Filter device with vented core, static discharge suppression, or both

Abstract

A liquid filter device is described that includes a housing, an interior within the housing, a cartridge assembly (alternatively known as a "filter cartridge") contained within the housing, and a vent that allows gaseous fluid to be vented from the interior of the housing to the exterior of the housing or that includes an electrostatic suppression mechanism, as well as an associated method.

Description

[Technical field]

[0001] The present invention relates to a liquid filter device that includes a housing, an interior portion within the housing, a cartridge assembly (alternatively known as a "filter cartridge") contained within the housing, and a vent, an electrostatic discharge mechanism, or both a vent and an electrostatic discharge mechanism that allows gaseous fluid to escape from the interior of the housing to the exterior of the housing. [Background technology]

[0002] Liquid filtration systems allow for the preparation and control of the flow of purified liquids, e.g., high purity liquids. These systems have a wide range of applications in the chemical processing and manufacturing industries, e.g., pharmaceutical, food processing and packaging, industrial and commercial chemicals and chemical products, and processing of liquids used in semiconductor and microelectronic processing. In the case of semiconductor and microelectronic processing, liquid filtration systems are used to filter liquids used in the manufacture of solar panels, flat panel displays, and semiconductor and microelectronic devices. The liquids may be used in processes such as photolithography, bulk chemical transport, chemical mechanical processing (CMP), wet etching, or cleaning, among other types of processing.

[0003] Various designs of filter assemblies used in the treatment (filtration) of liquids include a multi-piece filter housing that defines an interior that contains a filtration membrane that removes impurities from a liquid as the liquid passes through the membrane. In use, the liquid is flowed through the interior in a flow path that includes flow through the filtration membrane. The filtration membrane is a component of a replaceable filter cartridge (i.e., a "cartridge assembly") that can be removed from the housing and replaced after a period of use.

[0004] The housing of such filter devices typically includes two main external structures: a manifold and a bowl. The manifold includes a fluid inlet through which fluid enters the filter housing (unfiltered liquid) and a fluid outlet through which fluid exits the filter device after passing through the filtration membrane (filtrate). Between the inlet and outlet, the fluid must pass through a porous filtration membrane. The filtration membrane is supported by a replaceable filter cartridge housed in the housing. The bowl includes an open end that engages the manifold to form a fluid-tight seal between the manifold and the bowl.

[0005] A standard installation for this type of filter device is with a manifold connected to an input conduit and an output conduit. The input conduit is connected to a manifold inlet, which directs the incoming flow of unfiltered liquid into the housing. The output conduit is connected to a manifold outlet to receive the flow of fluid (i.e., "filtrate") that exits the assembly through the manifold output after passing through the filtration membrane.

[0006] The standard installation configuration of such a filter housing assembly is designed to be mounted with the bowl extending vertically downward below the manifold. This configuration is often referred to as the standard configuration or the "bowl down" configuration. When mounted in this manner, since the manifold rests above the housing bowl, a vent port may be included in the manifold and may be selectively opened to vent air or other gases that accumulate within the filter device at the upper portion of the housing to the outside. During start-up or use, when filtering liquid fluid, the exemplary filter assembly may accumulate a large amount of gas (e.g., air) in the internal space of the filter cartridge, for example, in the internal core volume located in the central channel of the filter cartridge contained within the housing. This gas may be removed using the vent.

[0007] In certain applications, for example when these filter devices are used by semiconductor manufacturers, a more preferred installation configuration may be an inverted "bowl up" configuration in which the cartridge assembly and the bowl of the housing are located above the manifold. Although the bowl up configuration has advantages, there are also challenges that arise from the different orientation. The bowl up orientation allows the piping (inlet and outlet conduits) that connect to the manifold to be located at the lower portion or bottom of the filter device, below the bowl and filter cartridge, in line with the manifold. This configuration may be preferred as it positions the bowl and cartridge assembly in a more accessible position above the manifold and also allows for more efficient drainage of the filter during the filter replacement step.

[0008] However, in the bowl-up orientation, the vent hole is located at the bottom of the filter assembly, so the through-manifold vent mechanism is inoperative and gaseous fluids that accumulate within the housing, for example within the interior space of the filter cartridge (i.e., the "cartridge core volume" or "core volume" for short), can accumulate at the top of the filter assembly, i.e., the top of the bowl.

[0009] The venting mechanism of a liquid filtration device can be important for at least two major reasons. One reason is to prevent the presence of gas pockets within the filter housing during use, which could reduce the performance of the filtration device. A second (and not entirely unrelated) reason is to prevent the risk of electrostatic discharge.

[0010] Regarding the former, if the interior of the liquid filtration device housing contains pockets of trapped air or another gaseous fluid, liquid passing through the housing will not contact the entire area of ​​the filtration membrane, removing moisture from the membrane, which can be a concern for different types of filtration membranes, such as hydrophobic filtration membranes.

[0011] A second concern is electrostatic discharge. Filter housings, housing structures and components are typically made of chemically resistant polymeric materials that are non-conductive (insulating). If the liquid passing through the filter housing also has low conductivity, significant static electricity can build up within the fluid, the filter housing, or its components or structures. Charge build-up poses a risk of electrostatic discharge. Large amounts of trapped air in the upper regions of the liquid filter device housing can result in turbulence or free fall of the liquid flowing through the filter housing, which can lead to static electricity build-up within the liquid, filter device, structure, or housing.

[0012] More specifically, static charge buildup within a filtration system can occur due to frictional contact between the flow of liquid through the filtration system and surfaces of the filtration system (e.g., tubing, conduits, plumbing, valves, fittings, filter housings, and filter cartridges, etc.). Charge buildup can be increased by uneven flow or turbulence of liquid through the filter housing caused by large amounts of gas within the filter housing, particularly gas in a core volume located within the filter cartridge assembly. The magnitude of charge buildup is affected by factors such as the nature of the housing (e.g., chemical composition), the type and composition of liquid passing through the housing, the velocity of the liquid, the viscosity of the liquid, the conductivity of the liquid, the path to ground, turbulence and shear in the liquid, the presence and location of air in the fluid of the fluid handling system (e.g., filter device), and the size of the contact area between the fluid and the fluid handling components.

[0013] Furthermore, as fluid flows through a fluid handling system, charge may be carried downstream in a phenomenon known as streaming charge, which may result in charge accumulating at a location different from where it originated. A sufficient amount of charge build-up may cause electrostatic discharge in the structure of components of the fluid handling system, for example in a filter device. However, in some cases, the discharge may occur at another location connected to the fluid handling system, such as in processing equipment (e.g., semiconductor manufacturing tools) that is connected to and served by the fluid handling system.

[0014] Semiconductor and microelectronic device substrates are highly susceptible to static electricity. Electrostatic discharge involving semiconductor or microelectronic device substrates can result in damage and destruction of the substrate. For example, circuitry on the substrate may be destroyed, and uncontrolled electrostatic discharge may cause photoactive compounds to be activated before normal exposure to light. In addition, accumulated static electricity may discharge from within the fluid handling system to the external environment, potentially damaging components of the fluid handling system (e.g., tubing or plumbing, fittings, components, vessels, filters, etc.), resulting in damage to the fluid handling system, which may cause leakage, flooding, or reduced performance of fluids in the system. In some environments, discharge may lead to fires, explosions, or safety hazards if the fluids handled by the system are flammable, toxic, or corrosive.

[0015] In some fluid handling systems, to reduce static electricity buildup, certain metallic or conductive components are used to connect the system to earth ground to inhibit static electricity buildup within the system. The use of conventional multiple grounding straps can lead to excessive mechanical noise within the fluid handling system and can result in complex grounding system networks requiring extensive maintenance or a complex system prone to failure.

[0016] It would be desirable to have improved static suppression systems and techniques to improve performance and reduce the risk of potentially damaging electrostatic discharge events in fluid handling systems that include filter devices. Summary of the Invention

[0017] The present disclosure, in certain respects, provides a filtration device that includes an improved venting mechanism, particularly with respect to venting gaseous fluids from an internal core volume within a filter cartridge of a liquid filtration device during use of the device installed in a bowl-up configuration.

[0018] Also, according to certain exemplary embodiments, the liquid filtration device alternatively or additionally includes a static dissipation mechanism, also referred to as an ESD suppression mechanism. The ESD suppression mechanism may be incorporated into the device by constructing any one or more components of the device with a conductive material, for example, a conductive polymer or a conductive fluoropolymer. In the exemplary device, the vent mechanism or other components of the housing can be made of a conductive material, such as a conductive polymer or a hybrid conductive / non-conductive polymer structure. If a conductive structure such as a vent tube is present, it is bonded to the housing and ultimately to earth to suppress the risk of ESD. In some embodiments, a conductive fitting extending through the manifold of the insulating polymer completes the circuit from the electrical path in the filter core to ground (e.g., an electrical connection can be made between the vent tube and ground).

[0019] In one aspect, the invention relates to a liquid filtration device including a bowl including an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end, a manifold capable of sealingly engaging the open end of the bowl, the manifold including a fluid inlet and a fluid outlet, a cartridge assembly disposed therein, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal, a core volume centrally inside the cartridge assembly, a housing volume external to the cartridge assembly between the cartridge assembly and the bowl, and a vent extending through the manifold to a distal portion of the core to fluidly connect the distal portion of the core volume to an exterior of the liquid filtration device.

[0020] In another aspect, the invention relates to a method of filtering a liquid using a liquid filtration device including a housing including a manifold and a bowl, the bowl being mounted vertically above the manifold, the housing including a bowl having an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end, a manifold engaged with the open end of the bowl to form a manifold-to-bowl seal, the manifold including a fluid inlet and a fluid outlet, a cartridge assembly disposed therein, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal, a core volume centrally inside the cartridge assembly, a housing volume external to the cartridge assembly between the cartridge assembly and the bowl, and a vent extending through the manifold to a distal portion of the core volume to fluidly connect the distal portion of the core volume with an exterior of the bowl. The method includes passing liquid through the device by entering the liquid into an inlet, passing the liquid from the inlet through the housing volume, through a filtration membrane to the core volume and then through an outlet, whereby gas accumulates in a distal portion of the core volume, and releasing the gas through a vent.

[0021] In another aspect, a method relates to a method for replacing a cartridge assembly of a liquid filtration device comprising a housing including a manifold and a bowl, the bowl being mounted vertically above the manifold, the housing comprising: a bowl having an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold engaged with the open end of the bowl to form a manifold-to-bowl seal, the manifold having a fluid inlet and a fluid outlet; a cartridge assembly disposed therein, the cartridge assembly comprising a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; a core volume centrally inside the cartridge assembly; a housing volume exterior to the cartridge assembly between the cartridge assembly and the bowl; and a vent extending through the manifold to a distal portion of the core volume to fluidly connect the distal portion of the core volume with an exterior of the housing. The method includes draining the liquid fluid from the liquid filtration device, disassembling the manifold-to-bowl seal, lifting the bowl and cartridge assembly vertically above the manifold to create vertical play between the bowl and manifold and between the cartridge assembly and the manifold, and moving the bowl and cartridge assembly together laterally to create play between the manifold and bowl and between the manifold and the cartridge assembly.

[0022] In yet another aspect, the invention relates to a liquid filtration device including a bowl including an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold capable of sealingly engaging the open end of the bowl, the manifold including a fluid inlet and a fluid outlet; a cartridge assembly disposed therein, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; and an electrostatic discharge suppression mechanism including a conductive polymer capable of conducting charge through a ground circuit to inhibit static electricity buildup within the device. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 illustrates the filter apparatus in a bowl-down configuration. [Diagram 2] FIG. 1 illustrates the filter apparatus in a bowl-up configuration. [Diagram 3] FIG. 1 is a schematic diagram showing a filter apparatus in a bowl-up configuration with a core vent through the distal end of the filter housing. [Figure 4] FIG. 1 is a schematic diagram showing a filter apparatus in a bowl-up configuration with a core vent through the distal end of the filter housing. [Diagram 5] 5 is a cross-sectional view of the example filter device of FIG. 4. [Figure 6] 6 is an enlarged view showing a portion of the filter device of FIG. 5. [Figure 7] FIG. 13 is a detailed view showing a core vent adapted to include an optional electrostatic discharge mechanism. [Figure 8] FIG. 1 is a schematic diagram showing a filter apparatus in a bowl-up configuration with a core vent through the housing manifold. [Figure 9] 9 is a cross-sectional perspective view of the example filter device of FIG. 8. [Figure 10]10 is a semi-exploded cross-sectional view of the filter apparatus of FIG. 9 showing the vent assembly removed from the remaining filter apparatus components. [Figure 11] 9 is an enlarged cross-sectional perspective view showing a portion of the filter device of FIG. 8. [Figure 12] FIG. 12 is a top perspective view of the manifold of the filter device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The drawings are schematic and are not necessarily drawn to scale.

[0025] This disclosure relates to a novel inventive system involving improvements to a liquid filtration device. Without limiting the specific details, this disclosure relates to a liquid filtration device that may be operated in a bowl-up orientation and includes a vent mechanism extending through the bowl that vents a core volume within the interior of the liquid filtration device.

[0026] The present specification also relates to a liquid filtration apparatus that alternatively or additionally incorporates a system for reducing the buildup of static electricity within the liquid filtration apparatus to reduce the risk of electrostatic discharge (ESD) from the filter apparatus or from connected flow control devices or other types of equipment.

[0027] The liquid filtration device as described is of the type that includes a housing (sometimes referred to as a "filter housing") that includes both a manifold and a bowl. The bowl has a structure that includes an open end and a distal end opposite the open end. Between the open end and the distal end, the bowl includes a sidewall structure that also defines an interior of the bowl that is disposed between the open end, the sidewall, and the distal end. The "open" end refers to the end that includes an aperture or opening through which a cartridge assembly can be coupled to position the cartridge assembly within the interior.

[0028] The distal end of the bowl is substantially closed with the exception of one or more vent holes through the distal end. When the liquid filtration device is used in a "bowl up" configuration, the distal end of the bowl may include an opening that allows ventilation between the exterior of the distal end and the core volume. Alternatively or additionally, the distal end of the bowl may include an opening that allows ventilation between the exterior of the distal end and the housing volume.

[0029] The housing also includes a manifold that faces and engages the open end of the bowl to form a fluid-tight seal therebetween, which may include a threaded engagement, a gasket, a clamp, or any other mechanical fastening engagement that provides a fluid-tight seal between the manifold and the open end of the bowl, referred to as a "manifold-to-bowl seal."

[0030] When engaged with the open end of the bowl, the manifold covers the open end of the bowl, plugging and closing the opening and covering the interior of the bowl. The bowl communicates with the exterior space through openings or passages in the manifold in the form of inlets and outlets, each of which is part of the manifold structure. The manifold inlets allow fluid (unfiltered liquid) to flow from an external source through the manifold into the interior space of the housing, which may be either the core volume of the filter cartridge or the housing volume. The manifold also includes outlets, which are passages through the manifold that allow liquid to exit the housing, either from the core volume to a location outside the housing, or from the open space to a location outside the housing.

[0031] The housing interior is configured to receive a cartridge assembly containing a porous filtration membrane through which unfiltered liquid entering the housing through the inlet must pass as it passes through the filtration device.

[0032] A cartridge assembly may be any structure that supports a filtration membrane for use within a filter housing of a liquid filtration device. Often, and typically, a cartridge assembly contains an annular, typically cylindrical, support structure that includes opposing ends, including a proximal end (or "cartridge assembly proximal end") and a distal end (or "cartridge assembly distal end"). The filtration membrane is held and supported by the support structure and is sealed between the two opposing ends and sealed in a position such that when the cartridge assembly is installed within an assembled housing, liquid entering the housing through the housing inlet must pass through the filtration membrane such that the liquid substantially passes through the housing outlet.

[0033] The cartridge assembly can be considered to include an axis (e.g., a central axis) that extends along the length of the cartridge assembly along a central or central location between the two opposing ends. The cartridge assembly also defines an open space in the central interior of the annular or cylindrical cartridge assembly facing the core side of the filtration membrane. The open space extends between the two opposing ends of the cartridge assembly and includes the central axis. This open space is called the "core volume" of the cartridge assembly, and is located on one side of the filtration membrane (the inner, central, or "core" side) and extends between the core side of the filtration membrane and either the housing inlet or the housing outlet (commonly, the housing outlet).

[0034] The cartridge assembly includes a second side, or housing side, opposite the core side, that faces the housing bowl when the cartridge assembly is installed in the assembled filter housing. The cartridge assembly and housing define a second open space within the annular cartridge assembly, which is referred to as the "housing volume" and is located between the inner surface of the housing bowl, the housing side of the cartridge assembly, and the housing side of the filtration membrane. The housing volume extends between the housing side of the filtration membrane, the inner surface of the housing bowl, and one of the housing inlet or housing outlet (typically the inlet).

[0035] The cartridge assembly proximal end is configured to engage the manifold and create a fluid-tight seal between the manifold and the cartridge assembly proximal end, i.e., a “cartridge assembly-to-manifold seal.” The cartridge assembly-to-manifold seal provides a fluid-tight flow path between the core volume and the manifold, allowing liquid to flow between the core volume and the manifold and through either the housing inlet or the housing outlet.

[0036] The cartridge assembly-to-manifold seal can be of any useful design that provides a sealed flow path between the manifold and the cartridge assembly proximal end. Examples include threaded engagement, snap-fit ​​engagement, and press engagement.

[0037] To facilitate removal of the cartridge assembly from the manifold during a cartridge assembly replacement step, a preferred engagement between the cartridge assembly proximal end and the manifold that forms the cartridge assembly-to-manifold seal may be a sealing engagement that is a press-fit engagement. With this type of engagement, the cartridge assembly-to-manifold seal can be formed by pressing a surface of the cartridge assembly proximal end into contact with a surface of the manifold and moving the cartridge assembly along a central axis toward the manifold, e.g., exclusively along the axial direction, without rotating the cartridge assembly relative to the central axis. Generally, the cartridge assembly proximal end includes a cylindrical outwardly facing surface that is aligned with and extends along the central axis of the cartridge assembly. The manifold includes an opening that defines a facing surface adapted to engage the cylindrical surface of the cartridge assembly proximal end. One or more gaskets, e.g., an "O-ring" type gasket, are disposed between the facing surface of the manifold and the proximal end to form a liquid-tight seal.

[0038] The sealing engagement can be made by forcing the proximal end into the opening of the manifold to align the two opposing surfaces with one or more gaskets contacting both of the opposing surfaces. If the housing is installed in a bowl-up configuration, this involves forcing the cartridge assembly in a vertically downward direction along the central axis of the cartridge assembly toward the top surface of the manifold. The sealing engagement can be broken by pulling a surface of the cartridge assembly proximal end away from the surface of the manifold. If the housing is installed in a bowl-up configuration, this involves lifting the cartridge assembly in a vertically upward direction along the central axis of the cartridge assembly away from the top surface of the manifold.

[0039] Examples of useful preferred housing designs include venting mechanisms that allow for the venting (removal) of gaseous fluids from a location within the core volume of the filter cartridge to a location outside the housing. During use of a liquid filtration device, such as described in the bowl-up configuration, where the flow of liquid is from the housing volume (connected to the housing inlet) to the core volume (connected to the housing outlet) through the filtration membrane, air or other gaseous fluids may collect in the upper portion of the core volume, which is also the "distal portion" of the core volume. The "upper portion" refers to the upper quarter, third, or half of the core volume when the housing is installed in the bowl-up configuration, which is also the portion of the core volume located away from the manifold at the distal end of the housing. Consistently, the "distal portion" refers to the quarter, third, or half of the core volume located at the distal end of the core, which is the end located proximal to the distal end of the bowl and away from the open end of the bowl.

[0040] According to the exemplary housing structure as described, the housing, in conjunction with the cartridge assembly, includes a venting mechanism that allows fluid communication between the core volume, e.g., an upper portion (distal portion) of the core volume, and the exterior of the housing to allow removal of gaseous fluids from the core volume that may accumulate in the core volume during use of the liquid filtration device.

[0041] The venting mechanism may include any structure that provides fluid communication between the core volume and the housing exterior. Examples include tubes, conduits, channels, or other passages that extend between the core volume and the housing exterior and can be used to allow gas to flow from the core volume and exit the core volume to an external location. The venting structure may be in the form of a single integral part, or an assembly of two or more parts that together form a continuous fluid flow path between the core volume and the housing exterior. The venting structure may be independent and separable from the structure of the housing (e.g., the manifold and bowl) and from the cartridge assembly. Alternatively, the venting structure may be part of the housing bowl, housing manifold, or cartridge assembly, and may be attached thereto during use and remain with one of these different structures during the step of replacing the cartridge assembly.

[0042] The core venting mechanism may be located at the proximal end of the housing and integrated into the housing manifold, or at the distal end of the housing and integrated into the distal end of the housing bowl. Optionally, as part of the latter configuration, the device as described may include a fluid-tight seal between the inner surface of the housing bowl and the cartridge assembly, which seal is referred to as the "cartridge assembly-to-bowl seal."

[0043] The cartridge assembly-to-bowl seal can be of any useful design that provides a fluid-tight passage between the inner surface of the bowl and the cartridge assembly distal end. Examples include opposing threaded engagements, snap-fit ​​engagements, and press-fit engagements. One example of a useful engagement between the cartridge assembly distal end and the inner surface of the bowl that forms the cartridge assembly-to-bowl seal is a sealing engagement, which is a press-fit engagement as described herein used to form the cartridge assembly-to-bowl seal. This type of engagement can be used to form the cartridge assembly-to-bowl seal by pressing a surface of the cartridge assembly distal end into contact with the inner surface of the bowl and moving the cartridge assembly along the central axis toward the distal end of the bowl. In general, the cartridge assembly distal end may include a cylindrical outwardly facing surface aligned with and extending along the central axis of the cartridge assembly. The inner surface of the bowl includes an opening that defines a facing surface adapted to engage the cylindrical surface of the cartridge assembly distal end. One or more gaskets, for example "O-ring" type gaskets, are disposed between the opposing surfaces and the distal end of the bowl to form a fluid-tight seal between the two opposing surfaces.

[0044] The sealing engagement can be made by forcing the distal end into the opening to align with the opposing surfaces and moving the cartridge assembly along the central axis toward the distal end of the bowl housing, contacting the gasket or gaskets with both of the opposing surfaces. The sealing engagement can be broken by pulling the cartridge assembly distal end surface away from the surface of the bowl and moving the cartridge assembly along the central axis away from the distal end of the bowl.

[0045] Instead of or in addition to the core vent mechanism, the exemplary liquid filtration apparatus may include an ESD suppression mechanism, which is a structure that suppresses the buildup of static electricity within the housing and its components to suppress the risk of charge accumulation that would be sufficient to result in an electrostatic discharge to earth. According to specific (non-exclusive) examples of these mechanisms, the ESD suppression mechanism may be included as part of the vent mechanism, for example the core vent mechanism. Thus, the ESD suppression mechanism may be located in the upper portion of the core volume in a location where gas may accumulate, a location where static electricity may be generated.

[0046] In many cases, depending on the anticipated use of the liquid filtration device, the structure of the device (e.g., bowl, manifold, cartridge assembly components, adjacent valves and flow conduits, etc.) are made of inert polymers that are particularly resistant to chemical degradation such as oxidation or corrosion. To meet the corrosion resistance and purity requirements for such applications, the components of the liquid filtration device, such as tubing, fittings, valves, conduits, housings, cartridge assemblies, and other items, are made from inert polymers. Examples of useful inert polymers include fluoropolymers such as tetrafluoroethylene polymer (PTFE), perfluoroalkoxyalkane polymer (PFA), ethylene tetrafluoroethylene polymer (ETFE), ethylene tetrafluoroethylene hexafluoropropylene polymer (EFEP), and fluorinated ethylene propylene polymer (FEP). In addition to providing a noncorrosive and inert construction, many fluoropolymers, such as PFA, are injection moldable and extrudable. Depending on the application, other polymers such as PP and HDPE may also be useful. Several types of connector fittings are available and known, such as PRIMELOCK® fittings, PILLAR® fittings, flare fittings, and other fittings made from such polymers. Exemplary fittings are illustrated, for example, in U.S. Patent Nos. 5,154,453, 6,409,222, 6,412,832, 6,601,879, 6,758,104, and 6,776,440. However, these types of inert polymers generally exhibit low electrical conductivity or are insulating, making the materials and components made therefrom susceptible to static electricity build-up. Thus, as described, the filter housings herein can include ESD suppression features.

[0047] An ESD suppression feature is a structure or portion of a structure of a housing (including a cartridge assembly) as described that prevents or minimizes the build-up of static electricity in a fluid or within the housing, or removes or dissipates generated or built-up charge from the structure of the housing. An ESD suppression feature can include a conductive element of the structure of the housing, such as a conductive component of the vent mechanism (e.g., a vent conduit or portion thereof), a conductive component of the housing bowl, a conductive component of the housing manifold, a conductive component of the cartridge assembly, etc.

[0048] The conductive components may be made of materials that are consistent with other materials of the housing, e.g., may be inert. Examples include conductive polymers, particularly conductive fluoropolymers. Conductive fluoropolymers may be based on non-conductive fluoropolymers that are formulated to include a conductive material that makes the fluoropolymer sufficiently conductive to be effective as part of an ESD mechanism. Examples of such fluoropolymers include perfluoroalkoxyalkane polymers (PFA), ethylene tetrafluoroethylene polymers (ETFE), ethylene tetrafluoroethylene hexafluoropropylene polymers (EFEP), fluorinated ethylene propylene polymers (FEP), tetrafluoroethylene polymers (PTFE), as well as other suitable polymeric materials. Exemplary conductive fluoropolymers include PFA that is combined with ("carries") a conductive material (e.g., a carried PFA). The carried PFA includes, but is not limited to, PFA carrying carbon fibers, nickel coated graphite, carbon fibers, carbon powder, carbon nanotubes, metal particles, and steel fibers. In various embodiments, the conductive components of the ESD suppression mechanism have a molecular weight of about 1×10 6 Materials that can have electrical resistivities at levels below Ω-m and are considered non-conductive are approximately 1×10 6 In a particular embodiment, the conductive components of the ESD suppression mechanism have a resistivity level of about 1×10 6 Materials that have a low efficiency below Ωm and are considered non-conductive have a low efficiency of about 1×10 6It has a resistivity level in excess of Ωm.

[0049] Referring now to the drawings, Figure 1 shows a liquid filtration apparatus 10 installed in a bowl-down configuration and which may include or be adapted to include one or more features as described herein, such as a venting feature as described, an ESD suppression feature as described, or both. The assembly 10 includes a housing, which includes a housing manifold 22 and a housing bowl 18. The housing bowl 18 includes a distal end 20 located at the bottom or lower end of the assembly 10 as shown, and an open end 17 located at the top of the bowl 18 (for a "bowl-down" orientation) as shown and engaged with the manifold 22. The bowl 18 is removably attached to the manifold 22 at a manifold-to-bowl seal 26, which may be a threaded engagement or another type of liquid-tight sealing engagement.

[0050] The assembled housing includes an interior in which the cartridge assembly 21 is retained. A liquid to be filtered ("unfiltered liquid") is caused to follow a flow path that includes entering the assembly 10 at inlet 14, passing through inlet 14 of manifold 22, then through a filtration membrane (not shown) supported by the cartridge assembly 21, and then exiting the assembly 10 at outlet 16 (see arrows showing an exemplary flow path of the liquid through the assembly 10). With respect to the cartridge assembly 21 and bowl 18, the interior of the housing includes a core volume 13 on the core side of the cartridge assembly 21 and its filtration membrane, and a housing volume 19 on the housing side of the cartridge assembly 21 and its associated filtration membrane. One or more vents can provide a path for a fluid (such as a gas) to be vented from the interior of the assembly on either side of the filtration membrane (e.g., on the housing space side of the membrane or the core volume side of the membrane) before or after passing through the filtration membrane. As shown in FIG. 1, the housing vent 12 is located at the distal end 20 of the bowl 18, and a core vent 24 is included as part of the manifold 22. The housing vent 12 allows fluid communication between the housing volume 19 and a location outside the housing. The core vent 24 allows fluid communication between the core volume 13 and a location outside the housing.

[0051] Although not specifically shown, the assembly 10 of FIG. 1 may include features herein, such as an ESD suppression device. The ESD suppression device may include a conductive component of the housing that is part of a static-reduction electrical circuit that extends from the housing to ground. The conductive component may be any one or more of the housing bowl, cartridge assembly, manifold, or associated valves, connectors, or fittings, made in whole or in part of a conductive polymer, for example a conductive fluoropolymer.

[0052] 2 illustrates an alternative bowl-up configuration of liquid filtration device 10. As illustrated, device 10 has substantially the same features as filter device 10 of FIG. 1 in a bowl-down configuration, but is vertically inverted such that bowl housing 18 is positioned above manifold 18 and distal end 20 of bowl 18 is positioned above open end 17 of bowl 18.

[0053] 2 presents challenges. For example, although not shown, during the use of the assembly to filter liquid, a large amount of gas phase (e.g., air) may accumulate in the upper portion of core volume 13. Such a large amount of accumulated gas in core volume 13 cannot be removed from assembly 10 through either vent 20 or vent 24.

[0054] Alternatively or additionally, during use of assembly 10 to filter liquids passing through assembly 10, core assembly 13, bowl housing 18, or both may build up static electricity, especially if a large amount of gas (e.g., air) accumulates in the upper portion of core volume 13. Therefore, it would be beneficial to improve the ventilation of filter apparatus 10, especially the core volume therein, when oriented in a bowl-up configuration. Improved electrostatic discharge (ESD) suppression as charge builds up during liquid filtration would also be beneficial in filter apparatus such as filter apparatus 10 of FIG. 2.

[0055] Shown in Figure 3 is an example of a liquid filtration device (30) including a vent mechanism as described herein. Filter device 30 includes a housing 41 including a bowl 42 and a manifold 48. Housing 41 includes a core vent 34 and a housing vent 44 at a distal (top) end of bowl 42. In the assembled state as shown, manifold 48 engages an open (bottom) end of housing bowl 42 at a manifold-to-bowl seal 60. Manifold-to-bowl seal 60 can be a fluid-tight seal, such as a threaded connection, a snap-fit ​​connection, a bayonet-style twist-lock connection, or any other suitable fluid-tight sealing connection.

[0056] Manifold 48 includes passageways, including a fluid inlet 82 and a fluid outlet 84, that connect device 30 to fluid input and output conduits (neither shown). Liquid 80 flows through inlet 82 into housing volume 77, then through filtration membrane 54 supported by cartridge assembly 56, and into core volume 83. As unfiltered liquid 80 passes through filtration membrane 54, contaminants in the unfiltered liquid are removed and retained by filtration membrane 54 to produce permeate 81 having reduced levels of contaminants. Permeate 81 exits core volume 83 and flows out of assembly 30 by passing through outlet 84.

[0057] Housing bowl 42 includes a core vent 34 at a distal end of housing bowl 42 (the top end when in the bowl-up configuration as shown). Core vent 34 includes a tube, conduit, channel, or other flow path that connects core volume 83 with a location external to assembly 30. Additionally, and optionally, housing bowl 42 also includes a housing vent 44, also located at the distal (top) end of bowl 42, that provides fluid communication between housing volume 77 and a location external to assembly 30.

[0058] Optionally, but not specifically shown, the assembly 30 may include an ESD suppression feature, such as a conductive polymer located in one or more of the structures of the assembly 30 that connects the interior of the assembly 30 to earth ground. An example ESD suppression feature may be a structure of the assembly 30 that includes a conductive polymer. For example, any one or more of the housing bowl 42, the core vent 34, the housing vent 44, and the cartridge assembly 56 may be made in whole or in part of a conductive polymer.

[0059] A second example of a liquid filtration device (32) as described, including a top-mounted core vent, is illustrated in FIG. 4. The assembly 32 of FIG. 4 includes structure and functionality comparable to device 30, but replaces the shorter core vent 34 of assembly 30 with a longer core vent 36 of assembly 32. The core vent 36 extends from an external location into the core volume 83 through the distal end of the housing 42 to a lower portion of the core volume 83. The core vent 36 includes a lower end located in the lower portion of the core volume 83 and has an opening at that end. Although not specifically illustrated, there may be one or more additional openings along the length of the core vent 36, including one or more openings that may be located in an upper portion of the core volume 83. An optional, and possibly preferred, feature of the core vent 36, not specifically illustrated, is an ESD suppression feature as described.

[0060] Assemblies 30 and 32 each illustrate a liquid filtration device that includes a core vent (34 and 36, respectively) that allows for venting of core volume 83 through a flow path, and a conduit that is generally aligned with the central axis of cartridge assembly 56 extending from an external location to either the upper portion of core volume 83 (assembly 30) or the lower portion of core volume 83 (assembly 32) when the assembly is in a bowl-up configuration.

[0061] 3 and 4, assembly 30 or 32 receives unfiltered liquid 80 that enters housing 41 through inlet 82. As unfiltered liquid 80 is received, the liquid flows and is distributed within housing volume 77 between cartridge assembly 56 and the interior of bowl 42. Filtration membrane 54 of filter cartridge 56 is in the fluid flow path between inlet 82 and outlet 84, such that fluid entering inlet 83 is filtered before exiting assembly 30 through outlet 84.

[0062] As indicated by the arrows, unfiltered liquid 80 flows through the filtration membrane 54 supported by the filter cartridge 56, whereby various contaminants, particles, or impurities present in the unfiltered liquid may be removed from the unfiltered liquid by mechanical or chemical mechanisms of the filtration membrane (e.g., pores, reactive functional groups, adsorption onto the membrane surface). Filtered fluid (known as the "permeate") 81 may exit the housing 41 from the core volume 83 through an outlet 84. Various pumps, valves, flow controllers, conduits, and the like may be effective to cause the desired amount and rate of fluid to flow through the assembly.

[0063] In use, a less dense fluid phase, such as gas, can be separated from the liquid phase (80, 81) passing through the assembly 30 or 32 before or after the liquid passes through the filtration membrane 54. The fluid 80 is in liquid phase upon entering the housing volume 77, but may contain gas bubbles or dissolved gas. Bubbles from dissolved gas may be formed, for example, by a pressure drop in the fluid during filtration. Gas may form and accumulate in the valve core gas pocket 46 in the upper portion of the housing volume 77. In addition, a core-side gas pocket 58 may form and accumulate in the gas-side space 83 in the upper portion of the gas-side space 83. The gas phase is less dense than the liquid phase of the liquid 80, 81 and accumulates above the liquid from which it was separated.

[0064] Housing gas pockets 46 located in the upper portion of housing volume 77 can be vented to the exterior of housing 41 via housing vent 44 as gas 88. Gas in pockets 58 located in the upper portion of gas side space 83 can be vented to an exterior location as gas 86 through core vent 34 (FIG. 3) or through vent 36 (FIG. 4). By providing vents on both the housing space side 77 and the core volume side 83 of filtration membrane 54, beneficially, substantially all of the gas accumulated within device 30 can be vented to an exterior location.

[0065] 3 and 4 , at the distal (top) end of bowl 42 of assembly 30, a sealed headspace 76 is defined in part by the inner surface of bowl 42, such as by a partition 74 as shown. Partition 74 separates a housing volume 77 from sealed headspace 76, which contains vent holes 34 or 36. Sealed headspace 76 may also be defined in part by a surface of the distal end of cartridge assembly 56 that contacts a surface of partition 74 when the cartridge assembly is installed within housing bowl 42.

[0066] Headspace 76 can be shaped and positioned at a location above cartridge assembly 56 and can provide a fluid-tight space at the distal end of the housing bowl between the distal end of filter cartridge 56 and the inner surface of the housing bowl. As shown in Figures 3 and 4, vents 34 and 36, respectively, are sealed from headspace 76 while passing through headspace 76. In other exemplary embodiments, vents 34 or 36 can be in fluid communication with headspace 76.

[0067] The cartridge assembly distal end may be mated with partition 74 by any useful manner that forms a fluid-tight cartridge assembly-to-bowl seal. The engagement may be, for example, a threaded engagement, a press-fit engagement, a snap-fit ​​engagement, or the like.

[0068] 5, 6, and 7 are views of the example assembly 32 of FIG. 4, using like numbering designations for like features and structures, and adding detail, particularly with respect to the cartridge assembly-to-bowl seal, the cartridge assembly manifold seal, and the ESD suppression features.

[0069] 5-7 show the assembly 32 including a core vent 36 that extends to the lower (proximal) portion of the core volume 83, i.e., the half, third, or quarter portion of the core volume 83 closest to the manifold 48. The vent 36 can be any structure along which fluid travels from the core volume 83 to an external location. The vent 36 can be a hollow tube or a slotted tube (see FIG. 7) that serves as a conduit for venting, as well as an ESD suppression mechanism. The vent 36 can be configured to provide venting of the core volume 83 to an external location, as described herein. As one optional vent 36, a vent (slotted) probe 96 as shown in FIG. 7 may be used (see discussion of FIG. 7 below). Alternatively, the vent 36 can be a hollow tube or pipe that includes one or more apertures or holes along the length of the vent 36, thereby venting various depths of the core volume 83, including the upper portion. Either type of vent structure may be made partially or entirely from a conductive polymer, for example a conductive fluoropolymer, to create an ESD suppression technology.

[0070] Figures 5 and 6 show in greater detail the filter apparatus 32 of Figure 4. In particular, these figures show examples of press-fit type seals used for the cartridge assembly-to-bowl seal 72 and the cartridge assembly-to-manifold seal 64, respectively.

[0071] Cartridge assembly-to-bowl seal 72 is shown as a seal between a cylindrical surface at the distal end of cartridge assembly 56 and the opposing inner cylindrical surface of housing bowl 42 that sits on the inner cylindrical surface of partition 74. When these two opposing surfaces are engaged, there are two "O-ring" type gaskets 71 and 71 between them that provide a fluid-tight seal between the surfaces. This cartridge assembly-to-bowl seal also fluid-tightly seals sealed headspace 76 from housing volume 77.

[0072] The cartridge assembly-to-manifold seal (64) is shown as a seal between a cylindrical surface at the proximal end of the cartridge assembly 56 and the opposing inner cylindrical surface of the manifold 48 that is part of the partition 65. When these two opposing surfaces are engaged, there are two "O-ring" type gaskets 66 and 66 between them.

[0073] As shown, the assembly 32 also includes a core vent upper fixture 38 that includes screws 40 for mounting to a distal end or portion of a bowl 42. The fixture 38 can be screwed to secure the core vent 36 of the assembly 32 to the distal end of the bowl 42 and can provide a sealed attachment to the distal end of the bowl 42. The fixture 38 connection to the bowl 42 and vent 36 can be part of an ESD suppression mechanism, such as by serving as part of a circuit between an ESD mechanism located at the vent 36 and ground (not shown).

[0074] Also shown are example details regarding manifold-to-bowl seal 60. For example, as shown in Figures 5 and 6, manifold 48 is provided with external threads 62 of manifold-to-bowl seal 60, and a fitting 61 is shown that threads onto manifold threads 62 to securely attach bowl 42 to manifold 48. Operation of threaded fitting 61 places housing volume 77 in fluid communication with inlet 84 and core volume 83 in communication with outlet 84 when cartridge assembly 56 and bowl 42 are tightened against manifold 48.

[0075] The cartridge assembly 56 and its filtration membrane 54 may include structures generally known in the filtration arts, including filtration membranes as described herein, that are particularly useful for filtering fluids and liquids used in semiconductor and microelectronic device processing.

[0076] A lower core vent 50 between the outlet 84 of the manifold 48 and an external location may optionally be provided on the manifold 48. Since the assembly 32 is preferably mounted in a bowl-up configuration, the vent 50 may be provided as a drain or high pressure fluid release valve and is optional.

[0077] FIG. 7 illustrates an exemplary vent (e.g., vent 36) in one embodiment as a slotted core vent or probe 94 with a vent slot 96 and a probe body 98. As illustrated, the probe 94 is not hollow, but other embodiments can implement hollow tubular probes or other vents 36. A ring 100 is also provided on the probe 94. The probe 94 can be conductive to provide ESD suppression as described herein. The probe 94 can optionally remain associated with the bowl 42 and not be removed or replaced with the cartridge assembly 56. The probe 94 is one example of a vent 36, but only represents a non-existent example of a vent 36. The vent 36 can be substantially tubular, hollow, perforated, or otherwise shaped to allow for venting of the core volume when installed as part of a liquid filtration device.

[0078] Some of the embodiments described with reference to Figures 3-7 may require a dedicated or modified version for the housing bowl 42 relative to many current filtration products. Additionally, the design of the cartridge assembly 56 may also require modifications to current filtration products to interface and function with the modified housing bowl and accommodate the core venting mechanism. Accordingly, as described below, various alternative embodiments are described with reference to Figures 8-12 that may be useful with existing (e.g., currently commercially available) housing bowl products, or other existing portions of currently commercially available filter device designs, and add a core venting mechanism as described.

[0079] 8-12, an alternative set of embodiments of filter device 102 are illustrated and described in accordance with the present disclosure. A difference between assemblies 30 and 32 is that core vent 110 extends downward from core volume 83 to manifold 106 instead of extending upward to the distal end of housing bowl 127. As a result, device 102 can include a more conventional housing bowl 127 (based on many current commercially available designs) that does not include a core vent aperture and does not require an inner surface configured to contact and create a seal with the distal end of cartridge assembly 56.

[0080] With the assembly 102, the core vent 110 is positioned through the manifold 106 and may include ESD suppression features as described herein. For example, a conductive striped perfluoroalkoxy (PFA) vent tube 110 assembly may be included as a component of the cartridge assembly 56. The assembly 102 thus allows for venting of the core volume 83, particularly in the upper portion of the core volume 83, for example, to remove gas from the gas pocket 58 shown in FIG. 8. In an exemplary embodiment, the core vent 110 may be engaged with and secured as part of the cartridge assembly 56. In such an embodiment, the core vent 110 is considered a component of the cartridge assembly 56.

[0081] Desirably, the cartridge assembly 56 includes as a component thereof a core vent 110 which may engage the manifold 106 in a press-fit engagement to form a cartridge assembly-to-manifold seal as described herein. In this engagement, an upper elongated portion of the vent 110 extends vertically within the core volume 83. A lower portion of the vent 110 is connected to a proximal end of the cartridge assembly 56 which engages an opening in the manifold 106 to form a press-fit cartridge assembly-to-manifold seal. The bowl 127 may be a conventional (based on current commercially available products) filter bowl according to various industrial applications and may include a housing vent 44 as described above, but contact with the distal end of the cartridge assembly 56 is not required and may preferably be avoided.

[0082] 9, 10, and 11, the assembly 102 is shown in a cutaway side perspective view, but may be installed and used in a bowl-up configuration. FIG. 9 shows a horizontal cross-sectional perspective view of the assembly 102 in an assembled state. FIG. 10 shows an exploded view of the horizontal cross-sectional perspective view of the assembly 102 of FIG. 9, with the vent 104 separated from the cartridge assembly 56. FIG. 11 shows a horizontal cross-sectional perspective view of the assembly 102 of FIG. 9, but additionally includes a cutaway cross-sectional view of the adapter 128 installed within the manifold 106.

[0083] As shown, assembly 102 of Figures 9, 10, 11, and 12 includes features corresponding to assembly 102 of Figure 8, including bowl housing 127, manifold 106, and cartridge assembly 56. Additional exemplary details of these features are shown in Figures 9, 10, 11, and 12.

[0084] 9 and 10 (which show the vent assembly 104 separated from other components for illustrative purposes), the vent assembly 104 includes an elongated core vent 110 adapted to fit within the core volume 83. At the proximal end of the core vent 110 is an adapter 128 that is configured to fit within the space (90) of the manifold 106 during use. The vent assembly 104 may be fixedly secured in position relative to the cartridge assembly 56 and may be considered a component of the cartridge assembly 56.

[0085] The adapter 128 is engaged with the proximal end of the core vent 110 at the tube head adapter 108 (see FIG. 11). As shown with reference to FIG. 11, a conductive connection can be provided between the manifold 106, adapter 128, and vent tube 110 via an extended surface 112 that extends inwardly from a (cylindrical or annular) collar of the coupler 130. The extended surface 112 can be included as an interference fit, snap fit, or other structure that creates a secure connection between the coupler 130 of the adapter 128 and the proximal end of the vent tube 110. The secure connection allows for reliable contact for electrical and ESD conductivity.

[0086] Vent tube 110 provides a passageway between an upper (distal) portion of core volume 83 and manifold 106, thereby allowing core volume 83 to be vented to an external location by core vent orifices 116 on manifold 106. As shown in Figures 9 and 10, manifold 106 can also optionally include housing vents 124 in communication with housing volume 77, thereby allowing fluid to be removed from housing volume 77 from the bottom of assembly 102, e.g., liquid fluid to be drained from housing volume 77.

[0087] As shown, the adapter 128 including the coupler 130 (e.g., Entegris CHEMLOCK system) is sized and shaped to fit within a central opening of the manifold 106 located directly below the cartridge assembly 56. In various embodiments, during removal and replacement of the cartridge assembly 56 of the device 102, the vent assembly 104 remains part of the cartridge assembly 56 being replaced. In this regard, the elongated core vent 110 and adapter 128 of the vent assembly 104 are each attached components of the cartridge assembly 56, such that when the assembly 56 is removed from engagement with the manifold 106, the elongated core vent 110 and adapter 128 remain with the assembly. Fasteners 114 are located along the length of the core vent 110 and allow the core vent 110 to be inserted into the core volume 83, connecting the vent assembly 104 to the cartridge assembly 56 for this purpose. The fastener 114 has an opening through the core vent 110 and prongs that function to exert pressure on the interior of the filter core to position and align the core vent 110. In some embodiments, end caps may be placed on the ends of the filter cartridge to provide openings through the core vent 110 to provide positioning and alignment.

[0088] Additionally, assembly 102 as shown includes a vent 136 at the distal end of housing bowl 127. When assembly 102 is installed in a bowl-up configuration, during operation, bowl 127 may accumulate gaseous fluid in upper portion 134 of housing volume 77. Assembly 102 includes vent 136, which optionally includes a valve that may be selectively opened and closed to allow gas that may accumulate in headspace 134 to escape from the interior of the housing.

[0089] 11 and 12, these figures show a variation of the assembly 102 of FIGS. 9 and 10 in which an adapter 128 is included as an integrally molded part of the manifold 106. The manifold 106 and adapter 128 together form a single molded part including a plurality of concentric rings or partitions. The innermost partition 120 includes an opening that engages the proximal end of the vent tube 110. The middle partition 65 is the surface of the manifold 106 that contacts the opposing surface of the proximal end of the cartridge assembly 56 to provide a fluid-tight seal between the manifold 106 and the cartridge assembly 56 as described above, i.e., a surface that is part of the cartridge assembly-to-manifold seal between the cartridge assembly 56 and the manifold 106. Also shown is an "O-ring" 67 between the two opposing surfaces. The manifold 106 also includes an outer wall 122, including any threads 62 as described above that can be part of the bowl-to-manifold seal. A coupling mechanism (coupler) 130 is also shown from a perspective view, with a surface of the vent tube 110 adapted to engage the adapter 128 .

[0090] The liquid filtration device as described can be used in a method of removing undesirable particles, particulates, contaminants, or impurities from a source of unfiltered liquid. The particles or impurities can include inorganic and organic materials, such as dissolved organic compounds, dissolved metals, solid metals, and other solid organic or inorganic materials. The described method is carried out by flowing the unfiltered liquid into the device, for example through an inlet as described, and passing it through a filtration membrane supported within the device by a cartridge assembly. After passing through the filtration membrane, the filtered fluid ("filtrate") can exit the device, for example through an outlet as described. During use of the liquid filtration device as described, if gaseous fluid accumulates in the upper portion of the core volume, a venting mechanism as described can be used to remove that volume of gaseous fluid from the core volume.

[0091] Liquid filtration apparatus as described may be useful for processing various types of fluids for use in different industries. As an example, the apparatus and methods described herein may be useful for preparing purified liquids for use in semiconductor and microelectronic processing, for example, in methods used to manufacture solar panels, flat panel displays, and semiconductor and microelectronic devices. The liquids may be used in processes such as photolithography, bulk chemical transport, chemical mechanical processing (CMP), wet etching, or cleaning, among other types of processing.

[0092] In use, the filtration membrane of the cartridge assembly removes impurities from the flow of liquid passing through the membrane. The filtration membrane has a limited operating life and must be replaced after a certain amount of unfiltered liquid has passed through the filtration membrane. A method of replacing a cartridge assembly and associated filtration membrane in a liquid filtration device installed in a bowl-up configuration may include draining liquid from the housing, including from both the housing volume and the core volume. Once liquid has been drained from both interior spaces, the manifold-to-bowl seal may be disassembled. The bowl may then be separated from the manifold by lifting it vertically away from the manifold.

[0093] In an exemplary method of replacing a cartridge assembly, depending on the type of engagement used to create the cartridge assembly-to-manifold seal, the cartridge assembly may need to remain in place while the bowl is removed, with the cartridge assembly proximal end remaining engaged with the manifold. Depending on these designs, if there is a cartridge assembly-to-bowl seal at the distal end of the cartridge assembly, it must be disassembled before removing the cartridge assembly from the manifold. With the cartridge assembly proximal end remaining engaged with the manifold, the bowl is raised to a height where the open end (bottom end) of the bowl is above the height of the distal end (top end) of the cartridge assembly (engaged with the manifold) and the cartridge assembly is uncovered. The cartridge assembly may then be removed from the manifold by disassembling the cartridge assembly-to-manifold seal at the proximal end of the cartridge assembly. A replacement cartridge assembly may then be engaged with the manifold by engaging the proximal end of the cartridge assembly with the manifold. The bowl may then be reinstalled over the manifold and cartridge assembly.

[0094] In this exemplary method of replacing a filter cartridge in a liquid filtration device, a core vent mechanism at the distal end of the housing bowl as described, such as vent 34 or 36 in Figures 3, 4, 5, or 6, may remain engaged with the bowl during replacement of the cartridge assembly. A core vent as described may remain engaged at the distal end of the bowl during the replacement step and need not be removed and replaced with the cartridge assembly. Alternatively, in other exemplary devices, the vent may be considered part of the cartridge assembly and may be removed from the housing as part of the cartridge assembly and replaced as part of the cartridge assembly.

[0095] In some installed liquid filtration apparatus, a preferred method of replacing the cartridge assembly of a liquid filtration apparatus installed in a bowl-up configuration may desirably eliminate the need to lift the housing bowl to a height of the bowl open end above the height of the cartridge assembly while still keeping the proximal end of the cartridge assembly engaged with the manifold. For example, in certain types of semiconductor and microelectronic device processing systems (e.g., "tools") and their locations of use (clean rooms), the value of space within the tool or room, including the space above the filtration apparatus, is considerable.

[0096] Advantageously, according to the present disclosure, certain examples of liquid filtration devices can be disassembled for the purpose of replacing the cartridge assembly without having to raise the bowl to a height (of the bowl open end) above the height of the cartridge assembly to uncover and expose the cartridge assembly while it remains engaged with the manifold. Specifically, various devices as described include a combination of a manifold and a cartridge assembly proximal end that can be assembled to form a cartridge assembly-to-manifold seal by pressing the cartridge assembly proximal end into contact with a surface of the manifold. See, for example, Figures 5, 9, 10, and 11. The movement of pressing the cartridge assembly toward the manifold to form the seal can be exclusively along the central axis of the cartridge assembly toward the manifold, and the formation of the seal does not require any movement of the cartridge assembly in any other direction, such as any rotation of the cartridge assembly about the central axis of the cartridge assembly. The engagement that creates the seal does not include a threaded engagement, a twist lock engagement, or any other engagement that requires the cartridge assembly to move in any direction other than along the central axis.

[0097] This type of preferred press-fit seal can be disassembled by movement in the opposite direction, which involves exclusively moving the cartridge along the central axis of the cartridge assembly away from the manifold, i.e., upward, as described (and illustrated in detail in Figures 5, 9, 10, and 11). The required distance of movement is limited, and the proximal end of the cartridge assembly need only be lifted a distance above the manifold that provides physical vertical play (space) between the proximal end of the cartridge assembly and the manifold. Once the bowl and cartridge assembly have been lifted to a height that disassembles both the bowl-to-manifold seal and the cartridge assembly-to-manifold seal and provides vertical play both between the bowl and the manifold, and between the proximal end of the cartridge assembly and the manifold, both the bowl and cartridge assembly may be moved laterally away from the space above the manifold, with the cartridge assembly remaining at least partially (or substantially) within the interior space of the bowl. The lateral movement creates lateral play between the manifold and the bowl, and between the manifold and the cartridge assembly.

[0098] When the cartridge assembly and bowl are removed away from the manifold, the cartridge assembly distal end may remain connected to the interior of the distal end of the bowl at a cartridge assembly-to-bowl seal. This seal may be disassembled to allow the cartridge assembly to be removed from the interior space of the bowl. The movement required to disassemble the cartridge assembly-to-bowl seal depends on the type of seal, e.g., threaded, twist lock, or press fit. For example, in the case of a press fit seal, as shown in Figures 5 and 6, the seal may be disassembled exclusively by a movement that pulls the cartridge assembly away from the bowl distal end along the central axis of the cartridge assembly.

[0099] In this exemplary method of replacing a filter cartridge of a liquid filtration device, a vent mechanism as described, such as vent 34 or 36 of Figures 3, 4, 5, or 6, may remain engaged with the bowl during replacement of the cartridge assembly. A vent as described may be engaged and fixed at a location at the distal end of the bowl and need not be removed and replaced with the cartridge assembly. In other embodiments, the vent may be considered part of the cartridge assembly and may be removed from the housing and replaced as part of the cartridge assembly.

[0100] In a first aspect, a liquid filtration device includes a bowl including an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold capable of sealingly engaging the open end of the bowl, the manifold including a fluid inlet and a fluid outlet; a cartridge assembly disposed therein, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; a core volume centrally inside the cartridge assembly; a housing volume external to the cartridge assembly between the cartridge assembly and the bowl; and a vent extending through the manifold to a distal portion of the core volume to fluidly connect the distal portion of the core volume with an exterior of the liquid filtration device.

[0101] In a second aspect according to the first aspect, the cartridge assembly has a central axis extending within the core volume between the cartridge assembly proximal end and the cartridge assembly distal end, and the cartridge assembly-to-manifold seal can be formed by pressing the cartridge assembly proximal end surface into contact with the surface of the manifold and moving the cartridge assembly along the central axis toward the manifold, and the cartridge assembly-to-manifold seal can be disassembled by pulling the cartridge assembly proximal end surface away from the surface of the manifold and moving the cartridge assembly along the central axis away from the surface of the manifold.

[0102] In a third aspect according to the first or second aspects, the cartridge assembly includes a vent assembly including a core vent extending from a proximal end of the cartridge assembly to a distal portion of the core volume.

[0103] In a fourth aspect according to any of the preceding aspects, the fluid inlet communicates with the housing volume and the fluid outlet communicates with the core volume.

[0104] In a fifth aspect according to any preceding aspect, the vent comprises a conduit having a first end and a second end, the first end being located in a distal portion of the core volume and the second end being located outside.

[0105] In a sixth aspect according to any preceding aspect, the vent comprises a conductive material electrically connecting the core volume to earth.

[0106] In a seventh aspect, an apparatus according to any of the above aspects is placed in combination with a semiconductor manufacturing tool to provide filtered fluid flowing from the fluid outlet to the semiconductor manufacturing tool.

[0107] In an eighth aspect, a method of filtering a liquid using a liquid filtration device comprising a housing including a manifold and a bowl, the bowl being mounted vertically above the manifold, the housing comprising a bowl having an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end, a manifold engaged with the open end of the bowl to form a manifold-to-bowl seal, the manifold having a fluid inlet and a fluid outlet, and a cartridge assembly disposed therein, the cartridge assembly having a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end contacting a surface of the manifold to filter the cartridge assembly. the device includes a cartridge assembly including a surface adapted to form a re-manifold seal; a core volume in a central interior of the cartridge assembly; a housing volume outside the cartridge assembly between the cartridge assembly and the bowl; and a vent extending through the manifold to a distal portion of the core volume to fluidly connect the distal portion of the core volume with an exterior of the housing, the method including passing liquid through an inlet, passing the liquid from the inlet through the housing volume, through a filtration membrane to the core volume, and then through an outlet, whereby gas accumulates in the distal portion of the core volume; and releasing the gas through the vent.

[0108] In a ninth aspect according to the eighth aspect, the cartridge assembly has a central axis extending within the core volume between the cartridge assembly proximal end and the cartridge assembly distal end, and the cartridge assembly-to-manifold seal can be formed by pressing the cartridge assembly proximal end surface into contact with the surface of the manifold and moving the cartridge assembly along the central axis toward the manifold, and the cartridge assembly-to-manifold seal can be disassembled by pulling the cartridge assembly proximal end surface away from the surface of the manifold and moving the cartridge assembly along the central axis away from the surface of the manifold.

[0109] In a tenth aspect according to the eighth or ninth aspects, the cartridge assembly includes a vent assembly including a core vent extending from a proximal end of the cartridge assembly to a distal portion of the core volume.

[0110] In an eleventh aspect according to the eighth to tenth aspects, the vent comprises a conduit having a first end and a second end, the first end being located in a distal portion of the core volume and the second end being located outside.

[0111] In a twelfth aspect according to the eighth to eleventh aspects, the vent includes a conductive material that electrically connects the core volume to earth.

[0112] In a thirteenth aspect, there is provided a method of replacing a cartridge assembly of a liquid filtration device comprising a housing including a manifold and a bowl, the bowl being mounted vertically above the manifold, the housing comprising: a bowl having an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold engaged with the open end of the bowl to form a manifold-to-bowl seal, the manifold having a fluid inlet and a fluid outlet; a cartridge assembly disposed therein, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; and a cartridge assembly having a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal. the cartridge assembly having a core volume centrally inside the cartridge assembly, a housing volume external to the cartridge assembly between the cartridge assembly and the housing, and a vent extending through the manifold to a distal portion of the core volume to fluidly connect the distal portion of the core volume with an exterior of the housing, and the method includes draining liquid fluid from the liquid filtration device, disassembling the manifold-to-bowl seal, lifting the bowl and cartridge assembly vertically above the manifold to create vertical play between the bowl and manifold and between the cartridge assembly and the manifold, and moving the bowl and cartridge assembly together laterally to create lateral play between the manifold and bowl and between the manifold and the cartridge assembly.

[0113] In a fourteenth aspect according to the thirteenth aspect, the cartridge assembly has a central axis extending within the core volume between the cartridge assembly proximal end and the cartridge assembly distal end, and the cartridge assembly-to-manifold seal can be formed by pressing the cartridge assembly proximal end surface into contact with the surface of the manifold and moving the cartridge assembly along the central axis toward the manifold, and the cartridge assembly-to-manifold seal can be disassembled by pulling the cartridge assembly proximal end surface away from the surface of the manifold and moving the cartridge assembly along the central axis away from the surface of the manifold, and the method includes disassembling the cartridge assembly-to-manifold seal by lifting the cartridge manifold vertically above the manifold.

[0114] In a fifteenth aspect according to the thirteenth or fourteenth aspects, the cartridge assembly includes a vent assembly including a core vent extending from a proximal end of the cartridge assembly to a distal portion of the core volume.

[0115] In a sixteenth aspect according to any of the thirteenth to fifteenth aspects, the vent comprises a conduit having a first end and a second end, the first end being located in a distal portion of the core volume and the second end being located outside.

[0116] In a seventeenth aspect according to any of the thirteenth to sixteenth aspects, the vent includes a conductive material that electrically connects the core volume to earth.

[0117] In an eighteenth aspect, a liquid filtration device includes a bowl including an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold capable of sealingly engaging the open end of the bowl, the manifold having a fluid inlet and a fluid outlet; a cartridge assembly disposed therein, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; and an electrostatic discharge suppression mechanism including a conductive polymer capable of conducting charge through a ground circuit to inhibit static electricity buildup within the device.

[0118] In a 19th aspect according to the 18th aspect, the cartridge assembly further comprises a core volume in the central interior of the cartridge assembly, a housing volume outside the cartridge assembly between the cartridge assembly and the housing bowl, and a vent extending between the core volume and a position outside the housing, fluidly connecting the core volume with the outside, the vent comprising a conductive polymer that is part of a circuit.

[0119] In a twentieth aspect according to the eighteenth or nineteenth aspects, the vent extends between a distal portion of the core volume and a location exterior to the housing.

[0120] In a twenty-first aspect according to any of the eighteenth to twentieth aspects, the vent extends between a distal portion of the core volume and a location exterior to the housing through a distal end of the bowl.

[0121] In a twenty-second aspect according to any of the eighteenth to twenty-first aspects, the vent extends between a distal portion of the core volume and a location exterior to the housing and through the manifold.

Claims

1. 1. A liquid filtering device comprising: a bowl including an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold capable of sealingly engaging the open end of the bowl, the manifold including a fluid inlet and a fluid outlet; a cartridge assembly disposed within the cartridge assembly, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; a core volume centrally inside said cartridge assembly; a housing volume external to the cartridge assembly and between the cartridge assembly and the bowl; a core vent extending through the manifold to a distal portion of the core volume to fluidly connect the distal portion of the core volume with an exterior of the liquid filtration apparatus; Equipped with A liquid filtration device, wherein the fluid inlet is in communication with the housing volume and the fluid outlet is connected to the core volume.

2. the cartridge assembly having a central axis extending within the core volume between the cartridge assembly proximal end and the cartridge assembly distal end; the cartridge assembly-to-manifold seal may be formed by pressing a cartridge assembly proximal end surface into contact with a surface of the manifold and moving the cartridge assembly along the central axis toward the manifold; the cartridge assembly-to-manifold seal can be disassembled by pulling the cartridge assembly proximal end surface away from the surface of the manifold and moving the cartridge assembly along the central axis away from the surface of the manifold; 2. The apparatus of claim 1.

3. The device of claim 1 or 2, wherein the cartridge assembly includes a vent assembly including the core vent extending from a cartridge assembly proximal end to the distal portion of the core volume.

4. 4. The apparatus of claim 1, wherein the core vent comprises a conduit having a first end and a second end, the first end being located in a distal portion of the core volume and the second end being located externally.

5. 5. The apparatus of claim 1, wherein the core vent comprises a conductive material that electrically connects the core volume to earth.

6. 6. The apparatus of claim 1 in combination with a semiconductor manufacturing tool to provide filtered liquid flowing from the fluid outlet to the semiconductor manufacturing tool.

7. 1. A method of filtering a liquid using a liquid filtering device, comprising: Introduction of liquid into the liquid filtering device, the liquid filtering device comprising a housing including a manifold and a bowl, the bowl being mounted vertically above the manifold, the housing comprising: the bowl having an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold engaged with the open end of the bowl to form a manifold-to-bowl seal, the manifold having a fluid inlet and a fluid outlet; a cartridge assembly disposed within the cartridge assembly, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; a core volume centrally inside said cartridge assembly; a housing volume external to the cartridge assembly and between the cartridge assembly and the bowl; a core vent extending through the manifold to a distal portion of the core volume to fluidly connect the distal portion of the core volume with an exterior of the liquid filtration apparatus, the core vent comprising a conduit having a first end and a second end, the first end being located at the distal portion of the core volume and the second end being located at the exterior; placing a liquid in the liquid filtering device; passing the liquid into the fluid inlet, through the fluid inlet, into the housing volume, through the filtration membrane to the core volume, and then through the fluid outlet, where gas accumulates in the distal portion of the core volume; releasing the gas through the core vent; Including, The method, wherein the fluid inlet is in communication with the housing volume and the fluid outlet is connected to the core volume.

8. the cartridge assembly having a central axis extending within the core volume between the cartridge assembly proximal end and the cartridge assembly distal end; the cartridge assembly-to-manifold seal may be formed by pressing a cartridge assembly proximal end surface into contact with a surface of the manifold and moving the cartridge assembly along the central axis toward the manifold; the cartridge assembly-to-manifold seal can be disassembled by pulling the cartridge assembly proximal end surface away from the surface of the manifold and moving the cartridge assembly along the central axis away from the surface of the manifold; The method of claim 7.

9. The method of claim 7 or 8, wherein the cartridge assembly includes a vent assembly including the core vent extending from a cartridge assembly proximal end to the distal portion of the core volume.

10. 10. The method of claim 7, wherein the core vent comprises a conductive material that electrically connects the core volume to earth.

11. 1. A liquid filtering device comprising: a bowl including an open end, a distal end opposite the open end, and an interior extending between the open end and the distal end; a manifold capable of sealingly engaging the open end of the bowl, the manifold including a fluid inlet and a fluid outlet; a cartridge assembly disposed within the cartridge assembly, the cartridge assembly including a filtration membrane, a cartridge assembly proximal end, and a cartridge assembly distal end, the cartridge assembly proximal end including a surface adapted to contact a surface of the manifold to form a cartridge assembly-to-manifold seal; an electrostatic discharge suppression mechanism comprising a conductive polymer and capable of conducting charge through a ground path to suppress the build-up of static electricity within the liquid filtration device; a core volume centrally inside said cartridge assembly; a housing volume external to the cartridge assembly and between the cartridge assembly and the bowl; a core vent extending between a distal portion of the core volume and an exterior of the bowl, fluidly connecting the core volume with the exterior and passing through the distal end of the bowl; Equipped with the core vent includes the conductive polymer that is part of the ground circuit; A liquid filtration device, wherein the fluid inlet is in communication with the housing volume and the fluid outlet is connected to the core volume.

12. The device described in claim 11, further comprising a housing vent located at the distal end of the bowl fluidly connecting the housing volume with the outside.

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