WO2021092280A1

WO2021092280A1 - Filtration system apparatus and method

Info

Publication number: WO2021092280A1
Application number: PCT/US2020/059273
Authority: WO
Inventors: Benjamin A. CASTRO
Original assignee: Evoqua Water Technologies Llc
Priority date: 2019-11-08
Filing date: 2020-11-06
Publication date: 2021-05-14

Abstract

Tertiary filtration systems are disclosed. A tertiary filtration system includes an influent portion, a filtration portion fluidly connectable to the influent portion, a first water level sensor, at least one filter cartridge disposed within the filtration portion, a controller, and a backwash subsystem comprising a sprayer arm and a sprayer head. The controller is configured to, responsive to receiving a signal from the first water level sensor, adjust an inlet valve and adjust a filtrate outlet valve. The backwash subsystem is constructed and arranged to travel along the at least one filter cartridge with a position of the backwash subsystem along the at least one filter cartridge being a function of at least a level of the filtrate in the filtration portion. Methods of facilitating tertiary water filtration are also disclosed.

Description

FILTRATION SYSTEM APPARATUS AND METHOD

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Serial No. 62/932,788 titled “Filtration System Apparatus and Method” filed November 8, 2019, the entire disclosure of which is hereby incorporated herein by reference in its entirety for all purposes.

FIELD OF TECHNOLOGY

Aspects and embodiments disclosed herein are generally related to the field of filtering water using a tertiary filtration system.

SUMMARY

In accordance with an aspect, there is provided tertiary filtration system. The tertiary filtration system may comprise an influent portion comprising an inlet connectable to a source of influent. The tertiary filtration system may comprise a filtration portion fluidly connectable to the influent portion, with the filtration portion comprising a filtrate outlet and a reject portion comprising a reject outlet. The tertiary filtration system may further comprise a first water level sensor constructed and arranged to measure a level of influent in the influent portion. The tertiary filtration system may comprise at least one filter cartridge disposed within the filtration portion, the at least one filter cartridge fluidly connectable to the reject portion. The tertiary filtration system may further comprise a controller coupled to at least an inlet valve on the inlet, a filtrate outlet valve on the filtrate outlet, and the first water level sensor. The controller may be configured to, responsive to receiving a signal from the first water level sensor, adjust the inlet valve and adjust the filtrate outlet valve. The tertiary filtration system may additionally comprise a backwash subsystem comprising a sprayer arm and a sprayer head. The backwash subsystem may be constructed and arranged to travel along the at least one filter cartridge, with a position of the backwash subsystem along the at least one filter cartridge being a function of at least a level of the filtrate in the filtration portion.

In some embodiments, the controller may be further operable to, responsive to receiving a signal from the first water level sensor, adjust a reject valve on the reject outlet. In further embodiments, the tertiary filtration system may comprise a second water level sensor constructed and arranged to measure the level of filtrate in the filtration portion. In some embodiments, the controller may be further operable to, responsive to receiving a signal from the second water level sensor, adjust the filtrate outlet valve and adjust the inlet valve. . In some embodiments, the controller may be further operable to, responsive to receiving a signal from the second water level sensor, adjust the reject valve.

In further embodiments, the backwash subsystem may comprise a stabilization system constructed and arranged to maintain a position of the sprayer arm and sprayer head along the at least one filter cartridge and in relation to the level of filtrate. In some embodiments, a spray angle of the sprayer head is adjustable. In some embodiments, a flow rate of the sprayer head is adjustable.

In further embodiments, the tertiary filtration system may comprise a pre-filtering screen constructed and arranged to retain debris exceeding a predetermined size. The pre-filtering screen may be positioned upstream of the inlet. In further embodiments, the tertiary filtration system may comprise a bypass line positioned within the influent portion.

In some embodiments, the at least one filter cartridge may comprise a body, a filtering medium, and a frame constructed and arranged to secure a periphery of the filtering medium to the body.

In further embodiments, the tertiary filtration system may comprise a discharge limiting subsystem positioned within the filtration portion. The discharge limiting subsystem may be constructed and arranged to reduce discharge of filtrate from the filtrate outlet of filtrate below a predetermined minimum threshold level in the filtration potion.

In accordance with another aspect, there is provided a water filtration system. The water filtration system may comprise an influent portion comprising a first water level sensor. The water filtration system may comprise a filtration portion fluidly connectable the influent portion. The filtration portion may comprise at least one filter cartridge disposed within the filtration portion. The water filtration system may further comprise a controller coupled to at least the first water level sensor. The controller may be operable to operate the system in a filtration mode by directing a flow of influent from the influent portion to the at least one filter cartridge positioned in the filtration portion to produce filtrate until a level of influent within the influent portion exceeds a predetermined threshold level as determined by the first water level sensor. The controller may be further operable to operate the system in a backwash mode responsive to a signal received from the first water level sensor by adjusting a flow of filtrate discharged from the filtration portion to allow a backwash subsystem to travel along the at least one filter cartridge with the position of the backwash subsystem being a function of at least a level of the filtrate in the filtration portion.

In some embodiments, the controller may be further operable to, responsive to receiving a signal from the first water level sensor, adjust a pump fluidly connected to the backwash subsystem to direct filtrate onto the at least one filter cartridge. In some embodiments, the controller may be further operable to, responsive to receiving a signal from the first water level sensor, allow a reject to be discharged from a rejection portion.

In some embodiments, the controller may be further operable to stop the backflush mode responsive to the level of filtrate reaching a predetermined minimum threshold level in the filtration portion. The predetermined minimum threshold level may be determined by a second water level sensor positioned in the filtration portion. In some embodiments, the controller may be further operable, responsive to receiving a signal from the second water level sensor, return the system to the filtration mode.

In some embodiments, the controller may be further operable to operate the system in the backwash mode according to a predetermined schedule. In some embodiments, the controller may be further operable to operate the system in the backwash mode for a predetermined length of time.

In accordance with another aspect, there is provided a method of facilitating tertiary filtration. The method may comprise providing a tertiary filtration system comprising an influent portion connectable to a source of influent and a filtration portion fluidly connectable to the influent portion comprising at least one filter cartridge, and a backwash subsystem constructed and arranged to travel along a length of the at least one filter cartridge. The method may further comprise providing a controller. The provided controller may be operable to operate the system in a filtration mode by regulating the introduction of influent into the influent portion and the discharge of filtrate from filtration portion. The provided controller may be further operable to operate the system in a backwash mode responsive to at least a water level in the influent portion by allowing the backwash subsystem to travel along the length of the at least one filter cartridge whose position along the at least one filter cartridge being a function of at least a level of the filtrate in the filtration portion.

In further embodiments, the method may comprise providing a first water level sensor constructed and arranged to measure the level of influent in the influent portion. In further embodiments, the method may comprise providing a second water level sensor constructed and arranged to measure the level of filtrate in the filtration portion.

In further embodiments, the method may comprise instructing a user to connect the tertiary filtration system to the source of influent. In further embodiments, the method may comprise instructing the user to activate the tertiary filtration system to introduce influent into the influent portion and the filtration portion to produce filtrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

FIG. 1 illustrates a filtration system operating in a treatment mode, according to one embodiment;

FIG. 2 illustrates the filtration system illustrated in FIG. 1 transitioning from the treatment mode to a backwash mode, according to one embodiment;

FIG. 3 illustrates the filtration system illustrated in FIG. 1 operating in a backwash mode, according to one embodiment;

FIG. 4 illustrates the filtration system illustrated in FIG. 1 transitioning from the backwash mode to the treatment mode, according to one embodiment;

FIGS. 5A and 5B illustrate a filter cartridge, according to one embodiment. FIG. 5A illustrates the structural components of the filter cartridge. FIG. 5B. illustrates the installation of the filter cartridge illustrated in FIG. 5 A in a filtration system, according to one embodiment;

FIG. 6 illustrates a backwash subsystem, according to one embodiment;

FIG. 7 illustrates an enlarged view of the fluid connections of the backwash subsystem illustrated in FIG. 6, according to one embodiment; FIG. 8 illustrates a pulley mechanism used to operate a backwash subsystem, according to one embodiment;

FIGS. 9A and 9B illustrate a stabilization subsystem for a backwash subsystem, according to one embodiment. FIG. 9A illustrates a stabilizing rod extended above the tertiary filtration system. FIG. 9B illustrates a float connected to a stabilizing rod;

FIG. 10 illustrates an embodiment of a tertiary filtration system including a bypass line; and

FIGS. 11 A-l IB illustrate a filtration system including a pre-filtering screen positioned upstream of the filtration system, according to one embodiment. FIG. 11 A illustrates the pre filtering screen collecting solids. FIG. 1 IB illustrates the collected solids being discharged from the filtration system.

DETAILED DESCRIPTION

The aspects and embodiments disclosed herein in accordance with the present invention are not limited in their application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. These aspects are capable of assuming other embodiments and of being practiced or of being carried out in various ways. Examples of specific implementations are provided herein for illustrative purposes only and are not intended to be limiting. In particular, acts, components, elements, and features discussed in connection with any one or more embodiments are not intended to be excluded from a similar role in any other embodiments. For example, the teachings of this invention apply not only to an “outside-in” type of filter cartridge, but also apply to other types of filter configurations, including an “inside-out” filter cartridges or any other type of filter cartridge.

Water filtration processes typically include primary, secondary, and tertiary processes to treat wastewater to remove contaminants, such as suspended solids, biodegradable organics, phosphorous, nitrogen, microbiological contaminants, and the like, to provide a clean effluent. The first or primary treatment process typically involves mechanically separating large solids and other suspended matter in the wastewater from the less dense solids and liquid in the wastewater. Primary treatment processes are typically done in sedimentation tanks using gravity and provide a primary effluent. Secondary treatment typically includes biological treatment of the primary effluent. The biological treatment units or vessels used for secondary treatment typically include bacteria that break down components of the wastewater, such as organic components. The biological treatment processes in the biological treatment units or vessels may reduce the total organic content and/or biochemical oxygen demand of the wastewater. This is typically done by promoting the consumption of the carbonaceous and nutrient material by bacteria and other types of beneficial organisms already present in the wastewater or mixed into the wastewater.

Tertiary or advanced filtration takes place after secondary wastewater treatment to provide a final treatment stage before it is reused, recycled or discharged to the environment. Tertiary treatment options include coagulation assisted filtration, absolute barrier filtration, and nutrient removal which include biological denitrification and chemical phosphorus removal. As wastewater is purified to higher degrees by such treatment processes, the treated effluent can then be reused for irrigation, recreational use, or water recharge. Tertiary processes further can include the addition of any one or more of chemicals, UV light, and ozone.

A conventional biological wastewater treatment plant typically incorporates a gravity clarifier at the end of the process, to clean the effluent water to a sufficient level to allow for discharge into a natural body of water such as a lake or river. In regions where water is scarce, it may be desirable to further filter and disinfect the water to allow for safe “reuse” of the water, for example, watering grass on public grounds.

Many currently available tertiary filtration systems occupy a large footprint with a treatment facility where floor space is at a premium or are positioned in an outdoor facility on a large area of real estate. In general, tertiary filtration systems include serially positioned filtering media, where water to be treated is passed to one filtering medium, then onto at least one other filtering medium before discharge. Positioning of different filtration stages contributes, at least in part, to the larger size of these systems. Tertiary filtration systems of the present disclosure are advantageous because of the reduced physical footprint without a reduction in performance, in part due the type, number, and internal layout of various internal components, e.g., filter cartridges and backwash subsystems, and the simplicity of the system design and construction.

Systems and methods for the filtration of water are disclosed herein. The systems and methods described herein further provide for the operation and cleaning of one or more components of a filtration system by dislodging and clearing contaminants from said one or more components of the filtration system.

In accordance with an aspect, there is provided a water filtration system. The water filtration system may include an influent portion comprising a first water level sensor and a filtration portion fluidly connectable the influent portion. The filtration portion may include at least one filter cartridge disposed within. The water filtration system further may include a controller coupled to at least the first water level sensor. The controller may be operable to operate the system in a filtration mode by directing a flow of influent from the influent portion to the at least one filter cartridge positioned in the filtration portion to produce filtrate until a level of influent within the influent portion exceeds a predetermined threshold level as determined by the first water level sensor. The controller further may be operable to operate the system in a backwash mode responsive to a signal received from the first water level sensor by adjusting a flow of filtrate discharged from the filtration portion to allow a backwash subsystem to travel along the at least one filter cartridge with the position of the backwash subsystem being a function of at least a level of the filtrate in the filtration portion.

In accordance with an aspect, there is provided a tertiary filtration system. The tertiary filtration system may include an influent portion comprising an inlet connectable to a source of influent, a filtration portion fluidly connectable to the influent portion, and a first water level sensor constructed and arranged to measure a level of influent in the influent portion. The filtration portion may include a filtrate outlet and further may include a reject portion comprising a reject outlet. The tertiary filtration system further may include at least one filter cartridge disposed within the filtration portion fluidly connectable to the reject portion.

The tertiary filtration system additionally may include a controller coupled to at least an inlet valve on the inlet, a filtrate outlet valve on the filtrate outlet, and the first water level sensor. The controller may be operable to, responsive to receiving a signal from the first water level sensor, adjust the inlet valve and adjust the filtrate outlet valve to allow a filtrate to be discharged from the filtration portion. The tertiary filtration system further may include a backwash subsystem comprising a sprayer arm and a sprayer head. The backwash subsystem may be constructed and arranged to travel along the at least one filter cartridge, with a position of the backwash subsystem along the at least one filter cartridge being a function of at least a level of the filtrate in the filtrate portion. An embodiment of a tertiary filtration system according to the present disclosure is illustrated in FIGS. 1-4. In each of FIGS, 1-4, the tertiary filtration system is depicted in a different mode of operation determined, at least in part, by the location or status of one or more system components. With reference to FIG. 1, a filtration system 100 includes an inlet 102a connectable to a source of influent 101a and a filtrate outlet 102b. The system 100 includes an influent portion 104a fluidly connectable with a filtration portion 104b and the inlet 102a. The filtration portion 104b is in fluid communication with the filtrate outlet 102b and a reject portion 106a comprising a reject outlet 106b. The tertiary filtration system 100 includes a first water level sensor 108a constructed and arranged to measure a level of influent 101a in the influent portion 104a. Disposed within the filtration portion 104b is at least one filter cartridge 110. The at least one filter cartridge 110 is in fluid communication with the influent portion 104a and reject portion 106a. The system 100 further includes a backwash subsystem 112a comprising a sprayer arm 112b and a sprayer head 112c. The system 100 additionally includes a controller 120 operatively coupled (as indicated by the dashed lines) to at least an inlet valve 102c, a filtrate outlet valve 102d, and the first water level sensor 108a. The controller is operable, responsive to receiving a signal from the first water level sensor 108a, to adjust the inlet valve 102c and adjust the filtrate outlet valve 102d to allow a filtrate 101b to be discharged from the filtration portion 104b. In the tertiary filtration system embodiment illustrated in FIG. 1, influent 101a enters the influent portion 104a through inlet 102a and is directed into the at least one filter cartridge 110, with the direction shown by the arrows. The filtrate 101b formed by passing through the at least one filter cartridge 110 begins to fill the filtration portion 1104b.

With reference to FIG. 2, and using the same numbering convention as FIG. 1, tertiary filtration system 100 is illustrated at a transition between filtering influent 101a through the at least one filter cartridge 110 and the discharging of filtrate 101b from the filtration portion 104b. In FIG. 2, the level of influent 101a in the filtration portion 104a has exceeded a predetermined threshold water level. At this threshold level, which may occur due to a reduction in filter performance of the at least one filter panel 110, the first water level sensor 108a registers the threshold level (as indicated by the lines emanating from the first water level sensor 108a) and provides a signal to controller 120 that a cleaning process for the at least one filter cartridge 110 should occur. The controller, responsive to this signal from the first water level sensor 108a, adjusts the inlet valve 102c and adjusts the filtrate valve 102d and reject valve 106c to allow filtrate 101b to be discharged from the filtration portion 104b. In parallel, the backwash subsystem 112a begins to circulate filtrate 101b through the sprayer arm 112b using a pump (not illustrated) and out through sprayer head 112 onto the at least one filter cartridge 110, forming a reject 101c that is discarded from reject portion 106a through reject outlet 106b. As indicated by the arrows in FIG. 2, as the filtrate 101b is discharged from the filtration portion 104b, the backwash subsystem 112a travels along a length of the at least one filter cartridge 110, that is, as the level of filtrate 101b in the filtration portion 104b decreases, the backwash subsystem 112a travels down as indicated by the arrows, with the generated backwash being discharged from the reject portion 106a through reject outlet 106b.

In some embodiments, the position of the backwash subsystem 112a along the at least one filter cartridge 110 may be a function of at least a level of the filtrate in the filtration portion, i.e., the position of the backwash subsystem 112a may be a function of a rate the filtrate 101b is discharged from the filtration portion 104b. Without wishing to be bound by any particular theory, the position change of the backwash subsystem 112a is a direct function of the rate of discharge of filtrate 101b. The position change of the backwash subsystem 112a may also be a function of the physical properties of the tertiary filtration system 100, such as the dimensions and/or volume of the filtration portion 104b. In general, a faster rate of discharge of filtrate 101b will increase the rate at which the position of the backwash subsystem 112a changes along the at least one filter cartridge 110. One of skill in the art can appreciate the rate of discharge from the filtration portion 104b may be controlled to provide for a desired amount of backwashing and cleaning performance.

With reference to FIG. 3, and using the same numbering convention as FIGS. 1 and 2, tertiary filtration system 100 is illustrated at a point where the filtrate 101b has been discharged from the filtration portion 104b and the backwash subsystem 112a is at a minimum point along the length of the at least one filter cartridge 110, i.e., the backwash subsystem cannot travel past this point. As further illustrated in FIG. 3, there is filtrate 101b in the filtration portion 104b at a minimum level defined, in part, by the discharge limiting subsystem 114. The discharge limiting subsystem 114 is constructed and arranged to not permit the water level in an area of the filtration portion 104b immediate to the at least one filter cartridge 110 to drop below a minimum level. In some embodiments, the discharge liming subsystem 114 may comprise a partition, such as a wall, a weir, or other similar structural element, positioned within the filtration portion 104b that defines the minimum level. This minimum level is set to not allow any solids that may have accumulated at the bottom of the filtration portion 104b to be discharged with the filtrate 101b. The minimum level set by the discharge limiting subsystem 114 further may not allow the backwash subsystem 112a to travel further than its position, i.e., the backwash subsystem 112a cannot travel below the level set by the discharge limiting subsystem 114.

With reference to FIG. 4, and using the same numbering convention as FIGS. 1-3, the tertiary filtration system 100 is illustrated at a transition between discharging filtrate 101b and allowing influent 101a to enter the influent portion 104a and into the at least one filter cartridge 110 for filtration. When the second water level sensor 108b transmits a signal to controller 120 (as indicated by the lines emanating from the second water level sensor 108b) that the water level in the filtration portion 104b has reached a predetermined minimum threshold, the controller 120 is operable to adjust the reject valve 106c and the filtrate outlet valve 102d and adjust the inlet valve 102c to allow influent 101a to enter the influent portion 104a and further enter the at least one filter cartridge 110. In parallel, as the level of filtrate 101b rises in the filtration portion 104b, the rising filtrate 101b directs the backwash subsystem 112a up along the length of the at least one filter cartridge 110 to a position located at the top of the at least one filter cartridge 110 (as indicated by the arrows on the at least one filter cartridge 110 and the backwash subsystem 112a).

An embodiment of a filter cartridge 110 is illustrated in FIGS. 5A and 5B. With reference to FIGS. 5 A and 5B, a filter cartridge may include a cartridge body 110a, a filtering medium 110b, a frame 110c constructed and arranged to secure a periphery of the filtering medium 110b to the cartridge body 110. The filter cartridge 110 further may include fluid connections, such as influent inlet 1 lOd and cartridge exit 1 lOe. Without wishing to be bound by any particular theory, as influent 101a enters the filter cartridge 110, it passes through the filtering medium 110b and out into a vessel or other similar storage container where the filter cartridge 110 is housed. Collected debris may be removed from the filtering medium 110b during a cleaning process, such as a backwash, and the reject from cleaning may be directed out through away from the filter cartridge 110 through cartridge exit 1 lOe. According to various embodiments, the at least one filter cartridge 110 may be configured as an “inside-out” cartridge. In this configuration, influent 101a to be filtered enters the influent inlet 1 lOd of the at least one filter cartridge 110 and flows outwardly through the filtering medium 110b and into the filtration portion 104b, with the difference in head pressure between an inside surface and outside surface of the filter cartridge 110 providing a driving force for filtration. Thus, under these filtering conditions, debris present in the influent 101a are captured on the inside surface of the filtering medium 110b. When an “inside-out” filter cartridge is backwashed using a backwash subsystem 112a as described herein, the sprayer nozzle 112c is positioned in such a manner as to direct filtrate 101b onto an outside surface of the filtering medium 110b, agitating the filtering medium 110b such that the debris captured on an inside surface is removed and discharged from the tertiary filtration system 100. Alternatively, or in addition, the at least one filter cartridge 110 may be configured as an “outside-in” filter cartridge. In this configuration, influent 101a to be filtered flows inwardly through the filtering medium 110b and into the filtration portion 104b using an external source of motive force, such as a vacuum system or the like. Thus, under these filtering conditions, debris present in the influent 101a are captured on the outside surface of the filtering medium 110b. When an “outside-in” filter cartridge is backwashed using a backwash subsystem 112a as described herein, the sprayer nozzle 112c is positioned in such a manner as to direct filtrate 101b onto the inner surface of the filtering medium 110b, agitating the filtering medium 110b such that the debris captured on the outside surface is removed and discharged from the tertiary filtration system 100.

The filter cartridges shown in FIGS. 5 A and 5B may employ a filtering medium 110b that is a pleated filtering medium to increase surface area. In some embodiments, the filtering medium 110b may be a flat panel. The filtering medium 110b may be woven or non-woven. In addition, pile cloth, needle felt, microfiltration, nanofiltration, reverse osmosis, or other membranes may be employed as a filtering medium 110b constructions. Non-limiting examples of materials for use in making a filtering medium 110b include polyester, metal-coated polyester, antimicrobial-coated polyester, polypropylene, nylon, stainless steel wire, bronze, brass, titanium, nickel, metal alloys, glass fiber, alumina fiber, glass-filled polypropylene (e.g., 17%), glass-filled acetal, glass-filled nylon, or any combination thereof. It should also be noted that the term "filtering medium" should be interpreted broadly to cover any component that filters a fluid. Other terms included within the definition of filter media include membrane, element, filter device, and the like. As such, the term "filtering medium" should not be narrowly interpreted to exclude any component that filters fluid. The materials used and the size of the pores of the filtering medium 110b are chosen based on the likely contaminants in the influent, the flow rate of the influent, and additional physical and chemical factors. In one embodiment, the pore size of the filtering medium 110b is in a range of about 10 to about 1000 microns in diameter, e.g., about 10 microns to about 1000 microns, about 50 microns to about 900 microns, about 100 to about 800 microns, about 200 microns to about 700 microns, about 300 microns to about 600 microns, or about 400 microns to about 500 microns. Smaller and larger openings are also within the scope of this disclosure. For example, in some applications, the filter media may have openings that are in a range of 6 to 300 microns in diameter. According to another example, the filter media has openings that are about 100, 150, or 200 microns in diameter.

As illustrated in FIG. 6, a tertiary filtration system 100 may employ a plurality of filter cartridges 110 to increase the overall filtration area. The number and size of the filter cartridges 110 can be varied depending on the flow requirements of the system. For example, and as illustrated in FIG. 6, additional filter cartridges 110 can be connected in parallel to increase the volumetric filtering capacity of the tertiary filtration system 100.

FIG. 6 further illustrates the backwash subsystem 112a having a sprayer arm 112b and sprayer head 112c positioned proximate the at least one filter cartridge 110. Without wishing to be bound by any particular theory, backwash of the at least one filter cartridge 110 may be achieved by positioning the sprayer arm 112b and sprayer head 112c such that nearly all of the surface area of the filtering medium 110b of the at least one filter cartridge 110 is contacted by water delivered from the sprayer head 112c. In some embodiments, the sprayer head 112b may have a single opening or nozzle for spraying filtrate onto the at least one filter panel. In further embodiments, the sprayer head 112b may include more than one nozzle for spraying water and/or nutrients. An embodiment of a sprayer head 112b having a plurality of openings or nozzles is illustrated in FIG. 6. The openings or nozzles may be of any size or shape capable of distributing a liquid. For example, the openings or nozzles may comprise jet, spiral, cone, or fan nozzles. The spray angle of the openings or nozzles may be selected to optimize fluid distribution over the surface area of the at least one filter cartridge 110 as described herein. The openings or nozzles may be all the same size, or may be of varying size. For example, the opening or nozzle size may vary with distance from where the fluid connection to the backwash subsystem 112a is made. In some embodiments, the openings or nozzles may increase in size farther from the fluid connection to the backwash subsystem to accommodate a higher flow rate and pressure required to cover the surface area of the at least one filter cartridge 110 at positions further from the fluid connection. In some embodiments, the connection supplying the openings or nozzles with filtrate may include a filter to reduce clogging of the openings or nozzles. A pump is configured to direct filtrate 101b into the backwash subsystem 112a and out of the sprayer head 112c, and the resultant water pressure may be adjusted by the pump as a function of the level of cleaning required during a backwash.

In further embodiments, the backwash subsystem 112a may include a connection to a source of a cleaning agent to be added to the filtrate 101b that is pumped through the sprayer arm 112b and out of sprayer head 112c. The cleaning agent may be housed in a suitable reservoir, such as a tank or the like, and further may include any fluid connections and fluid distribution components, such as concentration sensors or metering valves operatively coupled to controller 120. The filtering medium 110b of the at least one filter cartridge 110 may accumulate contaminants where water pressure from the sprayer head 112c may not be sufficient for removal, e.g., fats, oils, greases, mold, and/or mineral deposits. To aid in backwash, a cleaning agent may be added to the filtrate 101b that is sprayed onto the at least one filter cartridge 110 during a backwash. The cleaning agent may be any suitable cleaning agent chosen for the expected contamination on the filtering media 110b of the at least one filter cartridge 110. For example, a general-purpose cleaning agent may include an strong acid, e.g., phosphoric acid, a weak acid, e.g., citric acid, and a liquid detergent comprising one or more surfactants. Other cleaning agents are known in the art, and one of skill in the art can appreciate the chemistry of a cleaning agent may be adjusted to optimize the cleaning performance and downstream processing of the backwash.

Additionally, illustrated in FIG. 6 and shown in FIG. 7 is an embodiment of a mechanism that provides for travel of the backwash subsystem 112a as the level of filtrate 101b in the filtration portion 104b changes, either from discharge or refilling. With reference to FIG. 7, backwash subsystem 112a includes sprayer arm 112b that is connected to a source of filtrate using fluid connections 112d, 112e, that provide water to backwash the at least one filter cartridge 110. The fluid connections 112d, 112e, may be flexible and/or movable, e.g., rotating or swiveling, connections that maintain a watertight seal as the backwash subsystem 112a travels along the length of the at least one filter cartridge 110. Further shown is a portion of a translation mechanism 113, in this illustration a pulley 113a with a cable 113b, counterweight 113c, and float 113d, that allows the backwash subsystem 112a to travel along the length of the at least one filter cartridge 110 to provide cleaning.

FIG. 8 illustrates a vertical cross-section of a translation mechanism 113 (outlined in the dashed line box) constructed and arranged to allow the backwash subsystem 112a to travel along the length of the at least one filter cartridge 110, with the position of the backwash subsystem 112a being a function of a rate the filtrate 101b is discharged from the filtration portion 104b. In the illustrated configuration, the translation mechanism 113 includes a pulley 113a affixed to a position above the sprayer arm 112b of the backwash subsystem 112a. The pulley 113a allows a counterweight 113c affixed to one end of a cable 113b, with the other end affixed to the sprayer arm 112b of the backwash subsystem 112a, to move up and down. Further shown is one end of a rod 113e connected to the sprayer arm 112b of the backwash subsystem 112a near the connection of the backwash subsystem 112a to the cable 113b of the pulley 113a. The other end of the rod 113e is connected to a float 113d positioned within the filtration portion 104b of the tertiary filtration system 100. In the illustrated configuration, the float 113d is positioned within the minimum level of filtrate 101b remaining in the filtration portion 104b established by the discharge limiting subsystem 114. Without wishing to be bound by any particular theory, the position of the float 113d, responsive to the level of filtrate 101b in the filtration portion 104b, modulates the position of the backwash subsystem 112a. That is, as the float 113d travels up within the filtration portion 104b, the backwash subsystem 112a also travels up along the length of the at least one filter cartridge 110. As the filtrate 101b is discharged from the filtration portion 104, the float 113d begins to travel downward, allowing the backwash subsystem 112a to travel downward at substantially the same rate the position of the float 113d is changing, itself a function of rate of discharge of filtrate 101b. While a translation mechanism comprising a pulley 113a, cable 113b, counterweight 113c, and float 113d as illustrated is exemplary, there are other mechanisms suitable for the raising and lowering of the backwash subsystem as disclosed herein. For example, the translation mechanism may be a linear actuator operatively coupled to the controller 120. This disclosure is in no way limited by the type of mechanism used to allow the backwash subsystem 112a to travel along the length of at least one filter cartridge 110.

FIGS. 9A and 9B illustrate an embodiment of a stabilization system 115a, 115b constructed and arranged to maintain a position of the sprayer arm 112b and sprayer head 112c as the backwash subsystem 112a travels along the at least one filter cartridge 110. The stabilization system may be configured to be incorporated into the translation mechanism 113 or a component thereof illustrated in FIG. 8. Alternatively, or in addition, the stabilization system 115a, 115b may be incorporated into a larger component of the tertiary filtration system 100, such as a housing, vessel, or the like. With reference to FIGS. 9 A and 9B, the stabilization system,

115a, 115b may include upper and lower guide tubes 115a, 115b, respectively, positioned at different locations on the tertiary filtration system 100 where the rod 113e sits and travel within the lumen of the guide tubes 115a, 115b. Without wishing to be bound by any particular theory, the stabilization system 115a, 115b allows the rod 113e to remain plumb as it travels along the length of the at least one filter cartridge 110, thus maintaining a position of the backwash subsystem 112a proximate to the filtering medium 110b of the at least one filter cartridge 110.

In some embodiments, the tertiary filtration system 100 further may include a bypass line 118 positioned within the influent portion 104a. The bypass line 118 may be constructed and arranged to divert excess influent 101a which exceeds the volumetric capacity of the influent portion 104a such that it cannot enter the filtration portion 104b. The bypass line 118 may be a conduit having one end positioned within the influent portion 104a and another end fluidly connected to an exit, such as the reject portion 106a. Alternatively, or in addition, the bypass line 118 may be constructed and arranged to act as a recirculation line fluidly connected to the source of influent 101a to allow excess influent 101a to re-enter the influent portion 104a for filtration.

In some embodiments, the tertiary filtration system 100 further may include a pre filtering screen 116 constructed and arranged to retain debris exceeding a predetermined size.

The pre-filtering screen may be positioned upstream of the influent portion 104a such that debris exceeding the predetermined size does not enter the influent portion 104a and contact the filtering medium 110b of the at least one filter cartridge 110. The pre-filter 116 provides a certain degree of filtering to a downstream filtration process such as filtering using the at least one filter cartridge 110. For example, the pre-filtering screen may be configured to remove material that is larger than 100 microns, including large debris from treatment plant upset caused by storm surges or other natural events. An embodiment of a pre-filtering screen 116 positioned upstream of the influent portion 104a of the tertiary filtration system 100 is illustrated in FIGS.

11 A and 1 IB. With reference to FIGS. 11 A and 1 IB, the pre-filtering screen 116 is positioned between where influent 101a carrying debris 103 enters to the at least one filter cartridge 110. In FIG. 11 A, the debris 103 is collecting on the pre-filtering screen 116 and not getting into the at least one filter cartridge 110. When a sufficient amount of debris 103 has collected on the pre filtering screen, the reject valve 106c is opened to flush the collected debris 103 away from the at least one filter cartridge 110 and out of the tertiary filtration system 100.

The pre-filtering screen 116 may be constructed from any corrosion resistant metal material. In some embodiments, the pre-filtering screen 116 is a metal mesh material. Non limiting examples of metal mesh material include stainless steel, nickel alloys, other metal alloys, brass, bronze, titanium, or any combination thereof. In one embodiment, the pre-filtering screen 116 is a wire screen material. In other embodiments, the pre-filtering screen 116 is a polymer material. In some embodiments, the pre-filtering screen 116 is a woven filter media material.

In some embodiments, the controller 120 may be operatively coupled to at least an inlet valve 102c, a filtrate outlet valve 102d, and the first water level sensor 108a. For example, responsive to receiving a signal from the first water level sensor 108a, the controller 120 may be operable to adjust the inlet valve 102c and adjust the filtrate outlet valve 102d to allow a filtrate 101b to be discharged from the filtration portion 104b. In this configuration, the tertiary filtration system 100 does not allow influent 101a to enter the influent portion 104a to be treated. The controller 120 may be further configured, responsive to receiving a signal from the first water level sensor 108a, to adjust a reject valve 106c connected to reject outlet 106b of reject portion 106a. In this configuration, as filtrate 101b is discharged from the filtration portion 104b, the backwash generated by backwash subsystem 112a is discharged from the tertiary filtration system 100. The controller 120 may be further configured, responsive to receiving a signal from the second water level sensor 108b, to adjust the filtrate outlet valve 102d and adjust the inlet valve 102c. In this configuration, the level of filtrate 101b reached a minimum threshold level to maintain operation of the tertiary filtration system 100. For example, as described herein, the discharge limiting subsystem 114, in part, defines the minimum threshold level to maintain operation of the tertiary filtration system 100 by at least preventing any solids that may have accumulated in the bottom of the filtration portion 104b from being discharged with filtrate 101b. In this configuration, the influent portion 104a begins to fill with influent 101 to be filtered by the at least one filter cartridge 110 and filtrate 101b fills the filtration portion 104b. In some embodiments, the controller 120 further may be operable to, responsive to receiving a signal from the second water level sensor 108b, adjust the adjust the reject valve 106c. Adjusting the reject valve 106c aids in the filtration of influent 101b and in allowing the filtration portion 104b to fill with filtrate 101b without excessive or unnecessary losses to the reject outlet 106b.

In some embodiments, the controller 120 may be further operable to, responsive to receiving a signal from the first water level sensor 108a, adjust a pump (not illustrated) fluidly connected to the backwash subsystem 112a to direct filtrate 101b onto the at least one filter cartridge 110. The pump to direct filtrate onto the at least one filter cartridge 110 may be activated in parallel with the adjusting of the inlet valve 102c and the filtrate outlet valve 102d to direct filtrate 101b from the backwash subsystem 112a as the filtrate 101b is discharged from the filtration portion 104b. In some embodiments, the controller 120 may be further operable to, responsive to receiving a signal from the first water level sensor 108a, allow a reject to be discharged from a reject portion 106a. The reject may be the backwash formed from the backwash subsystem 112a directing filtrate 101b onto the at least one filter cartridge 110.

In some embodiments, the controller 120 may be further operable to stop the backflush mode responsive to the level of filtrate 101b reaching a predetermined minimum threshold level in the filtration portion 104b. As described herein, the predetermined minimum threshold level may be determined and measured by a second water level sensor 108b positioned within the filtration portion 104b. Thus, the controller 120 may be further operable to stop the backflush mode responsive to receiving a signal from the second water level sensor 108b as described herein. In further embodiments, the controller 120 may be operable to responsive to receiving a signal from the second water level sensor 108b, return the system 100 to the filtration mode as described herein.

In some embodiments, the controller 120 may be further operable to operate the system in the backwash mode according to a predetermined schedule. For example, the controller 120 may be operable to operate the system may be operated in the backwash mode at any practical interval of time, for example, once per day, once every 2 days, once every 3 days, once every 4 days, once every 5 days, once every 6 days, once per week, biweekly, monthly, or in any time interval therebetween. Alternatively, operating the system in the backflush mode may occur according to indications of reduced system performance or operation, such as a level of water within a point in the system exceeding a predetermined threshold level, indicating the at least one filter cartridge may require servicing or maintenance. In some cases, operation in the backwash mode according to a predetermined schedule may be a preventative measure, not allowing the system performance to degrade to the level where a system takedown for maintenance would be needed.

In some embodiments, the controller 120 may be further operable to operate the system in the backwash mode for a predetermined length of time. As described herein, the backwash subsystem 112a travels along the length of the at least one filter cartridge 110 to effect cleaning. As described herein, the rate (and thus the position) at which the backwash subsystem 112a travels along the length of the at least one filter cartridge 110 may be substantially the same as the rate the filtrate 101b is discharged from the filtration portion 104b. Thus, in some embodiments, the rate at which the filtrate 101b is discharged from the filtration portion 104b may determine the predetermined length of time operation in the backwash mode occurs. As a non-limiting example, the backwash subsystem 112a may operate in the backwash mode for a length of time of about 30 seconds (s) to about 120 s, e.g., about 30s to about 120 s, about 40 s to about 110 s, about 50 s to about 100 s, about 60 s to about 90 s, or about 70 s to about 80 s. One of skill in the art can appreciate that the predetermined length of time the backwash mode occurs may depend on at least the volume of filtrate to be discharged, where the filtrate is being discharged to, and the level of performance of the backwash subsystem, and the operation of the backwash subsystem is not limited in predetermined length of time the backflush mode occurs.

The first and second water level sensors 108a, 108b, inlet valve 102c, filtrate outlet valve 102d, reject valve 106c, and any other system components, e.g., pumps, may be either directly connected to the controller or indirectly connected to the controller 120 using a communication network that is operatively coupled to the controller. For example, first and second water level sensors 108a, 108b may be configured as input devices that are directly connected to the controller and inlet valve 102c, filtrate outlet valve 102d, reject valve 106c, and/or pumps of the may be configured as output devices that are connected to the controller, and any one or more of the above may be coupled to another ancillary computer system or component so as to communicate with the controller 120 over a communication network. Such a configuration permits one sensor, such as first water level sensor 108a, to be located at a significant distance from another sensor, such as second water level sensor 108b, or allow any sensor to be located at a significant distance from any system component and/or the controller 120, while still providing data therebetween.

The controller 120 may be implemented using one or more computer systems. The computer system may be, for example, a general-purpose computer such as those based on an Intel CORE®-type processor, a Motorola POWERPC® processor, a Sun ULTRASPARC® processor, a Hewlett-Packard PA-RISC® processor, or any other type of processor or combinations thereof. Alternatively, the computer system may include programmable logic controllers (PLCs), specially programmed, special-purpose hardware, for example, an application-specific integrated circuit (ASIC) or controllers intended for analytical systems.

The controller can include one or more processors typically connected to one or more memory devices, which can comprise, for example, any one or more of a disk drive memory, a flash memory device, a RAM memory device, or other device for storing data. The one or more memory devices can be used for storing programs and data during operation of the odor control system and/or the control subsystem. For example, the memory device may be used for storing historical data relating to the parameters over a period of time, as well as operating data. Software, including programming code that implements embodiments of the invention, can be stored on a computer readable and/or writeable nonvolatile recording medium, and then typically copied into the one or more memory devices wherein it can then be executed by the one or more processors. Such programming code may be written in any of a plurality of programming languages, for example, ladder logic, Java, Visual Basic, C, C#, or C++, Fortran, Pascal, Eiffel, Basic, COBOL, or any of a variety of combinations thereof.

The controller 120 can include one or more computer storage media such as readable and/or writeable nonvolatile recording medium in which signals can be stored that define a program to be executed by one or more processors. The storage or recording medium may, for example, be a disk or flash memory. In typical operation, the processor can cause data, such as code that implements one or more embodiments of the invention, to be read from the storage medium into a memory device that allows for faster access to the information by the one or more processors. The memory device is typically a volatile, random access memory such as a dynamic random access memory (DRAM) or static memory (SRAM) or other suitable devices that facilitates information transfer to and from the one or more processors. Although the controller 120 is described by way of example as one type of computer system upon which various aspects of the invention may be practiced, it should be appreciated that the invention is not limited to being implemented in software, or on the computer system as exemplarily shown. Indeed, rather than implemented on, for example, a general-purpose computer system, the controller 120, or components or subsections thereof, may alternatively be implemented as a dedicated system or as a dedicated PLC or in a distributed controller. Further, it should be appreciated that one or more features or aspects of the invention may be implemented in software, hardware or firmware, or any combination thereof. For example, one or more segments of an algorithm executable by the one or more controllers can be performed in separate computers, which in turn, can be communication through one or more networks.

In accordance with another aspect, there is provided a method of facilitating tertiary filtration. The method may include a step of providing a tertiary filtration system as described herein comprising an influent portion connectable to a source of influent and a filtration portion fluidly connectable to the influent portion comprising at least one filter cartridge, and a backwash subsystem constructed and arranged to travel along a length of the at least one filter cartridge. The method further may include a step of providing a controller as described herein. The provided controller may be operable to operate the system in a filtration mode by regulating the introduction of influent into the influent portion and the discharge of filtrate from filtration portion. The provided controller further may be operable to operate the system in a backwash mode responsive to at least a water level in the influent portion by allowing the backwash subsystem to travel along the length of the at least one filter cartridge whose position along the at least one filter cartridge being a function of at least a level of the filtrate in the filtration portion.

In some embodiments of the method of facilitating, the method may include providing a first water level sensor constructed and arranged to measure the level of influent in the influent portion. In some embodiments of the method of facilitating, the method may include providing a second water level sensor constructed and arranged to measure the level of filtrate in the filtration portion.

In further embodiments of the method of facilitating, the method may include instructing a user to connect the tertiary filtration system to the source of influent. In further embodiments of the method of facilitating, the method may include instructing a user to activate the tertiary filtration system to introduce influent into the influent portion and the filtration portion to produce filtrate.

The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the term “plurality” refers to two or more items or components. The terms “comprising,” “including,” “carrying,” “having,” “containing,” and “involving,” whether in the written description or the claims and the like, are open-ended terms, i.e., to mean “including but not limited to.” Thus, the use of such terms is meant to encompass the items listed thereafter, and equivalents thereof, as well as additional items. Only the transitional phrases “consisting of’ and “consisting essentially of,” are closed or semi-closed transitional phrases, respectively, with respect to the claims. Use of ordinal terms such as “first,” “second,” “third,” and the like in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

Having thus described several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Any feature described in any embodiment may be included in or substituted for any feature of any other embodiment. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only. Those skilled in the art should appreciate that the parameters and configurations described herein are exemplary and that actual parameters and/or configurations will depend on the specific application in which the disclosed methods and materials are used. Those skilled in the art should also recognize or be able to ascertain, using no more than routine experimentation, equivalents to the specific embodiments disclosed.

Claims

What is claimed is: CLAIMS

1. A tertiary filtration system comprising: an influent portion comprising an inlet connectable to a source of influent; a filtration portion fluidly connectable to the influent portion, the filtration portion comprising a filtrate outlet and a reject portion comprising a reject outlet; a first water level sensor constructed and arranged to measure a level of influent in the influent portion; at least one filter cartridge disposed within the filtration portion, the at least one filter cartridge fluidly connectable to the reject portion; a controller coupled to at least an inlet valve on the inlet, a filtrate outlet valve on the filtrate outlet, and the first water level sensor, the controller configured to, responsive to receiving a signal from the first water level sensor, adjust the inlet valve and adjust the filtrate outlet valve; and a backwash subsystem comprising a sprayer arm and a sprayer head, the backwash subsystem constructed and arranged to travel along the at least one filter cartridge, a position of the backwash subsystem along the at least one filter cartridge being a function of at least a level of the filtrate in the filtration portion.

2. The system of claim 1, wherein the controller is further operable to, responsive to receiving a signal from the first water level sensor, adjust a reject valve on the reject outlet.

3. The system of claim 2, further comprising a second water level sensor constructed and arranged to measure the level of filtrate in the filtration portion.

4. The system of claim 3, wherein the controller is further operable to, responsive to receiving a signal from the second water level sensor, adjust the filtrate outlet valve and adjust the inlet valve.

5. The system of claim 4, wherein the controller is further operable to, responsive to receiving a signal from the second water level sensor, adjust the reject valve.

6. The system of claim 1, wherein the backwash subsystem further comprises a stabilization system constructed and arranged to maintain a position of the sprayer arm and sprayer head along the at least one filter cartridge and in relation to the level of filtrate .

7. The system of claim 1, further comprising a pre-filtering screen constructed and arranged to retain debris exceeding a predetermined size, the pre-filtering screen positioned upstream of the inlet.

8. The system of claim 1, further comprising a bypass line positioned within the influent portion.

9. The system of claim 1, wherein a spray angle of the sprayer head is adjustable.

10. The system of claim 9, wherein a flow rate of the sprayer head is adjustable.

11. The system of claim 1, wherein the at least one filter cartridge comprises a body, a filtering medium, and a frame constructed and arranged to secure a periphery of the filtering medium to the body.

12. The system of claim 1, further comprising a discharge limiting subsystem positioned within the filtration portion, the discharge limiting subsystem constructed and arranged to reduce discharge of filtrate from the filtrate outlet of filtrate below a predetermined minimum threshold level in the filtration potion.

13. A water filtration system comprising: an influent portion comprising a first water level sensor; a filtration portion fluidly connectable the influent portion, the filtration portion comprising at least one filter cartridge disposed within; and a controller coupled to at least the first water level sensor, the controller operable to: operate the system in a filtration mode by directing a flow of influent from the influent portion to the at least one filter cartridge positioned in the filtration portion to produce filtrate until a level of influent within the influent portion exceeds a predetermined threshold level as determined by the first water level sensor; and operate the system in a backwash mode responsive to a signal received from the first water level sensor by adjusting a flow of filtrate discharged from the filtration portion to allow a backwash subsystem to travel along the at least one filter cartridge with the position of the backwash subsystem being a function of at least a level of the filtrate in the filtration portion.

14. The system of claim 13, wherein the controller is further operable to, responsive to receiving a signal from the first water level sensor, adjust a pump fluidly connected to the backwash subsystem to direct filtrate onto the at least one filter cartridge.

15. The system of claim 14, wherein the controller is further operable to, responsive to receiving a signal from the first water level sensor, allow a reject to be discharged from a rejection portion.

16. The system of claim 15, wherein the controller is further operable to stop the backflush mode responsive to the level of filtrate reaching a predetermined minimum threshold level in the filtration portion.

17. The system of claim 16, wherein the predetermined minimum threshold level is determined by a second water level sensor positioned in the filtration portion.

18. The system of claim 17, wherein the controller is further operable, responsive to receiving a signal from the second water level sensor, return the system to the filtration mode.

19. The method of claim 12, wherein the controller is further operable to operate the system in the backwash mode according to a predetermined schedule.

20. The method of claim 12, wherein the controller is further operable to operate the system in the backwash mode for a predetermined length of time.

21. A method of facilitating tertiary filtration, comprising: providing a tertiary filtration system comprising an influent portion connectable to a source of influent and a filtration portion fluidly connectable to the influent portion comprising at least one filter cartridge, and a backwash subsystem constructed and arranged to travel along a length of the at least one filter cartridge; and providing a controller operable to: operate the system in a filtration mode by regulating the introduction of influent into the influent portion and the discharge of filtrate from filtration portion; and operate the system in a backwash mode responsive to at least a water level in the influent portion by allowing the backwash subsystem to travel along the length of the at least one filter cartridge whose position along the at least one filter cartridge being a function of at least a level of the filtrate in the filtration portion.

22. The method of claim 21, further comprising providing a first water level sensor constructed and arranged to measure the level of influent in the influent portion.

23. The method of claim 22, further comprising providing a second water level sensor constructed and arranged to measure the level of filtrate in the filtration portion.

24. The method of claim 21, further comprising instructing a user to connect the tertiary filtration system to the source of influent.

25. The method of claim 24, further comprising instructing the user to activate the tertiary filtration system to introduce influent into the influent portion and the filtration portion to produce filtrate.