Fluid filtration system with backwash valve and method of operation thereof - Patents.com

Abstract

The filtration device of the present invention has a housing (102) defining an inlet opening (116), first and second bores (1041, 104) with first and second pistons (1061, 1081) therein, respectively, first and second inlet channels (1181, 118) extending from the inlet opening (116) to the first and second bores (1041, 104), respectively, first and second outlet channels (1201, 1202, 120) communicating with the first and second bores (1041, 104), respectively, and a first backwash channel (1321). The first piston (1061, 108) defines a filtering cavity (1091, 1092, 109, 1101, 1102) that is in fluid communication with the first inlet (116) and outlet channels (1201, 1202, 120) when the first piston (1061, 108) is in a production mode. The second piston (1062) defines a filtering cavity (1091, 1092, 109, 1101, 1102) that is in fluid communication with the second inlet (116) and outlet channels (1201, 1202, 120) when the second piston (1062) is in a production mode. The device has backwash valves (1241, 1341, 1343, 1344, 1) that compress fluid through the first backwash channel (1321) towards the filtering cavity (1091, 1092, 109, 1101, 1102) of the first piston (1061, 108) during the backwash operation, increasing the pressure in the cavity (1091, 1092, 109, 1101, 1102).

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates generally to filtration systems for filtering fluids, such as high viscosity fluids, and specifically to systems and methods for cleaning filter elements of the filtration systems.

[0002] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 848,456, filed May 15, 2019, the disclosure of which is incorporated by reference herein as if set forth in its entirety. [Background technology]

[0003] Filtration devices known as piston-type screen changers are generally used to filter high-viscosity media such as plastic melts. They typically have a housing, a feed channel and a pair of pistons arranged movably in the housing. Each of these pistons has at least one cavity, and at least one filter element or screen is arranged in each cavity. In a production mode of operation, the feed channels in the housing branch off towards the cavities so that the melt is guided through the corresponding filter element. Behind the filter element, as seen in the direction of flow, an outlet channel is provided through which the plastic melt is discharged. The outlet channels are joined at several points in the housing. When the melt flows through the at least one filter element, impurities and agglomerations in the melt can become trapped in the at least one filter element.

[0004] A filtering device with two pistons with a filtering element and movable essentially perpendicular to the direction of the fluid flow has several advantages. One of them is that no additional valves are required, since the pistons are not only filter carriers, but also open and close the flow passages depending on the movement of the pistons. Due to a suitable design of the flow passages, the pistons can be moved from a production mode of operation to a backwash mode of operation. In the backwash mode of operation, a fluid is led through the filtering element in a countercurrent direction (i.e., upstream direction) from the downstream side of the filtering element in order to loosen the impurities stuck to the filter and to flush them out of the housing. Furthermore, the pistons can be moved partially out of the housing in order to access the filtering element in case it becomes necessary to clean or replace it. Summary of the Invention

[0005] In one embodiment, a filtration device configured to filter a fluid includes a housing, a first piston and a second piston, a first filtering element and a second filtering element, and a backwash valve. The housing defines at least one inlet opening, a first bore and a second bore, at least one first inlet channel extending from the at least one inlet opening to the first bore and at least one second inlet channel extending from the at least one inlet opening to the second bore, first and second outlet channels in communication with the first and second bores, respectively, and first and second backwash channels. The first and second pistons are movably disposed within the first and second bores, respectively. The first piston defines a first cavity within the first piston, the first cavity being in fluid communication with at least one first inlet channel and a first outlet channel when the first cavity is in a production mode. The second piston defines a first cavity within the second piston, the first cavity of the second piston being in fluid communication with at least one second inlet channel and a second outlet channel when the first cavity of the second piston is in a production mode. The first filtration element is disposed within the first cavity of the first piston, and the second filtration element is disposed within the first cavity of the second piston. The first backwash channel extends between the first bore and the backwash valve, and the second backwash channel extends between the second bore and the backwash valve. The backwash valve includes an inner surface that defines a valve chamber within the backwash valve, the valve chamber being configured to fill with fluid when the filtration device is operated in the backwash mode such that the backwash valve (1) compresses fluid from the valve chamber through the first backwash channel to increase the pressure of the fluid in the first cavity, and (2) opens to discharge the compressed fluid from the first cavity and out of the backwash valve.

[0006] Another embodiment includes a method of operating a filtration device having a housing and a first piston and a second piston disposed in a first bore and a second bore of the housing. The method includes moving the first piston to move a first cavity of the first piston from a production mode in which the first cavity is in fluid communication with at least one first inlet channel and a first outlet channel of the housing to a first isolated position in which the first cavity is not in fluid communication with at least one first inlet channel or first outlet channel of the housing. The method includes pressurizing the first cavity with a fluid by flowing the fluid from the first cavity of the second piston through at least one backwash channel of the housing to a first filtration element disposed in the first cavity of the first piston, and then isolating the first cavity in the second piston from the at least one backwash channel. The method includes opening a backwash valve of the filtration device to allow pressurized fluid in the first cavity to flow from the first cavity, through the first backwash channel and out of the backwash valve. The method includes backwashing the first filtration element by moving the first piston to a second isolated position in which the cavity is in fluid communication with the first outlet channel but not in fluid communication with the at least one first inlet channel such that fluid flows from the first outlet channel, along an upstream direction through the first filtration element, through the first backwash channel and out of the backwash valve.

[0007] Yet another embodiment is a filtration device configured to filter a fluid. The filtration device includes a backwash valve, a housing, and a first piston and a second piston. The housing defines at least one inlet opening, a first bore and a second bore, at least one first inlet channel, at least one second inlet channel, and a first backwash channel and a second backwash channel. The at least one first inlet channel extends from the at least one inlet opening to the first bore. The at least one second inlet channel extends from the at least one inlet opening to the second bore. The first outlet channel and the second outlet channel are in communication with the first bore and the second bore, respectively. The first backwash channel extends between the first bore and the backwash valve, and the second backwash channel extends between the second bore and the backwash valve. The first piston is movably disposed within the first bore and defines a first cavity within the first piston, the first cavity being in fluid communication with at least one of the first inlet channel and the first outlet channel when the first cavity is in a production mode. The first piston defines a groove on an upstream side of the first piston extending away from the first cavity of the first piston. Further, the first piston is movable to align the groove of the first piston with the first backwash channel. The second piston is movably disposed within the second bore and defines a first cavity within the second piston, the first cavity of the second piston being in fluid communication with at least one of the second inlet channel and the second outlet channel when the first cavity of the second piston is in a production mode. The second piston defines a groove on an upstream side of the second piston that extends away from the first cavity of the second piston, and the second piston is movable to align the groove of the second piston with the second backwash channel.

[0008] The following description of the illustrative embodiments may be better understood when read in conjunction with the accompanying drawings, in which: It is understood that potential embodiments of the disclosed systems and methods are not limited to those depicted. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a front perspective view of a filtering device according to one embodiment. [Diagram 2] FIG. 2 is a rear perspective view of the filtration device of FIG. 1. [Diagram 3] 2 is a front perspective view of a piston of the filtration device of FIG. 1 with a first filtration element and a second filtration element of the piston in an exploded position, according to one embodiment. [Figure 4] FIG. 4 is a rear perspective view of the piston of FIG. [Diagram 5] 2 is a front view of the filtration device of FIG. 1 with the first and second pistons in production mode and the inlet channel shown in hidden lines; [Figure 6] 2 is a top cross-sectional view of the filtration device of FIG. 1 with the first and second pistons in production mode and the inlet and manifold channels of the filtration device shown in hidden lines; [Figure 7] 2 shows a rear view of the filtration device of FIG. 1 with the outlet channel of the filtration device shown in hidden lines. [Figure 8] 2 is a perspective view of the manifold of the filtration device of FIG. 1, showing the manifold channels in hidden lines. [Figure 9] 2 is a side cross-sectional view of the filtration device of FIG. 1 according to one embodiment through one of the first and second backwash valves of the filtration device, the backwash valve being in an open position. [Figure 10] 2 is a side cross-sectional view of the filtration device of FIG. 1 taken through one of the first and second backwash valves of the filtration device, the backwash valve being in a closed position, according to one embodiment. [Figure 11] 2 is a simplified flow diagram of a method of operating the filtration device of FIG. 1 according to one embodiment. [Figure 12] 2 is a perspective view of the filtration device of FIG. 1, with the first and second pistons in fluid communication with one another through a backwash channel, and with the backwash channel and inlet channel of the filtration device shown in hidden lines. [Figure 13] FIG. 13 is an enlarged view of a portion of the view in FIG. 12. [Figure 14] 13 is a front view of the filtration device of FIG. 1 with the first and second pistons positioned as shown in FIG. 12. [Figure 15] 13 is a rear view of the filtration device of FIG. 1 with the first and second pistons positioned as shown in FIG. 12. [Figure 16] 2 is a perspective view of the filtration device of FIG. 1 with a first filtration element of the filtration device in an isolated position, the first filtration element being isolated from the inlet and outlet channels of the filtration device but in fluid communication with the second filtration element through the backwash channel. [Figure 17] FIG. 17 is an enlarged view of a portion of the view in FIG. 16. [Figure 18] 17 is a front view of the filtration device of FIG. 1 with the first and second pistons positioned as shown in FIG. 16. [Figure 19] 17 is a rear view of the filtration device of FIG. 1 with the first and second pistons positioned as shown in FIG. 16. [Figure 20] 2 is a perspective view of the filtration device of FIG. 1 with the first filtration element in a separated position, where the first filtration element is isolated from the inlet and outlet channels and isolated from the second filtration element. [Figure 21] FIG. 21 is an enlarged view of a portion of the view in FIG. 20. [Figure 22] 21 is a front view of the filtration device of FIG. 1 with the first and second pistons positioned as shown in FIG. 20. [Diagram 23] 21 is a rear view of the filtration device of FIG. 1 with the first and second pistons positioned as shown in FIG. 20. [Figure 24] 2 is a front view of the filtration device of FIG. 1 with the first filtration element in a backwash position, where the first filtration element is isolated from the inlet channel of the filtration device and in fluid communication with the outlet channel of the filtration device. [Diagram 25] 25 is a rear view of the filtration device of FIG. 1 with the first and second pistons positioned as shown in FIG. 24. [Figure 26] FIG. 2 is a front perspective view of a filtering device according to another embodiment. [Figure 27] FIG. 27 is a rear perspective view of the filtration device of FIG. 26. [Figure 28] 27 is a side cross-sectional view of the filtration device of FIG. 26 taken through a pair of opposed backwash valves of the filtration device, according to one embodiment with both backwash valves in a closed position. [Figure 29] 27 is a side cross-sectional view of the filtration device of FIG. 26 taken through a pair of opposing backwash valves of the filtration device, with a first one of the backwash valves in a closed position and a second one of the backwash valves in an open position, according to one embodiment. [Diagram 30] 27 is a side cross-sectional view of the filtration device of FIG. 26 taken through a pair of opposing backwash valves of the filtration device, with a first one of the backwash valves in an open position and a second one of the backwash valves in a closed position, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A fluid filtration device and a method of operation thereof are described herein. In some embodiments, a first cavity of a first piston of the filtration device is isolated from the inlet and outlet channels of the filtration device, and the first cavity can be removed from a production mode. The first cavity can then be pressurized by applying a fluid flow from a first backwash channel to a first filtration element disposed in the first cavity. In some embodiments, the pressure in the first cavity can be increased above the normal operating pressure of the first cavity in the production mode. The fluid in the pressurized cavity can then be released in a reverse direction (i.e., upstream direction) to the atmosphere and the fluid flows through the first filtration element to wash impurities and agglomerates from the first filtration element. The process can be similarly performed on one or more other cavities of the filtration device.

[0011] 1 and 2, a filtration device 100 is shown according to an embodiment. Generally, the filtration device 100 comprises a plurality of filtration elements, each of which can be selectively switched between a production mode and a backwash mode. When the filtration element is in the production mode, the filtration element is configured to receive a fluid, filter the fluid to remove impurities and agglomerates, and communicate the filtered fluid with a process downstream of the filtration device 100 for further processing. The fluid may be a high viscosity fluid, such as a molten thermoplastic, or any other suitable fluid. When the filtration element is in the backwash mode, the filtration device 100 is configured to reverse the flow of the fluid through the filtration element to dislodge impurities and agglomerates from the filtration element and flush them out of the filtration device 100.

[0012] Filtration device 100 includes a housing 102 defining a first bore 104(1) and a second bore 104(2) therethrough. First bore 104(1) and second bore 104(2) may extend through the housing along a lateral direction A. Filtration device 100 includes a first piston 106(1) disposed within first bore 104(1) and a second piston 106(2) disposed within second bore 104(2). First piston 106(1) is configured to translate along lateral direction A within first bore 104(1). Filtration device 100 includes a first actuator 108(1) configured to translate first piston 106(1) along lateral direction A within first bore 104(1), although it will be understood that first actuator 108(1) can be disposed as a separate component from filtration device 100. Similarly, second piston 106(2) is configured to translate along lateral direction A within second bore 104(2). Filtration device 100 includes a second actuator 108(2) configured to translate second piston 106(2) along lateral direction A within second bore 104(2), although it will be understood that second actuator 108(2) can be disposed as a separate component from filtration device 100. Each actuator 108(1) and 108(2) can be any suitable actuator, such as (but not limited to) a linear actuator, such as a hydraulic actuator, a pneumatic cylinder, or a piezoelectric actuator.

[0013] The filtration device 100 can include at least one backwash valve configured to enable backwashing of the filtration device 100. In one embodiment, the filtration device 100 can include a first backwash valve 134(1) and a second backwash valve 134(2). Each backwash valve 134(1) and 134(2) can be disposed on the upstream side 102a of the housing 102. However, it should be noted that in alternative embodiments, one or both of the backwash valves 134(1) and 134(2) can be disposed on the downstream side 102b of the housing 102. The first backwash valve 134(2) can be offset along the lateral direction A from the second backwash valve 134(2).

[0014] The housing 102 can have an upstream side 102a and a downstream side 102b offset from one another along a longitudinal direction L. The housing 102 can have a first side 102c and a second side 102d offset from one another along a lateral direction A. The housing 102 can have a top end 102e and a bottom end 102f offset from one another along a transverse direction T. The housing can be rectangular in shape as shown, or can have any suitable alternative shape. The first bore 104 and the second bore 106 can extend through the housing 102 along the lateral direction A. The first bore 104 and the second bore 106 can be offset from one another along the transverse direction T.

[0015] 3 and 4, an embodiment of the first piston 108 of the filtration device 100 is shown. The first piston 108(1) and the second piston 108(2) can be implemented as shown in FIGS. 3 and 4, respectively. The piston 108 has a first end 108a and a second end 108b offset from each other along a lateral direction A. The piston 108 has an outer surface 108c extending between the first end 108a and the second end 108b. In one embodiment, the piston 108 can have a circular cross-sectional shape along a plane perpendicular to the lateral direction A. Thus, the piston 108 can have a cylindrical shape, and the outer surface 108c can be a curved outer surface. However, in alternative embodiments, the piston 108 can have other suitable cross-sectional shapes, for example, a rectangular shape.

[0016] The piston 108 can define at least one cavity therein. In some embodiments, the at least one piston 108 can include a first cavity 109 and a second cavity 110. Each cavity 109, 110 can extend into an outer surface 108c of the piston 108 along a selected direction. In one embodiment, the selected direction can be a longitudinal direction L. Each cavity 109, 110 can extend into the piston 108 on an upstream side of the piston 108 configured to receive a fluid. Each cavity 109, 110 can have a circular cross-sectional shape in a plane perpendicular to the selected direction, although it will be understood that each cavity can have another suitable cross-sectional shape.

[0017] The piston 108 may define a groove 107 extending from each of the at least one cavities. Each groove 107 may extend into the outer surface 108c of the piston 108. Each groove 107 may be defined on the upstream side of the piston 108. However, in alternative embodiments, such as when one or both of the backwash valves 134(1) and 134(2) are on the downstream side 102b of the housing 102, each groove 107 may be defined on the downstream side of the piston 108. Each groove 107 may extend outwardly away from a corresponding one of the cavities 109, 110 along the lateral direction A and may be open to the corresponding one of the cavities 109, 110. Each groove 107 may be used to pressurize a corresponding one of the cavities 109, 110, as discussed in more detail below. In one embodiment, each groove 107 can have a triangular shape in a plane extending along the lateral direction A and the transverse direction T, although other shapes are contemplated within the scope of this disclosure. Each groove 107 has a cross-sectional dimension along the transverse direction T that is less than the cross-sectional dimension along the transverse direction T of a corresponding one of the cavities 109, 110. Each groove 107 is in fluid communication with a corresponding one of the cavities 109, 110.

[0018] The piston 108 can define at least one piston outlet. In some embodiments, the at least one piston outlet can include a first piston outlet 111 and a second piston outlet 112. Each piston outlet 111, 112 can extend into an outer surface 108c of the piston 108 along a selected direction toward a corresponding one of the cavities 109, 110. Each piston outlet 111, 112 can extend into the piston 108 on a downstream side of the piston 108 configured to distribute the fluid. Thus, each piston outlet 111, 112 can be offset from a corresponding cavity 109, 110 along a downstream direction. In one embodiment, the downstream direction can be aligned with the longitudinal direction L. Each piston outlet 111, 112 can be in fluid communication with a corresponding cavity 109, 110.

[0019] Each piston outlet 111, 112 may be elongated along the transverse direction A. Thus, each piston outlet 111, 112 may have a width along the transverse direction A that is greater than the height of the piston outlet 111, 112 along the transverse direction T. The elongated shape of the piston outlets 111 and 112 allows one cavity 109, 110 to remain in fluid communication with at least one inlet channel 118 and outlet channel 120 (both discussed below) of the housing as the piston 108 moves between different positions, thereby backwashing the other cavity 109, 110. Each piston outlet 111, 112 may have a first end 111a, 112a and a second end 111b, 112b that are offset from one another along the transverse direction A. Each piston outlet 111, 112 may have an intermediate portion 111c, 112c between its first end 111a, 112a and its second end 111b, 112b. The first end 111a, 112a and the second end 111b, 112b of each outlet 111, 112 may be enlarged relative to the intermediate portion 111c, 112c. For example, the first end 111a, 112a and the second end 111b, 112b may have a height greater than the height of the intermediate portion 111c, 112c. In one embodiment, the first end 111a, 112a and the second end 111b, 112b of each outlet 111, 112 may have a circular cross-sectional shape, and the intermediate portion 111c, 112c may have a rectangular cross-sectional shape. However, it will be appreciated that each piston outlet 111, 112 can have another suitable shape.

[0020] The filtration device 100 can include at least one filtration element for each piston 108. Each cavity 109, 110 can be configured to receive at least one of a plurality of filtration elements. For example, the first cavity 109 can be configured to receive a first filtration element 114, and the second cavity 110 can be configured to receive a second filtration element 115. Each filtration element can be a screen, such as a wire mesh with small openings that create a flow resistance, or any other suitable filtration element suitable for filtering the particular fluid received by the filtration device 100.

[0021] 5 and 6, which respectively show a front view and a top view of the filtration device 100 in a production mode. In FIGS. 5 and 6, the housing 102 is shown transparent to show the multiple channels of the housing 102. The first piston 106(1) can include a first cavity 109(1) with at least one filtration element 114(1) disposed within the first piston 106(1). In some embodiments, the first piston 106(1) can include a second cavity 110(1) with at least one filtration element 115(1) disposed within the first piston 106(1). Similarly, the second piston 106(2) can include a first cavity 109(2) with at least one filtration element 114(2) disposed within the second piston 106(2). In some embodiments, second piston 106(2) can include a second cavity 110(2) with at least one filtration element 115(2) disposed within second piston 106(2). When first piston 106(1) and second piston 106(2) are in a production mode, first cavities 109(1) and 109(2) can be aligned with one another along a transverse direction T, and second cavities 110(1) and 110(2) can be aligned with one another along the transverse direction T.

[0022] The housing 102 defines at least one inlet opening 116 therein. The inlet opening 116 may be defined on the upstream side 102a of the housing 102. The housing 102 defines a plurality of inlet channels 118 therein, each inlet channel extending from the at least one inlet opening 116 to a corresponding one of the bores 104(1), 104(2). The housing 102 may define at least one inlet channel 118 for each of the cavities 109(1), 110(1), 109(2), 110(2). In some embodiments, the housing 102 may define two or more inlet channels 118 for each of the cavities 109(1), 110(1), 109(2), 110(2). Each channel 118 may extend from the at least one inlet opening 116 along a direction having a directional component along the lateral direction A. Additionally, or alternatively, each channel 118 may extend along a direction having a directional component along the transverse direction T away from the at least one inlet opening 116 .

[0023] The housing 102 can define at least one inlet channel 118(1) to the first cavity 109(1) of the first piston 106(1) and at least one inlet channel 118(2) to the first cavity 109(2) of the second piston 106(2). The at least one inlet channel 118(1) to the first cavity 109(1) of the first piston 106(1) is in fluid communication with the first bore 104(1), and the at least one inlet channel 118(2) to the first cavity 109(2) of the second piston 106(2) is in fluid communication with the second bore 104(2). When first piston 106(1) is in the production mode, at least one inlet channel 118(1) to first cavity 109(1) of first piston 106(1) is in fluid communication with first cavity 109(1). When second piston 106(2) is in the production mode, at least one inlet channel 118(2) to first cavity 109(2) of second piston 106(2) is in fluid communication with first cavity 109(2).

[0024] Similarly, in embodiments in which first piston 106(1) and second piston 106(2) have first and second cavities, respectively, housing 102 may define at least one inlet channel 118(3) to second cavity 110(1) of first piston 106(1) and at least one inlet channel 118(4) to second cavity 110(2) of second piston 106(2). The at least one inlet channel 118(3) to second cavity 110(1) of first piston 106(1) is in fluid communication with first bore 104(1), and the at least one inlet channel 118(4) to second cavity 110(2) of second piston 106(2) is in fluid communication with second bore 104(2). When the first piston 106(1) is in the production mode, the at least one inlet channel 118(3) to the second cavity 110(1) of the first piston 106(1) is in fluid communication with the second cavity 110(1). When the second piston 106(2) is in the production mode, the at least one inlet channel 118(4) to the second cavity 110(2) of the second piston 106(2) is in fluid communication with the second cavity 110(2).

[0025] 6 and 7, the housing 102 defines a number of outlet channels 120 (e.g., 120(1), 120(2), 120(3), 120(4)) therein, with each outlet channel 120 extending from a corresponding one of the bores 104(1) and 104(2). Each outlet channel 120 is positioned downstream of the inlet opening 116 relative to the direction of fluid flow through the filtration device 100. The housing 102 may define at least one outlet channel 120 for each of the cavities 109(1), 110(1), 109(2), 110(2). When in a production mode, each outlet channel 120 may extend along a downstream direction away from a corresponding one of the cavities 109(1), 110(1), 109(2), 110(2). In the production mode, fluid flows from inlet channels 118(1), 118(2), 118(3), 118(4) through filtration elements 114(1), 114(2), 115(1), 115(2) to outlet channels 120(1), 120(2), 120(3), 120(4). The filtration elements restrict fluid flow through cavities 109(1), 110(1), 109(2), 110(2) and as a result, the pressure in the inlet channels can be higher than the pressure in the outlet channels. In other words, in a production mode, fluid in inlet channels 118(1), 118(2), 118(3), 118(4) may be at a first pressure and fluid in outlet channels 120(1), 120(2), 120(3), 120(4) may be at a second pressure that is less than the first pressure. Thus, each filtration element 114(1), 114(2), 115(1), 115(2) may have a high pressure side upstream of the filtration element and a low pressure side downstream of the filtration element.

[0026] Each outlet channel 120 can define an inner opening 122 in a corresponding one of the bores 104(1), 104(2). In some embodiments, the size and shape of each inner opening 122 can match the size and shape of the corresponding one of the piston outlets 111, 122. For example, each inner opening 122 (e.g., 122(1), 122(2), 122(3), 122(4)) can be elongated along the lateral direction A. Thus, each inner opening 122 can have a width along the lateral direction A that is greater than a height of the inner opening 122 along the transverse direction T. Each inner opening 122 can have a first end 122a and a second end 22b that are offset from one another along the lateral direction A. Each inner opening 122 can have an intermediate portion 122c between the first end 122a and the second end 122b. Each of the first end 122a and the second end 122b of each inner opening 122 can be enlarged relative to the intermediate portion 122c. For example, each of the first end 122a and the second end 122b can have a height that is greater than the height of the intermediate portion 122c. In one embodiment, each of the first end 122a and the second end 122b of each inner opening 122 can have a circular cross-sectional shape, and the intermediate portion 122c can have a rectangular cross-sectional shape. However, it will be understood that each inner opening 122 can have another suitable shape.

[0027] Each outlet channel 120 can define an outer opening 124 (e.g., 124(1), 124(2), 124(3), 124(4)). Each outer opening 124 can be defined downstream of the inner opening 122 of the channel 120. For example, each outer opening 124 can be defined on the downstream side 102b of the housing 102. Each outer opening 124 can have a circular shape, as shown, or any other suitable shape. Each channel 120 can narrow inwardly from the inner opening 122 to the outer opening 124 as the channel 120 extends along the downstream direction.

[0028] 7, the housing 102 can define an outlet channel 120(1) for the first cavity 109(1) of the first piston 106(1), the outlet channel 120(1) having an inner opening 122(1) and an outer opening 124(1). The housing 102 can define an outlet channel 120(2) for the first cavity 109(2) of the second piston 106(2), the outlet channel 120(2) having an inner opening 122(2) and an outer opening 124(2). An outlet channel 120(1) to the first cavity 109(1) of the first piston 106(1) is in fluid communication with the first bore 104(1), and an outlet channel 120(2) to the first cavity 109(2) of the second piston 106(2) is in fluid communication with the second bore 104(2). When the first piston 106(1) is in a production mode, the outlet channel 120(1) to the first cavity 109(1) of the first piston 106(1) is in fluid communication with the first piston outlet 111 of the first piston 106(1). When the second piston 106(2) is in the production mode, the outlet channel 120(2) to the first cavity 109(1) of the second piston 106(2) is in fluid communication with the first piston outlet 111 of the second piston 106(2).

[0029] 2 and 8, the filtration device 100 can include a manifold 126 disposed on the downstream side 102b of the housing 102. The manifold 126 can be configured to receive fluid flow from a plurality of outlet channels 120(1), 120(2), 120(3), and 120(4) and combine the fluid flow to an outlet 126c of the filtration device 100. The manifold 126 can have an upstream side 126a and a downstream side 126b. The outlet 126c can be disposed on the downstream side 126b. The manifold 126 can have a plurality of manifold channels 128(1), 128(2), 128(3), 128(4). Each manifold channel 128(1), 128(2), 128(3), 128(4) can define a manifold inlet opening 130(1), 130(2), 130(3), 130(4) at the upstream side 126a. Thus, each manifold channel 128(1), 128(2), 128(3), 128(4) can extend from the outlet 126c to a corresponding one of the manifold inlet openings 130(1), 130(2), 130(3), 130(4). Each manifold channel 128(1), 128(2), 128(3), 128(4) can extend from the outlet 126c along a direction having a directional component along the lateral direction A. Additionally or alternatively, each manifold channel 128(1), 128(2), 128(3), 128(4) can extend from outlet 126c along a direction having a directional component along the transverse direction T. It will be appreciated that in alternative embodiments, manifold 126 can be omitted from filtration device 100. For example, channels 128(1), 128(2), 128(3), 128(4), and outlet 126c can be defined by housing 102.

[0030] 9, 10, 12, and 13, the housing 102 can define at least one backwashing channel, such as a plurality of backwashing channels 132(1), 132(2), 132(3), 132(4) within the housing 102. Each backwashing channel can extend from an upstream side 102a of the housing 102 to a corresponding one of the bores 104(1), 104(2). The housing 102 can define a backwashing channel for each of the cavities 109(1), 110(1), 109(2), 110(2). Each backwashing channel 132(1), 132(2), 132(3), 132(4) can be offset outwardly from the at least one inlet 116 along the lateral direction A. Each backwash channel can be completely separated from at least one of the inlets 116 and the inlet channels 118(1), 118(2), 118(3), 118(4).

[0031] The housing 102 may define a first backwashing channel 132(1) and a second backwashing channel 132(2). The first backwashing channel 132(1) and the second backwashing channel 132(2) may be offset from one another along the transverse direction T. The first backwashing channel 132(1) may extend between an inlet of the first backwashing valve 134(1) and the first bore 104(1). Thus, the first backwashing channel 132(1) is in fluid communication with the first backwashing valve 134(1) and the first bore 104(1). The first backwashing channel 132(1) is configured to be in fluid communication with the first cavity 109(1) of the first piston 106(1) when the first piston 106(1) is in the backwashing mode. The second backwash channel 132(2) can extend between the inlet of the first backwash valve 134(1) and the second bore 104(2). Thus, the second backwash channel 132(2) is in fluid communication with the first backwash valve 134(1) and the second bore 104(2). The second backwash channel 132(2) is configured to be in fluid communication with the first cavity 109(2) of the second piston 106(2) when the second piston 106(2) is in the backwash mode. The second backwash channel 132(2) can also be in fluid communication with the first backwash channel 132(1).

[0032] Similarly, in embodiments in which the first piston 106(1) and the second piston 106(2) have first and second cavities, respectively, the housing 102 may define a third backwashing channel 132(3) and a fourth backwashing channel 132(4). The third backwashing channel 132(3) and the fourth backwashing channel 132(4) may be offset from one another along the transverse direction T. The third backwashing channel 132(3) extends between an inlet of the second backwashing valve 134(2) and the first bore 104(1). Thus, the third backwashing channel 132(3) is in fluid communication with the second backwashing valve 134(2) and the first bore 104(1). The third backwash channel 132(3) is configured to be in fluid communication with the second cavity 110(1) of the first piston 106(1) when the first piston 106(1) is in the backwash mode. The fourth backwash channel 132(4) extends between the inlet of the second backwash valve 134(2) and the second bore 104(2). Thus, the fourth backwash channel 132(4) is configured to be in fluid communication with the second backwash valve 134(2) and the second bore 104(2). The fourth backwash channel 132(4) is configured to be in fluid communication with the second cavity 110(2) of the second piston 106(2) when the second piston 106(2) is in the backwash mode.

[0033] 9 and 10, the first backwash valve 134(1) can be configured to selectively move between an open position (FIG. 9) and a closed position (FIG. 10). In the open position, the first backwash valve 134(1) places the first backwash channel 132(1) and the second backwash channel 132(2) in fluid communication with an atmosphere outside the filtration device 100. In the closed position, the first backwash valve 134(1) closes the first backwash channel 132(1) and the second backwash channel 132(2) out of fluid communication with an atmosphere outside the filtration device 100. The first backwash valve 134(1) can be a pressure-boosting shut-off valve configured to increase pressure in the first backwash channel 132(1) and the second backwash channel 132(2) during a backwashing operation, which is described in more detail below. Alternatively, first backwash valve 134(1) may be a standard shut-off valve, such as, without limitation, shut-off valve 134(1) as shown in FIGS. 28-30, or any other suitable shut-off valve that can be opened and closed without increasing pressure in first backwash channel 132(1) and second backwash channel 132(2).

[0034] Similarly, second backwash valve 134(2) can be configured to selectively move between an open position ( FIG. 9 ) and a closed position ( FIG. 10 ). Note that the cross sections of first backwash channel 134(1) and second backwash valve 134(2) can be identical, and thus FIGS. 9 and 10 can depict either first backwash channel 134(1) or second backwash valve 134(2). In the open position, second backwash valve 134(2) places third backwash channel 132(3) and fourth backwash channel 132(4) in fluid communication with the atmosphere outside filtration device 100. In the closed position, the second backwashing valve 134(2) closes the third backwashing channel 132(3) and the fourth backwashing channel 132(4) from fluid communication with the atmosphere outside the filtration device 100. The second backwashing valve 134(2) may be a pressure boost valve configured to increase pressure in the third backwashing channel 132(3) and the fourth backwashing channel 132(4) during a backwashing operation, which will be described in more detail below. Alternatively, the second backwashing valve 134(2) may be a standard shut-off valve, such as, but not limited to, the shut-off valve 134(1) shown in FIGS. 28-30, or any other suitable shut-off valve that can be opened and closed without increasing pressure in the third backwashing channel 132(3) and the fourth backwashing channel 132(4).

[0035] As described above, in one embodiment, the first backwash valve 134(1) and / or the second backwash valve 134(2) can be implemented as a pressure boost backwash valve. FIGS. 9 and 10 show an example of a pressure boost backwash valve. However, it will be understood that the pressure boost backwash valve can be configured in another suitable manner. The pressure boost backwash valve has a valve inlet 134a and a valve outlet 134b. The valve inlet 134a can be in fluid communication with at least one backwash channel, such as the backwash channels 132(1) and 132(2). The pressure boost backwash valve 134 can have an inner surface 134c that defines a valve chamber 134d within the pressure boost backwash valve 134. The valve chamber 134d can have a first end and a second end that are offset from one another along a valve axis A. In one embodiment, the valve axis A can extend along a transverse direction T. The valve inlet 134a can extend through the inner surface 134c such that the valve inlet 134a is open to the valve chamber 134d at a location between the first and second ends of the valve chamber 134d. The valve outlet 124b can be defined at the second end of the valve chamber 134d. The valve outlet 124b can be positioned such that the valve axis A extends through the valve outlet 124b.

[0036] The pressure boost backwash valve can have a valve stem 134e configured to translate within the valve chamber 134d. The valve stem 134e can be configured to translate along a valve axis A. The valve can include a valve seat 134f fixedly attached to the valve stem 134e such that the valve seat 134f translates with the valve stem 134e. The valve is configured to translate the valve seat 134f along the valve axis A opposite the valve inlet 134a. The valve seat 134f has an inner surface 134g, an outer surface 134h opposite the inner surface 134g, and a sealing surface 134j extending between the valve seat inner surface 134g and the valve seat outer surface 134h. The sealing surface 134j is configured to seal against the inner surface 134c of the valve chamber 134.

[0037] The valve stem 134e may have a cross-sectional dimension in a plane perpendicular to the valve axis A that is less than the cross-sectional dimension of the valve chamber 134d in the same plane. Thus, when the valve is in the closed position, a space 134k may be defined between the inner surface 134c of the valve chamber 134d and the valve stem 134e. In one embodiment, the space 134k may have an annular cross-sectional shape in a plane perpendicular to the valve axis A. The space 134k may be dimensioned to receive a fluid in the space 134k. The sealing surface 134j of the valve chamber 134 may have a cross-sectional dimension in a plane perpendicular to the valve axis A that is greater than the cross-sectional dimension of the valve stem 134e in the same plane and substantially equal to the cross-sectional dimension of the valve chamber 134d in the same plane. As described in more detail below, during a backwashing operation, the space 134k may be filled with fluid, and the valve may be opened to force the fluid into the backwashing channel, thereby increasing the pressure in the backwashing channel.

[0038] 11, a method 200 of operating filtration device 100 will be discussed. With further reference to FIGS. 5-7, method 200 includes steps 202 of operating filtration device 100 with first filtration element 114(1) and second filtration element 114(2), as well as third filtration element 115(1) and fourth filtration element 115(2) in a production mode (if included) and with respective backwash valves 134(1), 134(2) in a closed position. For example, first piston 106(1) can be positioned within first bore 104(1) such that first filtration element 114(1) of first piston 106(1) is in fluid communication with at least one inlet channel 118(1), if included, and second filtration element 115(1) of first piston 106(1) is in fluid communication with at least one fluid channel 118(3). Additionally, first piston outlet 111(1) of first piston 106(1) is aligned with first outlet channel 120(1) of first piston 106(1), and, if included, second piston outlet 112(1) of first piston 106(1) is aligned with third outlet channel 120(3).

[0039] Similarly, the second piston 106(2) can be positioned within the second bore 104(2) such that the first filtration element 114(2) of the second piston 106(2) is in fluid communication with at least one inlet channel 118(2), if included, and the second filtration element 114(4) of the second piston 106(2) is in fluid communication with at least one fluid channel 118(4). Additionally, the first piston outlet 111(2) of the second piston 106(2) is aligned with the second outlet channel 120(2), if included, and the second piston outlet 112(2) of the second piston 106(2) is aligned with the fourth outlet channel 120(4).

[0040] When filtration elements 114(1), 114(2), 115(1), 115(2) are in a production mode, step 202 may include receiving a fluid to be filtered at inlet opening 116. Each filtration element 114(1), 114(2), 115(1), 115(2) receives the fluid from inlet opening 116 through at least one corresponding inlet channel 118(1), 118(2), 118(3), 118(4). The fluid flows downstream through each filtration element 114(1), 114(2), 115(1), 115(2) to a corresponding piston outlet 111(1), 111(2), 112(1), 112(2) and from each piston outlet to a corresponding outlet channel 120(1), 120(2), 120(3), 120(4). As fluid flows through each filtration element 114(1), 114(2), 115(1), 115(2), the filtration element can restrict fluid flow therethrough such that the pressure on the upstream side of the filtration element exceeds the pressure on the downstream side of the filtration element.

[0041] 11-15, after operating one or more of the filtration elements in a production mode, method 200 can include steps 204-212 of backwashing select cavities 109(1), 109(2), 110(1), 110(2) and subsequently select filtration elements 114(1), 114(2), 115(1), 115(2) of filtration apparatus 100. For ease of explanation, the method will be described in which the select cavity is first cavity 109(1) and the select filtration element is first filtration element 114(1) of first piston 106(1). However, it will be understood that steps 204-212 can be similarly performed to backwash any of the four filtration elements 114(1), 114(2), 115(1), 115(2).

[0042] Method 200 may optionally include step 204 of flushing at least one backwashing channel, such as first backwashing channel 132(1) corresponding to first cavity 109(1) of first piston 106(1) and first filtration element 114(1), by flushing first backwashing channel 132(1) out of outlet 134b of first backwashing valve 134(1) and discharging any depleted material disposed within first backwashing channel 132(1) to the atmosphere outside filtration device 100. Step 204 may additionally flush second backwashing channel 132(2) corresponding to first cavity 109(2) of second piston 106(2) and first filtration element 114(2). The depleted material may be a quantity of fluid that remains at temperature. For example, if the fluid is a plastic melt, the fluid may discolor (e.g., turn brown) and carbonize over time if it remains in the selective backwash channel 132(1). Therefore, it may be beneficial to flush the first backwash channel 132(1) to drain any degraded fluid that is in the first backwash channel 132(1).

[0043] Step 204 may include moving the first piston 106(1) within the first bore 104(1) until the first backwash channel 132(1) is in fluid communication with the groove 107(1) of the first cavity 109(1). In this position, the first piston 106(1) is still in production mode and fluid may continue to flow through the selective filtration element 114(1) to the first outlet channel 120(1) and through the second filter 115(1) (if implemented) to the third outlet channel 120(3). As shown in FIG. 15, the first piston outlet 111(1) and the second piston outlet 112(1) of the first piston 106(1) still overlap to some extent and are therefore in fluid communication with the outlet channels 120(1) and 120(3) of the housing 102. Additionally, step 204 may include moving the second piston 106(2) within the second bore 104(2) until the second backwash channel 132(2) is in fluid communication with the groove 107(2) of the first cavity 109(2) of the second piston 106(2). In this position, the second piston 106(2) is still in production mode and fluid may continue to flow through the first filter 114(2) of the second piston 106(2) to the second outlet channel 120(2) and through the second filter 115(2) (if implemented) to the fourth outlet channel 120(4). 15, first piston outlet 111(2) and second piston outlet 112(2) of second piston 106(2) still overlap to some extent and thus are still in fluid communication with outlet channels 120(2) and 120(4) of housing 102. Step 204 may include moving first backwash valve 134(1) to an open position (e.g., as shown in FIG. 9) such that fluid received by first cavities 109(1) and 109(2) of first piston 106(1) and second piston 106(2), respectively, is distributed from first backwash valve 134(1) to atmosphere through first backwash channel 132(1) and second backwash channel 132(2), respectively.

[0044] Method 200 may optionally include step 206 of moving first backwash valve 134(1) to a closed position (e.g., as shown in FIG. 10) after a predetermined period of time. In an embodiment in which first backwash valve 134(1) is a pressure boost backwash valve, step 206 may include filling chamber 134k of backwash valve 124(1) with fluid. Specifically, chamber 134k may be filled with fluid when valve seat 134f moves along a direction extending from a first end of valve chamber 134k, past valve inlet 134a, to a second end of valve chamber 134k. In step 206, pistons 106(1) and 106(2) do not move compared to their positions in step 204, and filtration elements 114(1), 114(2), 115(1), and 115(2) may remain in production mode.

[0045] 11 and 16-19, the method may include step 208 of isolating and pressurizing first cavity 109(1) and first filtration element 114(1). Specifically, step 208 may include moving first piston 106(1) to a first isolated position, in which first cavity 109(1) and first filtration element 114(1) are isolated from at least one of first inlet channel 118(1) and first outlet channel 120(1), and fluid cannot flow through first filtration element 114(1) and out of housing 102. Thus, as shown in FIG. 18, first cavity 109(1) and first filtration element 114(1) are not in fluid communication with any of inlet channels 118(1), 118(2), 118(3), 118(4). 19, first cavity 109(1) and first piston outlet 111(1) corresponding to first filtration element 114(1) do not overlap and therefore are not in fluid communication with any of outlet channels 120(1), 120(2), 120(3), 120(4). Second cavity 110(1) of first piston 106(1) (if implemented) may remain in production mode. Thus, as shown in FIGS. 18 and 19, second cavity 110(1) may overlap and thus be in fluid communication with at least first channel 118(1) to some extent, and second piston outlet 112(1) of first piston 106(1) may overlap and thus be in fluid communication with first outlet channel 120(1) of housing 102 to some extent. First backwash valve 134(1) can remain in a closed position and second piston 106(2) does not move from that position at the end of step 206. Thus, cavity 109(2), cavity 110(1) (if implemented), and cavity 110(2) (if implemented) can remain in production mode.

[0046] In the first isolated position, first cavity 109(1) and first filtration element 114(1) can be in fluid communication with first cavity 109(2) of second piston 106(2). With first cavity 109(1) and first filtration element 114(1) in the first isolated position, step 208 can include pressurizing first cavity 109(1) of first piston 106(1) by flowing fluid through first filtration element 114(1). Specifically, step 208 may include flowing fluid from first cavity 109(2) of second piston 106(2), e.g., from groove 107(2) of first cavity 109(2), through second backwashing channel 132(2) and first backwashing channel 132(1) to the upstream side of first filtration element 114(1). As the fluid flows into first cavity 109(1), first cavity 109(1) pressurizes such that the pressures on both the upstream and downstream sides of first filtration element 114(1) are substantially equal. In the illustrated embodiment, the fluid flows to the upstream side of first filtration element 114(1). However, it will be understood that first backwash valve 134(1) and backwash channels 132(1) and 132(2) can be configured to direct fluid flow downstream of first filtration element 114(1).

[0047] 20-23, once first cavity 109(1) has been pressurized to a desired pressure for a desired time, step 208 may include isolating first cavity 109(1) of first piston 106(1) from first cavity 109(2) of second piston 106(2). Specifically, step 208 may include moving second piston 106(2) such that first cavity 109(2) of second piston 106(2) is no longer in fluid communication with second backwash channel 132(2).

[0048] 22 and 23, first cavity 109(2) of second piston 106(2) may overlap and thus be in fluid communication with second at least one channel 118(2) to some extent, and first piston outlet 111(2) of second piston 106(2) may overlap and thus be in fluid communication with second outlet channel 120(2) of housing 102 to some extent. First backwash valve 134(1) may remain in a closed position, and first piston 106(1) does not move from its isolated position. Thus, filtration element 114(2), filtration element 115(2) (if implemented), and filtration element 115(1) (if implemented) may remain in production mode.

[0049] 9, 10, and 11, once first cavity 109(1) has been pressurized to a desired pressure for a desired time, the method may include step 210 of moving first backwash valve 134(1) to an open position, as shown in FIG 9, to relieve pressure in first cavity 109(1) by exhausting fluid in first cavity 109(1) to the atmosphere. Thus, step 210 may include flowing fluid from first cavity 109(1), through first backwash channel 132(1) and out valve outlet 134(b).

[0050] In embodiments where backwash valve 134(1) is a pressure boost backwash valve, step 210 of opening first backwash valve 134(1) may include increasing the pressure in first backwash channel 132(1), and subsequently in first cavity 109(1), to a third pressure when first backwash valve 134 is opened. The third pressure may be greater than the first pressure (i.e., the upstream pressure at first filtration element 114(1) when first filtration element 114(1) is in production mode). The seal between piston 106(1) and housing 102 should be sufficient to maintain the pressure in first cavity 109(1) at the third pressure. Specifically, increasing the pressure may include moving valve seat 134f along the selected direction toward the first end of chamber 134k, and thus toward valve inlet 134a, such that fluid within valve chamber 134k passes from valve inlet 134a to first backwash channel 132(1) and is subsequently compressed in first cavity 109(1). Step 210 may include further moving valve seat 134f along the selected direction toward the first end of valve chamber 134k such that valve seat 134f, and specifically valve seat outer surface 134h, moves past at least a portion of valve inlet 134a, thereby opening first backwash valve 134(1) and placing valve inlet 134a and valve outlet 134b in fluid communication. As outer surface 134h of valve seat 134f moves past at least a portion of valve inlet 134a along a direction extending from the second end of the valve chamber to the first end of the valve chamber, fluid in first cavity 109(1) is exhausted through valve outlet 134b to the atmosphere, thereby relieving pressure in first cavity 109(1). Increasing the pressure in first cavity 109(1) above a first pressure and then rapidly decreasing the pressure can cause the fluid to exert a greater force upstream on first filtration element 114(1) to pull impurities and agglomerates away from first filtration element 114(1).This increase and rapid drop in pressure can create a powerful, explosive-like impact on filtration element 114(1), thereby loosening any impurities or agglomerations embedded within filtration element 114(1).

[0051] 11, 24, and 25, the method 200 can include step 212 of backwashing the first filtration element 114(1) with a fluid. Step 212 can include moving the first piston 106(1) to a second isolated position where the first cavity 109(1) is in fluid communication with the first outlet channel 120(1) of the housing 102 while isolating the first cavity 109(1) from the first inlet channel 118(1) while leaving the first cavity 109(1) in fluid communication with the first backwashing channel 132(1). As shown in FIG. 24, the first cavity 109(1) is not in fluid communication with either of the input channels. Additionally, as shown in FIG. 25, the first piston outlet 111(1) overlaps and is in fluid communication with the first outlet channel 120(1) of the housing 102. Step 212 involves flowing fluid from first outlet channel 120(1) along an upstream direction through first filtration element 114(1), through first backwash channel 132(1), and out valve outlet 134b of first backwash valve 134(1) to atmosphere. Fluid pressure at outlet 126c (labeled in FIG. 6 ) of filtration device 100 can cause fluid to flow back from outlet 126c to first outlet channel 120(1). As shown in FIGS. 24 and 25 , second filtration element 115(1) of first piston 106(1) (if implemented), first filtration element 114(2) of second piston 106(2), and second filtration element 115(2) of second piston 106(2) (if implemented) can remain in production mode.

[0052] After first filtration element 114(1) has been backwashed, method 200 may include step 214 of returning first filtration element 114(1) to a production mode, as shown in Figures 5-7. Alternatively, method 200 may perform steps 208-212, and optionally steps 204 and 206, on another filtration element in filtration apparatus 100.

[0053] 1 and 2 show an embodiment of the filtration device 100 having at least one backwash valve 134(1) and 134(2) disposed on the upstream side 102a of the housing 102, but the embodiments of the present disclosure are not so limited. In alternative embodiments, at least one backwash valve can be disposed on the downstream side 102b of the housing 102. For example, a first backwash valve 134(1) and a second backwash valve 134(2) can be disposed on the downstream side 102b of the housing 102. In such an embodiment, at least one backwash channel 132(1) and 132(2) corresponding to the first backwash valve 134(1) and at least one backwash channel 132(3) and 132(4) corresponding to the second backwash valve 134(2) can each be disposed on the downstream side 102b of the housing 102.

[0054] In yet another embodiment, the filtration device can have at least one backwash valve on the upstream side 102a and at least one backwash valve on the downstream side 102b. For example, and with reference to FIGURES 26 and 27, the filtration device 300 can have a first backwash valve 134(1) and a second backwash valve 134(2) disposed on the upstream side 102a of the housing 102, and a third backwash valve 134(3) and a fourth backwash valve 134(4) disposed on the downstream side 102b of the housing 102. One or more, and up to all, of the backwash valves 134(1), 134(2), 134(3), and 134(4) can be pressure boost shutoff valves, as described above. Additionally or alternatively, one or more of backwash valves 134(1), 134(2), 134(3), and 134(4) can be standard shut-off valves. In some embodiments, a filtration device can have one or more pressure boost valves and one or more standard shut-off valves.

[0055] 28-30 illustrate an embodiment in which a filtration device 300 includes at least one standard shutoff valve, such as first standard shutoff valve 134(1) and second standard shutoff valve 134(2), disposed on the upstream side 102a of the housing 102, and at least one pressure boost valve, such as first pressure boost valve 134(3) and second pressure boost valve 134(4), disposed on the downstream side 102b of the housing 102. It will be understood that in other embodiments, the at least one standard shutoff valve 134(1) can alternatively be disposed on the downstream side 102b of the housing 102 and the at least one pressure boost valve 134(3) can alternatively be disposed on the upstream side 102a.

[0056] In one embodiment, standard shut-off valve 134(1) may be implemented as shown in FIGS. 28-30, although standard shut-off valve 134(1) may be implemented as any other suitable backwash valve. Standard shut-off valve 134(1) has a valve inlet 134a and a valve outlet 134b. Valve inlet 134a may be in fluid communication with at least one backwash channel, such as backwash channels 132(1) and 132(2). Backwash channels 132(1) and 132(2) extend from the upstream side 102a of housing 102 and thus may be considered upstream backwash channels.

[0057] The standard shutoff valve 134(1) can have an inner surface 134c that defines a valve chamber 134d within the standard shutoff valve 134(1). The valve chamber 134d can have a first end and a second end that are offset from one another along a valve axis A. In one embodiment, the valve axis A can extend along a transverse direction T. The valve inlet 134a can extend through the inner surface 134c such that the valve inlet 134a is open to the valve chamber 134d at a location between the first end and the second end of the valve chamber 134d. The valve outlet 124b can be defined at the second end of the valve chamber 134d. The valve outlet 124b can be positioned such that the valve axis A extends through the valve outlet 124b.

[0058] The standard shutoff valve 134(1) can have a valve stem 134m configured to translate within the valve chamber 134d. The valve stem 134m can be configured to translate along a valve axis A. The valve stem 134m can have a sealing surface 134 configured to seal against an inner surface 134c of the valve chamber 134. The valve stem 134m can have a cross-sectional dimension in a plane perpendicular to the valve axis A that is dimensioned to seal against the inner surface 134c. Unlike the pressure intensifier valves of FIGS. 9 and 10, the standard shutoff valve 134(1) can lack a space 134k configured to receive a fluid within the standard shutoff valve 134(1).

[0059] Pressure boost valve 134(3) may be configured as described above with respect to FIGS. 9 and 10, or may be implemented in any other suitable manner. Housing 102 may define at least one backwashing channel therein corresponding to backwashing valve 134(3), e.g., first backwashing channel 133(1) and second backwashing channel 132(3). Although not shown, housing 102 may define at least one backwashing channel therein corresponding to backwashing valve 134(4), such as a first backwashing channel and a second backwashing channel. Each backwashing channel 133(1), 132(2) extends from downstream side 102b of housing 102 to a corresponding one of bores 104(1), 104(2). Thus, each backwashing channel 133(1) and 132(2) may be considered a downstream backwashing channel. Housing 102 can define a downstream backwashing channel for each cavity 109(1), 110(1), 109(2), 110(2). Each downstream backwashing channel 132(1), 132(2) can be offset outwardly from at least one outlet of filtration device 300 along lateral direction A. Each downstream backwashing channel 132(1), 132(2) can be completely spaced apart from the at least one outlet and from outlet channels 120(1), 120(2), 120(3), 120(4).

[0060] The housing 102 may define a first downstream backwashing channel 133(1) and a second downstream backwashing channel 133(2) for the backwashing valve 134(3). The first downstream backwashing channel 133(1) and the second downstream backwashing channel 133(2) may be offset from one another along the transverse direction T. The first downstream backwashing channel 133(1) extends between an inlet of the backwashing valve 134(3) and the first bore 104(1). Thus, the first downstream backwashing channel 133(1) is in fluid communication with the backwashing valve 134(3) and the first bore 104(1). The first downstream backwashing channel 133(1) is configured to be in fluid communication with the first cavity 109(1) of the first piston 106(1) when the first piston 106(1) is in the backwashing mode. The second downstream backwashing channel 133(2) extends between the inlet of the backwashing valve 134(3) and the second bore 104(2). Thus, the second downstream backwashing channel 133(2) is in fluid communication with the backwashing valve 134(3) and the second bore 104(2). The second downstream backwashing channel 133(2) is configured to be in fluid communication with the first cavity 109(2) of the second piston 106(2) when the second piston 106(2) is in the backwashing mode. The second downstream backwashing channel 133(3) may also be in fluid communication with the first downstream backwashing channel 133(1).

[0061] Similarly, in embodiments in which the first piston 106(1) and the second piston 106(2) have a first cavity and a second cavity, respectively, the housing 102 may define a third downstream backwashing channel and a fourth downstream backwashing channel (not shown). The third downstream backwashing channel and the fourth downstream backwashing channel may be offset from one another along the transverse direction T. The third downstream backwashing channel may extend between an inlet of the backwashing valve 134(4) and the first bore 104(1). Thus, the third downstream backwashing channel 133(3) may be in fluid communication with the backwashing valve 134(4) and the first bore 104(1). The third downstream backwashing channel 133(3) may be configured to be in fluid communication with the second cavity 110(1) of the first piston 106(1) when the first piston 106(1) is in the backwashing mode. The fourth downstream backwash channel can extend between the inlet of the backwash valve 134(4) and the second bore 104(2). Thus, the fourth downstream backwash channel 133(4) is configured to be in fluid communication with the backwash valve 134(4) and the second bore 104(2). The fourth downstream backwash channel can be configured to be in fluid communication with the second cavity 110(2) of the second piston 106(2) when the second piston 106(2) is in the backwash mode.

[0062] Backwash valve 134(3) can be configured to selectively move between an open position ( FIG. 29 ) and a closed position ( FIG. 28 ). In the open position, backwash valve 134(3) places first downstream backwash channel 133(1) and second downstream backwash channel 133(2) in fluid communication with an atmosphere outside filtration device 300. In the closed position, backwash valve 134(3) closes first downstream backwash channel 133(1) and second downstream backwash channel 133(2) out of fluid communication with an atmosphere outside filtration device 100. Similarly, backwash valve 134(4) can be configured to selectively move between an open position and a closed position. In the open position, backwash valve 134(4) places third downstream backwash channel 133(4) and fourth downstream backwash channel in fluid communication with an atmosphere outside filtration device 300. In the closed position, backwash valve 134 ( 4 ) closes the third and fourth downstream backwash channels from fluid communication with the atmosphere outside filtration device 300 .

[0063] 11 and 28-30, filtration device 300 can be operated in a manner similar to that of filtration device 100, with a few notable exceptions. For example, in addition to or instead of cleaning first downstream backwashing channel 132(1) and second upstream backwashing channel 132(2), step 204 can include cleaning at least one downstream backwashing channel, e.g., first downstream backwashing channel 133(1) corresponding to first cavity 109(1) of first piston 106(1) and first filtration element 114(1), by flushing first downstream backwashing channel 133(1) out outlet 134b of backwashing valve 134(3) to expel any depleted material disposed in first downstream backwashing channel 133(1) to the atmosphere outside filtration device 300. Step 204 may additionally flush first cavity 109(2) of second piston 106(2) and second downstream backwashing channel 133(2) corresponding to first filtration element 114(2). To flush first downstream backwashing channel 133(1) and second downstream backwashing channel 133(2), backwashing valve 134(3) may be moved to an open position in a manner similar to that shown for valve 104(1) in FIG.

[0064] As another example, step 210 can include opening a pressure boost backwash valve 134(3) disposed on downstream side 102b of housing 102, as shown in FIG 29, and increasing the pressure in first downstream backwash channel 133(1) and subsequently in first cavity 109(1) to a third pressure when backwash valve 134(3) is opened. As discussed above, the third pressure can be greater than the first pressure (i.e., the upstream pressure at first filtration element 114(1) when first filtration element 114(1) is in the production mode). The step of increasing the pressure may include moving the valve seat 134f of the pressure boost backwash valve 134(3) along the selected direction toward the first end of the chamber 134k, and thus toward the valve inlet 134a, causing fluid in the valve chamber 134k to flow from the valve inlet 134a through the first downstream backwash channel 133(1) and subsequently into the first cavity 109(1).

[0065] In some embodiments, the pressure in the first cavity 109(1) can be vented through the first backwash valve 134(1). Specifically, the movement of the valve seat 134f of the backwash valve 134(3) can be stopped prior to placing the valve inlet 134a and the valve outlet 134b of the backwash valve 134(3) in fluid communication with one another, as shown in FIG. 29. Step 210 can then include opening the first backwash valve 134(1) to place the valve inlet 134a and the valve outlet 134b of the backwash valve 134(1) in fluid communication with one another, as shown in FIG. 30, thereby relieving the pressure in the first cavity 109(1).

[0066] In an alternative embodiment, step 210 may include draining the fluid through backwash valve 134(3) rather than through first backwash valve 134(1). Specifically, step 210 may further include moving valve seat 134f of backwash valve 134(3) along a selected direction toward a first end of valve chamber 134k such that valve seat 134f, and in particular the valve seat outer surface, moves past at least a portion of valve inlet 134a in a manner similar to that shown in FIG. 9, thereby opening backwash valve 134(3) and placing valve inlet 134a and valve outlet 134b in fluid communication. When the outer surface of valve seat 134f of backwash valve 134(3) moves past at least a portion of valve inlet 134a along a direction extending from the second end of the valve chamber to the first end of the valve chamber, fluid in first cavity 109(1) can be discharged to the atmosphere through valve outlet 134b of backwash valve 134(3), thereby relieving pressure in first cavity 109(1).

[0067] It should be noted that the illustrations and descriptions of the embodiments shown in the figures are for illustrative purposes only and should not be considered as limiting the present disclosure. Those skilled in the art will appreciate that the present disclosure contemplates various embodiments. Furthermore, it should be understood that the ideas discussed above with respect to the above-described embodiments can be used alone or in combination with any of the other embodiments discussed above. It should further be understood that the various alternative embodiments discussed above with respect to the illustrated embodiments are applicable to all embodiments described herein unless otherwise specified.

[0068] Unless otherwise expressly stated, each numerical value and range should be construed as approximations, as if the words "about," "approximately," or "substantially" were preceding the value or range.

[0069] Unless otherwise specifically stated or understood otherwise within the context of use, conditional language used herein, such as, inter alia, "can / could," "might / may," "for example," and the like, is generally intended to convey that certain features, elements, and / or steps are included in certain embodiments but not in other embodiments. Thus, such conditional language is generally not intended to imply that the features, elements, and / or steps are in any way required in one or more embodiments or that one or more embodiments necessarily include those features, elements, and / or steps. The terms "comprising," "including," "having," and the like are synonymous and used inclusively in an open-ended manner and do not exclude additional elements, features, acts, operations, and the like.

[0070] Although specific embodiments have been described, these embodiments are presented for illustrative purposes only and are not intended to limit the scope of the inventions disclosed herein. Thus, nothing in the foregoing description is intended to imply that any particular feature, function, step, module, or block is required or essential. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms, and various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions disclosed herein. The appended claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the particular inventions disclosed herein.

[0071] It is understood that the steps of the exemplary methods described herein do not necessarily have to be performed in the order described, and such method orders should be understood as merely exemplary. Similarly, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the present invention.

[0072] Although elements in the following method claims are recited in a particular order with corresponding labeling, if any, the elements are not necessarily intended to be limited to performance in that particular order, unless the claim recitations otherwise imply a particular order for performing some or all of the elements.

[0073] It will be understood that references herein to "a" or "one" to describe a feature, such as a component or step, do not exclude additional features or a plurality of those features. For example, a reference to an apparatus having or defining "one" of a feature does not exclude the apparatus having or defining two or more of those features, so long as the apparatus has or defines at least one of those features. Similarly, a reference herein to "one" of a plurality of features does not exclude the invention from including two or more, up to all, of those features. For example, a reference to an apparatus having or defining "one of X and Y" does not exclude the apparatus from having both X and Y.

Claims

1. 1. A filtration device configured to filter a fluid, the filtration device comprising: A housing, at least one inlet opening; a first bore and a second bore; at least one first inlet channel extending from the at least one inlet opening into the first bore, and at least one second inlet channel extending from the at least one inlet opening into the second bore; a first outlet channel and a second outlet channel communicating with the first bore and the second bore, respectively; a housing defining a first backwashing channel and a second backwashing channel; a first piston and a second piston movably disposed within the first bore and the second bore, respectively, the first piston defining a first cavity within the first piston, the first cavity being in fluid communication with the at least one first inlet channel and the first outlet channel when the first cavity is in a production mode, and the second piston defining a first cavity within the second piston, the first cavity of the second piston being in fluid communication with the at least one second inlet channel and the second outlet channel when the first cavity of the second piston is in the production mode; a first filter element disposed within the first cavity of the first piston and a second filter element disposed within the first cavity of the second piston; A backwash valve; the first backwashing channel extends between the first bore and the backwashing valve, and the second backwashing channel extends between the second bore and the backwashing valve; The backwash valve includes an inner surface that defines a valve chamber within the backwash valve, the valve chamber being configured such that when the filtration device is operated in a backwash mode, the backwash valve (1) compresses fluid from the valve chamber into the first cavity through the first backwash channel to increase the pressure of the fluid in the first cavity, and (2) fills with fluid to open and expel the compressed fluid from the first cavity and out of the backwash valve.

2. 2. The filtering apparatus of claim 1, wherein the backwash valve comprises a valve stem configured to translate within the valve chamber and a valve seat fixedly attached to the valve stem such that the valve seat translates with the valve stem.

3. 3. The filtration device of claim 2, wherein the valve stem has a cross-sectional dimension in a plane perpendicular to an axis of the backwash valve, the cross-sectional dimension being less than a cross-sectional dimension of the valve chamber in the plane such that the valve chamber defines a space between the valve stem and the inner surface of the backwash valve when the backwash valve is in a closed position, the space being configured to receive the fluid therein.

4. 4. The filtration device of claim 3, wherein the valve seat has a cross-sectional dimension in the plane perpendicular to the axis of the backwash valve that exceeds a cross-sectional dimension of the valve stem.

5. 3. The filtration device of claim 2, wherein the valve chamber has a first end and a second end that are offset from one another along a valve axis, and a valve inlet extends through the inner surface at a location between the first end and the second end of the valve chamber.

6. The filtration device of claim 5 , wherein a valve outlet is defined at the second end of the valve chamber.

7. 7. The filtration device of claim 6, wherein an outer surface of the valve seat is in fluid communication with the valve inlet and the valve outlet when moved past at least a portion of the valve inlet along a direction extending from the second end of the valve chamber to the first end of the valve chamber.

8. 2. The filtering device of claim 1, wherein the first piston defines a first piston outlet therein in fluid communication with the first cavity, the first piston outlet being elongated along a lateral direction parallel to an axis of the first piston.

9. 9. The filtration apparatus of claim 8, wherein the first outlet channel defines an internal opening in the first bore, the internal opening being elongated along the lateral direction such that the first outlet channel and the internal opening can overlap one another as the first piston moves to various positions between a production mode and a backwash mode.

10. the housing defines at least one third inlet channel extending from the at least one inlet opening to the first bore and a third outlet channel in fluid communication with the first bore; 2. The filtering device of claim 1, wherein the first piston defines a second cavity therein, the second cavity being in fluid communication with the at least one third inlet channel and a third outlet channel when the first cavity of the first piston is in a production mode, and the first cavity of the first piston is in a first isolated position in which the first cavity is not in fluid communication with the at least one first inlet channel or the first outlet channel.

11. 2. The filtering device of claim 1, wherein the first piston defines a first groove extending laterally from the first cavity and the second piston defines a second groove extending laterally from the first cavity of the first piston, and the filtering device is configured to move the first piston and the second piston to place the first groove and the second groove in fluid communication with the first backwashing channel and the second backwashing channel, respectively.

12. 2. The filtering device of claim 1, wherein the housing has an upstream side defining the at least one inlet opening and a downstream side defining the at least one outlet of the housing, the backwash valve being disposed on the upstream side.

13. 1. A method of operating a filtration device comprising a housing and a first piston and a second piston disposed within a first bore and a second bore of the housing, the method comprising: moving the first piston to move a first cavity within the first piston from a production mode, in which the first cavity of the first piston is in fluid communication with at least one first inlet channel and a first outlet channel of the housing, to a first isolated position, in which the first cavity of the first piston is not in fluid communication with the at least one first inlet channel or first outlet channel of the housing; pressurizing the first cavity of the first piston with fluid by directing fluid from the first cavity of the second piston through a first filter element disposed in the first cavity of the first piston through a first backwash channel in the housing and then isolating the first cavity in the second piston from the first backwash channel; opening a backwash valve of the filtration device to (1) increase the pressure of fluid in the first backwash channel and subsequently in the first cavity of the first piston as the backwash valve is opened, and (2) allow pressurized fluid in the first cavity of the first piston to flow from the first cavity of the first piston, through the first backwash channel and out of the backwash valve; and backwashing the first filtration element by moving the first piston to a second isolated position in which the first cavity of the first piston is in fluid communication with the first outlet channel but not in fluid communication with the at least one first inlet channel such that the fluid flows from the first outlet channel, along an upstream direction through the first filtration element, through the first backwash channel and out of the backwash valve.

14. 14. The method of claim 13, wherein the first cavity in the first piston is pressurized to a first pressure when the first cavity in the first piston is operated in the production mode, and the step of opening the backwash valve includes increasing the pressure in the first cavity of the first piston above the first pressure.

15. 14. The method of claim 13, wherein the step of opening the backwash valve includes moving the valve seat of the backwash valve along a selected direction toward a valve inlet of the backwash valve such that the valve seat of the backwash valve compresses the fluid in the valve chamber through a valve inlet and into the first backwash channel within a valve chamber of the backwash valve.

16. 16. The method of claim 15, wherein the step of opening the backwash valve comprises further moving the valve seat within the valve chamber along the selected direction such that an outer surface of the valve seat moves past at least a portion of the valve inlet, thereby opening the backwash valve and placing the valve inlet in fluid communication with a valve outlet.

17. 16. The method of claim 15, including filling the valve chamber of the backwash valve with the fluid before the valve seat compresses the fluid in the valve chamber.

18. 14. The method of claim 13, comprising operating the first cavity of the second piston in a production mode during each of the steps of pressurizing the first cavity of the first piston, flushing the fluid from the first cavity in the second piston, opening the backwash valve, and backwashing the first filtration element, wherein the first cavity of the second piston is in fluid communication with at least one second inlet channel and a second outlet channel of the filtration device.

19. 14. The method of claim 13, wherein the pressurizing step of pressurizing the first cavity of the first piston includes moving the first piston to move a second cavity in the first piston from a production mode in which the second cavity is in fluid communication with at least one third inlet channel and a third outlet channel of the housing to a production mode in which the second cavity of the first piston is in fluid communication with the at least one first inlet channel and the first outlet channel of the housing such that fluid passes from the at least one first inlet channel through a filtration element in the second cavity and out of the first outlet channel.

20. 1. A filtration device configured to filter a fluid, the filtration device comprising: A backwash valve; A housing, at least one inlet opening; a first bore and a second bore; at least one first inlet channel extending from the at least one inlet opening into the first bore, and at least one second inlet channel extending from the at least one inlet opening into the second bore; a first outlet channel and a second outlet channel communicating with the first bore and the second bore, respectively; a housing defining a first backwashing channel extending between the first bore and the backwashing valve and a second backwashing channel extending between the second bore and the backwashing valve; a first piston movably disposed within the first bore, the first piston defining a first cavity within the first piston, the first cavity of the first piston in fluid communication with the at least one first inlet channel and the first outlet channel when the first cavity of the first piston is in a production mode, the first piston defining a first groove on an upstream side of the first piston extending away from the first cavity of the first piston, the first piston being movable to align the groove of the first piston with the first backwash channel; a second piston movably disposed within the second bore, the second piston defining a first cavity within the second piston, the first cavity of the second piston in fluid communication with the at least one second inlet channel and the second outlet channel when the first cavity of the second piston is in a production mode, the second piston defining a groove on an upstream side of the second piston extending away from the first cavity of the second piston, the second piston being movable to align the groove of the second piston with the second backwash channel; a first filter element disposed within the first cavity of the first piston; a second filter element disposed within the first cavity of the second piston; It is equipped with 11. The backwash valve of claim 10, wherein the backwash valve comprises an inner surface defining a valve chamber within the backwash valve, the valve chamber being configured such that when the filtration device is operated in a backwash mode, the backwash valve (1) compresses fluid from the valve chamber into the first cavity of the first piston through the first backwash channel to increase the pressure of the fluid in the first cavity of the first piston, and (2) opens to expel the compressed fluid from the first cavity of the first piston and out of the backwash valve.

21. 21. The filtering device of claim 20, wherein each groove extends outwardly away from a corresponding one of the first cavity of the first piston and the first cavity of the second piston.

22. 21. The filtering device of claim 20, wherein each groove is open to a corresponding one of the first cavity of the first piston and the first cavity of the second piston and is in fluid communication with the corresponding one of the first cavities.

23. 21. The filtering device of claim 20, wherein each groove has a triangular shape.

24. 21. The filtering device of claim 20, wherein each groove has a cross-sectional dimension along a lateral direction that is less than a cross-sectional dimension of a corresponding one of the first cavities.

25. the housing defines the first bore, the second bore, the first backwashing channel, and a second backwashing channel; 14. The method of claim 13, wherein the first backwashing channel extends between the first bore and the backwashing valve and the second backwashing channel extends between the second bore and the backwashing valve.

Images