SEWER SYSTEM FLOW CONTROL TO REDUCE WASTEWATER TREATMENT COSTS

Abstract: A method and apparatus for diurnally storing and releasing municipal sewage in its conveyance network of sewers and interceptor piping to affect a reduction in peak energy demand and on-peak energy usage at the wastewater treatment plant. The apparatus comprises a sewer segment (10) having an upstream section (11) and a downstream section (12). The sewer segment also contains a liquid portion (13) and a gaseous portion (14). A control means (30) is located between the upstream section and the downstream section of the sewer segment.

Description: SEWER SYSTEM FLOW CONTROL TO REDUCE WASTEWATER TREATMENT COSTS FIELD OF THE INVENTION This tm ention relates to a method and an apparatus for the control of wastewaler flow to a wastewater treatment plant (WWTP) in order to reduce the cost during times of high electπcal charges The mv ention discloses the use of the sew age collection and com e\ ance netw orks as storage units m order to either reduce peak flow rates or to shift the time peπod when the peak flow reaches the WWTP BACKGROUND OF THE INVENTION Municipal sewage commonK flows thru a network ol si/ed se er and interceptor pipes from residential homes and industries to wastewater treatment facilities The wastewater treatment process at such facilities is intensiv e, with an approximate annual US electncal bill in the range of $500 million to SI billion dollars Because of the natural diurnal m wastewater flow waste ter flow rates at a WWTP tend to increase duπng the dav to coincide with the time period of higher electπc rales However, sewer networks have redundant and excess storage capacitv to meet infrequent extreme flows Sewers are generalK designed for a 50-\ r life and also include excess capacitv expected to be required during the design life of a sewer This excess capacitv can be used to store and thai deliver sewage flow to the treatment facilities so the wastewater can be treated in order to lake advantage of lo er electπc rates Electπcitv is used bv a WWTP for a anetv of uses such as compressing air for biological treatment processes pumping liquids and process sludge The electrical usage is related to the flow of sewage into the plant and increases as the flow increases In general waste ater flow is high duπng the and low at night while the cost ol electπcm is higher duπng the dav than at night Thus the cost of electπcitv vanes ith the time Another cost factor is the peak demand of electπcitv (maximum short-term power drawn duπng the billing peπod) bv the WWTP The pπor art descπbes a number of s that VVWTPs have utili/ed to lower electrical costs These methods include, pro iding on-site electπcitv generating capacitv . replacing existing electπcal motors with higher efficiencv motors, shifting electπcal use where possible, to peπods ol lower demand and replacing existing processes with higher efficiencv piocesses. Also replacing coarse bubble aeration w ith line bubble aeration will usuallv result in a significant electπcal savings as will the implementation of a dissol ed ox en control strategv and instrumentation None of these methods to lower WWTP electπcal costs teach flow shitting within the existing se er s stem as a av to reduce electπcal costs or to provide flow equalization In order to minimize the electπcifs expense, the se age flow into the plant needs to be controllable so that high flows occur when electπcttx rates are low and low flows occur when electπcitv rates are high, so that the new flow profile favors low peak demands In general, electπc utilitv rate structures \ arv among companies and between states and WWTPs and tv picalh are subject to complex rate structures classified under the heading industrial use Rates are generalK affected bv supph and demand with incentives to load shift and reduce peak demand duπng high use (davttme) hours Wastewater treatment plants are t picallv designed and built to tieat a fluctuating flow stream, one that \ anes ideh throughout the dav and possibh the season m both quaπtm and strength These Λ anations m loading require process units and equipment be large enough to meet reasonable dailv peak loadings periodic seasonal peak loadings such as rain events and the projected demand imposed future growth Bv controlling the flow to the process at a more ev en rate loadings are more consistent and biological and energv demands are more stable Through the dampening effects of equalization, onh the treatment units and equipment needed to meet the equalized loadings are required to operate One method known to accomplish equalization is the use of equalisation basins which have a volume generalK less than 35% of the WWTP capaαrv Thev can be located on site or upstream of the WWTP and arranged as separate in-line or off-line tanks The result is an overall impro ement in WWTP efficiencies more consistent removal rates reduced electπcal peak-demand charges and possiblv decreased po er consumption Additional benefits include the dissipation of shock loads that most WWTPs experience and the extension of the operating capacitv within the existing facihrv because the initial design capacitv was oversized to allow for peak demands The beneficial effects of equalization lor biological wastewater treatment processes are descπbed m the b S Patent Nos 5 853 589 issued to G Desjardms on Dec 29 1998 It is known from the prior art that sewage overflows from combined sewer interceptors results in continued degradation of receiv ing w ater qualm The prior art descπbes the construction of deep tunnels for the capture and storage of combined sewage and storm water runoff These tunnels collect storm ater and sewage duπng a storm so that it is not bvpassed to the receiving water Following the storm, the collected stoπn water and sewage in the tunnels is then pumped to the treatment plant Off-line basins or tanks are most wideK used In cases where stormwater and wastewater are combined in sewers flow rates are regulated bv s stem design features so that wastewater treatment plant capacities are not exceeded HistoπcalK diversion or regulator structures ere required to divert flows in excess of the treatment plant capacitv to the surface receiving water via the combined sewer overflow outlets Examples of flow control devices used lor diversion ol storm flow include U S Patent Nos 3 974 655 issued to R Halpern on Apr 14 1975 No 4 167 358 issued to J Besha on Sep I I 1979 and No 5 321 601 issued to D Riedel on June 14 1994 Therefore the use of existing se er capacitv to eliminate or minimize diversions from combined sewers is known Flow control devices are also available for preventing back- flow in sewer sv steins Examples of these include U S Patent Nos 5 406 972 issued to G Coscarella on Apπl 18 1995 No 4 503 881 issued to F Vecchio on Mar 12 1985 and No 4494 345 issued to B Peterson on Jan 22 1985 None of these flow control devices are descπbed for use to temporaπlv reduce diurnal on-peak flow rates to a WWTP on a regular basis for the express purpose of lo ering electπcal costs It is known m the prior art to utilize flow control de ices in networked sv stems to optimize sewer svstem capacitv and Iherebv reduce the amount of wastewater that is bvpassed to surface waters duπng extreme flow events None of these networked sv stems are descπbed as being useful to temporaπlv reduce diurnal on-peak flow rates to a WWTP on a regular basis to lower electπcal costs for the WWTP SUMMARY OF THE INVENTION This invention relates to a method and an apparatus for control of flow of sewage to a wastewater treatment plant (WWTP) for the express purpose of reducing eiectncal costs The invention discloses the use of the sewage collection and com ev ance netw orks as temporarv storage units in order to reduce or lime-shift peak w astevvater flows to the WWTP Electπcitv is among the largest expenses in a wastewater treatment plant (WWTP) budget, alongside debt and personnel costs Therefore, cost control through energv management is generalK a high pπoπtv for all WWTP managers Bv controlling the flow to the process at a more ev en rate, loadings are more consistent, and biological and energy demands are more stable Through the dampening effects of equalization, onlv the treatment units and equipment needed to meet the are required to operate The result is an ov erail tmprov ement m WWTP efficiencies, more consistent removal rates, reduced peak-demand charges, and decreased power consumption Utilization of the existing se er sv stem provides a to obtain electπcal cost reductions, flow equalization capacitv . or an optimized combination thereof However, with the disclosed invention it is possible to equali7e wastewater flows, or alternativeK to more dramaticalK shift flow peaks from the on-peak electπc rate periods to the off-peak electric rate periods winch can be designed to prov ide less equalization bv attenuating and shifting the flow peak This ould require utilizing additional storage volume in the sewer svstem and the economic benefits of equalization may outweigh the cost savings associated ith maximizing the energv bill reductions from time-shifting alone Additional benefits of flow equalization include the dissipation of shock loads that most WWTPs expeπence and extension of the operating capacitv of the existing facilitv There has thus been outlined, rather broadl . the more important features of the invention in order that the detailed descπpiion thereof that follows mav be better understood, and in order that the present contπbution to the art mav be better appreciated There are additional features of the invention that ill be descπbed hereinafter and which ill form the subject matier of the claims appended hereto In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the follow ing description or illustrated in the drawings The niv ention is capable of other embodiments and of being practiced and carried out in aπous avs Also, it is to be understood that the phraseologv and terminologv e plov ed herein are for the purpose of description and should not be regarded as limiting As such, those skilled m the art will appreciate that the conception, upon which this disclosure is based, mav readtlv be utilized as a basis for the designing of other structures, methods and systems for earning out the several purposes of the present invention It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as thev do not depart from the sptπt and scope of the present in ention It is therefore an obiect of the present invention to provide a new a method to control on-peak flow rates and thereby reduce the cost of electncitv for sewage treatment This new method and apparatus has anv of the advantages mentioned heretofore and se eral no el features that result m a new method and apparatus which is not anticipated rendered obvious suggested or even implied bv am of the pπor art methods to reduce the cost of electncitv for se age treatment either alone or in am combination thereof Still \ et another object of the present inv ention is to use the sew age collection and conv ev ance net orks as temporarv storage units in order to control flows resultuig in reduced on-peak flows and therebv lower the electrical costs for a WWTP It is another object of the present invention to pro ide a new method to reduce on-peak flow rates or prov ide flow equalization that can be easilv networked throughout a sewer s stem as needed It is another object of the present in ention to provide a new method to reduce on-peak flow rates or provide flow equahzanon that can be easih configured to meet the individualized requirements of a particular WWTP It is another ob|ect of the present invention to provide a new method to reduce on-peak flow rates or provide flow equalization that can be easiK automated li needed It is another object of the present invention to provide a new method to reduce on-peak flow rates or prov ide flow equalization that is rugged and reliable It is another object of the present invention to pro ide a new method to reduce on-peak flow rates or provide flow equalization which mav be easilv and efficienth manufactured and marketed It is another object of the present invention to pro ide a new method to control flow rates to a WWTP in a vvav that lowers the electπcal costs lor a WWTP An even further obiect of the present invention is to provide a new method to reduce peak flow rales or prov ide flow equalization which is susceptible of a low cost of manufacture with regard to both mateπals and labor These together with other otηects of the invention, along with the vaπous features ofnovelrv which characteπze the invention are pointed out with particulaπtv m the claims annexed to and forming a part of this disclosure For a better understanding of the inv ention, its operating advantages and the specific ob|ects attained bv its uses reference should be had to the accompanving drawings and descπptiv e matter in which there is illustrated preferred embodimaits of the inv ention BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and odiects other than those set forth above will become apparent when consideration is gi en to the follo ing detailed descπption thereof Such descπption makes reference to the annexed drawings herein Figure 1 is a side schematic elev ation v lew of a tv pical flow in a sew er or interceptor segment Figure 2 is a side schematic elev ation v lew of a control dev ice temporaπlv storing high flow s according to the present invention Figure 3 is a schematic diagram of the components of the flow control de ice Figures 4a and 4b are cross sectional v lew s of representativ e tv pes of flow control dev ices for use in the present inv ention Figure 5 is a schematic representation of a sewer network of segments connected in series and parallel Figure 6 is a cross sectional representation of se er segments connected in series and parallel 5 DESCRIPTION OF THE PREFERRED EMBODIMENT The method of this invention uses excess se er or interceptor capacity on a regular basis to store and then purposefullv release partial v olumes of the o erall sewage flow , to lessen on-peak treatment plant ener v consumption The method includes the analv sis of the sewage flows and the sewer and interceptor piping network to I t) determine an ad antageous configuration for stoπng and releasing partial sew ge olume Usuallv there are general similarities among each wastew ater treatment plant and its associated interceptor s stem and the rate structure for the electπcal utilitv it uses to obtain its electπcitv Howev er each s stem is unique with its own specific characteπstics Therefore, it is apparent that this inv ention will be custom designed to maximize the benefits for am particular installation GeneralK how ev er the method of this inv ention allow s sewage 15 in anv grav itv flow sewer or interceptor segment to purposefullv be stored up to an elevation defined bv a maximum abo e which would be caused detnmental backups of sewage With reference to Figure 1 is shown a typical sewer segment ( 10) or conduit receiving wastew ater from service lines ( 15 ) unregulated bv a flow control dev ice (30) and therefore not utilizing the air or gaseous portion ( 14) directlv abov e the w asievv ater or liquid portion ( 13) The flow control dev ice defines an upstream section ( 1 1 ) and a 20 downstream section ( 12) For unregulated systems, the wastewater (20) passes unaffected through the flow control dev ice to the downstream section ( 12) and ultimatelv to the wastew ater treatment plant ( 16) Bv wav of example as shown in Table 2. the wastewater flow varies in a diurnal flow pattern throughout the dav with a high flow period centered around 3 00 PM and a low flow peπod centered around 4 00 AM With reference to Figure 1 and Figure 2. as the wastewater (20) flow m the upstream section ( 1 1 ) increases 25 anv flow in excess of a predetermined value will be limited bv the flow control dev ice (3(J) from reaching the downstream section ( 1 ) The wastewater (20) will then begin to backup into the upstream section of the sewei segment, displacing the gaseous portion with stored waste ater therebv increasing the liquid portion ( 13) Duπng this time, the wastewater flow reaching the downstream section is limited to what can pass through the flow control device 30 A number of flow control device ' s could be used with this invention Figures 4a and 4b show the planar v iew of a number of possible control dev ices The dev ice preferablv will hav e an opening near the base of the de ice that would allow the predeteπruned flow to pass unrestncted through the device As wastewater mov ers from the upstream section to the downstream section, the device will then impede the higher flo s. so that the wastew ater w ill back up into the gaseous phase of the upstream sew er segment W ith reference to Figure 4a. the flow control dev ice 35 (30) for regulating a wastewater or liquid flow is mounted in a sewer segment or conduit The flow control device has a bodv (3 ] ). with a planar shape, located between the downstream section and the upstream section For ease of installation and maintenance, the bodv (31) is preferablv remov abK attached in the conduit The body also has a first and second edge The bodv first edge (33) is located nearest the conduit lower surface (32) and creates an orifice ith the conduit The orifice restπcts the liquid flow between die upstream section and the downstream section The bodv second edge (34). is located opposite the conduit lower surface The bodv second edge (34) defines a eir surface for liquid flow between the upstream section and the downstream section Furthermore, the flow control device will have an overflow or bvpass capaci so that flows m excess of the anticipated peak capacity will o erflow or bvpass the control device without causing problems to the upstream sewer Depending on the specific site, it mav be preferable to utilize a fixed weir plate or a fixed adiustable opening weir plate to regulate flows, or an automated stem that would pro ide flow control based on a timer, local controller, or remote computer sxstem The flow control device s mav be. foτ example, a concentnc membrane check valve or a mo able gate or weir, mounted inside and extending outside of the sewer pipe that expands and contracts via feedback or timed control, or both, to respectivelv store and release the normal gravitv flow of the sewage, or the use of an existing parallel or alternate se er pipe lor purposeful storage and timed release which lessens on-peak treatment plant flows With respect to Figure 3. if configured for automated operation, the control portion of the apparatus functions with either a level indicator or a bubble tube or other pressure sensing de ice which provides leedback to a controller on the upstream elevation and which is installed to minimize clogging bv sewage debris The controller is programmed to ramp up to the maximum allowable head based on the pressure reading of the bubble tube, and ramp down to full open duπng off-peak times the exact ramping strategv is a result of algoπthms developed in the methodologv A second control sensor mav be located at the highest elevation point of the stored se age to provide for redundant control svstem by pass Optionallv . a flow meter mav be used to pro ide flow rate input to the controller to veπfv proper operation of the control device, or to provide for feedback control or both The methodologv bv which the inv ention must be applied is unique because each sewerage network, its flows and the aste ater treatment facilitv s electrical rate structure are diflerent As shown m Table 2. an electrical rate structure mav have an on-peak rate or high power cost period from 9 00 AM to 1 1 00 PM with the electπcal rate structure ' s off-peak rate, or low power cost peπod from 1 1 00 PM to 9 00 AM A schematic representation o! a simple sewerage network is shown in Figure 5 Cπtical comparisons at each sewerage network include the storage capacity within each sewerage segment, and the resulting cumulative storage capacity within the network, the average on-peak and off-peak wastewater flows, the relative on-peak to off-peak electncal energv usage the on- peak to off-peak energv charge, and the overall on-peak energv cost relative to the demand cost, and the flow at demand conditions relative to the a erage on-peak flow, and the relationship bet een WWTP flows and energv usage It is readiK apparent that generalK. available storage m interceptor capacitv near the W^WTP would be utilized first This would be preferable, since the largest interceptors which would provide the most storage for a given length, are usualiv installed immediately upstream of the WWTP In addition, it would be easier to coordinate the release of stored wastewater with the off-peak energv peπod for the WΛVTP when the stored wastewater is near the WWTP For v astevv ater stored aw av from the WWTP. the w astew ater trav el time mav also hav e to be considered to ensure that stored astewater is reaching the WWTP during the off-peak energv period As descπbed previouslv each application of tins invention ould result m a s stem thai would be unique to anv specific wastewater treatment plant However, the method of application of the invention includes the following steps 1 Analv ze the existing sewerage network specificallv to determine the relative positions of sewer pipes to each other the size and lengths of the sewer pipes, then inlet and outlet ele ations and the maximum sewage elev ation of a giv en sew er piping segment upstream of a pumping station or treatment plant Calculate total sv stem storage based on multiple segments A schematic of a sewer segment feeding a larger sewer network is shown in Figure 1 The cumulative storage requirements over a txpical 24-hr period is shown in Table 2 Figure 6 shows an example of WWTP inlet flows with and w ithout storage and the associated storage requirement 2 Analv ze the diurnal flows into the treatment plant specificallv to determine the ratio oi the on-peak av erage WWTP flow and the off-peak av erage WWTP flow and the magnitude and timing of the on-peak av eTage flow at demand conditions 3 Analv ze the diurnal energv use at the treatment plant, specificallv to determine the magnitude and timing of the relative on-peak to off-peak energv demand and the ratio of the on-peak to ofl-peak energv usage as shown in Table 3 4 Determine the relationship between WWTP flow reduction and the energv reduction A constant relationship of 0 6 is shown in Table 3 for this simplified example 5 Analv ze the electrical rate structure, specificallv to determine the ratio ol the demand charge to the to the on-peak demand charge, and the ratio of the on-peak enerav charge to the ofl-peak energv charge Table 3 provides a simplified example of this anaKsis 6 Use a dvnamic modeling sv stems approach to implement a sv stematic temporarv storage of sewage to control mlet flo s into a astewater treatment facilitv to minimize facilitv electrical cost, to maximize the capacitv of plant claπiϊers aeration basins, channels and pumps or a combination thereoi Therefore the foregoing is considered as illustrative onlv of the pπnciples of the invention Further since numerous modifications and changes will readilv occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and descπbed. and accordinglv all suitable modifications and equiv alents mav be resorted to falling within the scope of the inv ention Table 1. Segment analysis to determine storage capacity Pump Segment Length (ft) Diameter (in) Pipe elevation slope Storage length (ft) Storage station high low partial 1 full gallons 2 5 200 8 721 5 719 5 0 010 67 133 392 4 100 12 719 5 718 5 0 010 0 100 529 3 100 12 718 5 717 5 0 010 0 100 529 2 150 16 717 5 716 0 010 0 150 1410 1 200 16 716 714 0 010 0 200 1880 On-peak average flow (gpd) 10000 assumed Off-peak average flow (gpd) 5000 assumed Estimated total storage capacity at pump station 1 (gallons) 1449 On-peak average flow, adjusted for flow storage (gpd) 7102 On-peak average flow reduction 29% Off-peak average flow, adjusted for storage release (gpd) 7898 Length of partial storage = (D/12)/slope 90% available Table 2. Effects of flow storage on WWTP flows Time Demand WWTP WWTP Cumulative Target Req'd WIG Cumulative status inlet MGD MG/hr MG inlet MGD 1 storage MG storage 8 9 ON-peak 18 075 075 1533333 011 01 10 ON-peak 24 100 175 1533333 036 05 11 ON-peak 26 108 283 1533333 044 09 12 ON-peak 32 133 417 1533333 069 16 1 ON-peak 36 150 567 1533333 086 25 2 ON-peak 40 167 733 1533333 103 35 3 ON-peak 44 183 917 1533333 119 47 4 ON-peak 42 175 1092 1533333 111 58 5 ON-peak 36 150 1242 1533333 086 67 6 ON-peak 32 133 1375 1533333 069 74 7 ON-peak 28 117 1492 1533333 053 79 8 ON-peak 26 108 1600 1533333 044 83 9 off-peak 24 100 100 35 -044 79 10 off-peak 22 092 192 35 -053 74 11 off-peak 20 083 275 35 -061 68 12 off-peak 18 075 350 35 -069 61 1 off-peak 16 067 417 35 -078 53 2 off-peak 14 058 475 35 -086 44 3 off-peak 14 058 533 35 -086 36 4 off-peak 12 050 583 35 -094 26 5 off-peak 16 067 650 35 -078 18 6 off-peak 18 075 725 35 -069 11 7 off-peak 20 083 808 35 -061 05 8 off-peak 22 092 900 35 -053 00 1 based on segment analysis -10- Table 3. Effect of flow storage on energy bill 12.5%

Claims: CLAIMS We claim 1 An apparatus for flow control in combination with a sewer svstem to reduce wastewater treatment electπcal costs comprising a sewer segment having an upstream section and a downstream section, the sewer segment also containing a liquid portion and a gaseous portion. a astevv ater being conv e ed vv rthin the sew er sv stem passing through the sew er segment from the upstream section to the downstream sectioa a wastewater treatment plant being subject to an electπcal rate structure, the waste ater treatment plant receiv mg a vv astevv ater flow through the se er sv stem, the electncai rate structure hav ing at least a high pow er cost peπod and a low po er cost period. a control means located between the upstream section and the downstream section of the sewer segment the control means perioώcalK reducing the vv astew ater flow reaching the vv astew ater treatment plant duπng the high po er cost period the wastewater being temporaπlv stored in the gaseous portion of the upstream section, the control means peπodicallv increasing the wastewater flow reaching the wastewater treatment plant duπng the low powei cost peπod 2 The apparatus of claim 1 in which the control means is a valve 3 The apparatus of claim 1 m which the control means further compπses a pressure measurement means located in the upstream sechon 4 The apparatus of claim 3 in which the control means further comprises a flow meter 5 The apparatus of claim 1 herein the control means is a eir plate 6 The apparatus of claim 1 wherein the control means is an orifice plate 7 The apparatus of claim 1 in which the control means is a pump 8 A method to regulate a waste ater flow within a se er svstem to reduce aste ater treatment electrical costs comprising the steps ol providing at least one flow control device within a sewer segment of the sewer sv stem utilizing a wastewater treatment plant for receiving a wastewater. the wastewater treatment plant subject to an electncai rate structure, the electπcal rate structure having at least a high po er cost peπod and a low power cost penod. using the flow control de ice to reduce a aste ater flow reaching the waste ater treatment plant duπng the high power cost peπod. temporaπlv storing a portion of the wastewater ithin the sewer svstem. and peπodicalh releasing the aste ater to increase the astewater flow reaching the wastewater treatment plant duπng the low pow er cost peπod 9 An apparatus for controlling a liquid flow compπstng a conduit having an upstream sectioa a downstream sectioa and a lower surface. a body, having a substantially planar shape, being removably attached in the conduit between the downstream section and the upstream section, the body further having at least a first and second edge, the body first edge, located nearest the conduit lower surface defining an orifice with the conduit, the orifice restnctmg the liquid flo between the upstream section and the downstream section. the body second edge, located opposite the conduit lower surface, defining a weir surface for liquid flo between the upstream section and the downstream section. 1 The apparatus of claim 1 wherein said control means is the apparatus of claim 9. 1 1. An apparatus for flow control in combination with a sew er system to provide flow equalization for a waste ater treatment plant comprising: a sew er segment having an upstream section and a downstream section, the sewer segment also containing a liquid portion and a gaseous portion. a wastewater being conveyed within the sewer svstem to the astewater treatment plant, the wastewater passing through the sewer segment from the upstream section to the downstream section, the wastewater treatment plant receiving a wastewater flow through the sewer sv stem the wastewater flow hav ing a diurnal flow pattern, the diumal flow pattern generalK hav ing a high flow peπod and a lo flo period. a control means located between the upstream section and the downstream section of the sewer segment, the control means periodically reducing the wastewater flow reaching the wastewater treatment plant during the high flow period, the wastewater being temporarily stored in the gaseous portion of the upstream sectioa the control means periodically increasing the wastewater flow reaching the wastewater treatment plant during the low flow period. 12 The apparatus of claim 11 in which the control means is a valve. 13. The apparatus of claim 11 in which the control means further compπses a pressure measurement means located in the upstream section. 14. The apparatus of claim 13 in which the control means further compπses a flow meter. 15. The apparatus of claim 1 1 wherein the control means is a weir plate. 16 The apparatus of claim 1 1 wherein the control means is an oπfice plate. 17. The apparatus of claim 1 1 in which the control means is a pump. 18. A method to regulate a wastewater flow within a sewer system to provide flow equalization for a wastewater treatment plant receiving a wastewater. the method comprising the steps of providing at least one flow control device within a se er segment of the sewer system, the wastewater flo having a diumal flow pattern, the diurnal flow pattern having at least a high flow period and a lo flow period, utilizing the flow control device to reduce the wastewater flow reaching the wastewater treatment plant during the high flow period, temporarily storing a portion of the wastewater w ithin the sewer system, and periodically releasing the wastewater to increase the wastewater flow reaching the wastewater treatment plant during the low flow period.

Inventors: ANDERSON CLAUDE T, JACOBSON RONALD L, RIETH MICHAEL G, ANDERSON, CLAUDE, T., JACOBSON, RONALD, L., RIETH, MICHAEL, G.
Applicants: ANDERSON CLAUDE T, AQUAFLOW TECHNOLOGIES LLC, JACOBSON RONALD L, RIETH MICHAEL G, ANDERSON, CLAUDE, T., JACOBSON, RONALD, L., RIETH, MICHAEL, G.
Application year: 2000
Main classification: E03F3
IPC codes: E03F5, E03F7