Patent Abstract:
An oxidation filtration system for cleaning groundwater, the system having an aeration tower and a filtration tank. Within the filtration tank is an upper chamber and a lower chamber. Contained within the lower chamber is a plurality of Styrofoam™ filter media. Separating the upper chamber from lower chamber is a filter media mash which keeps the filter media from entering into the upper chamber. The aerated water from the aeration tower enters into the base of the lower filter chamber and rises through the filter media into the upper filter chamber. As the water passes through the filter media, the dissolved solvents fallout of the groundwater and attach themselves to the Styrofoam™ media. An automated back flushing and clarifying process is also provided using a back flush port and a clarification port, a higher level water sensor in the aeration tower and a programmable logic controller. The controller opens and closes the back flush and clarification port depending on the settings within the resident software, the controller interfaces with a remote computer to remotely operate the back flushing, clarification and filtering of the groundwater. The controller receives signals from the sensor to determine emergency back flushing requirements. The controller operates at a minimum one, and maximum five oxidation filtration systems at one time.

Full Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority benefit of U.S. Ser. No. 60/588677, filed Jul. 16, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     a) Field of the Invention  
         [0003]     It is very common in rural locations to not have access to municipal utility services including potable water. Many times the water loads required by farms or dairies are such that the municipal services can be overburdened and consequently the dairy or farm may be required to obtain its own water. Generally the farms turn to on-site groundwater or surface water. On-site groundwater is usually un-potable and depending on the geographic location may have soluble iron or manganese due to the lack of dissolved oxygen content.  
         [0004]     As is generally known in the art, iron and manganese are common elements widely distributed in nature. In the absence of oxygen, both of these elements are soluble in water. Both elements may form compounds with other soluble elements and can pollute water making it undesirable for human use. An aeration process will help to remove the compounds. The soluble forms of iron and manganese are in the plus two valence oxidation state. Upon contact with oxygen, or any other oxidizing agents, both the ferrous iron and manganese are oxidized to higher valences, forming new ionic complexes which are not soluble to any appreciable extent. Therefore, with the addition of oxygen to the compound, the iron and manganese may be removed as a precipitate after aeration.  
         [0005]     In addition to aeration of the water converting the ferrous iron into a precipitate, chemical oxidants such as potassium permanganate can also be used. These chemical oxidants may sometimes be used in connection with an aeration process to increase processing speed.  
         [0006]     Iron particularly poses problems including taste, staining, and accumulation within the pipes themselves. Iron will generally cause a reddish-brown staining of laundry, porcelain, dishes, utensils, teeth and even glassware. Further, the iron will over time settle out and buildup deposits in pipelines, pressure tanks, water heaters, and water softeners. Thus there are associated increases in energy costs and maintenance costs for removal of the iron deposits. In dairies the iron content will directly contaminate the cows and limit milk output.  
         [0007]     To remove the soluble iron from the water an oxidation and filtration process is used. Filtering systems of this sort are generally comprised of two separate categories, the actual filtration process through which the water is cleaned and the backwashing operation through which the filter is cleaned. These operations are equally important in the overall filtration process. The most common practice for filtration is to use gravity filtration in a downward mode, but several other modes of operation are possible including up-flow, by-flow, and pressure or vacuum filtration.  
         [0008]     During the filtration process, the water is injected with oxygen and the soluble iron content oxidizes. The oxidized water is then filtered through a filter media, generally either by using a greensand glauconite (for gravity flow modes) or, a buoyant manufactured filter media (used in up-flow modes).  
         [0009]     In either case, the filter media will accumulate large amounts of insoluble iron content and the buildup must be removed by backwashing.  
         [0010]     The backwashing process must be performed on a regular basis, such as every other day or biweekly depending upon the size of the operation.  
         [0011]     With proper backwashing, the filtration process will successfully remove approximately 90% to 95% of the soluble iron content out of the source water. The filtered water is then treated to remove the remaining 5% to 10% of the soluble iron content.  
         [0012]     To initiate backwashing, many of the filtration systems utilize a siphoning process to initiate the backwashing. The siphoning system is generally an automated process. The siphoning process requires constant servicing and adjustments.  
         [0013]     When the pipes themselves are fully operable and not clogged with iron deposits, the automatic hydraulic siphoning system works well. But, after continuous use the pipe components tend to accumulate the iron content and consequently, reduced flow capacity and additional weight on the pipes themselves throws the siphoning system off-balance. Thus, continuous maintenance and servicing is generally required. This constant servicing can pose a hardship on the rural farms and dairies which are operating under tight financial constraints as well as posing logistical maintenance and servicing problems.  
         [0014]     In summary, an oxidation/filtration/backwash system to remove soluble iron or manganese content from source groundwater utilizing an improved backwashing system as well as an assembly of interchangeable and self serviceable components is strongly needed.  
         [0015]     b) Background Art  
         [0016]     Generally the most common practice for filtration is the gravity filtration in a downward mode, but several other modes of operation are possible including up-flow, by-flow, and pressure or vacuum filtration. Listed below are various filtration devices with emphasis on backflushing.  
         [0017]     U.S. Pat. No. 6,187,178 (Lecornu et al.) shows a filter with several back flow means including a siphon. There is an air bleed included which insures the siphon being broken at the proper point.  
         [0018]     U.S. Pat. No. 6,063,269 (Miller et al.) shows a filter in a hydraulic system in which a portion of the fluid in the return line, is drawn by Venturi, to the filter line.  
         [0019]     U.S. Pat. No. 5,705,054 (Hyrsky) provides a filtered water in-take in which water flows out through pipe. If intake is blocked, flow through siphon tubs brings water in through intake. There is a tube which can be used for siphon control.  
         [0020]     U.S. Pat. No. 4,537,687 (Piper) discusses a filter which is cleaned by backflushing. This device shows a reverse siphon started by the application of a section port to initiate a backflow siphon flow in tube.  
         [0021]     U.S. Pat. No. 4,317,733 (Xhomnneux) shows a filter with a body and a backflow washing means including a siphon tube. The siphon tube causes the flow of fluid to go backwards. The siphon starts when filter is clogged and the fluid in the chamber reaches a particular level.  
         [0022]     U.S. Pat. No. 4,229,292 (Mori et al) discloses a regenerating column which is provided with a flushing siphon that starts when the flushing fluid reaches the desired level. The regeneration operation is started by an operator rather than being an automatic means.  
         [0023]     U.S. Pat. No. 3,841,485 (Malkin) shows in a siphon system which has back pressure increases a siphon is developed through a pipe which draws fluid through pipes to draw water through the filter element. There is a siphon breaker tube provided to stop the back flow.  
         [0024]     U.S. Pat. No. 3,825,120 (Takahashi) shows a system which includes pump means for moving the fluid being handled. In addition to the pumps there is a siphon pipe means which passes fluid to container.  
         [0025]     U.S. Pat. No. 3,549,012 (Mackrle) shows a system in which under cleaning conditions a siphon starts when fluid in it reaches the proper level and air control valves are closed. The suction developed by the siphon is applied to a second siphon to clear an upper section.  
         [0026]     U.S. Pat. No. 3,502,212 (Ueda) provides a siphon tube which is filled by liquid as the filter clogs. There are also air flow and feeding means that controls the start and end of the cleaning cycle. When the cleaning cycle is started a siphon liquid flowing draws both liquid and filtered material to a drain.  
         [0027]     U.S. Pat. No. 3,342,334 (Soriente et al.) show a filter system in which during the cleaning operation a valve is opened and flushing fluid flows down a pipe. U.S. Pat. No. 3,111,486 (Soriente) shows a back flow system in which liquid is delivered by a tube. When the filter is blocked fluid accumulates so that it reaches a point high enough to flow into a siphon and passes out of the filter system drawing the blocking material with it.  
         [0028]     U.S. Pat. No. 2,879, 891 (Beohner et al.) shows a filter which is provided with a siphon tube that fills when the back pressure caused by filter blockage, and the position of the air control means allow it to fill. When the siphon tube fills it draws fluid backwards through tubes and backwards through the filter materials and removes it.  
         [0029]     U.S. Pat. No. 1,119,008 (Gibson) shows a water filtering system in which there is a pipe loop “L”, that appear to serve as a back flow cleaning siphon when valves are set for back washing. The control is in part a function of automatic float or flow control valves.  
         [0030]     U.S. Pat. No. 630,988 (Reisert) shows a back flow system in which as the pressure increases liquid flows up pipe “I”, and down inner pipe “s”, so that a siphon is established.  
         [0031]     Ukranian UA 411 (Dmitriyevich) discloses an oxidation/filtration apparatus where as the filtering medium muds the filter loss increases. The water level providing positive flow reaches a maximum height and primes a siphon to initiate rinsing of the filter medium.  
       SUMMARY OF THE INVENTION  
       [0032]     An object of the current embodiment is to provide an oxidation filtration system which removes dissolved solvents such as iron or manganese from groundwater sources located in rural districts. The current system uses an oxidation and filtration system. The oxidation process uses and aeration tower allowing the dissolved iron to be oxygenated which then allows a portion of the iron to fallout after reaching a solid-state.  
         [0033]     The filtration process uses a plurality of boyant filter media which in the current embodiment is constructed of small buoyant Styrofoam™ beads. The Styrofoam&#39;s valence attracts the oxygenated solvents and further filters out the solvents. The groundwater which passes through this filter media is then mostly clear of the dissolved solvents, thus being ready for additional filtering processes.  
         [0034]     An additional object of the current environment is to increase the water quality of the filtered water by reducing the number of transfer lines and junctions which accumulate within the oxidized material. By reducing the transfer lines, less maintenance is required on a regular basis and when maintenance is required, the filtering is more efficient and predictable.  
         [0035]     An additional object of the current embodiment is too provide an improved flushing system to clean the boyant filter media, thus reducing the on-site maintenance of the filtering unit.  
         [0036]     An automated system using sensors and discharge ports operated by valves and solenoids and being controlled by a programmable logic controller orchestrates the filtering of the water, the back flushing of the filter media, and the clarification of the back flushed water. Also, the programmable logic controller orchestrates the operation of multiple filtering tanks or units at a large production facility. The PLC is operable by a remote client computer.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0037]      FIG. 1  is an elevation view of a prior embodiment;  
         [0038]      FIG. 2  is an elevation view of the oxidation, filtration, back flush, system;  
         [0039]      FIG. 2   a  is an alternative embodiment elevational view of the oxidation, filtration, back flush, system;  
         [0040]      FIG. 3  is an elevation view of the backflushing system;  
         [0041]      FIG. 3   a  is an alternative embodiment elevational view of the backflushing system;  
         [0042]      FIG. 4  is an elevation view of the cleansing system;  
         [0043]      FIG. 4   a  is an alternative embodiment elevational view of the cleansing system;  
         [0044]      FIG. 5  is a diagram of the programmable logic controller and system elements;  
         [0045]      FIG. 6  is a diagram of the control application and control objects;  
         [0046]      FIG. 7  is a plan view of the oxidation filtration tank assembly.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0047]     A detailed description of a prior art embodiment will now be discussed followed by a detailed discussion of an embodiment of the present invention.  
         [0048]     In discussing the present embodiment a description of the existing systems will first be provided.  
         [0049]     As stated above, it is general practice to remove soluble iron from water by utilizing an oxidation/filtration process  11  as shown in  FIG. 1 . Filtering systems of this sort are generally comprised of two separate categories, the actual filtration process and the back-washing operation to clean the filter.  
         [0050]     Still referring to  FIG. 1 , a common oxidation/filtration system  11  is shown with a filter chamber  46  and a water tower  24 . The groundwater  12  is pumped from a groundwater well and fed into a pressurized source line  14 . To provide the oxygen, a Venturi-type aerator injector  15  forces compressed air into the groundwater  12 , thus creating the first stage of the aeration process. Next, the pressurized water passes through a spray nozzle  16  which disperses the groundwater  12  into a closed water tower  24  completing the aeration process. The water tower  24  is typically cylindrical and stands approximately 20 ft. in height. The aerated water descends to the bottom of the water tower  24 , and then it enters into an opening  84  of a cylindrical feed line  80  which is concentric within the water tower  24 . The water entering into the opening  84  will flow through a distribution line  82  which directs the water into a manifold  83 , the water passes upwardly through the filter chamber  46  in which is positioned a low density filter media  50 . At the same time the water is flowing upward through the filter media  50  thus filling the filter chamber  46 , the water is also rising in the cylindrical feed line  80 .  
         [0051]     As the water continues to flow into the filter tank  46 , it enters into the upper portion  45  of the filter take  46  and begins to flow out of the clean water outlet  54 . There is a screen  52  at about the mid height of the tank  46  which stops the filter media  50  from migrating from the filter tank lower portion  47  into the filter tank upper portion  45 .  
         [0052]     When efficient filtration occurs the water head in the water tower  24  will stay at approximately constant height, which also results in a constant output of clean water running through the clean water outlet  54  of the filter chamber  46 . Thus, as the filtration process  11  continues, particulate filtrate matter  51  will begin to accumulate as it attaches in, around and to the low density filter media  50 .  
         [0053]     Eventually the filter media  50  will become so congested with the particulate  51  that the backwash operation will engage.  
         [0054]     This engagement occurs because as more and more particulate  51  attaches to the filter media  50 , the filtration flow decreases and water pressure head in the water tower  24  begins to increase. With the building water pressure in the water tower  24  the height of the water in the cylindrical feed line  80  rises.  
         [0055]     The water in the cylindrical feed line  80  will reach the level of the connecting line  86  at the top of the feed line  80  which in turn leads to the discharge line  88 . The discharge line  88  extends downwardly into a waste lock basin  90  in a holding tank  92 . The flow of the water downward in the discharge line  88  creates the siphon vacuum. This vacuum starts drawing water out of the filter tank  46 . As the water drops down in the filter tank  46 , exiting the holding tank  92 , the level of the water in the filter tank  46  will reach the lower end  96  of the vacuum line  98 , or in other words, the upper part  45  of the filter tank  46 . With this drop in water level, the vacuum line  98  becomes open to atmospheric pressure, and thus interrupts the siphoning action which is occurring in the discharge line  88 . The water remaining in the discharge line  88  drops into the waste lock basin  90  and the water remaining in the cylindrical feed line  80  drops back to the distribution line  82  to restart the filtration process.  
         [0056]     As previously stated before, the oxidation filtration system  11  will need to perform the siphoning and back flush process on a regular basis. Over time the ferrous soluble iron content in the groundwater will adhere to the inner regions of the cylindrical feed line  80 , the distribution line  82 , and tend to clog the feed line opening  84 , as well as the discharge openings in the manifold  83 . Where the soluble iron content is high, the clogging of these various filtration system components will occur more frequently.  
         [0057]     This accumulation requires constant maintenance of the oxidation filtration system  11  and over the long term is more expensive to maintain than the preferred embodiment as discussed below.  
         [0058]     Even if operation continues unimpeded, the inner diameter of the cylindrical feed line  80  will tend to decrease in size due to the increase in filtrate particulate  51  accumulation. With a smaller diameter comes a slower flow rate through the distribution line  82  and the cylindrical feed line  80  during the discharge process. Additionally, the many bends and turns in the pipes which comprise the discharge system and siphoning process add a level of complexity to the overall design which is not needed.  
         [0059]     Additionally the backwash system itself likely will not carry the heavier filtrate particles  51  which are residing in the bottom of the filter chamber  46  up and over the connecting line  86 . This tends to leave filtrate particulate  51  accumulations in the elbow between the cylindrical feed line  80  and the distribution line  82 . Lastly, immediately after the back flushing process has occurred the groundwater  12  which begins to accumulates and flow upwards starting at the filter tank lower portion  47  and flowing upwards through the low density filter media  50  finally passing through the screen  52 , will be cloudy due to the violence turbulence associated with the back flushing process. This cloud will tend to dissipate over time but in many cases the finer particles will be discharged out of the cleaning water outlet  54  and fed into the potable water lines feeding the residences or dairy buildings. To allow the fine filtrate particulate  51  to settle out, a cleansing or clarification period should be provided.  
         [0060]     Within this context, an embodiment of the present concept will now be discussed.  
         [0061]     A detailed discussion of a single oxidation filtration system will first be discussed followed by detailed discussion of an assembly of oxidation filtration systems as provided in current embodiment. First referring to  FIGS. 2 and 2   a , the oxidation filtration system  10  is composed of three main elements: an aeration tower or water tower  24 , a filtration tank  46 , and an oxidation filtration monitoring and cleaning system or flushing system  35 . Each of the main components has a series of subcomponents which will be briefly discussed. The aeration tower  24  in the present embodiment is constructed of a 1 foot diameter polyvinyl chloride cylindrical pipe which stands approximately 20 feet in height. The aeration tower  24  has an upper zone  23  and a lower zone  25 . The upper zone is configured such that it can accept the outlet  17  of a pressurized groundwater source line  21 . Additionally, the lower zone  25  has a close-bottomed portion to keep the groundwater  12  contained. Feeding into the aeration tower upper zone  23  as previously discussed, is the groundwater source line  21  which holds pressurized groundwater  12  accumulated from the on-site water sources.  
         [0062]     The groundwater must be pressured prior to being sprayed into the aeration tower upper zone  23 . Pressure is provided from a pressure source, and a pressure meter  20  is attached to the source line  14  so that monitoring of the groundwater pressure can occur. A source line valve handle  19  enables the operator to turn the filtration system  10  on and off as desired. The pressurized water runs through a Venturi-type aerator injector  15  which is attached to the source line  14  near the source line outlet  17 . Connected to the end of the source line, is a spray nozzle  16 . After running through the Venturi-type aerator  15 , the groundwater exits through the spray nozzle  16  which further acts to aerate the groundwater  12  thus converting the soluble ferrous iron content into a nonsoluble form, completing the oxidation portion of the process and allowing the particulate ferrous content  51  as described further herein to drop out of the groundwater  12 .  
         [0063]     Once the groundwater has been aerated, the ferrous content is ready to drop out of the groundwater upon contact with a medium which has an attracting valence charge. Referring to  FIG. 2 , connected to the aeration tower lower zone  25  is a source water crossover pipe  26 . This crossover pipe feeds the groundwater  12  from the aeration tower into the filtration tank  46 . Referring to  FIG. 2   a , in an alternative embodiment, the aeration tower  24  is positioned within the filtration tank  46 . This combination eliminates the need for the crossover pipe  26  as seen in  FIG. 2 . In this alternative embodiment, the aerated water  9  exits directly out of the aeration tower lower zone  25  and into the filter tank lower zone  47  through an exit port  102 .  
         [0064]     Referring back to  FIG. 2 , the filter tank  46  is constructed of a 3 foot diameter cylindrical polyvinyl chloride housing or pipe and has a filter tank lower zone or lower chamber  47  and a filter tank upper zone or upper chamber  45 . In the current embodiment, the filter tank  46  stands approximately 6 feet in height. Approximately mid-height of filter tank  46  is a secured media mesh filter  52 , which is essentially a size  10  filter mesh. Contained within the lower chamber  47  is a plurality of low density buoyant filter media  50 . In the current embodiment, this filter media is composed of a plurality of very small Styrofoam™ spheres. Each sphere measures approximately 1/100  of an inch in diameter. To provide for effective filtration, in the current embodiment, the volume of the filter media  50  is approximately 30 inches deep and 3 feet in diameter, which corresponds to the inner diameter of the filter tank  46 . To contain the water, the filter tank lower chamber  47  has a closed bottom portion which is watertight.  
         [0065]     A brief discussion of the pipes or ports associated with the flushing system will now be provided. Part of the overall monitoring and cleaning or flushing system  35  is the opening and closing of various ports or exit and entrance pipes to create the desired turbulence in the filtration tank lower chamber  47  as well as to clarify the dislodged ferrous particulate after the turbulent back flushing.  
         [0066]     Referring to  FIG. 2 , the current embodiment is provided with a plurality of pipes which include the source water crossover pipe  26 , the clarifying or cleansing pipe  39 , and the backflush pipe  28 . Attached to the pipes are a series of control valves. As previously discussed, the crossover pipe  26  is positioned substantially at the bottom of the lower chamber  47  near the floor of the filtration tank  46 . Approximately midway between the filtration tank and the aeration tank the backflush pipe intersects the source water crossover pipe at a junction point. At this junction, the backflush pipe  28  is connected to a backflush valve  30 . The backflush valve  30  is a standard automated valve having a weir and a control box which operates the weir.  
         [0067]     A clarifying pipe  39  is provided at the filter tank upper chamber to allow cloudy or turbulent water to be drained. The cleansing or clarifying pipe  39  leads from the filter tank upper chamber  45  and connects to the vertically lower backflush pipe  28  at a second junction. The clarifying pipe  39  also has a clarifying valve  30  with the same standard automated valve with a weir and control box as the back flush valve.  
         [0068]     Referring now to  FIG. 2   a , the alternative embodiment for the monitoring and cleaning system  35  includes the use of a backflush line  104  and a clarification line  106 . In this embodiment, the backflush line and the source water exit port  102  are separated to provide for a simpler operating system. The backflush line  104  is positioned at or near the bottom of the filtration tank  46  in the filtration tank lower chamber  47 . Connected to the backflush line  104  is a backflush valve  30  having a control box and weir, the control box being electronically operable by the programmable logic controller  36 . During normal operation, the backflush valve  30  is in its closed position keeping water within the filter tank  46 .  
         [0069]     Providing a means of clarifying cloudy groundwater is a clarification line  106 . Within the upper chamber  45  of the filter tank, is a clarification port  108 , the port having a clarification line  106 . This clarification line also has a cleansing valve or clarification valve  38  which operates the same as the backflush valve  30 . After the turbulence in backflushing has occurred, a clarifying period is run which allows the finer particulate to settle out.  
         [0070]     During normal operational flow the aerated water  9  will generally accumulate in the aeration tower  24  building up a pressure head  22  which drives the corresponding discharge rate out of the filtration tank  46 . The discharge rate stays relatively constant based on a discharge pressure which correlates to the pressure head  22  in the aeration tower  24 . The filter media  50  has a certain porosity between the actual media particles which will allow for only a maximum flow rate through the filter media  50 . The pressure head  22  in the aeration tower  24  will build until the flow rate through this filter media equals the pressure head from the aeration tower. As the filtered water  7  enters into the upper chamber  45  of the filter tank, it accumulates until the top layer of the water reaches the filtered water exit pipe  54 . This exit pipe  54  has enough cross-sectional area to maintain a constant volume of filtered water  7  within the filter tank  45  upper chamber.  
         [0071]     As a natural consequence of filtering the iron or particulate out of the groundwater, the lower chamber  47  of the filter tank in the filter media  50  will accumulate the filtered particulate until such time as the filtering is ineffective. Also, the particulate will tend to reduce the flow rate through the filter media and the corresponding pressure head  22  will need to increase, thus building the height level of the aerated water within the aeration tower  24 .  
         [0072]     Many geographic regions have significant amounts of soluble iron or manganese within the groundwater and therefore flushing of the lower chamber  47  of the filter tank can be beneficial for the life expectancy of the oxidation filtration system. There are many ways to monitor and trigger the backflushing of the filtration tank  46 . Speaking broadly, these include monitoring of the pressure head  22  as it increases in the aeration tank  24 , monitoring the filtered water quality  7  in the upper chamber  46  of the filter tank, monitoring the amounts of soluble compounds in the local groundwater supply to determine an optimal periodic backflushing setting.  
         [0073]     To coordinate the sequence of monitoring and cleaning of the oxidation filtration system, an oxidation filtration monitoring and cleaning system  35  is provided that will now be discussed. Referring to  FIGS. 2 and 2   a , the system utilizes a programmable logic controller in combination with a series of sensors and valves. The sensors monitor the water levels within the aeration tank  24  and the filtration tank  46 , and the valves control the opening and closing of the backflush line  104  and the clarification line  106  as well as the water source line  14 . The programmable logic controller coordinates the sequencing of opening and closing various valves as well as monitoring the water levels to stay within operational parameters.  
         [0074]     During the course of filtration, an emergency such as a high-level water sensor may be engaged, the sensor then immediately sends from the PLC a signal to set off the alarm  111  and alert the owners of the of the system that there is high water levels within the aeration tower  24 . The PLC can also operate the solenoid of an oxidation filtration system control valve  212  which is designed to alternate the use of an off-line and online oxidation filtration system connected in series. This will be further discussed as seen in  FIG. 7  below.  
         [0075]     For remote operation, the PLC  36  is connected to a communications device  131  such as a modem. The modem  131  allows a remote client  133  to connect to the operating system of the PLC  36  and operate the control application  132 .  
         [0076]     The control application  132  is configured to allow for varying control and sensor settings for the various oxidation filtration systems  10 . The control application  132  is configured to operate the control components including the valves and sensors of the various oxidation filtration systems such as oxidation filtration system applications  1  through  3 ,  FIG. 6 .  
         [0077]     Because each oxidation filtration system  10  has essentially the same sensors  136  and control devices  138 , the control application can implement a sub-application such as oxidation filtration system application  1 ,  140 , the sub-application will then draw from a series of class objects  146  as seen in  FIG. 6 , to implement an instance of the particular control application  132  of the specific system  140 .  
         [0078]     Of course other programming paradigms may be used such as a non-object-oriented programming language including Basic, Fortran, or an assembly programming language specifically designed for the programmable logic controller.  
         [0079]     Still discussing  FIG. 6 , the functions or objects which run for each system include a back flush time  148 , where the back flush time indicates the time of day the oxidation filtration system  10  will initiate a system flush. Referring back to  FIG. 2   a , the programmable logic controller  36  will send a signal to the back flush valve  30  to open the valve and discharge the water in the filtration tank  46  and aeration tower  24 . The water in both tanks will provide enough pressure head to turbulantly force the water out through the back flush line  104 . This turbulence within the lower chamber  47  of the filter tank  46  will wash the filtration media  50  of most of the accumulated particulate.  
         [0080]     The users can also set a period of time for the back flushing to take place. This is considered the back flush cycle  150 . The back flush cycle tells the programmable logic controller  36  how long the back flush valve  30  is to stay open. Similarly, and referring back to  FIG. 6 , after the back flush has occurred the control application  132  will indicate to the programmable logic controller  36  the amount of time that the clarification valve  38  is to remain open so that the system can clarify the water previously back flushed. The clarification cycle or timer  152  can be set by the user usually to approximately 20 minutes.  
         [0081]     The control objects class  146  also contains a setting for emergency back flush  154 . This occurs when one of the high-level sensors within the aeration tower  24  such as the diaphragm sensor  107  as seen in  FIG. 2   a , signals to the PLC  36  that the pressure head  22  within the aeration tower  24  has increased beyond acceptable limits and the system must be back flushed. Thus the emergency back flush object  154  will signal the programmable logic controller to operate the back flush valve  30  and begin the flushing cycle. Also, a manual back flush object  156  is provided so that the users can either remotely through the remote client  133  or at the display screen of the programmable logic controller  36  operate a manual back flush of the entire filtration system  10 .  
         [0082]     An additional control object within the control application  132  is a calibration for normal back flush time  158 . This calibration for normal back flush time calculates the mean or the average time between the system back flushes, and provides an optimization or recommended setting for the back flush time object  148 . This calibration for normal back flush time  158  is beneficial because as previously discussed, each geographic region which requires the oxidation filtration services has different levels of soluble compounds and thus requires different frequencies for washing or cleaning of the filter media  50  as seen in  FIG. 2   a.    
         [0083]     To keep the filtration system running relatively smoothly, a high-level delay object  162  is provided. During the course of operation, the aeration tower  24  may experience high-level water false-starts or in other words false warnings, which have been triggered from splashing or a short period of reduced filtration flow. The high-level delay object  162  allows the user to set the amount of time that the high water float  34  or the diaphragm sensor  107  must be activated or raised before the emergency back flush object  154  will signal the back flush valve  30  to begin the system flush.  
         [0084]     To notify the system operator or the owner of the oxidation filtration device that an unscheduled back flushing event has occurred, a series of alarms have been designed to communicate the emergency status. After a signal has been received from one of the sensors  136  as seen in  FIG. 5 , the control application  132  as seen in  FIG. 6 , will activate an alarm object  160 . The alarm object will then send a control signal to the physical alarm  101  as seen in  FIG. 2   a  which in the current embodiment is attached to the top cover plate of the filter tank  46 . The alarm  111  has a flashing warning light as well as a sound/audible warning.  
         [0085]     The alarm object  160  has an alarm delay which delays the audible alarm initiation. This delay allows response from the pager alarm discussed below from irritating or annoying residents within the vicinity of the oxidation filtration system. The alarm object  160  will also send a signal through the communications device or modem  131  to a pager service located at a remote client  133  which then notifies the owner of the high-level emergency. The alarm object  160  has an audible silence control which when activated allows the operator to work on the emergency system without the audible alarm causing a distraction. If the high-level emergency is not corrected within a period of time, the audible alarm will then re-activate until such time as the back flush occurs.  
         [0086]     In addition to servicing dairy farms and other agricultural operations, the oxidation filtration system  10  can also be used to process groundwater for a small municipality. The current embodiment provides for each filtration unit to process approximately 25,000 gallons to 30,000 gallons per day. An average person will typically use between 75 to 100 gallons of water per day. Therefore, the typical 25,000 gallon processing filtration unit can service approximately 250 people each day. To service between 1,000 people to 2,500 people equating to a small municipality or medium-size subdivision, having between five and ten filtration units running in parallel producing between 125,000 gallons to 250,000 gallons of filtered water each day would be beneficial to the local governmental authority.  
         [0087]     The current preferred embodiment for the oxidation filtration tank assembly  250  as seen in  FIG. 7  has arranged a three unit filtration output in parallel, with two units for each output line in series. This tank assembly configuration  250  allows the users to perform maintenance on one of the off-line filtration tanks while still producing filtered water through the online tank.  
         [0088]     The system can produce approximately 75,000 gallons of water constantly per day. The current embodiment of the programmable logic controller  36  can coordinate five filtration tanks in parallel. The tanks currently producing filtered water and the assembly as shown in  FIG. 7  are online tank  1  at  200 , online tank  2  at  204 , and online tank  3  at  208 . The groundwater source line  14  provides the groundwater through an oxidation filtration system control valve  212 . The programmable logic controller  36  monitors the operation of the online tanks and if a back flushing sequence occurs or the tank goes off-line, then the PLC will signal the oxidation filtration system control valve  212  to redirect the groundwater from the groundwater source line  14  to the backup system such as backup oxidation filtration system  202  to keep the production output at a constant rate. Also, by having a plurality of filtration tanks in series and parallel, the assembly  250  is in a better position to meet peak load demands and low load demands based on daily population needs.  
         [0089]     A brief discussion of the overall process or method as it operates in the current embodiment will now be provided.  
         [0090]     Reference will be made to  FIGS. 2 through 7  including the alternative embodiments of  2   a  through figures for a period. Referring first to  FIG. 7 , the oxidation filtration tank assembly  250  of the current embodiment is arranged in a three parallel output filtration configuration with each parallel output line having  2  filtration tanks in series. The groundwater flows through the groundwater source line  14  and is directed through each of the oxidation filtration system control valves  212  to the online oxidation filtration system tank. Pressure in the source line  14  is provided by the source line pump and the pressure can be read on the pressure meter  20  as seen in  FIG. 2 . The operator can initiate the filtration process by first turning on the source line valve  19  by either utilizing the programmable logic control application  132  through a remote client  133  or by using a manual valve handle. The water is immediately injected into the Venturi-type aerator  15  and after the initial aeration, the groundwater passes through the spray nozzle  16  and falls into the aeration tower upper zone  23 . The groundwater is further aerated by dropping through the aeration tower  24  to the bottom of the tower. The groundwater then after being aerated enters into the lower chamber  47  of the filter tank  46  either through the source water crossover pipe  26  or through the exit port  102  as seen in  FIG. 2   a . The water level in the filter tank lower chamber  47  and the aeration tower  24  continues to rise at an equal constant rate until the filter tank lower chamber  47  is full. During this initial filling process, the filter tank lower chamber  47  containing the filter media  50  filters the water through the filter media and the filter media is pressed or pressurized against the media mesh  52  dividing the upper chamber from the lower chamber.  
         [0091]     At this stage, the source groundwater  12  begins to fully filter through the filter media  50  as the water pressure static head  22  in the aeration tower  24  begins to increase forcing the water through the filter media and beginning the filter rate of the source groundwater through the media until a steady-state flow rate is reached.  
         [0092]     The surface area of the individual filter media is such that it readily attracts the iron oxide particles thus taking the particulate out of the groundwater. The aerated water  12  filters through the filter media and enters into the upper chamber  45  of the filtered tank  46 . The filtered water contained within the upper chamber  45  will exit through the filtered water crossover pipe  54  or the exit port  54  and dropped into a holding tank  48 .  
         [0093]     Filtering of the groundwater continues unimpeded for the filtering cycle until such time as the filtration rate through the filter media decreases. As the filter rate slows, the static head pressure  22  in the aerated tower  24  begins to build. At a certain point the static head pressure  22  reaches the high-level flow  34  or the diaphragm sensor  107  and then sends a back flush or discharge signal from the back flush sensor  32  or diaphragm sensor  107  to the programmable logic controller  36 .  
         [0094]     At this point in the process, the programmable logic controller runs the control application  132  for the particular oxidation filtration system  140 . Depending on the operational settings held within the various control objects  146  the alarm  111  may be delayed from sounding because the users may have set the high-level delay  162  to for example five minutes. Simultaneously, the control application  132  will send a pager signal  164  through the modem  131  to the remote client  133  which in this case would be the pager of the on-site operator. The pager would then notify the operator of the emergency situation and the operator could take a number of actions. One of the actions would be for the operator to access the control application  132  through the remote client  133  connected to a modem  131 . The operator could then check the system status of the particular oxidation filtration system to determine if the alarm signal is an actual high-level emergency or is just a false alarm.  
         [0095]     The operator can then verify that the water pressure level  22  in the aeration tower  24  has reached the high-level flow  34  or the diaphragm sensor  107  and a back flush or system flush should be initiated. After the back flush has been initiated, the operator can direct the programmable logic control  36  to send a signal to the oxidation filtration system control valve  212  as seen in  FIG. 7 , to switch the groundwater source  14  from the back flushing oxidation filtration system  200  to the backup oxidation filtration system  202 .  
         [0096]     The calibration for the normal back flush time  158  will then take place recalculating the average amount of time between back flushes and reset the back flush time object  148 . This recalibration can occur for each of the oxidation filtration systems within the assembly  250 .  
         [0097]     The filtration will continue until the back flush time  148  signaled to the programmable logic controller  36  that a back flush cycle  150  should occur. The programmable logic controller will then signal the back flush valve  30 . Referring to  FIGS. 3 and 3   a , the solenoid of the back flush valve  30  will open the valve and the back flushing process will begin again. The static pressure head  22  within the aeration tower  24  as well as the filtered tank static pressure head  56  create a substantially large flow rate through the back flush line  104  and creating significant turbulence  51  in the lower chamber  47  of the filtered tank  46 . This turbulence  51  buffets and washes the filter media  50  as the groundwater contained within the aeration tower  24  in the filtration take  46  quickly exit through the back flush line  104 .  
         [0098]     This process of back flushing and rinsing the filter media  50  occurs for the entire period of the back flush cycle timer  150  as set in the control application  132 . After the time period has elapsed, the programmable logic controller then signals the clarification valve  38  as seen in  FIGS. 4 and 4   a  to open and simultaneously closes the back flush valve  30  allowing the water pressure from the source line  14  to accumulate in the aeration swap tower  24  and the filter tank  46 . The filter media  50  has been washed of the oxidation deposits and returns to its buoyant state.  
         [0099]     Because of the significant turbulence which occurred in the back flushing process, iron or other particulate is suspended within the groundwater and may be residual in the upper chamber  45  and the lower chamber  47  of the filter tank  46 . In lieu of waiting for the dislodged particulate to settle out, a clarification process is provided where the clarification port  108  in the upper chamber  45  is opened to clean and dispose of the cloudy groundwater  70 .  
         [0100]     The control application runs the clarification cycle for the desired period of time as set in the clarification cycle timer object  152 . Alternatively, the particulate sensor  103  can monitor the level of particulate within the upper chamber  45  as directly after the back flushing process to then send a signal to the programmable logic controller that the clarification cycle should terminate.  
         [0101]     However the clarification period  152  is determined, the cloudy water  70  exits through the clarification line  106  for the clarification cycle  52  until the cycle is complete. One embodiment has this cycle lasting approximately  30  minutes. After the clarification cycle is complete, the clarification port  38  is closed by the programmable logic controller sending a signal to the solenoid of the clarification valve to close the aperture.  
         [0102]     Once the entire flushing cycle has taken place, the groundwater within the aeration tower  24  is allowed to build up pressure head  22  until such time as the filtration rate reaches its normal equilibrium state and filtration of the groundwater continues.  
         [0103]     After continuous use of the oxidation filtration tanks  10 , such as for a year or two, maintenance of the oxidation filtration back flush assembly or tank  10  may be required. The accumulation of the iron particulate or other crud may occur generally within the crossover pipe  26  or block the exit port  102  as seen in  FIGS. 2 and 2   a . Consequently, either a plurality of cleanout pipes  72  is provided or cleanout ports within the bottom chamber of the filter tank  46  are provided.  
         [0104]     Each cleanout pipe section  72  is attached to a manifold  74  with a gasket  76 . When the crossover pipe  26  becomes clogged with particulate, the operator can shut down the system and remove the cleanout pipes  72 . Similarly, when the exit port  102  becomes clogged and the aeration tower  24  can no longer pass water from the aeration tower into the lower chamber of the filter tank  47 , the operator can shut down the entire process, remove the filter tank cover and extract the aeration tower  24  from the interior of the filter tank. The media mesh  52  can be removed and cleanout of the filter tank and of the aeration tower can occur relatively inexpensively. This use of maintenance allows for long life of the oxidation filtration tank  10 .

Technology Classification (CPC): 2