Abstract:
A smoke generating system that complies with the EPA&#39;s standard design criteria, which call for separate black and white smoke generation chambers, a smoke stack with exhaust fan, an electronic opacity monitor (transmissometer), and a recording device for the transmissometer data. It includes a redesigned black smoke burn chamber that can be operated on diesel fuel only, eliminating the need for toluene. The white smoke generator is improved by including an automatic temperature control circuit to maintain fuel evaporation chamber temperatures between 700 and 900 degrees F. The unit also employs an induced draft fan (injector) dilution air system. This system eliminated the prior art fan system and significantly improves the dilution air flow characteristic by establishing a gradual differential flow gradient. The entire system is mounted on a self-contained chassis that can be transported to any desired location. In addition, audio equipment installed provides amplification for the instructor during classes.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of Provisional application 61/087,305 filed Sep. 8, 2008. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to training simulators designed to produce both black and white smoke plumes and particularly to training simulator designed to produce both black and white smoke plumes using relatively safe materials to produce the smoke. 
     2. Description of the Prior Art 
     As part of the effort to improve air quality, programs for monitoring emissions have been put into place. Monitoring emissions involves the visual observance of smoke plumes, both black and white, in order to determine whether the smoke plume is in compliance. Compliance is measured in terms of opacity of the smoke, as compared to known opacities measured from zero to one hundred percent opacity. 
     Before inspectors can begin to observe, they must be trained to determine opacities. This is done using training stations that produce smoke at a known opacities and then having the trainees use that information to learn and test their skills. Today, devices exist that generate smoke under controlled conditions. Typically, they incorporate both white and black smoke generators, an exhaust stack and a fan to diffuse and mix the smoke before it enters the stack. While these systems are useful, they have some drawbacks. First, they produce black smoke using toluene, which is a highly flammable and the smoke produced is a neurologic toxin. The use of toluene constitutes a significant safety risk. The prior art units also have a radial fan configuration that is typically located between the white and black smoke generators and the stack base. This configuration limits the dilution airflow characteristic, which can produce puffing and smoke density instabilities. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The instant invention is a training simulator designed to produce both black and white smoke plumes at known opacities from zero to one hundred percent. The visible emissions generator is normally employed in visible emissions training and certification programs to certify field enforcement personnel involved in visual observations of stationary source emissions. 
     The purpose of the instant smoke generator is to train observers to employ U.S. EPA (Environmental Protection Agency) reference Method 9 to determine the opacity of the emissions. VEGA smoke generators comply with EPA&#39;s standard design criteria, which call for separate black and white smoke generation chambers, a smoke stack with exhaust fan, an electronic opacity monitor (transmissometer), and a recording device for the transmissometer data. 
     The invention improves over the prior art because it uses a redesigned black smoke burn chamber that can be operated on diesel fuel only. Thus, the need for toluene is eliminated. The white smoke generator is also improved by including an automatic temperature control circuit in order to maintain fuel evaporation chamber temperatures between 700 and 900 degrees F. The unit also employs an induced draft fan (injector) dilution air system. This system eliminates the prior art fan system and significantly improves the dilution airflow characteristic by establishing a gradual differential flow gradient. 
     The entire system is mounted on a self-contained chassis that can be transported to any desired location. In addition, audio equipment installed provides amplification for the instructor during classes. 
     It is an object of this invention to create a smoke generator to train observers to employ U.S. EPA reference Method 9 to determine the opacity of the emissions. 
     It is another object of this invention to create a smoke generator that complies with the EPA&#39;s standard design criteria, which call for separate black and white smoke generation chambers, a smoke stack with exhaust fan, an electronic opacity monitor (transmissometer), and a recording device for the transmissometer data. 
     It is yet another object of this invention to create a smoke generator that utilizes a black smoke burn chamber that can be operated on diesel fuel only. 
     It is a further object of this invention to create a smoke generator in which the white smoke generator has an automatic temperature control circuit in order to maintain fuel evaporation chamber temperatures between 700 and 900 degrees F. 
     It is yet another object of this invention to create a smoke generator that employs an induced draft fan (injector) dilution air system that establishes a gradual differential flow gradient. 
     It is yet another object of this invention to create a smoke generator system that is mounted on a self-contained chassis that can be transported to any desired location. 
     It is yet another object of this invention to create a smoke generator that includes audio equipment installed on the chassis to provide amplification for the instructor during classes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of the assembled unit. 
         FIG. 2  is a front view of the assembled unit. 
         FIG. 3  is a detail of the remote control unit. 
         FIG. 3   a  is a partial side view of the remote control unit. 
         FIG. 4  is a detail of the control panel. 
         FIG. 5  is a top internal view of the black smoke generator. 
         FIG. 6  is a left side internal view of the black smoke generator. 
         FIG. 7  is a side detail of the stack showing the flow-diverter and straightening chamber located at the stack base. 
         FIG. 8  is a front detail of the stack showing the flow-diverter and straightening chamber located at the stack base. 
         FIG. 9  is a top sectional view of the flow-diverter and straightening chamber taken along the lines  9 - 9  of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIG. 1 , a plan view of the assembled unit is shown. The components are mounted on a chassis  200  (see  FIG. 2 ). The basic components of the unit include a black smoke combustion chamber  10  that has black smoke generator air inlet louvers  12 . The black smoke generator is supplied by a propane line  14 . There is a black smoke generator pilot light adjustment valve  16  in the fuel line as shown. The black smoke generator is also supplied with diesel fuel through a fuel line, which connects to the fuel tank  78 . The output of the black smoke generator is passed through the black smoke duct  20 , which connects to an intake manifold  80  that then attaches to an exhaust stack  82 . The black smoke generator is supplied with air through a combustion air inlet  36 . Unlike other smoke generating units, the black smoke burn chamber  10  of this invention can be operated on diesel fuel only, eliminating the need for toluene. (Toluene, due to its flammability, constitutes a significant safety risk.) The structure of the black smoke generator is discussed in detail below. 
     As noted above, the output of the black smoke generator is passed into an intake manifold. An induced draft air injector  38  is used to inject moving air into the exhaust manifold. The induced draft injector  38  dilution air system eliminates older radial fan configurations. This design significantly improves the dilution airflow characteristic by establishing a gradual differential flow gradient, which improves the exhaust flow stability and eliminates the traditional puffing and smoke density instabilities of older units. 
     The induced draft air injector  38  has a main fan  40  with a fan motor  42 . The fan motor has a cover  44 . Air enters the induced draft air injector  38  through a dilution air inlet  46 . 
     The invention also includes a flow-diverter and straightening chamber located at the stack base to establish a smooth transition from horizontal duct flow to the vertical exhaust stack flow. This is discussed in detail below. 
     In addition to the black smoke generator, a white smoke generator is also installed on the chassis. The white smoke generator has a chamber  48  and a white smoke duct  50  as shown. The white smoke duct  50  also connects to the intake manifold  80 . 
     The white smoke generator system also includes a temperature sensor  52 , an automatic temperature control solenoid valve  54 , which is used to maintain fuel evaporation chamber temperatures between 700 and 900 degrees F., and a pilot light adjustment valve  56 . The white smoke generator is fed by a propane torch  58  that is supplied by a propane line  60  from propane tanks  74   a  and  74   b . The white smoke generator also has a flame adjustment valve  62 . Like the Black smoke generator, the white smoke generator also has a fuel line  18  that feeds fuel from the fuel tank  78 . 
     The chassis  200  has several other components. A storage compartment  66  is provided for holding equipment. A control console  68  provides overall system control, as discussed below. A propane regulator  70 , propane line  14 , propane tanks  74   a  and  74   b , and a propane shut-off valve  76 , complete the propane system. The propane tanks  74   a  and  74   b  are independent gas cylinders that can be individually tied into the system. The pressure regulator provides even gas flow. The remote-control solenoid shutoff valve is provided in line with the pressure regulator. The diesel fuel tank  78  is positioned as shown. 
     Monitoring equipment, including an opacity monitor control unit  84 , an opacity monitor sender unit  86 , and an opacity monitor receiver unit  88  are used for readings. 
     Two speakers  90   a  and  90   b  are provided as well. 
     Finally, a stack support  92  is used to support the exhaust structure, as shown and a stack cradle  38  is used to hold the stack when it is folded down for transport (see, e.g.,  FIG. 7 , which shows the stack  82  being tilted into a horizontal position for transport. 
     As noted, these components are housed on a double axle trailer chassis  200  with tires  201 . The chassis and details are shown in  FIGS. 2-4 . 
       FIG. 2  is a front view of the assembled unit. Here, various components are shown. The stack  82 , the opacity monitor sender unit  86 , and an opacity monitor receiver unit  88  are shown extending upward from the chassis. On the right side, the control panel  68  is shown behind the black smoke generator  10  and the black smoke generator air inlet louvers  12 . In the center is the stack support  92 . Also shown are the main fan  40 , and fan motor cover  44 . On the left side are the white smoke generator chamber  48  and the storage compartment  66 . 
       FIG. 3  is a detail of the remote control unit  100 .  FIG. 3   a  is a detail of the side of the remote unit. Because the unit is used for training, the instructor can operate the basic controls remotely. This allows the instructor to directly address the students during training exercises. On the front of the remote control, there is an opacity screen LED  101  that reads the opacity of the smoke from the opacity sensor. Below that, there is a fuel flow screen LED  102  that reads the percent open of the fuel flow valve being used at the time. A gas toggle switch  103  turns the propane valve on or off. A fuel toggle switch  104  turns the fuel being used at the time on or off. A white/black smoke toggle switch  105  turns the fuel flow valve for black smoke on and the fuel flow valve for white smoke off, or vise versa. A high/low valve speed toggle switch  106  changes the rate at which the fuel valve selected by the white/black switch opens and closes. The fuel valve up/down buttons  107 , and  108  control whether the valve is opening (up) or closing (down). The remote control is connected to the main control panel  68  (see e.g.,  FIGS. 1 and 2 ) through a cable  111 . 
       FIG. 3   a  shows a partial side view of the remote unit. A data acquisition port  109  is installed, which allows transmitting the opacity readings to a data acquisition device for recording the opacity at the time students are observing the opacity during each test reading period. A microphone jack  110  is also installed, which allows the operator to speak through a microphone to the students 
       FIG. 4  is a detail of the control panel  68 . Here, the basic controls of the system are shown. They include the on/off switch  120 , the remote/manual switch  121 , a stack switch  122  (used to raise and lower the stack), a purge switch  123 , a gas switch  124 , a fuel switch  125 , and a fan switch  126 . Below the switches is a communications box  127  that allows up to three microphones to be connected for outdoor classes. (Because the unit produces smoke, classes are held outdoors, as such, the instructors use the communication system to teach the class). A fuel flow meter (rotameter)  128 , a valve to change from black to white smoke  129  and a second remote/manual valve  130  are shown as well. 
     One of the biggest innovations in this device is the development of a new black smoke generator  10 . The design generates black smoke without using toluene. As discussed above, this increases the safety of the device. The black smoke combustion chamber is mounted in the rear of the generator. It has two chambers (front and back). Diesel fuel is used to produce black smoke within the chamber. It is constructed of two steel shells. It is insulated between both shells and lined with firebrick on the inside of the front chamber to promote even reaction temperatures and better burn control. The intake air inlet is equipped with louvers that can be adjusted to direct the combustion air into the combustion chamber at variable air flow angles to influence the combustion efficiency and to maximize the degree of black smoke generation. The geometry of the smoke chamber and the intake air louvers are set to promote maximum black smoke generation. Once the system has been sufficiently warmed up (using propane), the rate of fuel flow determines the density of the black smoke plume. The pilot light can be adjusted with an external control valve located next to the smoke chamber. 
       FIGS. 5 and 6  show internal details of the black smoke generator.  FIG. 5  is a top internal view of the black smoke generator.  FIG. 6  is a front internal view of the black smoke generator. The black smoke generator back chamber  22 , the black smoke generator front chamber  24 , and the fuel pan  26  are shown. A layer of insulation  28  is positioned around the unit as shown. The black smoke generator outer shell  30  and inner shell  32 , as well as the placement of firebrick  34  are also shown.  FIG. 6  shows the placement of the air intake louvers  12  as well. Finally, the output of the black smoke generator is passed through the black smoke duct  20 , located at the rear of the unit. 
     It was an unexpected and synergistic result that the specific dimensions of the black smoke chamber enable it to produce black smoke when only diesel fuel is burned in it. Because it has been discovered that some dimensional configurations do not produce black smoke, it is now expected that only specific inside dimensions do produce black smoke. Thus, in the preferred embodiment the inside dimensions of the chamber that are critical to producing black smoke with only diesel fuel are: the rectangular combustion air inlet  12  has an opening 12 inches wide by 4 inches high. 
     The black smoke generator chamber overall is 19.5 inches wide by 24 inches deep by 28.75 inches high. The black smoke generator is separated into front and back chambers by a ¼-inch sheet of steel  35 , which is 19.5 inches wide by 24 inches high. The front chamber is 19.5 inches wide by 13 inches deep with a flue path 4.75 inches over the top of the sheet steel separating the two chambers. The front chamber is lined with 1.25-inch thick firebrick to a height of 24 inches in the front of the chamber, and 20.5 inches on the sides and back of the chamber. The front chamber is also lined with two thicknesses of the same brick  34  on the bottom of the chamber. The back chamber is 19.5 inches wide by 10.75 inches deep by 28.75 inches high. The black smoke duct in the rear of the back chamber has a 10.00-inch outside diameter. 
     As discussed above, white smoke is produced in the white smoke generator. This is done by first evaporating and subsequently condensing distillate type oil (most commonly a #2 diesel fuel) into an aerosol cloud. This cloud is white and its opacity varies in proportion to the volume of oil vaporized. By altering the fuel flow to the burn chambers, the operator controls the visual densities (opacity) of the plume. A propane-fired vaporization chamber supplies the heat of evaporation. The vaporization chamber is located at the rear of the smoke generator. A propane fired burner nozzle at the front of the white smoke chamber supplies the evaporative heat. As discussed above, the propane is stored in two independent gas cylinders that can be individually tied in to the system. A pressure regulator provides even gas flow. A remote-control solenoid shutoff valve is provided in line with the pressure regulator. The switches for the shutoff valve are located on the main control panel and on the remote control unit (if provided). 
     The white smoke chamber includes an automatic temperature control circuit in order to maintain fuel evaporation chamber temperatures between 700 and 900 degrees F. It is this temperature control that is the novel enhancement to the white-smoke chamber, allowing continuous production of white smoke. In previous white-smoke generators white smoke production would occasionally fail because the white smoke chamber would cool down. The addition of a temperature control circuit solves the problem of having to delay training until the temperature for the white smoke chamber is again high enough to produce white smoke. 
     The primary fan system consists either of a radial fan unit with a 110 VAC motor with a 0.5 hp nominal output rating or an axial (propeller-type) fan and a 12-VDC motor with a 19 AMPS or 0.3 hp rating. A fan-speed controller is optional and can be operated from the central control console. It is also possible to operate the system with both an AC- and a DC-system to increase its range of operation by allowing the system to be used in a remote location where there is no access to line power. 
     The exhaust gases from both smoke generator chambers are drawn into the intake manifold by vacuum from the main induced-draft fan(s) located in the center rear of the smoke generator. The intake manifold acts as a mixing chamber. The exhaust gasses are routed from the common duct through a series of flow-straightening vanes while making the 90-degree turn into the vertical portion of the smoke stack. The design of the flue-gas architecture was specifically chosen in order to promote laminar flow and to minimize the characteristic “puffing” of traditional smoke generator units. The overall stack height from ground to stack tip is about 15 feet. The smoke stack pivots on a hinge so that it can lie flat for transport and storage. The stack can be raised and lowered with either electric or hydraulic actuators. A switch on the control panel controls the raising and lowering of the stack. 
     As discussed above, the invention includes a flow-diverter and straightening chamber  140  located at the stack base  144  to establish a smooth transition from horizontal duct flow to the vertical exhaust stack flow. The stack  82  and chamber  140  are shown in  FIG. 7 . Within the flow diverter and straightening chamber  140  are a series of flow straightening vanes  142  that curve upward to direct exhaust gases entering through the inlet  143  from the horizontal to the vertical direction (see arrows). Note,  FIG. 7  shows the stack partially tilted for storage. The stack is typically rotated into a horizontal position for transport and is secured sack cradle  38 .  FIG. 8  is a front detail of the stack  82  showing the flow-diverter and straightening chamber  140  and the vanes  142  positioned behind the inlet  143 . 
       FIG. 9  is a top sectional view of the flow-diverter and straightening chamber taken along the lines  9 - 9  of  FIG. 8 . Here, the vanes  142  are shown positioned within the stack base  144 . Note also the inlet  143 . 
     The present disclosure should not be construed in any limited sense other than that limited by the scope of the claims having regard to the teachings herein and the prior art being apparent with the preferred form of the invention disclosed herein and which reveals details of structure of a preferred form necessary for a better understanding of the invention and may be subject to change by skilled persons within the scope of the invention without departing from the concept thereof.