coals from polluting the air. 
     Lower-rank coals like subbituminous and lignite coals have gained increasing attention as heat sources for power plants because of their low sulfur content. Burning them as a fuel source can make it easier for power plants to comply with federal and state pollution standards. Also of great relevance is the fact that these subbituminous and lignite coals make up much of the available coal reserves in the western portion of the U.S. However, the higher moisture content of these lower-rank coal types reduces their heat values as a source of heat combustion. Moreover, such higher moisture levels can make such coals more expensive to transport relative to their heat values. They can also cause problems for industry because they break up and become dusty when they lose their moisture, thereby making it difficult to handle and transport them. 
     While natural gas and fuel oil have almost entirely replaced coal as a domestic heating fuel due to pollution concerns, the rising cost of oil and natural gas has led some factories and commercial buildings to return to coal as a heating source. Because of their higher heating values, bituminous and anthracite coals are generally preferred for these heating applications. 
     Coal is also the principal ingredient for the production of coke which is used in the manufacture of iron and steel. Bituminous coal is heated to about 2000° F. (1100° C.) in an air-tight oven wherein the lack of oxygen prevents the coal from burning. This high level of heat converts some of the solids into gases, while the remaining hard, foam-like mass of nearly pure carbon is coke. Most coke plants are part of steel mills where the coke is burned with iron ore and limestone to turn the iron ore into pig iron subsequently processed into steel. 
     Some of the gases produced during carbonization within the coke-making process turn into liquid ammonia and coal tar as they cool. Through further processing, these residual gases can be changed into light oil. Such ammonia, coal tar, and light oil can be used by manufactures to produce drugs, dyes, and fertilizers. The coal tar, itself, can be used for roofing and road surfacing applications. 
     Some of the gas produced during carbonization in the coke-making process does not become liquid. This “coal gas” burns like natural gas, and can provide heat for the coke making and steel-making processes. The alternative fuels industry has also developed processes for the gasification of coal directly without carbonization. High-energy gas and high-energy liquid fuel substitutes for gasoline and fuel oil result from such gasification processes. Thus, there are many valuable uses for coal besides its intrinsic heat value. 
     It has previously been recognized within the industry that heating coal reduces its moisture, and therefore enhances the rank and BTU production of the coal by drying the coal. Prior to its combustion in hot water boiler furnaces, drying of the coal can enhance the resulting efficiency of the boiler. 
     A wide variety of dryer devices have been used within the prior art to dry coal, such as rotary kilns, cascaded whirling bed dryers, elongated slot dryers, hopper dryers, traveling bed dryers, and vibrating fluidized bed dryers. The following dryer devices should give the reader an understanding of types of coal dryers developed thus far: U.S. Pat. No. 5,103,743 issued to Berg, U.S. Pat. No. 4,470,878 issued to Petrovic et al., U.S. Pat. No. 4,617,744 issued to Siddoway et al., U.S. Pat. No. 5,033,208 issued to Ohno et al, U.S. Pat. No. 4,606,793 issued to Petrovic et al., U.S. Pat. No. 4,444,129 issued to Ladt. While all of these different dryer devices may be used to remove moisture from particulate materials like coal, they are relatively complicated in structure, suffer from relative inefficiencies in heat transport, and in some cases are better suited for batch operations rather than continuous operations. 
     To remedy the above inefficiencies, fluidized-bed dryers or reactors have become well-known within the industry for drying coal. In such dryers, a fluidizing medium is introduced through holes in the bottom of the fluidized bed to separate and levitate the coal particles for improved drying performance. The fluidizing medium may double as a direct heating medium, or else a separate indirect heat source may be located within the fluidized bed reactor. The coal particles are introduced at one end of the reactor, and provide the propulsive means for transporting the particles along the length of the bed in their fluidized state. Thus, fluidized bed reactors are good for a continuous drying process, and provide a greater surface contact between each fluidized particle and the drying medium. See, e.g., U.S. Pat. Nos. 5,537,941 issued to Goldich; 5,546,875 issued to Selle et al.; 5,832,848 issued to Reynoldson et al.; 5,830,246, 5,830,247, and 5,858,035 issued to Dunlop; 5,637,336 issued to Kannenberg et al.; 5,471,955 issued to Dietz; 4,300,291 issued to Heard et al.; and 3,687,431 issued to Parks. 
     Many of these conventional drying processes, however, have employed very high temperatures and pressures. For example, the Bureau of Mines process is performed at 1500 psig, while the drying process disclosed in U.S. Pat. No. 4,052,168 issued to Koppelman requires pressures of 1000-3000 psi. Similarly, U.S. Pat. No. 2,671,968 issued to Criner teaches the use of updrafted air at 1000° F. Likewise, U.S. Pat. No. 5,145,489 issued to Dunlop discloses a process for simultaneously improving the fuel properties of coal and oil, wherein a reactor maintained at 850-1050° F. is employed. See also U.S. Pat. Nos. 3,434,932 issued to Mansfield (1400-1600° F.); and 4,571,174 issued to Shelton (≦1000° F.). 
     The use of such very high temperatures for drying or otherwise treating the coal requires enormous energy consumption and other capital and operating costs that can very quickly render the use of lower-ranked coals economically unfeasible. Moreover, higher temperatures for the drying process create another emission stream that needs to be managed. Further complicating this economic equation is the fact that prior art coal drying processes have often relied upon the combustion of fossil fuels like coal, oil, or natural gas to provide the very heat source for improving the heat value of the coal to be dried. See, e.g., U.S. Pat. Nos. 4,533,438 issued to Michael et al.; 4,145,489 issued to Dunlop; 4,324,544 issued to Blake; 4,192,650 issued to Seitzer; 4,444,129 issued to Ladt; and 5,103,743 issued to Berg. In some instances, this combusted fuel source may constitute coal fines separated and recycled within the coal drying process. See, e.g., U.S. Pat. Nos. 5,322,530 issued to Merriam et al; 4,280,418 issued to Erhard; and 4,240,877 issued to Stahlherm et al. 
     Efforts have therefore been made to develop processes for drying coal using lower temperature requirements. For example, U.S. Pat. No. 3,985,516 issued to Johnson teaches a drying process for low-rank coal using warm inert gas in a fluidized bed within the 400-500° F. range as a drying medium. U.S. Pat. No. 4,810,258 issued to Greene discloses the use of a superheated gaseous drying medium to heat the coal to 300-450° F., although its preferred temperature and pressure is 850° F. and 0.541 psi. See also U.S. Pat. Nos. 4,436,589 and 4,431,585 issued to Petrovic et al. (392° F.); 4,338,160 issued to Dellessard et al. (482-1202° F.); 4,495,710 issued to Ottoson (400-900° F.); 5,527,365 issued to Coleman et al. (302-572° F.); 5,547,549 issued to Fracas (500-600° F.); 5,858,035 issued to Dunlop; and 5,904,741 and 6,162,265 issued to Dunlop et al. (480-600° F.). 
     Several prior art coal drying processes have used still lower temperatures—albeit, only to dry the coal to a limited extent. For example, U.S. Pat. No. 5,830,247 issued to Dunlop discloses a process for preparing irreversibly dried coal using a first fluidized bed reactor with a fluidized bed density of 20-40 lbs/ft 3 , wherein coal with a moisture content of 15-30% wt, an oxygen content of 10-20%, and a 0-2-inch particle size is subjected to 150-200° F. for 1-5 minutes to simultaneously comminute and dewater the coal. The coal is then fed to a second fluidized bed reactor in which it is coated with mineral oil and then subjected to a 480-600° F. temperature for 1-5 minutes to further comminute and dehydrate the product. Thus, it is apparent that not only is this process applied to coals having relatively lower moisture contents (i.e., 15-30%), but also the coal particles are only partially dewatered in the first fluidized bed reactor operated at 150-200° F., and the real drying takes place in the second fluidized bed reactor that is operated at the higher 480-600° F. bed temperature. 
     Likewise, U.S. Pat. No. 6,447,559 issued to Hunt teaches a process for treating coal in an inert atmosphere to increase its rank by heating it initially at 200-250° F. to remove its surface moisture, followed by sequentially progressive heating steps conducted at 400-750° F., 900-1100° F., 1300-1550° F., and 2000-2400° F. to eliminate the water within the pores of the coal particles to produce coal with a moisture content and volatiles content of less than 2% and 15%, respectively, by weight. Again, it is clear that the initial 200-250° F. heating step provides only a limited degree of drying to the coal particles. 
     One of the problems that can be encountered with the use of fluidized bed reactors to dry coal is the production of large quantities of fines entrapped in the fluidizing medium. Especially at higher bed operating conditions, these fines can spontaneously combust to cause explosions. Therefore, many prior art coal drying processes have resorted to the use of inert fluidizing gases within an air-free fluidized bed environment to prevent combustion. Examples of such inert gas include nitrogen, carbon dioxide, and steam. See, e.g., U.S. Pat. Nos. 3,090,131 issued to Waterman, Jr.; 4,431,485 issued to Petrovic et al.; 4,300,291 and 4,236,318 issued to Heard et al.; 4,292,742 issued to Ekberg; 4,176,011 issued to Knappstein; 5,087,269 issued to Cha et al.; 4,468,288 issued to Galow et al.; 5,327,717 issued to Hauk; 6,447,559 issued to Hunt; and 5,904,741 issued to Dunlop et al. U.S. Pat. No. 5,527,365 issued to Coleman et al. provides a process for drying low-quality carbonaceous fuels like coal in a “mildly reducing environment” achieved through the use of lower alkane inert gases like propane or methane. Still other prior art processes employ a number of heated fluidizing streams maintained at progressively decreasing temperatures as the coal travels through the length of the fluidized bed reactor to ensure adequate cooling of the coal in order to avoid explosions. See, e.g., U.S. Pat. Nos. 4,571,174 issued to Shelton; and 4,493,157 issued to Wicker. 
     Still another problem previously encountered by the industry when drying coal is its natural tendency to reabsorb water moisture in ambient air conditions over time after the drying process is completed. Therefore, efforts have been made to coat the surface of the dried coal particles with mineral oil or some other hydrocarbon product to form a barrier against adsorption of moisture within the pores of the coal particles. See, e.g., U.S. Pat. Nos. 5,830,246 and 5,858,035 issued to Dunlop; 3,985,516 issued to Johnson; and 4,705,533 and 4,800,015 issued to Simmons. 
     In order to enhance the process economics of drying low-rank coals, it is known to use waste heat streams as supplemental heat sources to the primary combustion fuel heat source. See U.S. Pat. No. 5,322,530 issued to Merriam et al. This is particularly true within coking coal production wherein the cooling gas heated by the hot coke may be recycled for purposes of heating the drying gas in a heat exchanger. See, e.g., U.S. Pat. Nos. 4,053,364 issued to Poersch; 4,308,102 issued to Wagener et al.; 4,338,160 issued to Dellessard et al.; 4,354,903 issued to Weber et al.; 3,800,427 issued to Kemmetmueller; 4,533,438 issued to Michael et al.; and 4,606,793 and 4,431,485 issued to Petrovic et al. Likewise, flue gases from fluidized bed combustion furnaces have been used as a supplemental heat source for a heat exchanger contained inside the fluidized bed reactor for drying the coal. See, e.g., U.S. Pat. Nos. 5,537,941 issued to Goldich; and 5,327,717 issued to Hauk. U.S. Pat. No. 5,103,743 issued to Berg discloses a method for drying solids like wet coal in a rotary kiln wherein the dried material is gasified to produce hot gases that are then used as the combustion heat source for radiant heaters used to dry the material within the kiln. In U.S. Pat. No. 4,284,476 issued to Wagener et al., stack gas from an associated metallurgical installation is passed through hot coke in a coke production process to cool it, thereby heating the stack gas which is then used to preheat the moist coal feed prior to its conversion into coke. 
     None of these prior art processes, however, appear to employ a waste heat stream in a coal drying operation as the sole source of heat used to dry the coal. Instead, they merely supplement the primary heat source which remains combustion of a fossil fuel like coal, oil, or natural gas. In part, this may be due to the relatively high drying temperatures used within these prior art dryers and associated processes. Thus, the process economics for drying the coal products, including low-rank coals, continues to be limited by the need to burn fossil fuels in order to dry a fossil fuel (i.e., coal) to improve its heat value for firing a boiler in a process plant (e.g., an electric power plant). 
     Moreover, many prior art fluidized bed dryers can suffer from plugging as the larger and denser coal particles settle to the bottom of the dryer, and make it more difficult to fluidize the rest of the particles. Condensation within the upper region of the dryer can also cause the fluidized particles to agglomerate and fall to the bottom of the dryer bed, thereby contributing to this plugging problem. For this reason, many of the prior art fluidized dryer designs seem to be vertical in orientation or feature multiple, cascading dryers with fluidizing medium inlet jets directed to creating improved fluidizing patterns for the coal particles contained within the dryer. 
     The operation of a dryer unit such as a fluidized bed dryer at lower temperatures below 300° F. would be desirable, and could obviate the need to suppress spontaneous combustions of the coal particles within the dryer. Moreover, incorporation of mechanical means within the fluidized bed dryer for physically separating and removing larger, denser coal particles from the dryer bed region and eliminating condensation around the fluidized particles would eliminate potential plugging problems that can otherwise cause dryer inefficiencies. Perhaps more importantly for the present invention, none of the prior fluidized bed dryers discuss, disclose, teach or suggest a control system that controls the heated waste streams entering and/or leaving the fluidized bed dryer. 
     Controlling the drying process of coal prior to its introduction to the boiler furnace should improve the process economics of using low-rank coals like subbituminous and lignite coal. Such low-rank coal sources could suddenly become viable fuel sources for power plants compared with the more traditionally used bituminous and anthracite coals. The economical use of lower-sulfur subbitumionous and lignite coals, in addition to removal of undesirable elements found within the coal that causes pollution, would also be greatly beneficial to the environment. 
     SUMMARY OF THE INVENTION 
     A control system for controlling the fluidization of particulate matter such as coal. The control system includes a number of graphic user interfaces that interact with programmable logic to monitor and/or control various devices and apparatuses that regulate the particulate drying process. The graphic user interfaces allow an operator to more easily monitor and/or control these various devices. 
     The control system controls three basic operations or processes. First, it controls the particulate or coal handling, which entails conveying raw (wet) coal from at least one bunker for at least temporarily storing the raw coal; a vibrating feeder that receives the raw coal from the bunker and feeds it into a crusher where it is crushed and eventually conveyed to the dryer for drying. 
     Secondly, the control system controls fluid handling or the introduction of warmed fluids into the dryer. Fluid handling includes entails regulating the temperature of fluids such as air and water by controlling the mixing and or blending, either physically or via conduction, hot or warmed air or water and cooled or cold air or water. In an example embodiment, the control system regulates the flow of heated water from the cooling towers and using it to heat a stream of air and/or allowing it to flow into the dryer to assist in drying the raw coal. 
     Lastly, the control system controls the discharge of discarded or separated coal from the dryer. The control system also controls the discharge and storage of dried coal from the dryer and into a storage bunker. During the fluidization process, fine coal particles can be forced into a dust collector where they accumulate and are eventually conveyed to a bunker for storage or further processing. In the event that some coal or other objects are rejected, either because of content of pollutants, size, or foreign object, control system can control the process that conveys it away from the dryer. 
     One object of the present invention is to allow an electric power plant or other processing plants to maximize the production and efficiency of their goods by utilizing heated waste streams as efficiently as possible. One way that this is achieved is by using an integrated control system that is self balancing, cost effect, and easy to use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawing wherein: 
         FIG. 1  is a schematic illustration of an electric power plant having raw coal handling, coal drying, and dry coal storage operations. 
         FIG. 2  is a flow diagram illustrating an example embodiment of a control system for controlling the drying of particulate material such as coal. 
         FIG. 3  is an interactive graphic user interface illustrating auto select capabilities for different apparatuses of the electric power plant. 
         FIG. 4  is an interactive graphic user interface illustrating coal drying conveying overview for different apparatuses of the electric power plant. 
         FIG. 5  is an interactive graphic user interface illustrating coal drying fluid flow overview for an electric power plant. 
         FIG. 6  is an interactive graphic user interface illustrating coal drying tagging. 
         FIG. 7  is an interactive graphic user interface illustrating coal master menu having depressible icons to access other interactive graphic user interfaces. 
         FIG. 8A  is a schematic illustration of fluid handling and particularly fluid warming utilizing heated waste streams from other parts of the electric power plant. 
         FIG. 8B  is a schematic illustration of a coal dryer receiving the warmed fluids from the fluid handling operations of the electric power plant. 
         FIG. 9  is a flow diagram of portions of the fluid handling operations of the electric power plant the portions of the dryer they operate. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A control system for controlling the operation of a dryer apparatus for particulate materials within a low-temperature, open-air drying process without plugging in an industrial plant operation is provided by the invention. Such invention allows for the drying of the material on a continuous, higher-throughput, more economical basis, thereby enabling the use of lower-ranked (e.g., higher-moisture) material as a combustion on feedstock source that might not otherwise be viable within an industrial plant operation. Use and control of the dryer apparatus may also enable reduction in pollutants and other undesirable elements contained within the material before it is processed or combusted within the industrial plant operation. 
     Although the controller system of the present invention has application to many varied industries, such as food, chemical, and electronic industries, for illustrative purposes, the invention is described herein with respect to a typical coal-burning electric power generating plant, where removal of some of the moisture from the coal in a dryer is desirable for improving the heat value of the coal and the resulting boiler efficiency of the plant. Although particular embodiments of dryers will be discussed in describing example embodiments of the present invention, one skilled in the art will understand that the present invention can be used with other example embodiments of dryers for numerous items or goods. 
     Controlling the drying of coal in a fluidized bed with heated waste streams from the plant can enhance or even enable the use of low-rank coals like subbituminous and lignite coals. By reducing the moisture content of the coal, regardless of whether it constitutes low-rank or high-rank coal, other enhanced operating efficiencies may be realized, as well. For example, drier coal will reduce the burden on the coal handling system, including conveyers, and coal crushers in the electric generating plant. Since drier coal is easier to convey, this reduces maintenance costs and increases availability of the coal handling system. Drier coal is also easier to pulverize, so less “mill” power is needed to achieve the same grind size (coal fineness). With less fuel moisture, moisture content leaving the mill is reduced. This will improve the results of grinding the coal. Additionally, less primary air used to convey, fluidize, and heat the coal is needed. Such lower levels of primary air reduces air velocities and with lower primary air velocities, there is a significant reduction of erosion in coal mills, coal transfer pipes, coal burners, and associated equipment. This has the effect of reducing coal transfer pipe and mill maintenance costs, which are, for lignite-fired plants, very high. Reductions in stack emissions should also be realized, thereby improving collection efficiency of downstream environmental protection equipment. 
     The following definitions are provided to aid the reader in understanding the described example embodiment of the controller system. The definitions should therefore not be considered limiting but rather merely as an aid. Other definitions of the terms may likewise be applicable to the present invention. 
     For purposes of the present invention, “particulate material” means any granular or particle compound, substance, element, or ingredient that constitutes an integral input to an industrial plant operation, including but not limited to combustion fuels like coal, biomass, bark, peat, and forestry waste matter; bauxite and other ores; and substrates to be modified or transformed within the industrial plant operation like grains, cereals, malt, coffee, and cocoa. 
     In the context of the present invention, “industrial plant operation” means any combustion, consumption, transformation, modification, or improvement of a substance to provide a beneficial result or end product. Such operation can include but is not limited to electric power plants, coking operations, iron, steel, or aluminum manufacturing facilities, cement manufacturing operations, glass manufacturing plants, ethanol production plants, drying operations for grains and other agricultural materials, food processing facilities, and heating operations for factories and buildings. Industrial plant operations encompass other manufacturing operations incorporating heat treatment of a product or system, including but not limited to green houses, district heating, and regeneration processes for amines or other extractants used in carbon dioxide or organic acid sequestration. 
     As used in this application, “coal” means anthracite, bituminous, subbituminous, and lignite or “brown” coals, and peat. Powder River Basin coal is specifically included. 
     For purposes of the present invention, “quality characteristic” means a distinguishing attribute of the particulate material that impacts its combustion, consumption, transformation, modification, or improvement within the industrial plant operation, including but not limited to moisture content, carbon content, sulfur content, mercury content, fly ash content, and production of SO 2  and NO N , carbon dioxide, and mercury oxide when burned. 
     As used in this application, “heat treatment apparatus” means any apparatus that is useful for the application of heat to a product, including but not limited to furnaces, dryers, cookers, ovens, incubators, growth chambers, and heaters. 
     In the context of the present invention, “dryer” means any apparatus that is useful for the reduction of the moisture content of a particulate material through the application of direct or indirect heat, including but not limited to a fluidized bed dryer, vibratory fluidized bed dryer, fixed bed dryer, traveling bed dryer, cascaded whirling bed dryer, elongated slot dryer, hopper dryer, or kiln. Such dryers may also consist of single or multiple vessels, single or multiple stages, be stacked or unstacked, and contain internal or external heat exchangers. 
     For purposes of this application “principal heat source” means a quantity of heat produced directly for the principal purpose of performing work in a piece of equipment, such as a boiler, turbine, oven, furnace, dryer, heat exchanger, reactor, or distillation column. Examples of such a principal heat source include but are not limited to combustion heat and process steam directly exiting a boiler. 
     As used in this application, “waste heat source” means any residual gaseous or liquid by-product stream having an elevated heat content resulting from work already performed by a principal heat source within a piece of equipment within an industrial plant operation that is used for the secondary purpose of performing work in a piece of equipment instead of being discarded. Examples of such waste heat sources include but are not limited to cooling water streams, hot condenser cooling water, hot flue or stack gas, spent process steam from, e.g., a turbine, or discarded heat from operating equipment like a compressor, reactor, or distillation column. 
     As mentioned above, coal fired in the boiler furnace of an electric power plant shall be used as exemplary particulate material and industrial plant operation for purposes of this application, but it is important to appreciate that any other material that constitutes a useful, necessary, or beneficial input to an industrial plant operation is covered by this application, as well. 
     The control system of the present invention can control and/or monitor various components of any type of dryer and any processes that are connected thereto. The control system will be discussed as being able to control the fluidized bed coal dryers described in the U.S. Ser. No. 11/107,152, filed on Apr. 15, 2005, which claims the benefit of U.S. provisional application Ser. No. 60/618,379 filed on Oct. 12, 2004; U.S. Ser. No. 11/107,153, filed on Apr. 15, 2005, which claims the benefit of U.S. provisional application Ser. No. 60/618,379 filed on Oct. 12, 2004; and U.S. patent application entitled “Apparatus For Heat Treatment Of Particulate Materials”, filed on the same date as this application, which is a continuation-in-part of U.S. Ser. No. 11/107,152 filed on Apr. 15, 2005; U.S. Ser. No. 11/199,743 filed on Aug. 8, 2005, which is a continuation-in-part of U.S. Ser. No. 11/107,153 filed on Apr. 15, 2005; and U.S. provisional application Ser. No. 60/618,379 filed on Oct. 12, 1004, all of which are hereby incorporated by reference in their entirety. 
     A brief description of the process of drying coal at an electric power plant is provided to aid the reader in understanding the control system of the present invention. 
     Referring to the schematic illustration of an electric power plant of  FIG. 1 , after raw (wet) coal is brought to the electric power plant it is can be stored in a bunker  32  until it passes through a feed gate  34  and onto a vibrating feeder  36 . The vibrating feeder  36  moves the raw coal through a chute  37  and into a crusher  38 . The crusher  38  typically uses mechanical means to crush the raw coal to a generally predefined size. As the crushed coal falls from the crusher  38  it falls onto a sizing screen  40  that separates the coal and other material such as rocks and other debris by size. Raw coal of an acceptable predetermined size is permitted to fall through the sizing screen  40  and onto at least one feed conveyor  42  that feeds it into a hopper  44 . At least one feed vane  46  is operatively disposed to or in the hopper  44  to feed the raw crushed coal into a dryer  48 . In an example embodiment, the dryer  48  is a fluidized bed having a first stage  49   a  and a second stage  49   b . The dryer  48  operates with low-temperatures, wherein the total moisture on the surface of and within the pores of the coal particles is reduced to a predetermined level to yield “dried” coal having an average moisture level of approximately 28-30% wt. The coal is fluidized in the first stage  49   a  and then flows over or through to the second stage  49   b  where additional heat is applied to complete the drying process. After the raw coal is dried it is disposed on a transport or dry coal conveyor  50  that conveys the dried coal to bucket elevator  52  that lifts the dried coal and deposits it into a dried coal storage bunker  54  where it is stored until it is fed into a boiler for burning and ultimately electricity generation. In an example embodiment, multiple dried coal storage bunkers can be arranged such that once one is filled the dried coal can be automatically deposited into a subsequent bunker. In one embodiment, as illustrated in  FIG. 1 , cascading conveyor belts can be disposed above the bunkers to convey an overflow of coal to a subsequent bunker. 
     Referring to the example embodiment of  FIG. 2 , the control system  60  can comprise a general programmable computer  62  having a processor  64  controlling a memory unit  66 , a storage unit  68 , an input/output (I/O) control unit  70 , and at least one monitor  72 . One skilled in the art will recognize that other peripheral components such as printers, drives, keyboards, and the like can also be used in conjunction with programmable computer  62 . Additionally, one skilled in the art will recognize that programmable computer  62  can utilize known hardware, software and the like configurations of varying computer components to optimize the monitoring and/or control of a dryer  48 . 
     Continuing with  FIG. 2 , control system  60  can also include a software program  74  residing on the programmable computer  62  having a plurality of graphic user interfaces (GUIs) that permit the interaction, monitoring, and control between an operator and the dryer  48  and affiliated processes. Additionally, software program  74  includes a subsystem of feedback loops or networks to automatically monitor and/or control predetermined functions of the dryer  48 . 
     Referring back to  FIG. 1 , and as briefly described above, control system  60  controls at least three basic operations of a particulate or coal drying process. In the example embodiment of drying raw coal, the control system  60  controls coal handling, indicated as numeral  100 , which is the transportation of raw coal from the bunker  32  to the dryer  48 . It also controls the drying process indicated as numeral  200 . Lastly, control system  60  controls various operations of dried coal delivering and storage, indicated as numeral  300 , which includes delivering dried coal from the dryer  60  to a bunker  54  where it is stored until it is either processed or is sent to a boiler or furnace for generating electricity. 
     The following discussion will focus on the control of each section, division, or operation of the plant by control system  60 . It will follow the natural progression of the particulate or coal to be dried and the process, steps, or interactions of an operator with control system  10  to ensure the efficiency of the drying process. Control system  60  is ideally easily adaptable to controlling other processes and regulating devices that may not be described herein. One skilled in the art will recognize from the detailed description that control system  60  could be used to control sensors, transmitters, switches, gates, valves, and the like that would be used other non-described embodiments. 
     Graphic User Interface 
     Referring to  FIGS. 3-6 , software  74  includes at least one, but preferably multiple, graphic user interfaces (GUIs) to permit an operator to set, monitor and/or control various aspects of each of the stages of operation. In an example embodiment, the GUIs include Coal Drying Auto Select  400 , Coal Drying Coal Conveying Overview  420 , Unit Overview  481   a , Coal Dryer Air Flow Overview  460 , Coal Master Menu  480 , Information  481   e , Data Screen  481   f , and Coal Drying Tagging  700 . Other interactive screens can also be utilized with control system  60 . Therefore, the example GUIs should not be considered limiting but rather as exemplary examples. 
     Referring to the Coal Drying Auto Select GUI  400  of  FIG. 3 , an operator can pre-select particular plant operations to run under an automatic or manual state. On at least one of the GUIs an operator can set an Operating Mode of the entire coal drying process. In one example embodiment, an operator can either press, or select (via a dropdown menu) automatic control, manual control, pause or the like to select a predefined operational state of each of the devices or apparatuses under its control. For instance, in the automatic mode, each device that can operate automatically will be placed in an automatic state until such time as there is an operational change or the operator changes its state. 
     In the manual mode an operator can place a particular device under control of the control system  60  in an automatic state. In one example embodiment, as illustrated in  FIG. 3 , an operator can mark or check a box or similar marking indicator, to set that particular apparatus device in its automatic state. If an operator wants to remove a device from the auto mode, he or she can remove the mark from the check box. The state of the affected device will not immediately change. For example, if the device was running it will remain running unless its run permit is lost. If the device was off it will remain off until its run permit (permissive on state) is granted. The transition between auto mode and manual mode is seamless. 
     While a device is in the auto state, control system  60  automatically monitors and/or controls the operation of the device. Control system  60  also includes and monitors feedback loops from and/or between the devices. In one example embodiment, a change in the state of one of the devices can alter or change the state of other either manually or automatically controlled devices. Particular apparatus that can be selected for automatic operation will be discussed below in conjunction with the various operations and/or processes. 
     Referring to  FIG. 7 , when an operator begins the process they may be initially shown the Coal Master Menu  480  which permits them to select between any of the available GUIs. As an example, the Coal Master Menu  480  can include a dryer conveying icon  481   a , a unit overview icon  481   b , a dryer air and water icon  481   c , an auto selection icon  481   d , an information icon  481   e , and a data screen icon  481   f . An operator can select any of the icons to go directly to the selected GUI. The Coal Master Menu  480  permits an operator to quickly move between GUIs which in turn permits them to quickly monitor and control various aspects of the plant operations. The remainder of the example GUIs will be discussed in conjunction with the control of the various processes. Each of the other GUIs includes icons  481   a - 481   f  to permit an operator to quickly move between each of the GUIs. Additional the present invention includes other GUIs that are associated with each aspect of the coal drying operation. These GUIs will be discussed in conjunction with their particular operation. 
     Control of Coal Handling 
     As illustrated in  FIG. 1 , raw (wet) coal is temporarily stored in a bunker  32  before entering the coal handling system. Referring to the Coal Drying Coal Conveying Overview GUI  420  of  FIG. 4 , the amount of raw coal in bunker  32  can be displayed by a weight indicator  401  disposed on a graphic illustration of bunker  32 . Weight indicator  401  can display the weight of raw coal in tons or any other weight measurement. Control system  60  can monitor and/or control a level of the raw coal or particulate material in bunker  32 . In one example embodiment, a level switch can be operatively disposed in bunker  32  to monitor a level of coal therein and report back to control system  60  if the level does not decrease over a predetermined period of time. If the level of coal does not decrease over the predetermined period of time, it can indicate to control system  60  that bunker  32  is plugged. Control system  60  can then automatically shut down or stop the coal feeding and/or drying process. 
     A feed gate  34  regulates the coal or particulate material entering onto a vibrating feeder  36  that controls the feed rate of the coal. Feed gate  34  is typically in an open or closed state. However, in one example embodiment, feed gate  34  also has a permissive-to-open state that permits to automatically open. The permissive-to-open state is actuated when vibrating feeder  36  is in the on-state and when the level switch indicates bunker  32  is full of coal. Feed gate  34  will automatically shut off if vibrating feeder  36  is off and/or level switch indicates a low level of coal in bunker  32 . Feed gate  34  will also automatically close in the event there is an emergency shut off actuated by an operator. 
     Referring to the Coal Drying Coal Conveying Overview GUI  420  of  FIG. 4 , if feeder gate  34  is open, feeder gate indicator  402  will illuminate red. If feeder gate is closed it will illuminate green. In one example embodiment, as illustrated in  FIG. 4 , two feeder gate indicators  402  can be displayed. When both indicators are red it means the feeder gate  34  is open. When both indicators are green it means feeder gate  34  is closed. However, when feeder gate  34  is in mid-travel a left indicator is green and a right indicator is red. If both indicators are yellow feeder gate  34  is locked out and cannot be used. If both indicators are magenta feeder gate  34  is tagged out for repairs and the like. 
     Other colors and/or types of indicators such as numbers, symbols and the like can also be used to identify the operational status of feeder gate  34  or any other apparatus controlled by control system  60 . An operator can select feeder gate icon  402  to call up a control box that allows the operator to place feeder gate  34  in an open state, closed state or lock out state. 
     Referring to the Coal Drying Auto Select GUI of  FIG. 3 , an operator can select to automatically control vibrating feeder  36  by placing a check or like indicator next to the vibrating feeder icon  404   a . If the operator does not place a check next to vibrating feeder icon  404   a , he or she will be able to operate vibrating feeder  36  manually. However, by selecting vibrating feeder icon  404   a  the vibrating feeder  36  receives a signal to modulate its vibration and thereby regulate the feed rate of the coal. When vibrating feeder  36  is on it feeds raw coal into chute  37  that deposits the coal into a crusher  38  that reduces the size of the coal through mechanical means to a predetermined size or other dimension such as weight, shape and the like. 
     Referring to Coal Drying Coal Conveying Overview GUI  420  of  FIG. 4 , if vibrating feeder  36  is operating under predefined conditions a vibrating feeder indicator  404   b  will be illuminated red. However, if the vibrating feeder  36  is not operating under predefined conditions it will be illuminated green. In one embodiment, there are two vibrating feeder indicator portions  404   b . When both portions of vibrating feeder indicator  404   b  are red it indicates to an operator that vibrating feeder  36  is operating in auto mode. When one portion of vibrating indicator is red and one is green it indicates to an operator that vibrating feeder  36  is operating in manual mode. When both portions of vibrating feeder indicator  404   b  are green it indicates vibrating feeder  36  is off. The off indication is the same for automatic and manual modes. In one example embodiment, when both vibrating indicator portions  404   b  are illuminated yellow it means vibrating feeder  36  is locked out, while magenta indicates vibrating feeder  36  is tagged out, and white indicates vibrating feeder  36  is tripped. The vibrating feeder  36  will be tripped or shut down if a chute  37  feeding coal away from vibrating feeder  36  becomes plugged (detected by a level switch disposed therein) or if crusher  38  is turned off or shuts down. 
     When vibrating feeder  36  is in auto mode it cycles as predefined in software  74  logic. However, when vibrating feeder  36  is in manual mode it will run as long as permissive requirements are met. The permissive requirements for continued operation of vibrating feeder  36  are the running or operation of crusher  38  and chute  37  reporting back in a non-plugged state, or non-operational state. 
     In one embodiment, an operator can click on or otherwise select vibrating feeder indicator  404   b  to open another window that displays the current speed and/or spread of vibrating feeder  36 . When vibrating feeder  36  is in the auto mode an operator can input a feeder flow rate based on a weigh scale further down the coal handling line. In the manual mode, an operator can manually enter or input vibrating feeder  36  speed. 
     Control system  60  is also in communication with a crushing mechanism of crusher  38 . Referring to  FIG. 3 , an operator can check crusher icon  406   a  to set it for automatic operation or to leave it blank for manual operation. Under automatic operation the motor of the crushing mechanism will operate at a predefined speed measured in rotations-per-minute (rpm). As illustrated in  FIG. 4 , a crusher motor indicator  406   b  can display the rpms of the motor of the crushing mechanism. An operator may be able to manually alter the rpms at any time during the coal drying process. 
     Crusher  38  also has a permissive-to-start state that permits it to operate in the event sizing screen  40  is running and chute  37  is not plugged (as indicated by a level switch disposed therein). Referring to  FIG. 4 , at least one crusher indicator  406   c  will illuminate green if crusher  38  is operating and will illuminate red if it is not. In another embodiment, at least two crusher indicator portions  406   c  are displayed. In this embodiment, if both portions are red it indicates that crusher  38  is in auto mode, while two green indicator portions indicate that crusher  38  is stopped. When one indicator portion is red and the other is green it indicates that crusher  38  is in manual mode. Similar to other devices, when both portions are magenta crusher  38  is locked out and when both portions are white it indicates crusher  38  is tripped. Crusher will trip or shut down if chute  37  becomes plugged or screen  40  is turned off. In the auto mode crusher  38  will cycle according to the predefined logic of software  74 . 
     In the manual mode crusher  38  will cycle while the permissive requirements are met. An operator can also select indicator  406   b  to open another window to set rpms of crusher  38  within the devices&#39; limits. 
     Control system  60  is also in communication with a level switch operatively disposed or coupled to crusher  38  to monitor if crusher  38  becomes clogged. If crusher  38  becomes clogged a feedback loop of control system  60  can automatically stop vibrating feeder  36 . 
     Referring to  FIG. 3 , an operator can select a sizing screen icon  408   a  to set sizing screen  40  in either auto mode or manual mode. Permissive operation of sizing screen  40  requires operation of a raw coal feed conveyor  78   a  below sizing screen  40  so that sizing screen  40  does not become clogged because coal is not being conveyed away. It also requires operation of a bypass conveyor  76  that receives and conveys away oversized particulate material to a bunker for further processing or disposal. Lastly, permissive operation of sizing screen  40  requires chute  37  to be in an un-plugged state to ensure that coal will flow or fall onto sizing screen  40 . 
     Control system  60  can also be in communication with at least one level switch operatively disposed on sizing screen  40  to monitor if coal is flowing onto bypass conveyor  76  or feed conveyor  78   a . Control system  60  can also be used to control the rate of oscillation of independent frames of sizing screen  40 . By increasing or decreasing the rate of oscillation of the independent frames the rate of separation can also be controlled. In one embodiment, screen material of sizing screen  40  oscillates from a flat position toward an arched position to purge the oversized particulate material from the screen openings. 
     Referring to  FIG. 3 , an operator can select a bypass conveyor icon  410   a  to place the bypass conveyor  76  in either an auto mode or a manual mode. Permissive operation of bypass conveyor  76  requires operation of a dry coal conveyor  50 , chute  37  in an un-plugged state, emergency pull cords in non-pulled states and a belt alignment switch un-triggered. A change of state of any one or more of the required permissive states will trip bypass conveyor  76 , thereby stopping operations. 
     Turning now to  FIG. 4 , a bypass conveyor indicator  408   b  is illustrated to permit an operator to monitor and/or control bypass conveyor  76 . An operator can select indicator  408   b  to open another window to start, stop and/or lock out bypass conveyor  76 . Indicator  408   b  will illuminate red if bypass conveyor  76  is operating within predefined limits and/or there is no change in the states of the permissive requirements. If bypass conveyor  76  is not operating within predefined limits or there is a change of state of the permissive requirements, indictor  408   b  will be illuminated green. In one example embodiment, there are at least two bypass conveyor indicator portions  408   b . When both indicator portions  408   b  are red it indicates bypass conveyor  76  is operating in auto mode. When one indicator portion is red and the other indicator portion is green it indicates bypass conveyor  76  is operating in manual mode. Again, when both indicator portions  408   b  are yellow the device is locked out, while two white indicator portions  408   b  indicate a tripped device. Two magenta indicator portions  408   b  indicate a tagged out device. 
     In one embodiment, a weigh scale is operatively disposed to bypass conveyor  76  to monitor the amount of particulate material being conveyed. The weigh scale can send a signal back to control system  60  to gather and calculate measurements, totals, and history. Control system  60  can then archive the material for later retrieval. A permissive start of weigh scale requires bypass conveyor  76  operating. If dryer  48  stops operating weigh scale will trip or automatically shut down. 
     In one embodiment, control system  60  monitors and/or controls the speed of bypass conveyor  76 . Control system  60  is also in communication with a level switch that is in operative communication with bypass conveyor  76  to monitor if particulate material is conveyed from bypass conveyor  76  to dry coal conveyor  50 . 
     As illustrated in  FIG. 2 , bypass conveyor  76  dumps or deposits the rejected particulate material onto dry coal conveyor  50 . Referring to  FIG. 3 , an operator can select dry coal conveyor icon  412   a  to set either auto mode or manual mode for dry coal conveyor  50 . Permissive operation of dry coal conveyor  50  requires operation of bucket elevator  52 , an un-plugged state of chute  47 , full air pressure under conveyor belt, un-triggered belt alignment switch and operation of a blower  78  in fluid communication with dry coal conveyor  50 . If any of the permissive requirements are not met dry coal conveyor  50  will be tripped and automatically shut down. 
     Referring to  FIG. 4 , an operator can monitor and/or control dry coal conveyor  50  by a dry coal conveyor indicator  412   b  that illuminates red if dry coal conveyor  50  is operating and illuminates green if dry coal conveyor  50  is not operating. In one example embodiment, there are at least two indicator portions  412   b . When both indicator portions  412   b  are red dry coal conveyor  50  is in auto mode. When one indicator portion is red and the other indicator portion is green it indicates that dry coal conveyor  50  is in the manual mode. When both indicators are green dry coal conveyor  50  is stopped. Similar to other devices, yellow indicators mean a locked out device, magenta indicator means a tagged out device and white indicators mean a tripped device. 
     In one example embodiment, an operator can select indicator  412   b  to open a new window and select start, stop or locked out. Control system  60  can also in communication with a level switch operative coupled to dry coal conveyor  50  to monitor the conveyance of rejected particulate material from sizing screen  40 . If control system  60  does not detect rejected particulate material it can automatically stop dry coal conveyor  50 . 
     Referring again to  FIG. 3 , an operator can select a blower icon  414  to set blower  78  to either auto mode or manual mode. The blower  78  has the same permissive requirements as dry coal conveyor  50  and can trip if dry coal conveyor  50  is not operating. In one example embodiment, there is a time delay before shutting off blower  78  to permit additional drying of the particulate material thereon. In embodiment, the time delay can be 30 seconds, however, any time can be programmed into control system  60 . Referring to  FIG. 4 , blower  78  includes a blower icon  414   b  to indicate the status of blower  78  to the operator. In one embodiment, if a portion of blower icon  414   b  is red it indicates its running. If a portion of blower icon  414   b  is green it indicates blower  78  has stopped. A magenta color indicates the device is tagged out. Other color schemes, patterning and the like such as all grey can be used to indicate a loss of power to blower  78 . A bad PV can be indicated by magenta on grey, crosshatch, gradient or the like. 
     Referring again to  FIG. 3 , an operator can select a bucket elevator icon  416   a  to set bucket elevator  52  to either auto mode or manual mode. The bucket elevator  52  has permissive requirements of operation of dry coal conveyor  50  and an un-plugged state of chute  47 . Bucket elevator  52  can be tripped if chute  47  becomes plugged, dry coal conveyor  50  is not operating, low speed is detected or if an explosion is detected. 
     Referring to  FIG. 4 , a bucket elevator indicator  416   b  is provided to permit an operator to monitor the status of bucket elevator  52 . In one example embodiment, an operator can select bucket elevator indicator  416   b  to open another window to select start, stop and lock out bucket elevator  52 . 
     In one embodiment, if bucket elevator indicator  416   b  is red it indicates it&#39;s running. If bucket elevator indicator  416   b  is green it indicates it is non-operational. In another example embodiment, there are at least two bucket elevator indicator portions  416   b  to indicate various states of the bucket elevator  52 . If both indicator portions are red it indicates it is running in auto mode. If one indicator portion is red and another indicator portion is green it is running in manual mode. If both indicator portions are green it indicates it is non-operational. Similar to other devices, yellow indicators mean a locked out device, magenta indicator means a tagged out device and white indicators mean a tripped device. 
     The explosion suppression system operatively disposed in bucket elevator  52  is kept in an energized and armed state whenever bucket elevator  52  is operating. In one example embodiment, control system  60  can monitor the pressure of gases within bucket elevator  52 . Upon the detection of an explosion pressure spike control system  10  control system  60  can actuate and causes the discharge of inert chemicals from high pressure canisters. In another embodiment, explosion suppression system includes a control panel that permits the device to be turned on and off. It can also house the circuitry that monitors the pressure level and discharges the canisters appropriately. Control system  60  can also control a similar explosion suppression system operatively disposed to or within dryer  48  to suppress any fires that may develop. The control of the explosion suppression system for the dryer  48  is can be similar or identical to that of the bucket elevator  52 . 
     The bucket elevator  52  deposits the rejected particulate material onto a bunker feed conveyor  80  that is also monitored and/or controlled by control system  60 . Referring to  FIG. 3 , an operator can select a bunker conveyor icon  418   a  to set either auto mode or manual mode for bunker conveyor  80 . Permissive operation of bunker conveyor  80  requires an un-plugged state of chute  47 , full air pressure under conveyor belt of bunker conveyor  80 , un-triggered belt alignment switch and operation of a blower  82  in fluid communication with bunker conveyor  80 . If any of the permissive requirements are not met bunker conveyor  80  will be tripped and automatically shut down. 
     Referring to  FIG. 4 , an operator can monitor and/or control bunker conveyor  80  by a bunker conveyor indicator  418   b  that illuminates red if bunker conveyor  80  is operating and illuminates green if bunker conveyor  80  is not operating. In one example embodiment, there are at least two indicator portions  418   b . When both indicator portions  418   b  are red bunker conveyor  80  is in auto mode. When one indicator portion is red and the other indicator portion is green it indicates that bunker conveyor  80  is in the manual mode. When both indicators are green bunker conveyor  80  is stopped. Similar to other devices, yellow indicators mean a locked out device, magenta indicator means a tagged out device and white indicators mean a tripped device. 
     In one example embodiment, an operator can select indicator  418   b  to open a new window and select start, stop or locked out. Control system  60  can also be in communication with a level switch operative coupled to bunker conveyor  80  to monitor the conveyance of rejected particulate material from sizing screen  40 . If control system  60  does not detect rejected particulate material it can automatically stop dry coal conveyor  50 . 
     Referring again to  FIG. 3 , an operator can select a blower icon  420   a  to set blower  82  to either auto mode or manual mode. The blower  82  has the same permissive requirements as bunker conveyor  80  and can trip if bunker conveyor  80  is not operating. In one example embodiment, there is a time delay before shutting off blower  80  to permit additional drying of the particulate material thereon. In one embodiment, the time delay can be 30 seconds, however, any time can be programmed into control system  60 . Referring to  FIG. 4 , blower  80  includes a blower icon  420   b  to indicate the status of blower  80  to the operator. In one embodiment, if a portion of blower icon  420   b  is red it indicates its running. If a portion of blower icon  420   b  is green it indicates blower  80  has stopped. A magenta color indicates the device is tagged out. Other color schemes, patterning and the like such as all grey can be used to indicate a loss of power to blower  80 . A bad PV can be indicated by magenta on grey, crosshatch, gradient or the like. 
     For particulate material or coal that is of a predetermined acceptable size, weight, and/or dimension, control system  60  controls a first feed conveyor  78   a  receiving the coal from sizing screen  40 . Referring to  FIG. 3 , an operator can select a first feed conveyor icon  422   a  to place the first feed conveyor  78   a  in either an auto mode or a manual mode. Permissive operation of first feed conveyor  78   a  requires operation of a second feed conveyor  78   b  to catch the coal from the first feed conveyor  78   a , chute  37  in an un-plugged state, emergency pull cords in non-pulled states and a belt alignment switch un-triggered. A change of state of any one or more of the required permissive states will trip first feed conveyor  78   a , thereby stopping operations. 
     Turning now to  FIG. 4 , a first feed conveyor indicator  422   b  is provided to permit an operator to monitor and/or control first feed conveyor  78   a . An operator can select indicator  422   b  to open another window to start, stop and/or lock out first feed conveyor  78   a . Indicator  422   b  will illuminate red if first feed conveyor  78   a  is operating within predefined limits and/or there is no change in the states of the permissive requirements. If first feed conveyor  78   a  is not operating within predefined limits or there is a change of state of the permissive requirements, indictor  422   b  will be illuminated green. In one example embodiment, there are at least two first feed conveyor indicator portions  422   b . When both indicator portions  422   b  are red it indicates first feed conveyor  78   a  is operating in auto mode. When one indicator portion is red and the other indicator portion is green it indicates first feed conveyor  78   a  is operating in manual mode. Again, when both indicator portions  422   b  are yellow the device is locked out, while two white indicator portions  422   b  indicate a tripped device. Two magenta indicator portions  422   b  indicate a tagged out device. 
     The acceptable raw coal from first feed conveyor  78   a  is deposited on second feed conveyor  78   b , which then deposits the raw coal onto a third feed conveyor  78   c  that carries the raw coal to the dryer  48 . Second and third feed conveyors  78   b  and  78   c  respectively have the same permissive requirements as first feed conveyor  78   a  except second feed conveyor  78   b  requires operation of third feed conveyor  78   c  and third feed conveyor  78   c  requires operation of air locks feeding dryer  48 , no carbon indicated from sensors operatively disposed in a hood of dryer  48 , and a temperature indication below 100 degrees Fahrenheit by sensor operatively disposed in dryer  48 . If any of the permissive requirements for the respective feed conveyors is absent, the particular feed conveyor will be tripped and shut down. 
     As illustrated in  FIG. 3 , a second feed conveyor icon  424   a  and a third feed conveyor icon  426   a  is provided for the operator to select between auto and manual modes. Additionally, as illustrated in  FIG. 4 , a second feed conveyor indicator  424   b  and a third feed conveyor indicator  426   b  is provided for the operator to monitor and/or control the second and third feed conveyors respectively. The color or indication scheme illustrated by the second and third feed conveyor indicators  424   b  and  426   b  respectively are identical to the color scheme of first feed conveyor indicator  422   b.    
     In one embodiment, a weigh scale is operatively disposed to third feed conveyor  78   c  to monitor the amount of coal material being conveyed into dryer  48 . The weigh scale can send a signal back to control system  60  to gather and calculate measurements, totals, and history. Control system  60  can then archive the material for later retrieval. A permissive start of weigh scale requires third feed conveyor  78   c  operating. If dryer  48  stops operating weigh scale will trip and automatically shut down. In one embodiment, weigh scale operatively coupled to third feed conveyor  78   c  can feedback to vibrating feeder  36  to regulate the rate of feeding coal through coal handling 100 operations. 
     In one embodiment, control system  60  monitors and/or controls the speed of third feed conveyor  78   c . Control system  60  is also in communication with a level switch that is in operative communication with third feed conveyor  78   c  to monitor if raw coal is conveyed from third feed conveyor  78   c  to dryer  48 . As the raw coal is conveyed along third feed conveyor  78   c  weigh scale determines if a target or predetermined set point for feed rate to the particulate dryer  48  has been achieved. The weigh scale is in operative communication with the vibrating feeder  36  to increase or decrease the rate of raw coal through the system. 
     The raw coal is then feed from the third feed conveyor  78   c  into a hopper  44  that feeds directly into dryer  48 . As the raw coal is conveyed or feed into hopper  44  control system  60  can monitor a level switch to monitor the amount of raw coal entering the dryer  48 . Additionally, control system  10  is in communication with a level transmitter operatively disposed in hopper  44  to transmit a level of raw coal in the hopper  44 . When a predetermined level is obtained level transmitter and/or control system  60  can regulate the operation of other components in the coal handling 100 to increase, reduce or stop the forward progress of the raw coal toward the dryer  48 . 
     Referring to  FIG. 1 , at least one feeder vane or air lock  46  can be operatively disposed at a juncture between hopper  44  and dryer  48  to feed the raw coal into an interior of dryer  48 . In one embodiment, air lock  46  is disposed in a conduit or bore such that there is not a continuous opening between the outer ambient environment and the interior of dryer  48 . This ensures that fluidized coal does not float out of dryer  48  back through hopper  44 . Other coal feeding configurations are also possible and are considered to be within the spirit and scope of the invention. 
     Referring to Coal Drying Auto Select GUI  400 , an operator can select at least one air lock icon  460   a  to permit automatic operation of air lock  46 . In one example embodiment, a second air lock icon  460   b  can be provided to control a second air lock assisting in feeding the raw coal into the dryer  48 . The automatic operation of air lock  46  can increase the air lock&#39;s speed as control system  60  receives a signal from a level switch operatively disposed in hopper  44  indicating that the hopper  44  is full or nearly full. In one example embodiment of the invention, the air lock  46  will run at a speed generally greater than the actual feed rates to ensure that the hopper  44  is clear or empty. 
     Air locks  46  can also include a permissive-to-start requirement to start an air lock motor if the dryer  48  is ready to operate, fluidizing air is sensed by flow transmitters in the dryer  48 , a first stage conveyor is running, and a dust collector fan is running. Other feedbacks effecting a permissive-to-start requirement are also possible and could include operation of any of the devices performing coaling handling functions, fluid handling and/or coal discharging. Air lock  46  can also include a trips-to-close requirement that automatically shuts down the air lock  46  if there is a low speed indication signal received from the crusher  38 , there is a fire detected, a signal is received from a carbon monoxide detector that levels of carbon monoxide are greater than a predetermined level, there is an increased temperature above a predetermined level (e.g., 100 degrees F) detected by feed conveyor  78   c , and/or there is a loss of pressure detected by a first stage  49   a  dryer pressure indicator that is transmitted to the control system by a pressure transmitter. Air lock  46  will also shut down if there is an emergency stop. 
     Referring to the Coal Drying Coal Conveying Overview GUI  420  of  FIG. 4 , at least one air lock indicator  462   a  is provided to permit an operator to monitor and/or control air lock  46 . In one embodiment, a second air lock indicator  462   b  is provided to permit an operator to independently control separate air locks if they are provided. If an operator selects either indicator  462   a  or  462   b  it will create or bring up a new window or screen that permits the operator to start, stop, and/or lock out the device. Other types of selectable operations such as pause and purge are also possible. 
     In one embodiment, the air lock indicators  462   a  and/or  462   b  can change colors to notify the operator of the operational status of the device. For example, red indicators  462   a  and  462   b  indicate that the air locks  46  are running, green indicators  462   a  and  462   b  indicate that the air locks  46  are stopped, white indicators  462   a  and  462   b  indicate that the air locks  46  are tripped or shut down, yellow indicators  462   a  and  462   b  indicate that the air locks  46  are locked out, and magenta indicators  462   a  and  462   b  indicate that the air locks  46  are tagged out. 
     Under normal operation air locks  46  run in auto mode and cycle with system start and stop logic. If an operator puts them in manual mode they will run as long as run the permissive-to-start are met and trips-to-stop do not occur. In auto mode, when two air locks are utilized, if one becomes disabled or stops the other one will increase speed to maximum and the coal feed rate is restricted to a potentially programmable predetermined rate that is controlled by at least vibrating feeder  36 . 
     Continuing with Coal Drying Coal Conveying Overview GUI  420  of  FIG. 4 , an air lock output point (OP) icon  464  is provided to allow an operator to input a desired set point for air locks  46 . The air lock OP icon  464  can be selected to open another window or screen to input the desired set point. Referring to the Coal Drying Auto Select GUI  400  of  FIG. 3 , if the OP icon  464  is not available an operator can select, set and biases the air locks  46  by using a biasing input portion of GUI  420 . 
     Once the raw coal is in the interior of the dryer  48 , it can be fluidized to dry and separate the raw coal by size and/or weight Separation by weight is possible because a fluidization system lifts the lighter coal into the air while raw coal, potentially having increased levels of environmental impurities (e.g., sulfur and nitrogen) tend to be heavier, thereby causing them to sink or drop to the bottom of the dryer  48 . 
     Referring to  FIG. 1 , several control system  60  can control several conveyors to move the heavier un-fluidized raw coal and the lighter dry coal from dryer  48 . In one example embodiment, control system  60  can control a first stage conveyor  84   a  that is operatively coupled to the first stage  49   a  of dryer  48  to convey the heavier un-fluidized coal to a bunker  54 . It can also control a transfer conveyor  84   b  disposed proximate the first stage conveyor to collect and transfer the raw coal from first stage conveyor  84   a  to the dry coal conveyor  50 , which then takes it to bucket elevator  52  and then on to bunker  54 . In another example embodiment, the raw coal from first stage conveyor  48   a  or transfer conveyor  48   b  can be collected, fluidized further or processed by another means to either dry the coal further or separate the coal from the environmental contaminants. 
     Referring to the Coal Auto Select GUI  400  of  FIG. 3 , an operator can use control system  60  to select auto control of first stage conveyor  84   a  and/or transfer conveyor  84   b  by selecting or checking a first stage conveyor icon  624   a  and a first stage transfer conveyor icon  624   b . Whether first stage conveyor  84   a  and transfer conveyor  84   b  is in auto mode or manual mode, control system  60  can control its operation. Referring to Coal Drying Coal Conveying Overview GUI  420  of  FIG. 4 , and Coal Drying Air Flow Overview GUI  460  of  FIG. 5 , a first stage conveyor indicator  85   a  and transfer conveyor indicator  85   b  is provided on both GUI  420  and GUI  460  (identical numbering is used on GUI  420  and GUI  460  for consistence) operator can monitor and/or control first stage conveyor  84   a  and transfer conveyor  84   b . Both of the indicators  85   a  and  85   b  provide an indication of its operational state by color. For example, red indicators  85   a  and  85   b  indicate the conveyors  84   a  and  84   b  are in a running state, green indicators  85   a  and  85   b  indicate that conveyors  84   a  and  84   b  are in a stopped state, white indicators  85   a  and  85   b  indicate that conveyors  84   a  and  84   b  are in a tripped or shut down state, yellow indicators  85   a  and  85   b  indicate that the conveyors  84   a  and  84   b  are in a locked out state, and magenta indicators  85   a  and  85   b  indicate that the conveyors  84   a  and  84   b  are in a tagged out state. Other types of identification means are possible such as numbers, pattern, and objects. 
     Referring to  FIG. 8B , in one embodiment, the raw coal that is conveyed on conveyor  84   a  can travel through a scrubber box  86  that fluidizes and further separates fine coal particles from larger raw coal. These fine coal particles are sent back into the first stage  49   a  of dryer  48  for further fluidization. The remaining large raw coal can be discharged onto conveyor  84   b  through at least one discharge gate  87   a . In one embodiment, as illustrated in  FIG. 8B , there can be two discharge gates selectively cover a dual branched scrubber box. The discharge gate  87   a  is controlled by control system  60  in either the auto mode or manual mode. Referring to the Coal Drying Auto Select GUI of  FIG. 3 , an operator can select between auto mode and manual mode by selecting discharge gate icons or boxes  87   b  and  87   c.    
     Referring to the Coal Drying Air Flow Overview GUI  460  of  FIG. 5 , discharge gate indicators  88   a  and  88   b  can display the discharge gate  87  operational status with color coding such as red indicators  88   a  and  88   b  indicate the discharge gate  87  is in an auto, manual, and/or open state, green indicators  88   a  and  88   b  indicate that discharge gate  87  is in a stopped or closed state, white indicators  88   a  and  88   b  indicate that discharge gate  87  is in a tripped or shut down state, yellow indicators  88   a  and  88   b  indicate that the discharge gate  87  is in a locked out state, and magenta indicators  88   a  and  88   b  indicate that the discharge gates  87  is in a tagged out state. Other types of identification means are possible such as numbers, pattern, and objects. 
     After the coal is fluidized and sent to the second stage  49   b  of dryer  48  it is discharged through at least one discharge air lock  468  onto dry coal conveyor  50 . Referring to Coal Drying Auto Select GUI  400 , an operator can select at least one discharge air lock icon  470   a - 470   c , if there is more than one discharge air lock  468 , to permit automatic operation of discharge air lock  468 . The automatic operation of discharge air locks  468  can increase in speed as control system  60  receives a signal from a level switch operatively disposed dryer  48 . By increasing in speed the discharge air lock  468  is able to more quickly empty dryer  48 . In one example embodiment, of the invention, the air lock  468  will run at a speed generally greater than the actual feed rates to ensure that the dryer  48  is clear, empty, or at least does not become clogged with coal. 
     Air lock  468  can also include a permissive-to-start requirement to start a discharge air lock motor if a conveyor that feeds the dried coal away from the dryer is running. Other feedbacks effecting a permissive-to-start requirement are also possible. Air lock  468  can also include a trips-to-close requirement that automatically shuts down the air lock  468  if the conveyor taking the dried coal away from dryer  48  stops. Air lock  468  can also be automatically shut down if there is an emergency stop. 
     Referring to the Coal Drying Overview GUI  420  of  FIG. 4 , at least one discharge air lock indicator is provided to permit an operator to monitor and/or control discharge air lock  468 . In one embodiment, three discharge air lock indicators  469   a ,  469   b  and  469   c  are provided to permit an operator to independently control separate air locks if they are provided. If an operator selects either indicator  469   a - 469   c  it will create or bring up a new window or screen that permits the operator to start, stop, and/or lock out the discharge air locks  469   a - 469   c.    
     In one embodiment, the discharge air lock indicators  469   a - 469   c  can change colors to notify the operator of the operational status of the device. For example, red indicators  469   a - 469   c  indicate that the air locks  468  are running, green indicators  469   a - 469   c  indicate that the air locks  468  are stopped, white indicators  469   a - 469   c  indicate that the air locks  468  are tripped or shut down, yellow indicators  469   a - 469   c  indicate that the air locks  468  are locked out, and magenta indicators  469   a - 469   c  indicate that the air locks  468  are tagged out. 
     Under normal operation air locks  468  run in auto mode and cycle with system start and stop logic. If an operator puts the discharge air locks  468  in manual mode they will run as long as run the permissive-to-start requirements are met and trips-to-stop events do not occur. In auto mode, when at least two discharge air locks are utilized, if one becomes disabled or stops the other one will increase its speed to maximum and the coal feed rate will be restricted to a programmable predetermined rate that is controlled by at the least vibrating feeder  36 . 
     Continuing with Coal Drying Overview GUI  420  of  FIG. 4 , an air lock output point (OP) icon  470  is provided to allow an operator to input a desired set point for air locks  468 . The air lock OP icon  470  can be selected to open another window or screen to input the desired set point. Referring to the Coal Drying Auto Select GUI  400  of  FIG. 3 , if the OP icon  470  is not available an operator can select, set and biases the air locks  468  by selecting or entering the desired value in the biasing input  466 . 
     Referring to  FIGS. 1 and 8B , fine particulate matter such as coal dust is moved, blown, suctioned and the like from second stage  49   b  of dryer  48  to a dust collector  546  where it is collected and later used or disposed of. Referring to  FIGS. 1 and 8B , a dust collector fan  90  upstream from the dust collector  546  and a dust collector bolster fan  92  down stream from the dust collector  546  aid in moving the fine coal dust into the dust collector  546 . 
     Control of the dust collector can be by control system  60  or by a Dwyer control panel. Control of dust collector includes pulse type cleaning of dust bags and creating a pulse frequency based on differential pressure drops across tube sheets in the dust collector  546 . Control system  60  can control permissive-to-start requirements that automatically start the dust collector  546 . Examples of permissive-to-start requirements include if control system  60  senses that a predetermined amount of air pressure is detected in the dryer  48 . The dust collector can also be tripped or automatically shut down if control system  60  senses that an amount of air pressure in the dryer  48  is below the predetermined limit; if a fire is detected; or if it receives a signal that dust particles are in the exhaust air, which could be caused by a broken bag sending out a signal or alarm. Control system  60  or the operator can then shut down the dryer  48  after a predetermined amount of time. The dust collector  546  can also shut down if there is an emergency shut down such as by an operator selecting or depressing an Emergency Button  94  on any of the GUIs  400 ,  420  or  460 . 
     Dust collector fan  90  and dust collector booster fan  92  can also be controlled by monitored and/or controlled by control system  60 . Referring to the Coal Drying Auto Select GUI  400  of  FIG. 3 , an operator can select between auto mode and manual mode by selecting dust collector fan icon  95   a  and/or dust booster fan icon  95   b . In the auto mode control system  60  will increase the speed of the fan when it senses a pressure somewhere in the system below a predetermined limit. Control system  60  can also control the fan&#39;s motor such that it can have a soft start or a speed ramp up. In one embodiment the dust collector fan  90  will automatically stop if dampers controlling the fluid entering the dryer  48  closed or if the dust collector booster fan  92  is off Dust collector fan  90  can also be tripped or shut down if control system  60  senses a fire, or there is a broken dust bag emitting dust particles into the exhaust. Pressing the emergency stop button  94  will also trip the dust collector fan. 
     The dust collector booster fan  92  will automatically start if dust collector fan  90  is running and will automatically stop if any of the conveyors  50 ,  78   a ,  78   b , and  78   c  stop, if the crusher  38  stops or the vibrating feeder  36  stops. The dust collector booster fan  92  will also automatically stop if a fire is detected or someone presses the emergency stop button  94 . 
     Referring to Coal Drying Coal Conveying Overview GUI  420  of  FIG. 4 , and Coal Drying Air Flow Overview GUI  460  of  FIG. 5 , a dust collector fan indicator  96   a  and a dust collector booster fan indicator  96   b  are provided to permit an operator to monitor various operational states of fans  90  and  92 . The indicators  96   a  and  96   b  will turn red when running in auto or manual mode, and will turn green when they are stopped. The fans  96   a  and  96   b  will turn white if they are tripped and will turn yellow when they are locked out. Lastly, the fans  96   a  and  96   b  will turn magenta if they are tagged out for repairs or cleaning. In one embodiment, the control of dust collector booster fan is accomplished via a manual flow control  97 . 
     Once the fine coal particles are collected in the dust collector  564  they can be conveyed to storage or burning in a furnace. Referring to  FIG. 8B , in one embodiment, at least one dust collector conveyor  98  is operatively coupled to the dust collector  546  to convey the fine coal dust away from the dust collector  546 . Referring to the Coal Drying Auto Select GUI  400  of  FIG. 3 , an operator can select a dust collector conveyor icon  99   a  to switch the conveyor  98  between auto and manual modes. In one embodiment of the invention, as illustrated in  FIG. 3 , multiple dust collector conveyor icons can be displayed to allow the operator to select which conveyors to run automatically and which to run manually. Referring to the Coal Drying Air Flow Overview GUI  460  of  FIG. 5 , at least one dust collector conveyor indicator  99   b  is provided to display the various operational states of the conveyor  98 . 
     In one example embodiment, control system  60  will turn on conveyor  98  when the dust collector  546  turns on and will shut off if the dust collector  546  shuts off. The control system  60  also allows permissive-to-start requirements that will start conveyor  98  if the discharge air locks  468  are running and will automatically be tripped or shut down if control system  60  senses hopper  44  is full, a low speed of fine particulate coming from conveyors  98  is sensed, or the discharge air locks of the second stage  49   b  are not running. Lastly, conveyor  98  will also automatically shut down if an operator presses the emergency stop button  94 . 
     Control of Fluid Handling 
     As described in more detail in the incorporated references and briefly described above, raw fluids such as air and water fluidize and dry the raw coal in dryer  48 . An advantage of the present invention is that coal need not be dried to absolute zero moisture levels in order to fire the power plant boilers on an economically viable basis. Instead, by using and controlling available waste heat sources to dry the raw coal to a sufficient level, the boiler efficiency can be markedly increased, while maintaining the processing costs at an economically viable level. This provides true economic advantage to the plant operator. Reduction of the moisture content of lignite coals from a typical 39-60% level to 10% or lower is possible, although 27-32% is preferable. This preferred level is dictated by the boiler&#39;s ability to transfer heat. Control system  60  preferably controls multiple plant waste heat sources entering dryer  48  in various combinations and methods to dry the raw coal or other particulate material without adverse consequences to plant operations. 
     In a typical power plant, waste process heat remains available from many sources for further use. One possible source is a steam turbine. Steam may be extracted from the steam turbine cycle to dry the raw coal. Another possible source of waste heat for drying raw coal is the thermal energy contained within flue gas leaving the plant. In a Rankine power cycle, heat is rejected from the cycle in the steam condenser and/or cooling tower. Heat rejected in a steam condenser typically used in utility plants represents a large source of waste heat, the use of which for a secondary purpose minimally impacts plant operation. A portion of this hot condenser cooling water leaving the condenser could therefore be diverted and used instead for coal drying. Engineering analyses show that, at full unit load, only 2% of the heat rejected in the condenser is needed to decrease coal moisture content by 4% points. Utilization of this heat source, solely or in combination with other available plant waste heat sources, provides optimal use of plant waste heat sources without adverse impact on plant operations. 
     Referring now to  FIGS. 4 and 5 , control system  60  indicates or displays a multi-staged fluidized bed drier. However, both single and multiple-stage dryers can be utilized to pre-dry and further clean the material before it is consumed within the industrial plant operation. Other commercially known types of dryers may be employed with control system  60  of the present invention. The heat treatment apparatus associated with the controller system  60  of the present invention also provides a system for removing fly ash, sulfur, mercury-bearing material, and other harmful pollutants from the coal using the material segregation and sorting capabilities of fluidized beds, in contrast to current prior art systems that attempt to remove the pollutants and other environmental contaminates after the coal has been burned. Removal of such pollutants and other environmental contaminants before the coal is burned eliminates potential harm that may be caused to the environment by the contaminants in the plant processes, with the expected benefits of lower emissions, coal input levels, auxiliary power needs to operate the plant, plant water usage, equipment maintenance costs caused by metal erosion and other factors, and capital costs arising from equipment needed to extract these contaminants from the flue gas. 
     Turning now to  FIGS. 8A and 8B , schematics illustrating fluid (air and/or water) flow or fluid handling into, through and out of dryer  48  is provided. Control system  60  monitors and/or controls various devices that regulate the flow rates and temperatures of the fluids. In one example embodiment, dryer  48  uses two processes to lower the moisture content of raw coal and carry away the excess moisture. Referring to  FIG. 9 , in basic terms, which are described in greater detail in the incorporated applications, there is a hot air system  500  and a closed loop hot water system  608  that work together to increase an internal temperature of dryer  48  that is needed to dry the raw coal. 
     Control of Hot Air System Entering Dryer 
     The hot air system  500  fluidizes and heats the raw coal in dryer  48 . Additionally, hot air system  500  carries off excess moisture from the raw coal, thereby aiding in drying the raw coal. In one example embodiment, hot hair system  500  can receive heated primary air (PA) from air heated by steam waste heat, condenser waste heat and/or flue gas waste heat. Hot PA is taken or blown by a hot PA blower  508  fluidly coupled to a duct downstream of an air heater that increases the temperature of the hot PA. The flow of hot PA is regulated by isolation gate  523 . The hot PA is further regulated by an upstream control damper  524 . After passing through control damper  524 , hot PA enters hot air coil  526  where it is warmed to a predefined or selectable temperature. Once warmed in hot air coil  526  the hot PA flows into mixing box  528  where it blends with cold PA air that is taken from a duct downstream of the PA fan  530 . Cold PA then flows into an air heater where it is warmed to a predefined or selectable temperature. After flowing from the air heater, cold PA flows through an isolation gate  530  then to a control damper  532  before entering mixing box  528  where it blends with the hot PA. 
     A cold PA bypass  536  comprising a 12 inch diameter duct is disposed between the cold PA and an upstream side of hot air coil  526 . This air duct has a cold PA bypass gate  534  that regulates the flow of cold PA to hot air coil  526  to cool the hot air coil  526  during routine maintenance and repair. In one embodiment of the invention, gate  534  is pneumatically operated. However, mechanical, electrical and mechanical-electrical devices can be utilized to regulate the flow of cold PA to hot air coil  526 . 
     The fluidizing air destined for dryer  48  is blended at the mixing box  528  by a static blending device  536 , known to those skilled in the art, which is inserted inside a 70×70 inch square duct at the discharge of mixing box  528 . Referring to  FIG. 8B , the warmed fluidizing air splits into multiple ducts  538   a  and  538   b  before it travels across the air heater floor  540  to the dryer  48 . Each individual duct is designed to have a long straight section so flow measuring devices can be used on each duct feeding the dryer  48 . In one example embodiment, a first fluidizing damper  542   a  and a second fluidizing damper  542   b  are in fluid communication with ducts  538   a  and  538   b  to regulate an amount of fluidizing air entering a first stage  544   a  and a second stage  544   b  of dryer  48  respectively. 
     After fluidizing the raw coal, the fluidizing air or exhaust air passes from the dryer  48  to a bag house or dust collector  546  through six short vertical ducts from the roof of the dryer  48  to the bottom of the bag house  546 . In one example embodiment, the ducts do not have dampers. However, in other embodiments the ducts can include dampers to regulate the flow of exhaust air into dust collector  546 . In another embodiment, there is a temperature and/or humidity probe located in at least one of the ducts to measure the temperature and/or humidity of the exhaust air. Initially these instruments may need to be moved to each of the ducts to check variability of the exhaust gas conditions. 
     In one example embodiment, the dust collector  546  is a pulse type with cloth filter bags over cages. The bag pulse frequency can be controlled by a timer provided by the bag house supplier. Exhaust air leaves the dust collector  546  to an induced draft fan  548  that is in fluid communication therewith. The induced draft fan  548  can then discharge to a vertical stack  550  that carries the moisture laden exhaust gas through the roof of a building. 
     Referring to  FIG. 3 , an operator is able to select between auto mode and manual mode of the above describe fluid regulating devices. In one example embodiment, an operator can select or check a hot PA shutoff gate icon  556   a , a hot PA shutoff blower icon  556   b , a hot air control damper icon,  556   c , a cold PA shutoff icon  556   d , a cold air control damper icon  556   e , and/or a cold PA bypass icon  556   f  to place the selected devices into or out of auto mode. 
     Referring to  FIG. 5 , after placing the fluid regulating devices in either auto mode or manual mode an operator is able to monitor the operational status of each of the devices by monitoring coal air flow overview GUI  460  of  FIG. 5 . In one example embodiment, GUI  460  includes a hot PA shutoff gate indicator  560  that monitors whether the gate  523  is in an open state or a closed state. In an example embodiment, hot PA shutoff gate indicator  560  comprises at least two indicator portions. Dual red indicator portions indicate an open gate state and dual green indicator portions indicate a closed gate state. One red indicator portion and one green indicator portion indicates a gate in mid travel. Dual yellow indicator portions indicate a gate in a locked out state, and dual magenta indicator portions indicate a gate in a tagged out state. 
     In one embodiment, a single click or similar selection by an operator on hot PA shutoff gate indicator  560  will bring up another window or screen that allows the operator to control the state of hot PA shutoff gate  523 . A double click or similar selection by an operator on hot PA shutoff gate indicator  560  will bring up another window or screen that displays the point detail of the hot PA shutoff gate  523 . Control system  60  can also control an auto feature of hot PA shutoff gate  523  for sequential starting and stopping of coal drying and a trip to close when required by logic of software  74  whether in manual mode or auto select mode. 
     An operator (manually) or control system  60  (automatically) closes hot PA shutoff gate  523  during normal shut down and opens hot PA shutoff gate  523  when dryer  48  is running. Hot PA shutoff gate  523  can have a permissive-to-open requirement of requiring that hot air control damper  524  is closed. Hot PA shutoff gate  523  will trip or shut down if there is an emergency stop, a fire is detected, various high temperature alarms are triggered, such as high temperature of circulating water in a discharge portion of hot air coil  526 , or if there is a pulverizer/boiler upset condition. 
     Continuing with  FIG. 5 , GUI  460  also includes a hot PA blower icon  562  to monitor the status of hot PA blower  508 . When blower icon  562  is red it indicates to an operator that the blower  508  is operation or on. When blower icon  562  is green it indicates to an operator that the blower  508  is non-operational or in an off state. A white blower icon  562  means that the blower is tripped or in a shutoff state, a yellow blower icon  562  means that the blower  508  is in a locked out state, and a magenta blower icon  562  means that the blower  508  is in a tagged out state. In one example embodiment, an operator can select blower icon  562 , which will bring up another window or screen that allows the operator to select between the various states. 
     Control system  60  also controls permissive requirements of blower  508 . Since the shutoff blower  508  is used to seal air on the shutoff gate  523  when in its closed state, blower  508  includes a permissive-to-start requirement of having hot PA gate  523  closed. Therefore, when gate  523  closes blower  508  automatically starts. In one example embodiment, blower  508  also includes a trip-to-start requirement when gate  523  closes to ensure that a proper air seal is created. Similarly, blower  508  includes a trip-to-stop requirement when gate  523  is open. This ensures that blower  508  does not blow the hot PA through hot air coils too quickly. 
     Referring to GUI  460  of  FIG. 5 , a hot PA control damper icon  564  displays the status or state of hot PA control damper  524 . For example, a red hot PA control damper icon  564  indicates that the damper  524  is in an open state or at the maximum open limit predefined and programmed in control system  60 . A green hot PA control damper icon  564  indicates that the damper  524  is in a closed state or at it closed maximum. A grey hot PA control damper icon  564  indicates that the damper  524  is at a mid travel or controlling position. 
     At least one position bar  566  can be provided on GUI  460  generally adjacent to hot PA control damper icon  564  to display the relative open/closed position of damper  524 . In one embodiment, a second position bar can be provided to indicate OP (?). Each of the position bars can be color coded. 
     An operator can select hot PA control damper icon  564  to place damper  524  into an auto mode, a manual mode, or a cascade mode. In auto mode and/or cascade mode, control system  60  balances the amount of hot PA and cold PA entering mixing box. In one embodiment, control system  60  receives inputs from a temperature sensor at a discharge of mixing box  528 , utilizes predefined set points to determine the proper air flow of hot and cold PA. 
     Control system  60  also controls permissive requirements of hot air control damper  524 . In one example embodiment, a permissive-to-open requirement includes if cold air control damper  532  is near a predefined target and a cold PA shutoff gate  530  is open. Hot air control damper  524  also includes a trip-to-close requirement when emergency stop is required, fire is detected and/or a high temperature (e.g., greater than 300 degrees Fahrenheit) of circulating water at a discharge port of hot air coil  526  is detected or a high temperature and/or uncontrolled temperature (e.g., greater than 350 degrees Fahrenheit) is detected at beyond the mixing box  528 . 
     Referring to GUI  460  of  FIG. 5 , a cold PA shutoff gate indicator  580  is provided that monitors whether the gate  530  is in an open state or a closed state. In an example embodiment, cold PA shutoff gate indicator  580  comprises at least two indicator portions. Dual red indicator portions indicate an open gate state and dual green indicator portions indicate a closed gate state. One red indicator portion and one green indicator portion indicates a gate in mid travel. Dual yellow indicator portions indicate a gate in a locked out state, and dual magenta indicator portions indicate a gate in a tagged out state. 
     In one embodiment, selection by an operator on cold PA shutoff gate indicator  580  will bring up another window or screen that allows the operator to control the state of cold PA shutoff gate  530 . Control system  60  can also control an auto feature of cold PA shutoff gate  530  for sequential starting and stopping of coal drying and a trip to close when required by logic of software  74  whether in manual mode or auto select mode. 
     An operator (manually) or control system  60  (automatically) closes cold PA shutoff gate  530  during normal shut down and opens cold PA shutoff gate  530  when dryer  48  is running. Cold PA shutoff gate  530  can have a permissive-to-open requirement of requiring that cold air control damper  523  is closed. Cold PA shutoff gate  530  will trip or shut down if there is an emergency stop, a fire is detected, or there is a pulverizer/boiler upset condition. 
     Referring to GUI  460  of  FIG. 5 , a cold PA control damper icon  570  displays the status or state of cold PA control damper  532 . For example, a red cold PA control damper icon  570  indicates that the damper  532  is in an open state or at the maximum open limit predefined and programmed in control system  60 . A green cold PA control damper icon  570  indicates that the damper  532  is in a closed state or at its closed maximum. A grey cold PA control damper icon  570  indicates that the damper  532  is at a mid travel or controlling position. 
     At least one position bar  572  can be provided on GUI  460  generally adjacent to cold PA control damper icon  570  to display the relative open/closed position of damper  532 . In one embodiment, a second position bar can be provided to indicate OP (?). Each of the position bars can be color coded to assist the operator in monitoring the status of damper  532 . 
     An operator can select cold PA control damper icon  570  to place damper  532  into an auto mode, a manual mode, or a cascade mode. In auto mode and/or cascade mode, control system  60  controls cold PA control damper  570  to control a pressure downstream of mixing box  528  and coordinates control with the hot air control damper  524  for proper energy balance, temperature, and flow requirements. In one example embodiment, control system  60  will use hot PA first to achieve a predefined temperature and flow. It will then use cold PA to prevent over temperature conditions while maintaining the predefined flow. Other combinations or mixing can also be done to obtain the proper temperature and/or flow. 
     Control system  60  also controls permissive requirements of cold air control damper  532 . In one example embodiment, a permissive-to-open requirement includes if cold PA shutoff gate  530  is open. A trips-to-close damper requirement occurs if there is an emergency shut down or if a fire is detected. 
     When the hot air coil  526  and/or the mixing box  528  need to be repaired, inspected, and the like cold PA can be diverted through cold PA bypass gate  534  to cool them down. In one embodiment, cold PA bypass gate  534  is manually operated by either an operator on the plant floor or by a control room operator uses control system  60 . GUI  460  includes a cold PA bypass gate indicator  574  to display the different states of cold PA bypass gate  534 . In one embodiment, a red cold PA bypass gate indicator  574  indicates the bypass gate  534  is in an open state, a green cold PA bypass gate indicator  574  indicates the bypass gate  534  is in a closed state, a yellow cold PA bypass gate indicator  574  indicates the bypass gate  534  is in a locked out state, and a magenta cold PA bypass gate indicator  574  indicates that the bypass gate  534  is in a tagged out state. In one embodiment, cold PA bypass gate indicator  574  comprises at least two indicator portions. In this embodiment, when one indicator portion is red and the other indicator portion is green it means that the bypass gate  534  is in mid-travel between opening and closing. The cold PA bypass gate  534  will automatically open if the hot PA shutoff gate  523  is closed and a temperature, generally greater than 200 degrees Fahrenheit, of hot PA flowing into hot air coil  526  is detected. The cold PA bypass gate will automatically close if there is a pulverizer/boiler upset condition, a fire is detected, or there is an emergency stop. 
     Referring to  FIGS. 8A and 8B , and as briefly discussed above, as the blended air flows from the mixing box  528  it flows through ducting  538   a  and  538   b  which feed or flow directly into a bottom of the first stage  49   a  and second stage  49   b  of dryer  48  to fluidize and dry the coal. The blended air also flows through sparging or dilution duct  538   c  and into a top of the dryer  48  to further fluidize and draw moisture out of the fluidized coal. Cold PA is also diverted toward dryer  48 . In order to be able to monitor the temperature of the blended air and cold PA entering the dryer  48 , at least one temperature sensor  576   a  is operatively disposed to the ducting. Additionally, at least one flow meter  577   a  is operatively disposed to at least one, but preferably all of ducts  538   a - 538   c  to measure the flow rate of the blended air through ducts  538   a - 538   c . Lastly, at least one pressure meter  578   a  is operatively disposed to at least one, but preferably all, of ducts  538   a - 538   c  to measure the pressure of the blended air or fluids entering the dryer  48 . Sensors and/or monitors can be operatively disposed in any of the ducting feeding into, through, or out of dryer  48  to ensure that all operations are monitored and controlled. 
     Referring to  FIG. 5 , an operator can monitor each of the measurements of the sensors  576   a ,  576   a ,  577   a , and  578   a  by observing GUI  460 . Graphic User Interface  460  includes at least one blended air temperature sensor icon  576   b  to display to an operator the temperature of the blended air in the ducting. Additionally, at least one flow meter icon  577   b  is provided to display the pressure of the blended air or other fluids through the ducts. Lastly, at least one pressure meter icon  578   b  is provided to display the pressure of the blended air or other fluids through any of the ducts. In one embodiment, the measurements will be automatically displayed as they are sent to GUI  460  by control system  60  as they are received by sensors  576   a ,  577   a , and  578   a . In another embodiment, the sensor icons  576   b ,  577   b , and  578   b  can either be wave over or clickable to display a separate window or screen with the received measurements. 
     Referring to  FIG. 8B , the blended air flow entering the dryer is regulated by dampers  542   a ,  542   b , and  542   c . Cold PA flowing into dryer  48  is regulated by dryers  542   d  and  542   e . A first stage damper  542   a  is in fluid communication with the first stage  544   a  of dryer  48  and a second stage damper  542   b  is in fluid communication with the second stage  544   b  of the dryer  48 . A dryer outlet dilution air damper  542   c  is in fluid communication with a top side of dryer  48 . A first stage scrub box damper  542   d  is in fluid communication with a first stage scrubber box  590  that is in fluid communication with the first stage  544   a  of dryer  48 . Lastly, a second stage scrub box damper  542   e  is in fluid communication with a second stage scrubber box  592  that is in fluid communication with the first stage  544   a  of dryer  48 . 
     An operator can utilize control system  60  to control each of the dampers  542   a - 542   e , thereby regulating the flow of the blended air and cold PA into the respective parts of dryer  48  and the first stage  590  and second stage  592  of the scrubber box. Referring to  FIG. 3 , GUI  400  includes a first stage fluidizing damper icon  558   a , a second stage fluidizing damper icon  558   b , a first stage scrubber damper icon  558   c , and a second stage scrubber damper icon  558   d  to permit an operator to monitor the operation of each of the dampers  542   a ,  542   b ,  542   c ,  542   d , and  542   e  regulating the flow of the blended air into dryer  48 . An operator can selecting or check any of the icons  558   a - 558   e  to allow control system  60  to automatically control dampers  542   a ,  542   b ,  542   c ,  542   d , and/or  542   e . In the auto mode, control system  60  modulates dampers  542   a - 542   e  to control flow into dryer  48 . In the manual mode an operator can enter parameters for each of the dampers  542   a - 542   e  in the data screen (?). 
     Referring to  FIG. 5 , GUI  460  includes a first stage fluidizing damper icon  580   a , a second stage fluidizing damper indicator  580   b , a dryer outlet damper indicator  580   c , a first stage scrubber damper indicator  580   d , and a second stage scrubber damper indicator  580   e , all of which permit an operator to monitor the operation of each of the dampers  542   a ,  542   b ,  542   c ,  542   d , and  542   e  regulating the flow of the blended air and cold PA into dryer  48 . Each of the damper indicators  580   a - 580   e  can indicate various operational states to the operator. The indicators can be a color, pattern, number, or the like. In one embodiment, a red color indicates that the dampers  542   a ,  542   b ,  542   c ,  542   d , and  542   e  are in an open state or at their maximum open limit predefined and programmed in control system  60 . A green color indicates that the dampers  542   a ,  542   b ,  542   c ,  542   d , and  542   e  are in a closed state. A grey color indicates that the dampers  542   a ,  542   b ,  542   c ,  542   d , and  542   e  are at a mid-travel or controlling position. 
     GUI  460  can also include at least one first stage position bar  582   a  proximate the first stage damper indicator  580   a , at least one second stage position bar  582   b  proximate the second stage damper indicator  580   b , and at least one dryer outlet damper position bar  582   c  proximate the dryer outlet air damper indicator  580   c . Additionally, GUI  460  can include a first stage scrubber position bar  582   d  proximate the first stage scrubber damper indicator  580   d  and a second stage scrubber position bar  582   e  proximate the second stage scrubber damper indicator  580   e . Each of the position bars  582   a - 582   e  display the relative open/closed position of dampers  542   a - 542   e . Each of the position bars  582   a - 582   e  can be color coded to assist the operator in monitoring the status of dampers  542   a - 542   w.    
     Control system  60  also controls permissive requirements of each of the dampers  542   a - 542   e . The first stage air damper  542   a  will close when as flow meter inline with the first stage air damper  542   a  increases beyond a predefined flow rate. In one example embodiment, a permissive-to-open requirement includes if the dryer  48  is ready to operate, pressure at mixing box  528  is at a predefined target, plus or minus an allowable deviation, temperature in the air stream leaving the mixing box  528  is not greater than 150 degrees, temperature in the first stage  544   a  of dryer  48  is not greater than 140 degrees Fahrenheit, there is no indication of carbon monoxide detected by a carbon monoxide sensor  584  disposed outside of the dust collector  546 , and the dust collector  546  is running. The first stage air damper  542   a  also ha a permissive-to-close requirement if the coal feed has stopped. Lastly, the first stage air damper  542   a  has a trip-to-close requirement when there is a fire detected, a temperature in the air stream leaving the mixing box  528  is greater than 350 degrees Fahrenheit, any thermal sensor  586  in the first stage  544   a  of the dryer  48  is greater than 170 degrees Fahrenheit, if carbon monoxide is detected by the carbon monoxide sensor  584 , the dust collector is not running, or there a pressure at the top of the dryer bed greater than a predefined limit. 
     The permissive requirements for the second stage air damper  542   b  is the same a the permissive requirements for the first stage air damper  542   a , except that the second stage air damper  542  will automatically open if control system  60  receives signals from any of the thermal sensors  588  in the second stage  544   b  of dryer  48 , the exhaust duct, or a signal is received that the dust collector has an internal temperature less than 140 degrees Fahrenheit. Additionally, the second stage air damper  542   b  will automatically close if the control system  60  receives a signal from any of the thermal sensors  588  that the interior of the second stage  544   b  is greater than 180 degrees Fahrenheit. 
     The permissive requirements of the dryer outlet dilution air damper  542   c  include regulating its closing if control system  60  receives a signal from an air flow meter with an increased air flow rate. It also includes a permissive-to-open requirement when the dryer  48  is ready to operate, and/or the pressure at the mixing box  528  is at its predetermined target pressure. The dryer outlet dilution air damper  542   c  will be tripped or shutoff if control system  60  receives a signal of a fire, if the pressure at the mixing box  528  varies from the predefined target pressure by more than a predefined allowable deviation, if the dust collector fan is running, and/or there is an emergency stop. 
     The permissive requirements for the first stage scrubber box damper  542   d  and the second stage scrubber box damper  542   e  are the generally the same. However, depending upon the application their permissive requirements may also be different to optimize the efficiencies of the practiced process. In an example embodiment where they are the same, if control system  60  receives a signal from flow meters  577   a  downstream of the dampers  542   d  and  542   e  it indicates that the flow rate has increased and either one or both of the dampers  542   d  and/or  542   e  will close. Permissive-to-open requirements include if the dryer  48  is ready to run or operate, if the pressure at mixing box  528  is generally greater than a predefined target pressure, a signal is received from any of the first stage  544   a  thermal sensors  586  indicating an increase in an internal temperature greater than 140 degrees Fahrenheit, no signal is received from the carbon monoxide sensor  584  indicating the presence of carbon monoxide, and the dust collector fan is running. Lastly, the first stage scrubber box damper  542   d  and/or the second stage scrubber box damper  542   e  include the trip-to-close command when there is a fire detected, when a temperature greater than 350 degrees Fahrenheit is detected in the air stream leaving the mixing box  528 , when a signal is received from any of the thermal sensors  588  in either of the stages  544   a  and/or  544   b  of the dryer  48  that their internal temperature is greater than 170 degrees Fahrenheit, there is a signal received from the carbon monoxide sensor  584  that there is a presence of carbon monoxide, if the dust collector fan is not running, if a signal is received from a pressure sensor  578   a  that there is an increased pressure at the top of the dryer  48  bed, and/or there is an emergency stop. 
     Referring to  FIG. 8 , control system  60  also controls at least one first stage blowdown valve  590  in fluid communication with a plenum  592  of the first stage  544   a  of dryer  48  and at least one second stage blowdown valve  594  in fluid communication with a plenum  596  if the second stage  544   b  of dryer  48 . The first stage blowdown valve  590  and the second stage blowdown valve  594  are periodically opened to clean dust build-up in the clean air plenums  592  and  596 . When the blowdown valves  590  and  594  are opened any dust is blown up to the dust collector  546  where it is collected and either processed or disposed. 
     Referring to GUI  400  of  FIG. 3 , an operator can select a first stage blowdown icon  600   a  and at least one second stage blowdown icon  600   b  to set first stage blowdown valve  590  and/or second stage blowdown valve  594  in auto mode. In auto mode, control system  60  can regulate the time delay between openings and the length of time that each of the blowdown valves  590  and  594  are open. In one example embodiment, the time delay or frequency of opening can be between 2 and 120 minutes. The length of time open can be from anywhere between 10 to 120 seconds. Although ranges for the time delay and length of time open have been provided, one skilled in the art will appreciate that any range is permissible depending upon the process being practiced and the needs of the operator. Control system  60  also controls the permissive-to-open requirements of the blowdown valves  590  and  594 . In one embodiment, the permissive-to-open requirement is if a differential pressure is indicated between the first stage  544   a  and the second stage  544   b  of dryer  48 . The differential pressure required to trigger the opening of the blowdown valves  590  and  594  can be set by the operator. The blowdown valves  590  and  594  will automatically close if there is an emergency shutdown. 
     GUI  460  of  FIG. 5 , includes a first stage blowdown indicator  602   a  and at least one second stage blowdown indicator  602   b  to permit an operator to monitor and/or control the different operational states of the blowdown valves  590  and  594 . Similar to other operative devices of the present invention, red indicators  602   a  and  602   b  indicate the blowdown valves  590  and  594  are in an open state, green indicators  602   a  and  602   b  indicate the blowdown valves  590  and  594  are in a closed state, yellow indicators  602   a  and  602   b  indicate the blowdown valves  590  and  594  are in a locked out state, and magenta indicators  602   a  and  602   b  indicate the blowdown valves  590  and  594  are in a tagged out state. In one example embodiment, the blowdown indicators  602   a  and  602   b  comprise at least two indicator portions such that when one indicator portion is red and one indicator portion is green it indicates that the blowdown valves  590  and  594  are in mid-travel between the open and closed states. 
     As the coal is being feed into the dryer  48  by the coal handling system  100  it is fluidized, separated and dried by the blended air entering the dryer  48 . While in the dryer  48 , the coal is heated by water flowing through coils  604   a  and  604   b . The heated water flowing into dryer  48  is from a closed loop hot water system  608  that heats the fluidized coal bed  540 . Referring to  FIG. 9 , in one example embodiment, control system  60  controls heated water system  608  independently of hot air system  500  despite the fact that they may be heated by a similar pre-heater downstream. 
     Control of Heated Water Entering Dryer 
     Referring back to  FIGS. 8   a  and  8   b , in one example embodiment, the closed loop hot water system  608  includes at least 3 heated water regulating components. The components includes hot air coil  526  (often termed a heat exchanger) and coils  604   a  and  604   b  in the bed  540  of dryer  48 , a first circulating water pump  610   a  and, in some embodiments, a second circulating water pump  610   b  in fluid communication with heat hot air coil  526 . 
     The circulating water pumps  610   a  and/or  610   b  are used to mix hot water and cooler water returning from a first stage  49   a  of dryer  48  and/or a second stage  49   b  of dryer  48 . The system is able to re-circulate and reuse the heat remaining in the water exiting the dryer  48 . Mixing the cooler water exiting the dryer  48  with heated water or air permits the operator or plant to maximize its efficiencies it even further. 
     The circulating water pumps  610   a  and/or  610   b  can also control temperature of the water coils  604   a  and  604   b  in the first stage  49   a  and the second stage  49   b  of dryer  48 . Two existing or installed water pumps can also be used to control the main flow of water through hot air coil  526  and dryer  48  water coils  604   a  and  604   b.    
     Pumps  610   a  and/or  610   b  have permissive-to-start requirements that must be met before pumps  610   a  and  610   b  can be operated. In one example embodiment, the permissive-to-start requirements include a cleared emergency stop and a water system pressure at coils  604   a  and/or  604   b  above 100 psig. Pumps  610   a  and/or  610   b  can also have one or more permissive-to-stop requirements including a hot air coil  526  temperature no greater than 200 degrees Fahrenheit, a water temperature no greater than 200 degrees Fahrenheit, an air temperature flowing into air heater  526  not less than 150 degrees Fahrenheit, and a hot PA shutoff gate  530  in a closed state. Permissive-to-start and permissive-to-stop requirements can be added and/or removed depending upon the particulate material being dried and the dryer utilized. 
     Referring to  FIGS. 3 and 5 , circulating water pump icons  612   a  and  612   b  are available to permit an operator to control a flow of approximately 100 gallons per minute of hot water through hot coil  604   a  and/or  604   b  of dryer  48 . The temperature of the hot water will vary from 50 to 300 degrees Fahrenheit. Although a temperature range has been provided, variations in the temperature range are considered to be within the spirit and scope of the invention. Selection of pump icons  612   a  and  612   b  by an operator permits the operator to select an auto mode for sequential stopping and starting from software  74  of control system  60 . 
     Referring now to  FIG. 5 , control system  60  is in communication with at least one circulating pump indicator. In the example embodiment of  FIG. 5 , a first circulating pump indicator  614   a  and a second circulating pump indicator  614   b  are provided to display operational status of pumps  610   a  and  610   b  to an operator. Red pump indicators  614   a  and/or  614   b  can indicate an open state, green pump indicators  614   a  and/or  614   b  can indicate a closed state, yellow pump indicators  614   a  and/or  614   b  can indicate a locked out state, magenta pump indicators  614   a  and/or  614   b  can indicate a tagged out state, white pump indicators  614   a  and/or  614   b  can indicate a tripped or shut down state, and grey pump indicators  614   a  and/or  614   b  can indicate a loss of power to pumps  610   s  and/or  610   b . Other colors and pattern schemes are also envisioned within the spirit and scope of the invention. 
     In one example embodiment, selecting pump indicator  614   a  and/or  614   b  will bring up another window that will permit an operator to select between start, stop and lockout states for pumps  610   a  and  610   b . Other operational states such as pause and resume may also be offered for selection by an operator. 
     Referring to  FIGS. 5 and 8 , control system  60  is in communication with at least one valve  616  (see  FIG. 8 ) that is in fluid communication with circulating water pumps  610   a  and  610   b . The valve  616  is also in fluid communication with a cold water return  618  from dryer  48 . Valve  616  is positionable between an open state and a closed state. As illustrated in  FIG. 5 , at least one valve indicator  620  provides a color or similar indication to an operator of the status of the valve  616 . In one example embodiment, a red valve indicator  620  indicates an open valve  616 , a green valve indicator  620  indicates a closed valve  616 , yellow valve indicator  620  indicates the valve  616  is locked out, a magenta valve indicator  620  indicates a triggered state of the valve  616 , and a grey valve indicator  620  indicates a loss of power to valve  616 . 
     Tagging-Out Devices 
     Referring to  FIG. 6 , a tagging out GUI  700  is provided to allow an operator to easily and quickly tag out or shut down any of the above described devices controlled by control system  60 . It also allows an operator to manually enter the identification number associated with each of the above devices. In its simplest form, tagging out GUI  700  includes at least one chart or graph  702  having a listing  704  all of the devices either controlled by control system  60  or devices playing a part in facilitating the drying of the raw coal. Proximate the listing  704  of devices can be at least one identifier  706  that shows the current operational status of each device. The identifier  706  can be color coded as often described above, or it can be numbers, patterns, and the like. 
     Proximate the at least one identifiers  706  is at least one fillable box  708  that an operator can select, click or the like to fill in the identification number  710  of a tagged out device. In one embodiment, when an operator selects fillable box  708  another window or screen appears that will accept the identification number  710  of a device. Once a device is tagged out control system  60  prevents manual overrides of the device. Once repairs or cleaning are completed an operator can select the fillable box  708  having the repaired or cleaned device, highlight the identification number  710  and erase it. By erasing the identification number  710  it automatically un-tags the device allowing control system  60  or an operator or technician to place the device back in service. 
     Energy Control 
     By using the control system  60 , the operator is able to control the overall energy entering the dryer  48 . Several methods of controlling the energy entering dryer  48  is possible. In one example embodiment, control system  60  raises or lowers the temperature set point of the fluidizing air leaving the mixing body  528  and entering the dryer  48 . 
     Energy Control Method 1 
     The first calculation (E1) determines the amount of energy available to evaporate water by summation of sensible heat loss of the air and sensible heat loss of water:
 
 E 1=Hot Air flow rate×delta temperature of hot air×specific heat of air+cold air flow rate×delta temperature of cold air×specific heat of air+water flow rate×delta temperature of water×specific heat of water.
 
 E 1=((flow rate at the first stage 49 a  of the dryer 48+flow rate at the second stage 49 b  of the dryer 48+flow rate in duct 538 c )×(air temperature entering dryer 48−air temperature leaving dryer 48)×(0.242))+((flow rate in first scrubber box 590+flow rate in second scrubber box 592+air flow in a vent box)×(temperature entering scrubber boxes−temperature leaving dryer 48)×0.242))+(water flow rate between pumps 610 a  and  b  and dryer 48)×(water temperature leaving dryer 48−water temperature entering dryer 48)×1.0))
 
     Then by using a target set point for percent loss of weight from the coal or other particulate feed rate, a calculation is done to determine the energy required for the desired water removal rate (E2).
 
 E 2=(Target weight of water to remove from inlet coal flow rate,(e.g., 12%)×Time weighted average(1-15 min.)of coal on feed conveyor 78 c ×energy to heat(coal and water)and evaporate 1 pound of water).
 
     A ratio (R) comparison of energy available (E1) and energy required (e2) allows an adjustment to be made to the inlet air temperature target set point at the air flow entering the dryer  48 , such that a proper water removal target can be achieved.
 
 R=E 1 /E 2
 
     In one example embodiment of the invention, if R is less than 0.97, then control system  60  will increase the temperature of the air flowing into dryer  48 . If R is greater than 1.03, then control system  60  will decrease the temperature of air flowing into dryer  48 . Changes in the inlet air target set point for the air flowing into the dryer  48  can cause adjustments in the hot air damper  524 , thereby requiring adjustments to dryer  48  when a change in its internal pressure occurs. To permit the necessary adjustments, control system  60  can have a time delay program to avoid excess movement in the control devices. 
     Energy Control Method 2 
     The second method of energy control (E2). This method is very similar to E1 with the exception of measuring the air flow rate with at least one flow instrument operatively disposed in the cold PA air duct feeding the mixing box  528 . Control system  60  can use the mass flow rate of the cold PA air measured before the mixing box  528 ; the temperature of the cold PA air entering the mixing box  528 ; temperature of the hot PA air entering hot air coil  526 ; and temperature of the blended air to the dryer  48  to back calculate the mass flow rate of the hot PA air.
 
Flow(hot air entering mixing box 528)=cold PA air entering mixing box 528×((temperature of blended air entering the dryer 48−temperature of the cold PA air of the dryer 48)/(temperature of the hot PA air of the dryer 48−temperature of blended air entering the dryer 48).
 
Flow(mixed)=Flow(hot air entering mixing box 528)+temperature of the cold PA air flowing into the mixing box 528.
 
     Using the mass rates and temperatures of the hot and cold PA air control system  60  calculates the energy input to the dryer  48 . Next, the control system  60  calculates the amount of energy available to evaporate water by summation of the sensible heat loss of the air (in to out) and the sensible heat loss of the water (in to out). Using method 1, E1 is modified to:
 
 E 1=((flow rate(hot air entering mixing box)×(hot PA air temperature for dryer 48−air temperature leaving dryer 48)×(0.242))+((cold PA air flowing into mixing box 528)×(cold PA air temperature for dryer 48−air temperature leaving dryer 48)×0.242))+(water flow rate between pumps 610 a  and  b  and dryer 48)×(water temperature entering dryer 48−water temperature leaving dryer 48)×1.0))
 
 E 2=the target weight of water to remove from inlet coal flow rate×time weighted average(−15 min.)of coal flow on feed conveyor 78 c ×the energy to heat(coal and water)and evaporate 1 pound of water.
 
     A ratio (R) comparison of energy available E1 and energy required E2 allows an adjustment to be made to the inlet air temperature target set point of the air flowing into the dryer  48  so that the proper water removal target can be achieved.
 
 R=E 1 /E 2
 
The control of the ratio R is similar to the control of the ratio R in method 1 described above.
 
     Energy Control Method 3 
     A third method of controlling the energy entering the dryer  48  utilizes and measures the water carried in the exhaust stream and compares it to the target removal rate for water. In this embodiment, a humidity instrument is operatively disposed in ducting used to carry the exhaust gas stream from dryer  48 . 
     The first calculation (E1) determines the actual rate of water removal by the dryer  48  based on the amount of water measured in the exhaust gas stream. Using the mass flow rate of the cold PA air entering the mixing box  528 ; the temperature of the cold PA air for the dryer  48 ; the temperature of hot PA air for the dryer  48 ; and the temperature of blended air entering the dryer, control system  60  is capable of back calculating the mass flow rate of the hot PA air.
 
Hot Air=Cold Air((delta  T  cold to mixed)/(delta  T  hot to mixed))
 
Flow(hot air)=same as calculated in Method 2 above.
 
Flow(mixed)=Flow(hot air)+temperature of the cold PA air entering mixing box 528.
 
 E 1=Hot Air+Cold Air×Specific Humidity
 
 E 1=(Flow(hot air)+temperature cold PA air entering the mixing box 528×the specific humidity leaving the dust collector 546 and/or dust collector fan 90 on its way to the exhaust stack.
 
     Then by use of a target set point for percent loss of weight from the foal feed rate, control system  60  is capable of calculating the target water removal rate of the dryer  48  (E):
 
 E 2=the target weight of water to remove from inlet coal flow rate×time weighted average(1-15 min.)of coal flow on feed conveyor 78 c ×the energy to heat(coal and water)and evaporate 1 pound of water.
 
     A ratio (R) comparison of energy available E1 and energy required E2 allows an adjustment to be made to the inlet air temperature target set point of the air flowing into the dryer  48  so that the proper water removal target can be achieved.
 
 R=E 1 /E 2
 
The control of the ratio R is similar to the control of the ratio R in methods 1 and 2 described above.
 
in energy control The flow rate of the hot air is measured at the first stage  49   a  of the dryer  48 , the second stage  49   b  of the dryer  48  and the sparging or dilution duct  538   c.