Patent Document

This application is a continuation of U.S. patent application Ser. No. 13/274,350 filed on Oct. 16, 2011, which is a continuation in part of U.S. patent application Ser. No. 13/050,665 filed on Mar. 17, 2011 issued as U.S. Pat. No. 8,062,522 on Nov. 22, 2011, which is a divisional of U.S. patent application Ser. No. 12/954,809 filed on Nov. 26, 2010 issued as U.S. Pat. No. 8,066,887 issued on Nov. 29, 2011. The entire contents of U.S. patent application Ser. No. 12/954,809, 13/050,665 and 13/274,350 are hereby incorporated by reference. 
    
    
     FIELD OF INVENTION 
     The invention relates to wastewater transport, treatment and processing systems. Specifically, the invention relates to a system for diverting and processing wastewater from the wastewater collection piping system for the purpose of reducing the total liquid loading on the collection piping system. 
     BACKGROUND 
     Wastewater occurs whenever a foreign substance is added to water that is not considered to add positive value to the water. The water is the carrier for these undesirable components, such as silt, dirt, ionic species, chemicals and sanitary fecal material. The water can be re-purified, removing the contaminants by mechanical, chemical or biological means. 
     Sanitary wastewater as it enters a biological treatment plant contains 1.5%-2.0% of suspended solids that are mostly consumed by bacteria in the reaction vessel. The remaining solids, or sludge is carried off and disposed of. The wastewater suspended solids are often referred to as the Biological Oxygen Demand (BOD). This number is roughly 250-mg/liter for raw sanitary wastewater. A four member household can typically produce 550-750 liters per day of sanitary wastewater. In addition to the suspended solids (BOD), 125-150 mg/liter of total dissolved solids (TDS) are added. As an illustrative example, if water were to enter a household with 300 mg/liter of TDS, the same water will leave the household at 425-450 mg/liter TDS. Therefore, the water leaving the home is “carrying off” human waste, soap and other materials from the shower, laundry, kitchen, and other drainage pipes carrying household wastewater. 
     The wastewater from residential homes and other dwellings as well as restaurants, hotels, schools, and other commercial buildings finds its way to a wastewater or sewage treatment plant via forced (pumped) or gravity piping systems. This wastewater collection piping system is often referred to as a sewer main. 
     The wastewater treatment plant can be configured in numerous ways with strainers, settling basins, biological reactors and filters. The primary goal is to reduce the BOD to less than &lt;5 in the treated wastewater. The water is then further treated and often used for irrigation, or returned to deep wells, rivers or other bodies of water. 
     Municipal wastewater treatment plants at the time of their construction are often designed for projected future urban growth. Years after their construction, they are often expanded, as required, to satisfy actual urban growth demand. Similarly, wastewater collection piping systems are designed to handle a given quantity of wastewater based on projected demand. For the purpose of this disclosure, the term “wastewater loading” is defined as a quantity of wastewater flowing through a sewer main per unit time. Also for the purpose of this disclosure, the term “solids loading” is defined as a quantity of solids (i.e. matter with specific gravity greater than one) contained in the wastewater in a sewer main. 
     In growing cities and suburbs, many of the wastewater collection piping systems are overloaded or will be overloaded in the future with not enough capacity to handle the demand for wastewater flow. Those skilled in the art have devised several ways to remedy this situation. One solution is to lay parallel pipes or replace the current pipes with larger pipes to accommodate the additional wastewater loading. Another solution is to build additional waste treatment facilities to handle the additional loading. Both solutions can be expensive to implement. In addition, replacing or adding new pipe can be disruptive to a large portion of the neighborhoods and roads where the new pipes are being laid. 
     For the forgoing reasons, there is a need for a method, system or apparatus that can adjust the wastewater loading in a wastewater collection system in order to increase the system capacity. 
     SUMMARY 
     This Summary introduces a selection of concepts in simplified form that are described the Description. The Summary is not intended to identify essential features or limit the scope of the claimed subject matter. 
     The present invention is directed to a method, system, and apparatus that satisfy this need of adjusting the wastewater loading in a wastewater collection system in order to increase the collection system capacity. 
     An area of focus in the art has been to increase the system capacity by either increasing the volume capacity of the piping system by using larger pipes or parallel pipes in combination with increasing the capacity of the wastewater treatment plants. The inventor made the following observation. Wastewater treatment plants are often capable of handling a much higher amount of total suspended solids in the wastewater. The inventor also observed that there are potential benefits having higher suspended solids in the wastewater. For example, the biological treatment plant would operate a lot more efficiently if the suspended solids (BOD) to wastewater ratio or suspending solids (BOD) loading is increased. In many cases, the inventor estimates, the BOD loading could be doubled without increasing the plant capacity. 
     Based on this observation, a system and method in accordance with principles of the invention, can increase the effective volume (suspended solids loading) capacity of a wastewater piping collection system without the need to use larger pipes or adding additional parallel pipes. To accomplish this, in one embodiment, in accordance with the principals of the invention, a system located remotely from the wastewater treatment plant, diverts a portion of the wastewater from the wastewater piping collection system, or sewer main, separates the solid from the liquid, treats the recovered water for use locally, or for disposal, and reintroduces the concentrated solids back into the main sewage line that adjusts the wastewater loading of the wastewater piping collection system by a predetermined amount. The predetermined amount, in one embodiment, can be based on pre-determined solids to liquid ratio or alternatively on a desirable level of wastewater loading in the wastewater piping system or both. It can also be based on more complex ratios. 
     As a result, this system reduces the volume of water flowing through the piping system and increases the percent of concentrated solids and BOD. A number of these systems can be strategically placed around an urban and sub-urban area in order to increase the effective capacity of the wastewater treatment piping system without the need for new pipes. The liquid, which in one embodiment can be treated by mechanical, electrical, or chemical means alone or in combination can be used locally for landscape or crop irrigation, or in another embodiment, can be used as potable water. In further embodiments, can be used as industrial water, for example, boiler feeds makeup or other industrial process applications. In an alternative embodiment, the liquid can be treated, for example, by electrical, chemical, thermal, or mechanical means alone or in combination, and be disposed of, for example, by pumping it into the ground, or by diverting the treated liquid into bodies of water, for example, rivers, streams, lakes, or the ocean. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG. 1  shows a high-level system diagram of a wastewater concentrator system in accordance with principles of the invention; 
         FIG. 2  shows a more detailed system diagram of the wastewater concentrator system of  FIG. 1 ; 
         FIG. 3  shows an embodiment of a vortex separator using centrifugal force for separating the concentrated solids and liquid wastewater; 
         FIG. 4  shows a flow chart diagram in accordance with principles of the invention for controlling the wastewater loading in sewer main; 
         FIG. 5  shows a system diagram of a wastewater concentrator system of  FIG. 1  where the vortex separator is fed by a head tank; 
         FIG. 6  shows a high-level system diagram of a wastewater concentrator system that adjusts solids loading in a sewer main to a pre-determined amount; 
         FIG. 7  shows a more detailed embodiment of  FIG. 6 ; 
         FIG. 8  shows a flow chart diagram in accordance with principles of the invention for controlling solids loading in a sewer main; 
         FIG. 9  shows an alternate embodiment of  FIG. 1  showing a plurality of wastewater concentrators; 
         FIG. 10  shows an alternative embodiment of  FIG. 2  showing means for purifying the separated liquid and a combination of controlling both solids loading and wastewater loading; 
         FIG. 11  shows a flow chart, in accordance with principles of the invention, for the controlling both solids loading and wastewater loading; 
         FIG. 12  shows an alternative embodiment of  FIG. 2  showing alternative means for purifying separated liquid; and 
         FIG. 13  shows a control system diagram for the embodiment of  FIG. 12 . 
     
    
    
     DESCRIPTION 
     Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views,  FIG. 1  illustrates a system diagram of a wastewater concentrator system  101  in accordance with the principles of the invention. In one embodiment, raw wastewater  103  flows through the sewer main  105 . A portion of the raw wastewater  107  is diverted from the sewer main  105  through an inlet pipe  109  into the wastewater concentrator system  101 . The non-diverted wastewater  111  remains in the sewer main  105 . In accordance with principles of the invention that will be described, the wastewater is separated into separated liquid  113  through an outlet pipe  115  and concentrated solids  117  through a second outlet pipe  119 . The separated liquid  113  can be diverted for local reuse. In one embodiment, the separated liquid  113  is mostly water but may contain BOD or dissolved solids. This can be pumped deep into the ground in order to facilitate natural filtration. In accordance with local environmental or governmental regulations, the separated liquid  113  can be further purified before pumping into the ground. In another embodiment, the separated liquid  113  is further purified and sterilized and can be used for agricultural or commercial irrigation or for drinking water. In an alternative, embodiment, the separated liquid  113  can be further purified and disposed of into a body of water. For the purpose of this disclosure, the term “body of water” can refer to natural or man-made bodies of water, for example, oceans, seas, lakes, basins, or ponds as well as natural or man-made waterways, for example, rivers, streams, or canals. In another embodiment, the separated liquid  113  can be further purified and used for cooling tower makeup water or for other industrial processes. 
     The separated liquid  113  can be treated either for reuse or for disposal, for example, by electrical, chemical, thermal, or mechanical means alone or in combination. Electrical means can include, for example, UV light, electrically produced ozone, and electro-dialysis. Chemical means can include, for example, chlorination and other chemical disinfectants. Thermal means can include, for example, pasteurization, boiling, distillation, or solar heating. Mechanical means can include, for example, media or multi-media filtration, membrane filtration, cartridge filtration, and aeration. The above examples are meant to be exemplary and not limiting, other means of electrical, chemical, thermal, and mechanical means are possible. 
     The concentrated solids  117  in the second outlet pipe  119  are reintroduced in the sewer main  105 . The concentrated solids  117  are combined with the non-diverted wastewater  111  to form concentrated wastewater  121  in the sewer main. The resulting concentrated wastewater  121  has increased suspended solids. A portion of wastewater has been removed from the sewer main  105  that is approximately equal to the separated liquid  113  diverted through the outlet pipe  115 . This has the effect of increasing the system capacity of the sewer main  105  by an amount equal to the separated liquid  113 . By increasing the system capacity of the sewer main  105  in this way, the wastewater loading of the sewer main  105  has been effectively been decreased. 
     In accordance with principals of the invention, the wastewater loading of sewer main  105  is adjusted to a pre-determined level or pre-determined amount. This pre-determined amount may be set in accordance with a number of factors. For example, the pre-determined level may be set in order to make sure that the sewer main  105  is not over loaded during peak capacity. Similarly, the pre-determined level may be set in order to assure that the wastewater treatment plant  123  supplied by the sewer main  105  is not over loaded during peak demand. In one embodiment, a flow transmitter  125  determines the rate of flow of the concentrated wastewater  121  in the sewer main  105 . The flow transmitter  125  communicates with the wastewater concentrator  101  through a first signal path  127 . This information transmitted through the signal path can take many alternative forms, for example, analog voltage, or a digital signal. This may be either through wire or by wireless means. 
     One advantage of this wastewater concentrator system  101  is that it may be located where it is most needed. It may be desirable for the wastewater concentrator location  129  to be in an area of high depend where the sewer main  105  capacity is challenged. This may be in an urban or sub-urban area far away from the wastewater treatment plant  123 . Under other circumstances, where the demand on the system is more uniform, it may be desirable to locate the wastewater concentrator location  129  may be right outside of the wastewater treatment plant. 
       FIG. 2  is an embodiment, in accordance with principals of the invention, of  FIG. 1 . The diverted raw wastewater  107  flows through the inlet pipe  109  to a feed pump  201 . The feed pump  201  supplies a cyclone or vortex separator  203  post-feed pump wastewater  205  through feed pipe  207 . The feed pump  201  may be any pump capable of being controlled with a variable rate of flow and capable of supplying net positive suction pressure to the vortex separator  203 . For example, in one embodiment the feed pump  201  is a centrifugal feed pump. In another embodiment, the feed pump  201  is a centrifugal grinder pump. A grinder pump takes larger solid objects, for example, rags, condoms, tampons, or sanitary napkins, grinds or macerates them into smaller particulates. In another embodiment, the feed pump  201  and vortex separator  203  may be combined into one unit that performs the function of both feed pump and vortex separator. 
     In  FIG. 2 , the vortex separator  203  takes the post feed pump wastewater  205  and separates it into concentrated solids  117  that flow through the second outlet pipe  119  and separated liquid  113  that flows through the outlet pipe  115 . The vortex separator  203  uses centrifugal force to spin the wastewater forcing the heavier materials to the outside periphery of a containment pipe. The separated liquid  113 , which is mostly water, with a lower specific gravity, lighter, stays to the center of the containment pipe as the solution is flowing downstream in the containment pipe. The concentrated solids exit at the periphery of the containment pipe through the second outlet pipe  119 , while the mostly water or separated liquid  113  is drawn off of the center of the end of the containment pipe though the outlet pipe  115 . In one embodiment, the vortex separator  203  used is sold under the trade name “voraxial separator” and sold by Enviro Voraxial Technology Inc. In another embodiment, the vortex separator  203  is combined with feed pump  201 . 
     The basic principles of a vortex separator  203  are taught by U.S. Pat. No. 5,084,189 (Richter). The separator includes an impeller mechanism with a hollow core and a decreasing axial pitch in the direction of fluid flow. The combination of hollow core and axial pitch of the impeller mechanism creates a vortex or cyclone where lighter material stays in the center of the vortex where heavier material is force to the periphery. 
       FIG. 3  illustrates in more detail one example of a vortex separator  203 . The vortex separator  203  includes a housing  301 . Within the housing  301  are impellers  303 . The impellers  303  have hollow cores and a decreasing axial pitch in the direction of fluid flow. The impellers are driven by a drive shaft  305  attached to a gear box  307 . Other pump arrangements for driving the impellers  303  are also possible. The housing  301  is coupled to a discharge assembly or separation containment pipe  311 . This discharge assembly includes the containment pipe as described in a previous paragraph of this disclosure. The impeller pitch and hollow core impeller center create an outer portion of the vortex  309  with the concentrated solids  117 , which are heavier, being forced to the periphery and lighter water being contained in as a separated liquid  113  in the center of the vortex or cyclone. The concentrated solids  117  are taken off the outside periphery of the separating column. The concentrated solids contained in the outer portion of the vortex  309  exits the separation containment pipe  311  through a solids discharge port  313  as a concentrated solids stream  117 . The separated liquid  113  is removed through the outlet pipe  115 . The solids discharge port  313  is angled in the direction and pitch of the cyclone in order to more effectively separate the concentrated solids. 
     Referring again to  FIG. 2 , the flow transmitter  125  measures the rate of flow of the concentrated wastewater  121  in the sewer main  105  and communicates this information through a first signal path  127  to a control system  209 . The control system  209  controls the speed of the feed pump  201  in order to adjust the rate of flow of diverted raw wastewater  107  in the inlet pipe  109  and to the vortex separator  203 . In one embodiment, a variable frequency drive or VFD  213  controls the feed pump  201  through a second signal pathway  211 . The second signal path way can be, for example, an analog drive current, or digital signal or analog voltage and may be wired or wireless. 
     The control system  209  controls the rate of flow of the feed pump  201  in order to adjust the wastewater loading of the sewer main  105  to the pre-determined level or pre-determined amount. In one embodiment, the control system  209  uses an algorithm similar to the one shown in  FIG. 4 , to adjust the wastewater loading of the sewer main  105  to the pre-determined amount. The post system wastewater loading is determined  401  and compared  403  to the pre-determined amount or target wastewater loading  405 . In one embodiment, if the post system wastewater loading  401  is less than the target wastewater loading  403  than the rate of flow is decreased  407 , if the post system wastewater loading  401  is greater than the target wastewater loading  405 , than the rate of flow is increased  409 , and if the post system wastewater loading  401  is approximately equal to target wastewater loading  405 , than the rate of flow is not adjusted  411 . The algorithm loops back  413  to determine pre-system wastewater loading step  401  and repeats again. 
     In an alternate embodiment, the target wastewater loading  405  is not a specific value but a range of values. This pre-set range can be set in order to enhance stability of the feedback control system and the life of the variable frequency drive. The rate of flow would be decreased  407  if the post-system wastewater loading  401  was less than the pre-set range, increased rate of flow  409  would occur if the post-system wastewater loading  401  was greater than the pre-set range, and steady rate of flow  411  would continue if the post-system wastewater loading was within the pre-set range. 
     Referring to both  FIG. 4  and  FIG. 2 , determining the post system wastewater loading  401  in the control system  209  is facilitated by data from the flow transmitter  125 . The control system  209  compares the target wastewater loading  405  to the post system wastewater loading  401  and either adjusts directly or generates a signal to control the VFD  213  in order to control the rate of flow. If the post system wastewater loading  401  of the sewer main  205  is too high, then the VFD  213  speed is increased in order to increase the rate of flow to generate more separated liquid  113  and divert more wastewater from the sewer main  105 . If the post system wastewater loading  401  of the sewer main  105  is too low, then the VFD  213  speed is decreased in order to decrease the rate of flow to generate less separated liquid  113  and divert less wastewater from the sewer main. 
     The target wastewater loading  405 , in one embodiment is loaded into either program or data storage memory in the control system  209 . Optionally, the target wastewater loading  405  level may be adjusted on-site at the wastewater concentrator or remotely. For example, it can be updated through wired or wireless means such USB, 802.11, Ethernet, 3G or other standard communication protocol. 
     This algorithm of  FIG. 4  can be stored in the form of program instructions, for example, in a memory device connected to or internal to a microcontroller or microprocessor, a programmable logic device, a remote personal computer (PC) controlling the control system  209 , and executed by any combination of these devices. 
     When there is sufficient pressure created in the inlet of the vortex separator  203 , for example, by a gravity feed, a feed pump  201  as shown in  FIG. 2  may not be necessary.  FIG. 5  shows an alternative embodiment where an elevated tank or head tank  501  supplies diverted wastewater  503  through a pipe  507  to the vortex separator  203 . A VFD  509  is attached to the vortex separator  203 . Varying the speed of the VFD  509  attached to the vortex separator  203  controls the amount of wastewater diverted  107  from the sewer main  105 . 
     Referring to both  FIG. 4  and  FIG. 5 , the control system  209  controls the rate of flow of the VFD  509  attached to the vortex separator  203  in order to adjust the wastewater loading of the sewer main  105  to the pre-determined level or pre-determined amount. As previously described, the control system  209  uses an algorithm similar to the one shown in  FIG. 4 , to adjust the wastewater loading of the sewer main  105  to the pre-determined amount. The control system  209  compares the target wastewater loading  405  to the post system wastewater loading  401 , for example, provided by flow transmitter  125 , and either adjusts directly or generates a signal to control the VFD  509  attached to the vortex separator  203  in order to adjust the rate of flow. If the post system wastewater loading  401  of the sewer main  205  is too high, then the VFD  509  speed is increased in order to increase the rate of flow to generate more separated liquid  113  and divert more wastewater from the sewer main  105 . If the post system wastewater loading  401  of the sewer main  105  is too low, than then the VFD speed is decreased in order to decrease the rate of flow to generate less separated liquid  113  and divert less wastewater from the sewer main. 
     It may be desirable to adjust the wastewater concentrator  101  to a pre-determined solids loading instead of a pre-determined wastewater loading. For example, when it is known that the wastewater concentrator  101  has the potential to overload the solids loading capacity of the wastewater treatment plant  123 . 
       FIG. 6  shows a high-level system diagram of a wastewater concentrator  101  that is adapted to adjusting the solids loading to a pre-determined amount. Like the embodiment shown in  FIG. 1 , a portion of the diverted raw wastewater  107  is diverted from the sewer main  105  through an inlet pipe  109  into the wastewater concentrator system  101 . In a manor previously disclosed, wastewater is separated into separated liquid  113  through a outlet pipe  115  and concentrated solids  117  through a second outlet pipe  119 . The separated liquid  113  can be diverted for local reuse or for disposal. The concentrated solids  117  in the second outlet pipe  119  are reintroduced in the sewer main  105 . The concentrated solids  117  are combined with the non-diverted wastewater  111  to form concentrated wastewater  121  in the sewer main. The resulting concentrated wastewater  121  has increased suspended solids. A portion of wastewater has been removed from the sewer main  105  that is approximately equal to the separated liquid  113  diverted through the outlet pipe  115 . This has the effect of increasing the system capacity of the sewer main  105  by an amount equal to the separated liquid  113  and also increasing the solids loading in the concentrated wastewater  121 . 
     In accordance with principals of the invention, the solids loading of sewer main  105  is adjusted to a pre-determined level or pre-determined amount. The pre-determined amount, for example, may be selected to assure that the wastewater treatment plant  123  operates within its solids loading capacity. In one embodiment, a solids analyzer  601  determines the solids loading of the concentrated wastewater  121  in the sewer main  105 . The solids analyzer  601  communicates with the wastewater concentrator  101  through a signal pathway  603 . This information transmitted through the signal path  603  can take many alternative forms, for example, analog voltage, or a digital signal. This may be either through wire or by wireless means. 
       FIG. 7  is an embodiment, in accordance with principals of the invention, of  FIG. 6 . The embodiment of  FIG. 7  operates in a similar manner as the embodiment of  FIG. 2  except in the present embodiment the control system  209  controls the VFD  213  of the feed pump  201  in order to adjust the solids loading to a pre-determined amount rather than the solids loading. 
     The solids analyzer  601  measures solids loading of the concentrated wastewater  121  in the sewer main  105  and communicates this information through the signal path  603  to a control system  209 . The control system  209  controls the speed of the feed pump  201  in order to adjust the rate of flow of diverted raw wastewater  107  in the inlet pipe  109  and to the vortex separator  203 . In one embodiment, a variable frequency drive or VFD  213  controls the feed pump  201  through a second signal pathway  211 . The signal path  603  can be, for example, an analog drive current, or digital signal or analog voltage and may be wired or wireless. 
     The control system  209  controls the rate of flow of the feed pump  201  in order to adjust the solids loading of the sewer main  105  to the pre-determined level or pre-determined amount. In one embodiment, the control system  209  uses an algorithm similar to the one shown in  FIG. 8 , to adjust the post system solids loading of the sewer main  105  to the pre-determined amount. The post system solids loading  801  is determined and compared  803  to the pre-determined amount or target solids loading  805 . In one embodiment, if the post system solids loading  801  is greater than the target solids loading  803  than the rate of flow is decreased  807 , if the post system solids loading  801  is less than the target solids loading  805 , than the rate of flow is increased  809 , and if the post system solids loading  401  is approximately equal to target solids loading  805 , than the rate of flow is not adjusted  811 . The algorithm loops back  813  to determine pre-system wastewater loading step  801  and repeats again. 
     In an alternate embodiment, the target solids loading  805  is not a specific value but a range of values. This pre-set range can be set in order to enhance stability of the feedback control system and the life of the variable frequency drive. The rate of flow would be decreased  807  if the post-system solids loading  801  was greater than the pre-set range, increased rate of flow  809  would occur if the post-system solids loading  801  was less than the pre-set range, and steady rate of flow  811  would continue if the post-system solids loading was within the pre-set range. 
     Referring to both  FIG. 7  and  FIG. 8 , determining the post system solids loading  801  in the control system  209  is facilitated by data from the solids analyzer  601 . The control system  209  compares the desired solids loading  805  to the post system solids loading  801  and either adjusts directly or generates a signal to control the VFD  213  in order to adjust the rate of flow  807 . If the post system solids loading  801  of the sewer main  805  is too low, then the VFD  213  speed is increased in order to increase the rate of flow to generate more separated liquid  113  and divert more wastewater from the sewer main  105 . If the post system solids loading  801  of the sewer main  205  is too high, than then the VFD speed is decreased in order to decrease the rate of flow to generate less separated liquid  113  and divert less wastewater from the sewer main. 
     The target solids loading  805 , in one embodiment is loaded into either program or data storage memory in the control system  209 . Optionally, the target solids loading  805  level may be adjusted on-site at the wastewater concentrator or remotely. For example, it can be updated through wired or wireless means such USB, 802.11, Ethernet, 3G or other standard communication protocol. 
     As with the algorithm of  FIG. 4 , the algorithm of  FIG. 8  can be stored in the form of program instructions, for example, in a memory device connected to or internal to a microcontroller or microprocessor, a programmable logic device, a remote personal computer (PC) controlling the control system  209 , and executed by any combination of these devices. 
       FIG. 9  is a high-level system diagram showing a wastewater piping system with several laterals or secondary sewer mains. In addition to wastewater concentrator  101  shown in  FIG. 1 ,  FIG. 9  shows a second wastewater concentrator  901 . Wastewater  903  flows through the secondary sewer main  905 . A diverted wastewater portion  907  flows through inlet pipe  909 . The non-diverted wastewater  911  remains in the sewer main  905 . In accordance with principles of the invention that have been described in this disclosure, the wastewater is separated into separated liquid  913  through an outlet pipe  915  and concentrated solids  917  through a second outlet pipe  919  connected to the sewer main  905 . The separated liquid  913  can be diverted for local reuse or disposal. In one embodiment, the separated liquid  913  is mostly water but main contain BOD or dissolved solids. This can be pumped deep into the ground in order to facilitate natural filtration. In another embodiment, the separated liquid  913  is further purified and sterilized and can be used for agricultural or commercial irrigation or for drinking water. 
     The concentrated solids  917  in the second outlet pipe  919  are reintroduced in the sewer main  905 . The concentrated solids  917  are combined with the non-diverted wastewater  911  to form concentrated wastewater  921  in the sewer main. The resulting concentrated wastewater  921  has increased suspended solids. A portion of wastewater has been removed from the secondary sewer main  905  that is approximately equal to the separated liquid  913  diverted through the outlet pipe  915 . This has the effect of increasing the system capacity of the sewer main  905  by an amount equal to the separated liquid  913 . By increasing the system capacity of the sewer main  905  in this way, the wastewater loading of the sewer main  905  has been effectively been decreased. 
     In accordance with principals of the invention, the wastewater loading of secondary sewer main  905  is adjusted to a pre-determined level or pre-determined amount. This pre-determined amount may be set in accordance with a number of factors. For example, the pre-determined level may be set in order to make sure that the sewer main  905  is not over loaded during peak capacity. Similarly, the pre-determined level may be set in order to assure that the total wastewater  923  supplied to the wastewater treatment plant  123  supplied is not over loaded during peak demand. 
     In an embodiment, a flow transmitter  925  determines the rate of flow of the concentrated wastewater  921  in the secondary sewer main  905 . The flow transmitter  925  communicates with the second wastewater concentrator  901  through a signal path  927 . This information transmitted through the signal path can take many alternative forms, for example, analog voltage, or a digital signal. This may be either through wire or by wireless means. 
     As previously described, it may be desirable to adjust the flow in each wastewater lateral in accordance with a combination of the desired wastewater loading on the lateral itself and the overall wastewater loading on the entire wastewater system. In  FIG. 9  there are three laterals: the sewer main  105 , a first secondary sewer main  905 , and a second secondary sewer main  931 . The total wastewater supplied  923  supplied through sewer main portion  935  at the inlet of the wastewater treatment plant  123  is a combination of concentrated wastewater  121  from sewer main  105 , concentrated wastewater  921  from the first secondary sewer main  905  and wastewater  933  from the second secondary sewer main  931 . A flow transmitter  939  located long the sewer main portion  935  at the inlet of the wastewater treatment plant  123  measures the flow of the total wastewater supplied  923 . The flow transmitter  939  sends flow data to the second wastewater concentrator  901  through a signal path  943  and to the first wastewater concentrator  101  through another signal path  941 . These signal paths may be analog, digital, wired or wireless. Both signal paths may be combined into a single multiplexed signal path and received by each wastewater concentrator using a unique identifier. 
       FIG. 10  shows a wastewater concentrator system with additional filtration and capable of controlling both wastewater loading and solids loading. The separated liquid  113  from the vortex separator  203  enters a feed pump  1001 . The feed pump  1001  pumps the separated liquid  113  into a membrane filtration unit  1003 . The membrane filtration unit  1003  removes most of the remaining particulates producing purified water  1005  that is discharged through outlet pipe  115 . A VFD  1007  controls the speed of the feed pump  1001  used to pump the separated liquid  113  into the membrane filtration unit  1003 . The control system  209  regulates the VFD  1007  through a signal path  1009 . The signal path  1009  may be analog, digital, wired or wireless. In an alternative embodiment, a control valve can be used instead the VFD  1007  to control the flow of the separated liquid  113  into the membrane filtration unit  1003 . In this alternative embodiment, the control system would regulate the position of control valve and the feed pump  1001  would a constant speed. 
     The membrane filtration unit  1003  can use nano-filtration, ultra-filtration, micro-filtration, reverse osmosis, or other equivalent membrane filtration technique for separating particles from water for the purpose of purifying the water. In an alternate embodiment, the purified liquid may be further purified and sterilized for local reuse, for example, for irrigation, potable water, or industrial use. In another embodiment, the purified liquid can be disposed of in nearby body of water, such as rivers, lakes, streams, or the ocean. Alternatively, the purified liquid can be disposed of by pumping it into the ground and allowing for further natural filtration. Depending on local environmental requirements and/or governmental regulations, the purified liquid may be further purified or sterilized before disposal or reuse. 
     Membrane filtration units generally have an optimum operational rate of flow. In order to main a constant rate of flow through the membrane filtration unit  1003 , a storage tank  1011  can be employed to divert excess of the separated liquid  113  from the membrane filtration unit  1003  during periods of higher demand and reintroduce the separated liquid  113  to the membrane filtration unit  1003  during periods of lower demand. 
     The feed pump  1001  may be eliminated in a gravity feed system where there is sufficient pressure from the separated liquid  113  on the membrane filtration unit  1003  to allow the membrane filtration unit  1003  to operate. 
     In an alternative embodiment, a media or multi-media filter can be substituted for the membrane filtration unit  1003 . Media filtration devices can include, for example, sand, anthracite, manganese green sand, clinoptilolite (zeolite), or activated carbon filtration units. Multi-media filtration units can include multiple layers of filtration media, for example, in one embodiment, a multi-media filter includes a combination of layered sand, anthracite, and garnet. Using a media or multi-media filter in place of the membrane filtration unit  1003 , the storage tank can be eliminated if desired. 
     In another alternative embodiment, the membrane filtration unit  1003  and storage tank  1011  can be replaced by an aeration pond. The aeration pond can be used to oxidize aerobic bacteria and reduce the BOD and chemical oxygen demand of the separated liquid  113 . The resultant liquid then further purified by filtration. Depending on local regulatory or environment conditions, the aeration pond can be followed by chemical, mechanical, thermal, or electrical filtration methods before disposal or reuse. 
     The control system of  FIG. 10  can use both the solids loading of the concentrated wastewater  121  as measured by the solids analyzer  601  and the flow of the concentrated wastewater  121  as measured by the flow meter  125  to adjust the amount of diverted raw wastewater  107  removed from the sewer main  105  and the amount of concentrated solids  117  reintroduced into the sewer main  105 .  FIG. 11  is a flow chart for the wastewater concentrator of  FIG. 10  showing an example of a method for accomplishing this. 
     Referring to  FIG. 10  and  FIG. 11 , the solids analyzer  601  in combination with the control system  209  determines post-system solids loading  1101 . The determined post-systems solids loading  1101  is compared  1103  to target maximum solids loading  1105 . If the post-system solids loading  1101  is greater than or equal to the target maximum solids loading  1105  than the control system  209  decreases the input rate of flow  1107  by sending a signal to the VFD  213  to slow down the inlet feed pump  201 . If the post-system solids loading  1101  is less than the target maximum solids loading  1105  than control system in combination with the flow transmitter  125  determines the post-system wastewater loading and compares  1111  it to the retrieved target wastewater loading  1113 . If the post-system wastewater loading is less than the retrieved target wastewater loading than the control system  209  decreases input rate of flow  1115  of the feed pump  201  in order to decrease the flow of diverted raw wastewater  107  out of the sewer main  105 . If the determined post-system wastewater loading  1109  is greater than the retrieved target wastewater loading  1113 , than the control system  209  increases rate of flow  1117  of the feed pump  201  in order to increase the flow of diverted raw wastewater  107 . If the determined post-system wastewater loading  1109  is equal to the retrieved target wastewater loading  1113 , the rate of flow is not adjusted  1119 . The algorithm then loops back  1121  to the beginning and starts again. 
     Both the target maximum solids loading  1105  and target wastewater loading  1113  can be ranges of values rather then single values to enhance stability of the feedback control system. In one embodiment, if the post-system solids loading  1101  is greater than the target maximum solids loading range than the control system  209  decreases the input rate of flow  1107 . If the post-system solids loading  1101  is less than the target maximum solids loading range, than the determined post-system wastewater loading  1109  is compared with the target wastewater loading range. If the determined post-system wastewater loading  1109  is within the target wastewater loading range, the flow is not adjusted. If the determined post-system wastewater loading  1109  is less than the target wastewater loading range, than the control system  209  decreases input rate of flow  1115 . If the determined post-system wastewater loading  1109  is greater than the target wastewater loading range, the control system  209  increases input rate of flow  1117  so that more diverted raw wastewater  107  is removed from the sewer main  105  in order to decrease the wastewater loading. 
     Combining a multi-wastewater concentrator of  FIG. 9  with the wastewater concentrator disclosed in  FIG. 10  and  FIG. 11  that responds to both solids loading and wastewater loading, it is possible to create a wastewater system that can respond to changing conditions in each part of the system and target wastewater loading and total maximum solids loading accordingly. 
       FIG. 12  shows an embodiment with an alternative control and additional purification of the separated liquid. Referring to  FIG. 12 , the separated liquid  113  flows from the vortex separator  203  to the feed pump  1001 . The feed pump  1001  supplies enough net positive suction pressure to supply the separated liquid  113  to a nano-filtration membrane unit, also known as a membrane filtration membrane polisher or NFMP  1201 . Restricting and modulating the flow of the two streams can be used to determine the fractionation ratio and rate of flow. The concentrated solids stream flow can be regulated by the speed of the separator VFD  509  in combination with a first flow valve  1203 . The first flow valve  1203  can be controlled by the control system  209 . 
     The NFMP  1201  further fractionates the separated liquid  113  into two streams: a concentrate stream  1205  and a product stream  1207 . The concentrate stream  1205  is the water containing all residual suspended solids having a specific gravity to close to water to be efficiently removed by the voraxial separator plus a percentage of the dissolved solids. This is typically 10% to 15% of the total product fraction output of the NFMP. This portion may deviate significantly above or below this range depending on the efficiency of the vortex separator  203  at removing the suspended solids from the stream before it reaches the NFMP  1201  and also depending on the design of the NFMP  1201  itself. The concentrate stream  1205  resulting from the NFMP  1201  is combined with the concentrated solids stream  117 . Both streams are returned to sewer main  105 . The concentrated wastewater  121  in this embodiment is a combination of the non-diverted wastewater  111 +the concentrated solids stream  117 +the concentrate stream  1205 . A control valve  1209  creates backpressure on the concentrate stream  1205  leaving the NFMP  1201  and can be used to control the portion of concentrate stream leaving the NFMP  1201 . 
     The product stream  1207  is mostly water that is essentially free of suspended solids and typically has a BOD&lt;5 mg/liter. This portion is typically 85-90% of the total output of the NFMP  1201 . The percentage of product water to concentrate is referenced as the “recovery” of the NFMP  1201 . Additional steps of media filtration followed by a distillation/evaporator column can be added to further remove traces of suspended, colloidal matter, and volatile organics not removed by the vortex separator  203 . 
     The product stream  1207  passes through an ultraviolet light unit  1211  that destroys residual bacteria. A chlorine dispensing unit  1213  adds chlorine to the resulting purified water  1215  as a bacteria static agent (disinfection) to prevent the growth of bacteria during storage prior to use. Typically, enough chlorine is added to give a residual concentration of 1 to 1.5 mg/liter of free chlorine in the resulting purified water  1215 . Introduction of amounts of chlorine to produce other ratios are also possible and depend on national, regional and local regulatory standards. The resulting purified water  1215 , in one embodiment, may be used for local irrigation or may be further processed for use as potable drinking water. In another embodiment, the purified water  1215  can be used for cooling tower makeup water or other industrial uses. Alternatively, the purified water  1215 , or a portion of the purified water  1215 , can be diverted for disposal. This can be disposed of, for example, by pumping the purified water  1215  into the ground. Other examples of disposal include disposal into a nearby body of water, for example, an ocean, lake, river, stream, canal, or a constructed wetland. 
     The wastewater is diverted from the sewer main  105  at a deliberate rate and the resultant concentrated solids  117  and concentrate stream  1205  are reintroduced into the sewer main  105  in a deliberate amount in order to control the wastewater loading and concentrated solids of the wastewater system. This can be controlled by control system  209  dynamically as previously described. 
     While the control of wastewater loading and solids loading in the sewer main  105  can be accomplished with a minimal number of sensors and feed pumps as previously described, a system with more measurement and control capability may be desirable. Again referring to  FIG. 12 , additional flow transmitters and solids analyzers are employed. It should be understood by the reader that the flow transmitters and solids analyzers in  FIG. 12  are capable of communicating with the control system  209 . This communication may be analog, digital, wired or wireless. It may be multiplexed on a single transmission channel. 
     A pre-system located flow sensor  1217  installed in sewer main  105  can be used by the control system to determine wastewater loading conditions before the wastewater concentrator  101 . The quantity of raw wastewater diverted to the wastewater concentrator  101  is sensed by inlet flow sensor  1219 . A suspended solids transmitter  1221  measures the percent of suspended solids present. As previously described, the quantity of wastewater diverted is determined by the speed of feed pump  201 . In an embodiment, the speed of the feed pump  201  is adjusted by controlling the VFD  213  of the feed pump  201  through an adjustable set-point process control loop. The separation the diverted raw wastewater  107  in concentrated solids  117  and separated liquid  113  is controlled in  FIG. 12  by the first flow valve  1203  and speed adjustment of the separator VFD  509 . A flow transmitter  1223  measures the flow of the concentrated solids stream  117 . The separated liquid flow transmitter  1225  measures the flow of the separated liquid  113  into the feed pump  1001  supplying the NFMP  1201 . An analyzer transmitter  1227  measures the product stream  1207  conductivity. A pH analyzer transmitter  1229  measures the pH of the product stream  1207 . 
       FIG. 13  is a diagram outlining the use of three control loops for controlling the flow of the wastewater separator. This should not be taken as the only approach to maintaining control of the system. Control loop  1313  controls the final product output, which in the embodiment of  FIG. 12 , is the resulting purified water  1215 . In the final product control loop  1313 , three flow transmitters control the set point  1315  for the flow/ratio controller  1317 :separated liquid flow transmitter  1225 , concentrate stream flow transmitter  1231 , and product stream flow transmitter  1233 . A flow ratio controller  1317  uses these three flow transmitters to maintain the product stream  1207  at a constant rate of flow and a constant ratio of product stream  1207  to concentrate stream  1205 . This is desirable because membrane separators generally have an optimal operational rate of flow. The set point value  1315  for the final product control loop  1313  is feedback through the control system to determine the set point of  1305  in first control loop  1301 . In one embodiment, the output of the inlet flow transmitter  1219  will display the actual flow being transferred from the sewer main  105  for wastewater concentrator throughput. Flow Controller  1303  adjusts the VFD  213  on the inlet feed pump  201  to maintain correct flow to the system as required to maintain a constant flow of the product stream  1207 . The middle control loop  1307  is designed to maintain the operation of the vortex separator  203 . The separated liquid flow transmitter  1225  in the final product control loop  1313  is used to determine the second control loop set point  1311 . The speed of vortex separator  203  is adjusted to maintain a desired ratio of concentrated solids stream  117  as measured by the flow transmitter  1223  of the concentrated solids  117  and separated liquid  113  as measured by the flow transmitter  1225  of the separated liquid  113 . 
     Within this disclosure flow transmitters have been used to measure flow and report the rate of flow and flow related information to the control system  209 . Similarly, solids analyzers have been used to measure solids loading and report solids loading related information to the control system  209 . The invention is by no means limited to these instruments for measuring flow and solids loading. Those skilled in the art will readily recognize equivalents. For example, there many means for measuring flow, flow transmitters or flow meters can include but are not limited to a magnetic flow meter, turbine flow meter, vortex flow meter, differential pressure meter, and paddle wheel flow meter. Suspended solids meters can include mass flow meters or infrared meters. 
     Both  FIG. 1  and  FIG. 9  show the separated liquid  113  flowing through the outlet pipe  115  of the first wastewater concentrator  101 . Similarly,  FIG. 9  shows separated liquid  913  flowing through the outlet pipe  915  of the second wastewater concentrator  901 . It should be understood by the reader that in alternative embodiments further purified water could flow through either the outlet pipe  115  of the first wastewater concentrator  101  and/or the outlet pipe  915  of the second wastewater concentrator. For example, in  FIG. 10 , purified water  1005  flows through the outlet pipe  115 . In  FIG. 12 , further purified water  1215  flows through the outlet pipe  115  of the first wastewater concentrator  101 . 
     While various methods for treating the separated liquid  113  have been demonstrated, it is not the inventors intent to limit treatment of the separated liquid  113  to these methods and apparatus. It should be also understood, by those skilled in the art, that other treatment methods and apparatus can be applied either alone or in combination. Referring to  FIG. 12 , for example, a media filter, a multi-media filter, polymer coagulation unit, or a cartridge filtration unit (for example, pleated paper, porous ceramic, or filament wound cartridges) can be applied before the feed pump  1001  and NFMP  1201 . 
     Accordingly, a wastewater concentrator method and system meeting the herein described objectives have been described. It is not the intent of this disclosure to limit the claimed invention to the examples, variations, and exemplary embodiments described in the specification. Those skilled in the art will recognize that variations will occur when embodying the claimed invention in specific implementations and environments. For example, it is possible to implement certain features described in separate embodiments in combination within a single embodiment. Similarly, it is possible to implement certain features described in single embodiments either separately or in combination in multiple embodiments. It is the intent of the inventor that these variations fall within the scope of the claimed invention. While the examples, exemplary embodiments, and variations are helpful to those skilled in the art in understanding the claimed invention, it should be understood that, the scope of the claimed invention is defined solely by the following claims and their equivalents.

Technology Category: c