Method and system for improved flushing filters

Abstract

The filter includes a housing having an interior space, the housing having at least one open end. The filter further includes a membrane disposed within the housing having a length extending along a length of the housing, and a baffle disposed in at least the interior space of the housing. The baffle includes at least two baffle partitions extending along at least a portion of the length of the membrane and dividing the interior space of the housing into at least a first portion and a second portion, such that when a fluid is fed into the filter, the fluid first flows through the first portion and is then directed to the second portion.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to fluid treatment filters and methods of using the filters. [Background technology]

[0002] For example, fluids used in manufacturing in the semiconductor manufacturing industry often flow through multiple filters to remove contaminants or undesirable materials from the fluid before it is distributed. Useful fluids processed using filters include water, liquid industrial solvents and process fluids, industrial gases used in manufacturing or processing (e.g., in semiconductor manufacturing), and liquids with medical or pharmaceutical applications. Undesirable substances removed from fluids include impurities and contaminants such as particles, microorganisms, and dissolved chemical species. Specific examples of filter applications include use in the pharmaceutical industry to remove particles and bacteria from therapeutic solutions, use to process ultrapure aqueous and organic solvent solutions for use in microelectronics and semiconductor processing, and use for water purification processes.

[0003] To perform the filtering function, the filter includes a filter membrane, which serves to remove undesirable materials. The filter membrane may be in the form of a flat sheet, wound (e.g., spiral), pleated, or the like, as desired. The filter membrane may alternatively be in the form of hollow fibers. The filter membrane may be contained within a housing such that the fluid being filtered enters through a filter inlet and must pass through the filter membrane before passing through the filter outlet. Summary of the Invention

[0004] Disclosed herein is a filter comprising, consisting essentially of, or consisting of: a housing having an interior space and including at least an opening; a membrane disposed within the housing and having a length extending along the length of the housing; and a baffle disposed in at least the interior space of the housing. The baffle includes at least two baffle partitions extending along at least a portion of the length of the membrane and dividing the interior space of the housing into at least a first portion and a second portion, such that when a fluid is supplied to the filter, the fluid first flows through the first portion and is then directed to the second portion.

[0005] In one embodiment, the filter housing includes an inlet end, an outlet end formed at an end of the housing opposite the inlet end, an interior space, and a baffle. The baffle is disposed at least in the interior space and the inlet end of the housing, and the baffle includes at least two baffle partitions extending along at least a portion of the length of the filter housing and dividing the interior space of the housing into at least a first portion and a second portion, such that when a fluid is supplied to the filter housing, the fluid first flows along the first portion and is then directed to the second portion.

[0006] In one embodiment, a method for filtering a fluid includes introducing a fluid into a filter through an inlet. The method also includes directing the fluid through a baffle formed within a housing of the filter, the baffle including at least two baffle partitions extending along at least a portion of the length of the membrane and dividing the interior of the housing into at least a first section and a second section, and passing the fluid through the baffle and the at least two baffle partitions such that the fluid first flows through the first section and is then directed to the second section. The fluid is then directed through the membrane of the filter to an outlet.

[0007] The present disclosure may be more fully understood in consideration of the following description of various exemplary embodiments in connection with the accompanying drawings. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of an exemplary filter according to an embodiment. [Figure 2A] FIG. 2 is an exploded view of an exemplary filter. [Figure 2B] FIG. 2 is an exploded view of an exemplary filter. [Figure 3] FIG. 10 is an exploded view of another exemplary filter, according to an embodiment. [Figure 4A] FIG. 10 is a perspective view of a filter according to another exemplary embodiment. [Figure 4B] FIG. 10 is a perspective view of a filter according to another exemplary embodiment. [Figure 4C] FIG. 10 is a cross-sectional view of a filter according to another exemplary embodiment. [Figure 5A] FIG. 10 is a perspective view of a filter according to yet another exemplary embodiment. [Figure 5B] 10 is a cross-sectional view of a filter according to yet another exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] While the present disclosure is susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and have been described in detail. It should be understood, however, that it is not intended to limit aspects of the disclosure to the particular exemplary embodiments described. Rather, it is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

[0010] Like numbers refer to like parts throughout.

[0011] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include their plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in its sense including "and / or" unless the content clearly dictates otherwise.

[0012] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The detailed description and the drawings, which are not necessarily to scale, depict exemplary embodiments and are not intended to limit the scope of the invention. The exemplary embodiments shown are intended as examples only. Selected features of any exemplary embodiment may be incorporated into additional embodiments, unless expressly stated to the contrary.

[0013] In the field of filtration, improving the flow dynamics of fluids within filters is an important feature for many different applications, such as in manufacturing, medical, and pharmaceutical applications. For example, in the field of semiconductor manufacturing, controlling particulate contaminants in filtration processes requires the use of filters with membranes that remove submicron particles, such as those with contaminant levels below 5 ppb. It is understood that any particles that deposit on semiconductor wafers can create defects if they are large enough. Typically, in the semiconductor industry, failure defects can be created by particles as small as about one-tenth the size of the smallest feature on a semiconductor chip. Therefore, controlling contamination improves manufacturing yield and reliability by reducing wafer defect rates.

[0014] Disclosed herein is a filter including a baffle for dividing the interior space of the filter housing into at least a first section and a second section and for directing fluid flow within the filter housing. The baffle is designed to improve fluid flow patterns by creating circular flow paths within the filter housing to eliminate or reduce low-flow areas or dead zones within the filter, e.g., flows below about 0.05 cm / sec. By creating circular flow paths within the filter housing, it has surprisingly been found that the improved fluid distribution and flow improves chemical exchange in the filter membrane, thereby improving not only filter flushing and cleaning during filter preparation, but also improving fluid residence time during filter use, e.g., reducing fluid residence time. For example, without being bound by theory, during filter preparation, a filter with low-flow areas or dead zones may not receive the fluid flow contact necessary for proper cleaning and flushing, thus requiring subsequent flushing and / or additional time to meet any required filter cleanliness specifications. Furthermore, during use, filters with low-flow regions or dead zones may leave residual chemicals or contaminants in the low-flow regions or dead zones, may accumulate and / or provide areas for bacterial growth, and / or for time-sensitive reactive chemicals may not have adequate residence time for the use of time-sensitive reactive chemicals and may not utilize the entire filter membrane. In contrast, filters with baffles disclosed herein reduce or eliminate low-flow regions or dead zones, thereby improving fluid residence time and reducing or eliminating the accumulation of residual chemicals or contaminants during use, as well as improving the readiness of the filter for removing potential sources of contamination in semiconductor manufacturing processes; for example, filters with the present baffles can be conditioned, e.g., washed and / or flushed, to reduce contamination.

[0015] It is understood that the filters described herein are not limited to any particular type of filter design. Rather, it is understood that the disclosure described herein can be used with many different filter designs, for example, in liquid filtration using disposable, single-use filters or filters with replaceable filter cartridges that can include a filter membrane, core, housing, or a combination thereof. In one embodiment, the filter can be used to filter a fluid from one end of a filtration module to the other. In this type of filter, the supply and permeate connections are located at opposite ends of the filter, thereby moving the liquid flow from one end to the other. This flow configuration is referred to as an in-line flow configuration. The filter can be oriented horizontally or vertically without significantly affecting the filter's performance.

[0016] In another embodiment, the filter includes horizontally oriented feed and permeate ports at the top of the "head" ends on either side of the module. Due to this shape, these modules are referred to as having a T-shaped configuration. The T-shaped configuration facilitates connection of the head to the rest of the filtration module, including the bowl and filtration cartridge positioned within the bowl. In this filter design, the bowl and filtration cartridge comprise separate elements. Therefore, when constructing the filtration module, the filtration cartridge and bowl are separately secured and sealed to the manifold head.

[0017] That is, it is understood that the baffle designs of the present disclosure can be used in different types of filter designs, such as in-line, T-configuration, U-configuration, etc., to improve fluid flow patterns within the housing and eliminate or reduce dead zones or low flow areas within the filter. It is also understood that the baffle designs can be used in either outside-to-inside or inside-to-outside filter designs to improve flow patterns within the filter without departing from the scope of the present disclosure.

[0018] FIG. 1 is a cross-sectional view of an exemplary filter 100. The filter 100 can be a disposable filter for single-use applications in the semiconductor industry. The filter 100 includes a housing 105 having an interior space 106. The housing 105 includes at least one open end, which can include an inlet end 107 and an outlet end 108 at the opposite end of the housing 105. The filter housing 105 is generally tubular or cylindrical, but can be provided in any suitable geometric shape for the filtration process. The filter 100 further includes a membrane 110 disposed within the interior space 106 of the housing, a first end cap 115 connected to the inlet end 107, and a second end cap 120 connected to the outlet end 108. The first end cap 115 and the second end cap 120 can further define the interior space 106 of the housing. As shown in FIG. 1, in some embodiments, the filter can also include a core 125 around which the membrane 110 is disposed. In other embodiments, the core 125 shown in FIG. 1 can be omitted. The interior space 106 can house the different elements of the filter, such as the membrane 110 and optionally the core 125 , along with the fluid to be filtered using the membrane 110 .

[0019] Housing 105 can be made from any suitable moldable material typically used for filter housings, including, but not limited to, polypropylene, polyethylene, and perfluoroalkoxyalkane (PFA).

[0020] The membrane 110 can be porous and can have a pleated configuration. Suitable materials that can be used for the membrane include, by way of non-limiting example, polytetrafluoroethylene (PTFE), polyethylene (including ultra-high molecular weight polyethylene (UPE)), and polysulfone. The membrane has a first edge, a second edge, and a first (or interior) surface and a second (or exterior) surface extending between the first and second edges.

[0021] Core 125 may be a member surrounded by a membrane such that the membrane is disposed between core 125 and housing 105. In one embodiment, core 125 is tubular or cylindrical in shape. Core 125 may have a series of openings that allow fluid to pass between the membrane and the hollow center of core 125. In embodiments, the core may be any suitable material, including, but not limited to, polypropylene, polyethylene, and perfluoroalkoxyalkane (PFA).

[0022] The first end cap 115 is connected to one or more of the housing 105, the membrane 110, and, if present, the core 125. Similarly, the second end cap 120 can be attached to one or more of the housing 105, the membrane 110, and, if present, the core 125. The first and second end caps can be made of any suitable material, including, but not limited to, polypropylene, polyethylene, and perfluoroalkoxyalkane (PFA). In one embodiment, one or both of the first end cap 115 and the second end cap 120 can be made of the same material as the housing. The first and second end caps 115, 120 can be attached to the housing 105 and optionally other components using conventional means to form a fluid-tight seal and form an integrated filter. Non-limiting examples of such attachment include welding, such as heat or ultrasonic welding, threaded fittings, adhesives, mechanical attachments including seals provided at the joints, and the like.

[0023] In one embodiment, the first end cap 115 and / or the second end cap 120 include one or more connectors, such as connectors 116, 117. In one embodiment, each of the connectors 116, 117 includes threads surrounding an aperture 119. In an embodiment, only two such connectors may be included in each end cap, although additional connectors may be provided depending on the application or use of the filter. The threads may allow for connection of a fluid line to at least one of the connectors 116, 117. In an embodiment, the threads may be replaced with any other suitable mechanical connector for forming a sealed connection between the fluid line and the respective connector 116, 117. The aperture 119 may allow fluid to flow in and out of the housing 105, for example, to allow fluid being filtered to enter or exit the housing 105, or to allow air or any other fluid to exit the housing 105. In one embodiment, the first end cap 115 may include an inlet connector 116 and a vent to allow the fluid to be filtered to enter the housing 105. The second end cap 120 can include an outlet connector 117 and a vent that allows fluid filtered using the membrane 110 to exit the housing 105. It is understood that the inlet and outlet connectors 116, 117 and / or apertures can be located along different locations on the end cap as needed for fluid processing. For example, in one embodiment, at least one of the inlet and outlet connectors 116, 117 and / or aperture 119 can be located in the center of the end cap.

[0024] The outlet connector 117 can be positioned so that the membrane 110 is located within a fluid path through the interior space defined by the housing 105 and the first and second end caps 115, 120, from the inlet connector 116 to the outlet connector 117. For example, if the outlet connector 117 is provided in the center of the second end cap 120, the filter is an in-line filter in which fluid is filtered with an outside-to-inside flow relative to the membrane 110. The vent connectors 116, 117 can allow other fluids to exit the housing 105, such as, by way of non-limiting example, allowing air to exit the housing 105 when a fluid to be filtered is introduced into a previously unused filter 100. The fluid, including both the fluid filtered by the filter 100 and other fluids, such as those discharged at 116, 117, can be in either a gas or liquid phase.

[0025] As seen in FIG. 1 , the filter 100 further includes a baffle 130 disposed at least partially in the interior space 106, or in a space disposed in the first end cap 115, or in the inlet end 107 of the housing 105, or a combination thereof. The baffle 130 seals the open end of the membrane 110 at the inlet end 107 and includes at least two baffle partitions 135 extending from at least the sealed end of the membrane 110 along at least a portion of the length of the membrane 110 to divide the interior space 106 of the housing 105 into at least a first portion 106A and a second portion 106B. In one embodiment, the baffle 130 is fluidly connected to the connector 116 to receive fluid from the inlet and includes an opening 140 that directs fluid into the first portion 106A of the interior space. It will be understood that the opening 140 can be disposed in the first end cap 115, the interior space 106 of the filter housing 105, or a combination thereof.

[0026] In one embodiment, the baffle 130 is connected to the inlet end 107 of the housing 105 and can be connected to at least the first end cap 115. For example, the baffle 130 can be connected to the portion of the first end cap 115 that forms the aperture 119 using various joining techniques known in the art, such as, for example, a mechanical connection using, for example, a threaded fit, tabs, or the like, a press fit, thermal bonding, welding including heat, ultrasonics, or the like, or a combination thereof. A baffle partition 135 can be connected to the first end cap 115, the baffle 130, the membrane 110, the core 125, and / or the filter cartridge, or can be connected to the housing 105 to divide the interior space 106 of the housing 105, or a combination thereof.

[0027] The baffle partition 135 extends from at least the sealed end of the membrane 110 along at least a portion of the length parallel to the central axis of the filter 100, dividing the interior space 106 into a first portion 106A and a second portion 106B. The baffle partition 135 can also extend at least partially into or into the housing of the first end cap 115. Thus, the baffle partition 135 is designed to direct fluid flow from an inlet to one side of the filter membrane and then circulate the fluid on the other side of the filter, for example, to form a circular flow path to the second portion 106B. It will be appreciated that using the baffle partition 135 to direct fluid flow can eliminate or reduce low-flow areas, stagnant areas, or dead zones within the filter during filter preparation, e.g., conditioning, or during use. For example, the baffle partition 135 can extend the entire length of the membrane 110 to the second sealed end face of the membrane 110. In doing so, after the fluid is directed along the outer surface of the membrane 110 into the first portion 106A, the fluid is directed to circulate around the membrane 110, for example, within the space in the second end cap 120 or the interior space 106 of the housing 105, and then to flow across the outer surface of the membrane 110 in the second portion 106B. While the fluid is directed along the outer surface of the membrane 110 in the first portion 106A and the second portion 106B, it is understood that a portion of the fluid is filtered through the membrane 110, such that the permeate can flow through the outlet 117 of the second end cap 120, for example, along the interior space of the membrane, for example, through the core 125, to discharge the filtered fluid from the filter 100. It is understood that in some embodiments, depending on the nature and need of the fluid to be filtered, the fluid flow can be biased to filter through the membrane 110 so that more of the fluid is filtered while it flows through the first portion 106A or the second portion 106B. For example, in one embodiment, core 125 may include larger spaces or pores, allowing more flow through designated portions 106A or 106B, such that the flow through the designated portion has a preferential chemistry.It is also understood that the membrane can be designed to be more biasing towards the fluid being filtered, for example, by having larger pores that reduce the pressure drop across the membrane at certain portions of the membrane.

[0028] In one embodiment, the baffle 130 can include a gap 145 between the bottom surface of the housing of the first end cap 115 and the top of the baffle partition 135, with the baffle partition 135 extending only partially into the first end cap 115. The gap 145 is the portion of the baffle partition 135 that does not extend to the bottom surface of the housing of the first end cap 115 to allow fluid communication between the first portion 106A of the interior space and the second portion 106B of the interior space. For example, the baffle partition 135 can have a height equal to the baffle 130 connected to the portion of the first end cap 115 that forms the aperture 119. Thus, because the baffle partition 135 does not extend to the domed bottom surface of the first end cap 115, when fluid is fed through the inlet aperture 119 and directed through the opening 140 in the baffle 130 toward the first portion 106A of the interior space, a Venturi / siphon effect occurs, whereby stagnant or low-flow fluid in the second portion 106B of the interior space is drawn across the baffle partition 135 and combines with the fluid flow into the first portion 106A of the interior space to form a circular flow path within the fluid housing. It is understood that the gap can be sized to siphon a predetermined volume of flow based on well-known principles of flow mechanics based on area and flow velocity, such as Bernoulli's equation. A gap can be provided between each baffle partition 135 and the first end cap 115, or the gap can be an aperture in the baffle partition 135 and can be a single gap (or aperture) or multiple gaps (or apertures) having various geometries, for example, siphoning from the second portion 106B of the interior space, to control the amount of flow circulated with the first fluid in the first flow path.That is, the gap or aperture can be a structure provided between the baffle and first end cap 115, or a structure provided in baffle 130 and / or baffle partition 135, allowing fluid communication between the first and second portions of the filter housing through baffle 130 connected to first end cap 115, for example, at or near the fluid inlet flow.

[0029] As shown in Figures 2A and 2B, which show exploded views of filter 100, baffle 130 can be a single molded component including baffle 130, as well as baffle partition 135, opening 140, and / or gap 145. As seen in Figure 2A, baffle 130 can also be molded and / or combined with a filter cartridge, such as core 125, membrane 110, etc., or molded and / or combined with a housing. Figure 2B shows that once baffle 130 is molded and / or combined with a filter cartridge, the combined baffle can be inserted into housing 105 and sealed with first end cap 115 and second end cap 120, with baffle partition 135 dividing interior space 106 into first interior space portion 106A and second interior space portion 106B. As mentioned above, the baffle 130 can then be connected to the portion of the first end cap 115 that forms the aperture 119 using various joining techniques known in the art, such as, for example, a mechanical connection using threaded fittings, tabs, etc., a press fit, thermal bonding, welding including heat, ultrasonic, etc., or combinations thereof. The first and second end caps 115, 120 can be attached to the housing 105 and optionally other components using conventional means to form a fluid-tight seal and form an integral filter. Non-limiting examples of such attachments include welding, such as heat or ultrasonic welding, threaded fittings, adhesives, mechanical attachments including seals provided at the joints, etc.

[0030] In another embodiment, as seen in FIG. 3 , which shows an exploded view of filter 100, it is understood that baffle 130 can be constructed as a modular design, allowing several elements to be added together. For example, baffle 130 can include multiple connections for adding additional elements, such as additional baffle partitions 135A, to baffle 130 using joining techniques, such as slotted tongue and groove connections, press fits, pin connections, and the like. Having baffle 130 from a single molded component allows baffle 130 to be added to an existing design during manufacture or retrofit of filter 100, for example, to connect to first end cap 115 of a disposable filter, and then to a filter cartridge including membrane 110 and core 125, which can also include baffle partition 135B for dividing interior space 106. Baffle partitions 135A and 135B can include connecting tabs for connecting baffle partitions 135A and 135B to each other. Baffle 130 can be any suitable material, including, but not limited to, polypropylene, polyethylene, and perfluoroalkoxyalkane (PFA). Seals can be provided between different elements of filter 100. For example, outlet seal 160 can be provided near the outlet end of the housing connected to aperture 119 of outlet connector 117. Seals, such as rubber O-rings, can also be provided between baffle 130 and the filter cartridge and / or between baffle 130 and first end cap 115 to allow for a press-fit connection.

[0031] In another embodiment, as seen in Figures 4A-4C, filter 400 includes a different design for baffle 430. Filter 400 in Figures 4A-4C includes the same or similar elements and features of filter 100 shown in Figures 1-3, as described above, and shows only first end cap 415 and baffle 430, where baffle partition 435 does not extend along the entire length of the membrane. Instead, Figures 4A and 4B show that baffle 430 has a length extending from first end cap 415 and includes an outer circumferential surface 450 that is at least partially disposed within the space within first end cap 415, the interior space of the filter, or a combination thereof. Baffle 430 is fluidly connected to connector 416 to receive fluid from inlet aperture 419 and further includes opening 440 that directs fluid flow to one side of filter 400.

[0032] Baffle 430 can be connected to first end cap 415 and can be connected to or abut at least one of the inlet end of the housing or the membrane, e.g., a filter cartridge. For example, baffle 430 can be connected to first end cap 415 and / or the filter cartridge forming aperture 419 using various joining techniques known in the art, such as threaded fitting, mechanical connections using tabs or the like, press fit, thermal bonding, welding including heat, ultrasonic, molding, etc., or combinations thereof.

[0033] The baffle partition 435 is at least partially disposed in the end cap 415 or the interior space of the filter housing, or a combination thereof, and extends the length of the outer circumferential surface 450 to at least partially divide the interior space of the end cap 415 and / or the interior space of the filter housing into at least first and second portions. Thus, the flow path of the fluid entering the filter 400 can be circular using the baffle 430 connected to the first end cap 415.

[0034] Additionally, as seen in FIG. 4C , baffle 430 can include a gap 445 between first end cap 415 and baffle partition 435. In doing so, when fluid is directed through opening 440 in baffle 430, a Venturi / siphon effect siphons the fluid from the second portion of baffle 430, further forming a circular flow path, eliminating or reducing low-flow regions or dead zones within filter 400. For example, baffle partition 435 extends at least partially into the interior space of first end cap 415 and / or the housing, so that when inlet fluid is directed through opening 440 in baffle 430 into the first portion, the fluid flow follows at least a semicircular flow path from the first portion to the second portion. Thus, baffle partition 435 directs fluid flow from the inlet to one side of the filter membrane and circulates the fluid through gap 445 to the second portion, forming at least a semicircular flow path. It will be appreciated that by directing the fluid flow in this manner, low flow areas, stagnant areas, or dead zones of fluid flow within the filter can be eliminated or reduced when preparing, e.g., conditioning, or during use of the filter.

[0035] Baffle 430 may be a single molded component that includes baffle partition 435, opening 440, and / or gap 445 and is connected to first end cap 415 and / or filter cartridge. It is understood, therefore, that baffle 430 may be added to an existing design and connected to first end cap 415 of a disposable filter during manufacture or retrofit of filter 400, for example.

[0036] While the baffles 130, 430 are described above as having baffle partitions 135, 435 parallel to the central axis of the filter 100, 400, it is understood that the baffles 130, 430 can have different designs, e.g., profiles, to modify the flow dynamics of the fluid within the filter 100, 400. For example, the baffle partitions 135, 435 can be straight (or substantially straight), curved, wavy, etc., and can extend substantially parallel to the central axis of the filter or can be angled to modify the flow dynamics within the filter 100, 400. It is also understood that while the baffle partitions 135, 435 are described as having two dividers, the baffle partitions can include additional dividers as needed to modify the flow dynamics of the filter to eliminate or reduce low-flow regions or dead zones within the filter. For example, if the filter 100, 400 includes four baffle partitions 135, 435, separating the interior space of the housing into four portions, it will be understood that at least one of the portions receives fluid from the inlet of the filter, and the fluid is then directed to at least one of the other portions, e.g., in a counter-flow and / or parallel-flow arrangement.

[0037] A method for filtering a fluid by using baffles to create a circular flow pattern in an in-line filter is described below. Referring back to FIG. 1 , in one embodiment, the filter 100 receives the fluid to be filtered at an inlet aperture 119. One end of a baffle 130 having an opening 140 is connected to the inlet aperture 119 of the first end cap 115, and the other end abuts or connects to an end sealing surface of the membrane and / or core so that the fluid is directed through the opening 140 in the baffle 130. The baffle 130 includes at least two baffle partitions 135 extending along the length of the membrane 110 and dividing the interior of the housing into at least a first portion 106A and a second portion 106B. Thus, the baffle openings 140 direct the fluid flow toward at least the first portion 106A of the interior space 106.

[0038] Fluid flows in a direction parallel to the central axis of the filter across the outer surface of membrane 110 in first section 106A (which filters at least a portion of the fluid) to the end of membrane 110. The fluid then flows around membrane 110 either within the filter housing and / or within second end cap 120, and then flows in a countercurrent direction across the outer surface of membrane 110 in second section 106B. As the fluid is filtered through membrane 110, the filtrate flows toward the outlet aperture of filter 100 in second end cap 120.

[0039] In embodiments in which baffle 130 includes gaps 145 at the ends of baffle partition 135, it is understood that fluid flow through openings 140 toward at least first portion 106A creates a venturi / siphon effect that draws fluid toward first portion 106A into the fluid flow entering from the opposite side of the baffle partition, further creating a circular flow path within the filter housing. It is understood that such an effect further eliminates or reduces low flow regions or dead zones within the filter.

[0040] By forming circular flow channels within the filter housing, it has surprisingly been found that improved fluid distribution and flow improves chemical exchange in the filter membrane, which not only improves the efficiency of filter flushing and cleaning during filter preparation, but also improves fluid residence time during filter use, and at least prevents or reduces low-flow areas or dead zones within the filter housing, thereby preventing the accumulation of residual chemicals and / or contaminants. In conventional filter designs, low-flow or stagnant flow areas exist in the region of the interior space between the filter cartridge and the housing, including the second end cap and / or the first end cap. For example, previous in-line filter designs had approximately 15% of the interior space's flow area as stagnant or low flow, e.g., less than 0.05 cm / sec at 3 liters per minute. However, it has been found that filters with circular flow channels as disclosed herein reduce or eliminate the region of the interior space with low flow or stagnant flow to less than 10%, preferably less than 8%, and most preferably less than 6% of the interior space with such low flow or stagnant flow. That is, because the fluid flows through at least a portion of the second end cap and into the second portion of the interior of the housing, areas of low flow or stagnant flow previously present in conventional filters are reduced. Filter preparation and use can be improved by such improved flow patterns because areas of low flow or dead zones within a filter, e.g., flows less than about 0.05 cm / sec, can leave residual chemicals or contaminants that can accumulate and / or provide areas for bacterial growth, and / or do not utilize the entire filter membrane and / or result in excessive fluid residence times.

[0041] In yet another embodiment of the present invention, as seen in FIGS. 5A and 5B, a filter 500 is provided as a T-line reusable filter, with the baffle 530 disposed entirely within the housing 505. The filter 500 of FIGS. 5A-5B includes the same elements and features as the filters described above, with similar elements and materials not being repeated. The filter 500 includes a housing 505 having an interior space 506, the housing 505 including an open end 507. The filter 500 further includes a membrane 510 disposed within the interior space 506 of the housing and a cap 515 connected to the open end 507. The cap 515 can further define the interior space 506 of the housing. As shown in FIG. 5B, in some embodiments, the filter may also include a core 525 around which the membrane 510 is disposed. In other embodiments, the core 525 can be omitted. The interior space 506 can house different elements of the filter, such as the membrane 510 and, optionally, the core 525, along with the fluid to be filtered using the membrane 510.

[0042] The cap 515 is connected to one or more of the housing 505, the membrane 510, and, if present, the core 525. The cap 515 can be attached to the housing 505 and optionally other components using conventional means to form a fluid-tight seal and form an integrated filter. Non-limiting examples of such attachments include mechanical attachments including threaded fits, welding such as snap fits, seals provided at the joints, and the like. Such attachments allow the filter 500 to be reused.

[0043] In one embodiment, cap 515 includes one or more connectors, such as connectors 516, 517. In one embodiment, connectors 516, 517 each include a tubing connector surrounding an aperture 519, which may be threaded for a screw fit, a snap fit, a press fit, or the like. In an embodiment, only two such connectors may be included in the cap, although additional connectors may be provided depending on the application or use of the filter. The tubing connectors may allow for connection of a fluid line to at least one of connectors 516, 517. Aperture 519 may allow fluid to flow in and out of housing 505, for example, to allow fluid being filtered to enter or exit housing 505, or to allow air or any other fluid to exit housing 505. In one embodiment, cap 515 may include an inlet connector 516 and a vent to allow fluid to be filtered to enter housing 505. Cap 515 may include an outlet connector 517 and a vent to allow fluid filtered using membrane 510 to exit housing 505. It will be appreciated that inlet and outlet connectors 516, 517 and / or apertures can be provided along different locations on the end cap as needed for fluid handling.

[0044] The outlet connector 517 can be positioned so that the membrane 510 is located in a fluid path through the interior space defined by the housing 505 and the cap 515, from the inlet connector 516 to the outlet connector 517. For example, the outlet connector 517 is connected to the center of the cap 515, such that the filter is a T-line filter that filters fluid with an outside-to-inside flow relative to the membrane 510.

[0045] As seen in FIGS. 5A-5B, the filter 500 further includes a baffle 530 disposed in the interior space 506. The baffle 530 seals the open end of the membrane 510 at the open end 507 and includes at least two baffle partitions 535 extending from at least the sealed end of the membrane 510 along at least a portion of the length of the membrane 510 to divide the interior space 506 of the housing 505 into at least a first portion 506A and a second portion 506B. In this embodiment, the baffle 530 also includes an opening 531 disposed in the center of the baffle 530 for allowing fluid to exit the outlet connector 517. The baffle 530 is connected to the open end 507 of the housing 505 and can be connected to at least the cap 515. For example, baffle 530 can be connected to the portion of cap 515 that forms aperture 519 connected to outlet connector 517 using various joining techniques known in the art, such as, for example, a mechanical connection using threaded fittings, tabs, press fits, etc., or combinations thereof. Baffle partition 535 can be connected to baffle 530, membrane 510, core 525, and / or filter cartridge, or can be connected to housing 505 or a combination thereof to divide the interior space of the housing. That is, in some embodiments, baffle 530 can be provided on a filter cartridge for insertion into housing 505 and / or attached to housing 505 itself.

[0046] The baffle partition 535 extends from at least the sealed end of the membrane 510 along at least a portion of the length parallel to the central axis of the filter 500, dividing the interior space 506 into a first portion 506A and a second portion 506B. In one embodiment, the baffle partition 535 can also extend at least partially into or to the housing of the first end cap 515. Thus, the baffle partition 535 is designed to direct fluid flow from an inlet to one side of the filter membrane and circulate the fluid on the other side of the filter, e.g., to form a circular flow path to the second portion 506B. It will be appreciated that using the baffle partition 535 to direct fluid flow can eliminate or reduce low-flow regions, stagnant regions, or dead zones within the filter, reducing fluid residence time during filter preparation, e.g., conditioning, or during use. For example, the baffle partition 535 can extend the entire length of the membrane 510 to the second sealed end face of the membrane 510. In doing so, after the fluid is directed along the outer surface of membrane 510 into first portion 506A, the fluid circulates around membrane 510, for example, in the space within interior space 506 of housing 505, and is directed to flow across the outer surface of membrane 510 in second portion 506B. It will be appreciated that while the fluid is directed along the outer surface of membrane 110 in first portion 506A and second portion 506B, a portion of the fluid is filtered through membrane 510, such that permeate can be directed, for example, along the interior space of the membrane, for example, through core 525, to outlet 517 of second end cap 520 to discharge the filtered fluid from filter 100. As with the above-described embodiment, it will be appreciated that filtration of the fluid can be forced to occur while flowing through first portion 506A or second portion 506B, depending on the application of the filter and the fluid being filtered. Thus, baffle 530 is fluidly connected to connector 516 to receive fluid from the inlet, baffle partition 535 directs the fluid into first portion 506A of the interior space, and permeate is filtered through core 525 and exits filter 500 through opening 531 and connector 517.

[0047] Thus, filters using the baffle embodiments described herein result in filters with improved flow patterns that reduce or eliminate low flow areas or dead zones, e.g., areas of stagnant or no flow, in different portions of the filter's interior space, particularly between the membrane, housing, and second end cap.

[0048] Aspects: It is understood that any of embodiments 1-12 can be combined with any of embodiments 13-16 or 17. It is understood that any of embodiments 13-16 can be combined with any of embodiments 1-12 or 17.

[0049] Aspect 1. A filter comprising: a housing having an interior space and at least one open end; a membrane disposed within the housing and having a length extending along the length of the housing; and a baffle disposed at least in the interior space of the housing, the baffle comprising at least two baffle partitions extending along at least a portion of the length of the membrane to divide the interior space of the housing into at least a first portion and a second portion, such that when a fluid is supplied to the filter, the fluid first flows through the first portion and then is directed to the second portion.

[0050] Embodiment 2. The filter of embodiment 1, further comprising a first end cap connected to at least one open end, wherein a baffle is also provided in the first end cap and connected to at least the first end cap of the filter.

[0051] Embodiment 3. The filter of embodiment 2, wherein a gap is provided between the at least two baffle partitions and the bottom surface of the first end cap.

[0052] Embodiment 4. The filter of either embodiment 2 or 3, wherein the first end cap comprises a first aperture for receiving a fluid, the baffle comprises an opening in fluid communication with the first aperture, and the inlet is configured to direct the fluid into the first portion of the interior space.

[0053] Embodiment 5. The filter of embodiment 4, wherein the first end cap further comprises a second aperture that acts as a vent.

[0054] Embodiment 6. The filter of any of embodiments 2-5, wherein the baffle is configured to direct fluid flow along the outer surface of the membrane.

[0055] Embodiment 7. The filter of any of embodiments 2-6, further comprising a second open end of the housing and a second end cap provided at the second open end of the housing and having a third aperture for discharging fluid filtered through the membrane.

[0056] Embodiment 8. The filter of embodiment 7, wherein the third aperture is provided at the center of the second end cap.

[0057] Embodiment 9. The filter of any of embodiments 2-8, wherein each of the at least two baffle partitions has a first end located near, adjacent to, or within the first end cap, and a second end extending only to the end of the membrane within the housing.

[0058] Embodiment 10. The filter of any of embodiments 1-9, further comprising a core disposed within the housing, the membrane being positioned between the core and the housing.

[0059] Embodiment 11. The filter of any of embodiments 1-10, wherein the baffle is provided only in the interior space of the housing, the baffle further comprises an opening provided in the center of the baffle, and the filter further comprises a cap connected to at least one open end, the cap including an inlet for receiving fluid and an outlet fluidly connected to the opening in the baffle for removing fluid from the filter.

[0060] Embodiment 12. The filter of any of embodiments 1-11, wherein the baffles are provided such that low fluid flow areas between the membrane and the housing are minimized.

[0061] Aspect 13. A filter housing comprising: an inlet end; an outlet end formed at an end of the housing opposite the inlet end; an interior space; and a baffle disposed at least in the interior space and in the inlet end of the housing, the baffle comprising at least two baffle partitions extending along at least a portion of the length of the filter housing to divide the interior space of the housing into at least a first portion and a second portion, such that when a fluid is supplied to the filter housing, the fluid first flows along the first portion and then is directed to the second portion.

[0062] Embodiment 14. The filter housing of embodiment 13, further comprising a first end cap connected to the inlet end of the filter housing, the baffle being connected to at least the first end cap of the filter housing.

[0063] Embodiment 15. The filter housing of embodiment 14, wherein a gap is provided between the at least two baffle partitions and the bottom surface of the first end cap.

[0064] Embodiment 16. The filter housing of any of embodiments 13-15, wherein the baffles are provided to minimize regions of low fluid flow within the housing.

[0065] Embodiment 17. A method of filtering a fluid, comprising: introducing the fluid into a filter through an inlet; and directing the fluid through a baffle formed inside a housing of the filter, the baffle comprising at least two baffle partitions extending along at least a portion of the length of the membrane and dividing the interior of the housing into at least a first portion and a second portion; and passing the fluid through the baffle and the at least two baffle portions, whereby the fluid flows first through the first portion and is then directed to the second portion, wherein the fluid is passed through the membrane of the filter to an outlet.

[0066] Having thus described several exemplary embodiments of the present disclosure, those skilled in the art will readily appreciate that still other embodiments may be made and used within the scope of the appended claims. Many advantages of the present disclosure encompassed herein have been set forth in the foregoing description. It will be understood, however, that the present disclosure is in many respects merely illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts, without exceeding the scope of the present disclosure. The scope of the present disclosure is, of course, defined in the language in which the appended claims are expressed.

Claims

1. A filter, a housing having an interior space and including a first open end and a second open end; a membrane disposed within the housing and having a length extending along the length of the housing; a first end cap connected to the first open end of the housing and a second end cap provided at the second open end of the housing; a baffle disposed in at least the interior space of the housing, the baffle comprising at least two baffle partitions extending along at least a portion of the length of the membrane and dividing the interior space of the housing into at least a first portion and a second portion, such that when a fluid is supplied to the filter, the fluid first flows along an outer surface of the membrane through the first portion and then is directed to the second portion; and A filter comprising:

2. A filter as described in claim 1, wherein the baffle is also provided on the first end cap and is at least connected to the first end cap.

3. 2. The filter of claim 1, wherein the first end cap includes a first aperture for receiving the fluid, the baffle includes an opening in fluid communication with the first aperture, and an inlet in the first end cap is configured to direct the fluid into the first portion of the interior space.

4. A filter as described in claim 3, wherein gaps are provided between the at least two baffle partitions and the bottom surface of the first end cap so that when the fluid is supplied to the filter, it is directed through the openings in the baffles and the flow of the fluid through the openings toward the first portion creates a venturi / siphon effect, and the venturi / siphon effect draws stagnant or low-flow fluid from at least the second portion, which draws in fluid that combines with the flow of fluid toward the first portion to further form a circular flow path within the housing.

5. 3. The filter of claim 2, wherein each of the at least two baffle partitions has a first end located near, adjacent to, or within the first end cap and a second end extending only to an end of the membrane within the housing.

6. 10. The filter of claim 1, wherein the baffle is positioned such that low flow areas of the fluid between the membrane and the housing are minimized.

7. The filter of claim 1, wherein the filter is configured so that at least a portion of the fluid is filtered through the membrane while the fluid is guided along the outer surface of the membrane in the first portion.

8. 1. A method of filtering a fluid, comprising: introducing the fluid into the filter through an inlet at the inlet end connected to the first end cap; directing the fluid through a baffle formed within a housing of the filter, the baffle comprising at least two baffle partitions extending along at least a portion of a length of a membrane of the filter and dividing an interior of the housing into at least a first portion and a second portion; passing the fluid through the baffle and the at least two baffle partitions, whereby the fluid first flows along an outer surface of the membrane of the filter through the first portion and then is directed to the second portion; Including, The method wherein the fluid passes through the membrane of the filter and is directed to an outlet at an outlet end connected to a second end cap.

9. The method described in claim 8, wherein after the fluid is directed to the first portion, it circulates around the membrane of the filter and is directed to flow across the outer surface of the membrane in the second portion.

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