Filtration and degassing systems

Abstract

A degassing system is disclosed. A preliminary filter stage is configured to filter particles from a fluid flow and nucleate gas in the fluid flow to produce a filtered fluid flow. A primary filter stage is downstream of the preliminary filter stage, the primary filter stage being configured to separate the filtered fluid flow into a first liquid flow and an air cavity collection flow. A secondary filter stage is configured to receive the air cavity collection flow and separate the air cavity collection flow into a second liquid flow and a gas flow.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 924,901, filed on October 23, 2019, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to filters and degassers. More specifically, the present disclosure relates to a filtration and degassing system. Background Art

[0004] Various systems that utilize fluids can benefit from removing air / gas from the fluid (e.g., degassing). In particular, systems where the same fluid remains within the system for a period of time may accumulate air / gas in the fluid. For example, systems where the fluid is cycled through the system multiple times (such as a hydraulic system) may accumulate air in the fluid, resulting in reduced performance of the system.

[0005] Hydraulic systems and especially hydraulic machines rely on hydraulic fluid to work. Common examples of hydraulic systems include hydraulic machines, hydraulic drive systems, hydraulic transmission systems, hydraulic brakes, etc. Since hydraulic fluids typically remain in the system for a period of time and experience high and low pressure periods, air can accumulate in the fluid. The air in the fluid can exist in various forms, including dissolved air and free air. Free air can include entrained air and foam. The presence of air may cause pump cavitation, accompanied by phenomena such as component wear and increased noise, or cause the fluid bulk modulus to decrease, resulting in reduced efficiency and controllability of the hydraulic system. In addition, smaller storage tanks may aggravate the air problem in hydraulic fluids (e.g., oil) due to the shorter residence time of the fluid in the storage tank. The short residence time may not allow the air in the fluid to leave the fluid before the fluid is pumped out of the storage tank again. Summary of the invention

[0006] Some embodiments of the current technology relate to a degassing system. A primary filter element has a primary filter medium extending between a first end and a second end, and the primary filter medium has an upstream side and a downstream side. The housing is spaced apart from the upstream side of the primary filter medium to define a primary fluid flow path from the first end toward the second end. The system defines a primary fluid inlet between the first end of the primary filter medium and the housing, a primary fluid outlet extending outwardly from the upstream side of the primary filter medium on the second end of the primary filter medium, and a primary liquid outlet extending outwardly from the downstream side of the primary filter medium. The secondary filter element has a secondary filter medium, and the secondary filter medium has an upstream surface and a downstream surface. The secondary filter medium extends from the third end to the fourth end. The system defines a secondary fluid outlet that is the primary fluid outlet, a secondary fluid outlet that is the downstream surface of the secondary filter medium, and a gas outlet on the fourth end. The secondary fluid inlet is toward the third end.

[0007] In some such embodiments, the housing tapers toward the second end of the primary filter medium. Additionally or alternatively, the first end is configured to be positioned above the second end. Additionally or alternatively, the first end is configured to be positioned below the second end. Additionally or alternatively, the primary filter medium lacks a membrane. Additionally or alternatively, the primary filter medium has a porous baffle medium that defines a pore size range of 10 μm to 200 μm. Additionally or alternatively, the primary filter medium is arranged in a tubular configuration, wherein the downstream side defines a central passage extending from the first end to the second end. Additionally or alternatively, the secondary filter medium is arranged in a tubular configuration that defines a cavity, and the primary filter element and the housing are disposed in the cavity.

[0008] Additionally or alternatively, the system has a preliminary filtration stage upstream of the primary fluid inlet, wherein the preliminary filtration stage has a preliminary filter medium and defines a preliminary fluid flow path into and through the preliminary filter medium to the primary fluid inlet. Additionally or alternatively, the preliminary filter medium is positioned vertically above the primary fluid inlet. Additionally or alternatively, fluid flow from the secondary fluid inlet to the secondary liquid outlet is driven by gravity. Additionally or alternatively, the fluid flow path from the secondary fluid inlet to the gas outlet is driven by gravity.

[0009] Some embodiments disclosed herein relate to a degassing system. The degassing system has a preliminary filtration stage, which is configured to filter particles from a fluid flow and nucleate gas in the fluid flow to produce a filtered fluid flow. The primary filtration stage is downstream of the preliminary filtration stage and is configured to separate the filtered fluid flow into a first liquid flow and an air cavity collection flow. The secondary filtration stage is configured to receive the air cavity collection flow and separate the air cavity collection flow into a second liquid flow and a gas flow.

[0010] In some such embodiments, the gas stream is in open communication with the surrounding environment. Additionally or alternatively, the secondary filter stage is a settling tank in open communication with the surrounding environment. Additionally or alternatively, the settling tank has an impermeable base and a sidewall constructed of secondary filter media. Additionally or alternatively, the first liquid stream and the second liquid stream are configured to flow into the fluid tank. Additionally or alternatively, the primary filter stage has a primary filter media, and the first liquid stream is configured to pass through the primary filter media.

[0011] Additionally or alternatively, the air cavity accumulation flow is configured to bypass the primary filter media. Additionally or alternatively, the primary filter media has an upstream side and a downstream side, and the air cavity accumulation flow is configured to flow along the upstream side. Additionally or alternatively, the primary filter media has a pleated screen. Additionally or alternatively, the air cavity accumulation flow is configured to constitute up to 35% by volume of the filtered fluid flow. Additionally or alternatively, the air cavity accumulation flow is configured to constitute at least 5% by volume of the filtered fluid flow.

[0012] Some embodiments disclosed herein are directed to a method. Particles are filtered in a fluid stream and gas cavities are nucleated to produce a filtered and nucleated fluid stream. The filtered and nucleated fluid stream is separated into a first liquid stream and an air cavity collection stream. The first liquid stream is directed into a fluid tank and the air cavity collection stream is separated into a gas stream and a second liquid stream. The second liquid stream is directed into the fluid tank.

[0013] In some such embodiments, separating the air cavity accumulation flow includes directing the air cavity accumulation flow into a settling tank, wherein the settling tank is at atmospheric pressure. Additionally or alternatively, the second liquid flow is directed into a fluid tank by gravity driven through the sidewall of the settling tank, which is constructed of secondary filter media. Additionally or alternatively, separating the gas flow from the air cavity accumulation flow includes the natural release of the gas flow under atmospheric conditions. Additionally or alternatively, separating the air cavity accumulation flow includes directing the air cavity accumulation flow into a settling tank, wherein the settling tank is under a pressure of less than 10psi.

[0014] Additionally or alternatively, separating the filtered and nucleated fluid stream includes passing the filtered and nucleated fluid stream along an upstream surface of a primary filter medium. Additionally or alternatively, the first liquid stream passes through the primary filter medium. Additionally or alternatively, the air cavity collection stream bypasses the primary filter medium. Additionally or alternatively, the primary filter medium has a pleated screen. Additionally or alternatively, filtering particles and nucleating gas cavities includes passing the fluid stream through a preliminary filter medium.

[0015] The above summary is not intended to describe each embodiment or every implementation. Rather, a more complete understanding of the illustrative embodiments will become apparent and appreciated by referring to the following detailed description of exemplary embodiments and the claims in view of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present technology may be more fully understood and appreciated by considering the following detailed description of various embodiments in conjunction with the accompanying drawings.

[0017] Figure 1A is an exemplary system consistent with some embodiments.

[0018] Figure 1B yes Figure 1A An exemplary preliminary level of an exemplary system.

[0019] Figure 1C yes Figure 1A An exemplary primary level of an exemplary system.

[0020] Figure 1D yes Figure 1A An exemplary secondary stage of an exemplary system.

[0021] Figure 2 is a graph of comparative performance test results of an exemplary system.

[0022] Figure 3 is another exemplary system consistent with some embodiments.

[0023] Figure 4 is another exemplary system consistent with some embodiments.

[0024] Figure 5 is a flow chart of an exemplary method consistent with some embodiments.

[0025] The drawings are presented primarily for clarity and are therefore not necessarily drawn to scale. In addition, various structures / components (including, but not limited to, fasteners, electrical components (wiring, cables, etc.), etc.) may be illustrated diagrammatically or removed from some or all views to better illustrate aspects of the depicted embodiments, or the inclusion of such structures / components is not necessary for understanding the various exemplary embodiments described herein. However, the lack of illustration / description of such structures / components in a particular drawing shall not be construed as limiting the scope of the various embodiments in any way. DETAILED DESCRIPTION

[0026] The technology disclosed herein relates to a multi-stage degassing system configured to degas a fluid containing emulsified air. In some embodiments, the degassing system can be incorporated into a hydraulic fluid tank. The degassing system can allow the size of the hydraulic fluid tank to be reduced, thereby achieving a more compact hydraulic system. The degassing system can incorporate filter media, structures, and configurations consistent with those described in International Application No. PCT / US2020 / 015449 (WO 2020 / 0160014A1), which is incorporated herein by reference in its entirety.

[0027] Figure 1A 1 is an exemplary degassing system 100 consistent with various embodiments. The degassing system 100 is generally configured to remove entrained air from a fluid flow. The degassing system 100 generally has a preliminary filtration stage 110 (at Figure 1B ), primary filtration stage 120 (in Figure 1C ) and secondary filtration stage 140 (depicted separately in Figure 1D (depicted separately in ).

[0028] refer to Figure 1A and Figure 1B , the preliminary filter stage 110 is generally configured to filter particles from a fluid stream. The preliminary filter stage 110 is configured to nucleate gas / air cavities in the fluid stream, wherein "gas" and "air" are used interchangeably in the present disclosure. In some embodiments, the preliminary filter stage 110 is also configured to induce coalescence and growth of gas cavities. The preliminary filter stage 110 has an inlet 112 for receiving a fluid stream and an outlet 114 for releasing a filtered fluid stream produced by the preliminary filter stage 110.

[0029] The preliminary filter stage 110 has a preliminary filter medium 116 and defines a preliminary fluid flow path 118 from an inlet 112 to an outlet 114 and into and through the preliminary filter medium 116. In particular, in the current example, the preliminary filter stage 110 has a preliminary filter medium 116 surrounding a central opening 119 that is in fluid communication with the inlet 112. The first end structure 102 defines the inlet 112. The first end structure 102 is coupled to a first end 111 of the preliminary filter medium 116. The second end structure 135 is coupled to a second end 113 of the preliminary filter medium 116 and extends across the central opening 119 so that the fluid flow is directed through the preliminary filter medium 116. In the current embodiment, the outlet 114 of the preliminary filter medium 116 may be an outer boundary 115 of the preliminary filter medium 116.

[0030] The preliminary filter media 116 may be constructed from various types of filter media and combinations of filter media. In various embodiments, the preliminary filter media 116 has a gas nucleation media, which is now described.

[0031] Gas nucleation medium structure and materials

[0032] The gas nucleation media can be made of any suitable material capable of inducing gas nucleation and filtering particles. Without wishing to be bound by theory, it is believed that multiple aspects of the gas nucleation media affect the effectiveness and efficiency of the media in inducing nucleation based on the effects of these aspects on the chemical and physical interactions of the media with the fluid and the gas within the fluid. Aspects that may affect nucleation include, for example, the surface area of ​​the fibers in the media; accessible surface area; fiber size (e.g., diameter or lateral dimension); media pore size; the presence of sharp edges or corners; surface roughness; the chemical composition of the media (e.g., fibers and adhesives); media oleophilicity / oleophobicity; the presence and number of fiber intersections; the orientation angles of adjacent fibers; orientation relative to the flow direction; the tortuosity of the flow path; media sheet density; media sheet permeability; media sheet thickness; the residence time of the fluid in the media; the Peclet number of the media (e.g., the ratio of the advective transport rate to the diffusive transport rate); and the pressure difference between the plate and the individual fibers.

[0033] For example, it is believed that a medium with an appropriate (accessible) surface area, fiber size, and medium pore size is beneficial to nucleation efficiency. The accessible surface area of ​​the fibers in the medium is understood to refer to the media sheet (in m2) per unit of overall surface area. 2 The total surface area accessible to (e.g., in contact with) the fluid (including the surface area within the pores and between the fibers) (in m2) 2 The fiber surface area can be determined using a scanning electron microscope (SEM). The overall surface area of ​​a media sheet is understood to refer to the area calculated as the length of the sheet multiplied by the width (for pleated media, the width can be calculated using the pleat height and number of pleats). The surface area of ​​a gas nucleation media can be 0.1 m 2 Fiber / m 2 Medium, at least 1m 2 Fiber / m 2 Medium, at least 1.5m 2 Fiber / m 2 Medium, or at least 2m 2 Fiber / m 2 The surface area of ​​the gas nucleation medium can be as high as 50m 2 Fiber / m 2 Medium, up to 30m 2 Fiber / m 2 Medium, up to 10m 2 Fiber / m 2 Medium, up to 6m 2 Fiber / m 2 Medium, or up to 4m 2 Fiber / m2 medium.

[0034] Fiber size as used herein refers to the diameter or transverse dimension of the fiber of the medium. The diameter or transverse dimension of the fiber can be determined optically for larger fibers, and can be determined by using SEM for smaller fibers. The fiber size of the fiber in the gas nucleation medium can vary between different fibers and along a given fiber. The fiber size can also vary along a gradient from the upstream side of the medium to the downstream side of the medium. The fiber in the gas nucleation medium can have a fiber size of at least 10nm (nanometer), at least 50nm or at least 100nm. The fiber in the gas nucleation medium can have a fiber size of up to 500μm (micrometer), up to 100μm or up to 10μm.

[0035] The medium pore size of the gas nucleation medium is understood to refer to the size of each pore in the medium plate, as determined by ASTM F316-03 or ASTM D6767. The pores in the gas nucleation medium can have an average pore size of at least 0.5 μm, at least 1 μm, or at least 5 μm. The pores in the gas nucleation medium can have an average pore size of up to 5 μm, up to 10 μm, up to 20 μm, up to 100 μm, or up to 200 μm. The pores in the gas nucleation medium can have a maximum pore size of at least 1 μm, at least 5 μm, or at least 10 μm. The pores in the gas nucleation medium can have a maximum pore size of up to 10 μm, up to 20 μm, up to 100 μm, or up to 200 μm.

[0036] It is believed that the chemical composition of the medium and the oleophilicity / oleophobicity of the medium can affect nucleation. The chemical composition of the medium can include the chemical composition of the fibers in the medium and / or any adhesive or other components used in the medium. The fiber can include any suitable fiber material, including woven or non-woven media made of organic or inorganic materials or combinations thereof. The medium can include various structures combining different materials, such as core-sheath structures, side-by-side structures, island-in-the-sea structures, etc. The fiber can include a single material component, or two or more material components within a single fiber, including a mixture of materials. For example, the fiber material can include one or more of the following: cellulose; regenerated cellulose (e.g., rayon); synthetic materials, such as polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF); glass; ceramics; or carbon fibers. In one embodiment, the filter medium used as the gas nucleation medium is made of microglass and synthetic fibers. Examples of suitable filter media are described in U.S. Patent Nos. 7,314,497; 7,309,372; 8,057,567; 8,268,033; 8,277,529; 8,512,435; 8,641,796; and 9,795,906, and U.S. Publication Nos. 2012 / 0234748 and 2017 / 0225105. The media may include various binders, such as acrylic resins, phenolic resins, or epoxy resins.

[0037] The gas nucleation medium generally has suitable oleophilicity / oleophobicity to induce nucleation and release the formed gas cavity into the fluid stream (as opposed to being "trapped" to the surface of the fiber). In one embodiment, the gas nucleation medium is oleophobic. The oleophobicity of the material can be expressed as the contact angle of an oil droplet on a single fiber in air, and can be measured by dispensing bubbles or oil droplets onto the fiber and using, for example, a micro contact angle instrument (e.g., an MCA-3 instrument available from Kyowa Interface Science Co., Ltd., Niiza, Japan). The gas nucleation medium can have a contact angle of at least 30°, at least 50°, at least 70°, at least 90°, or at least 120°. The gas nucleation medium can have a contact angle of up to 120°, up to 150°, up to 170°, or up to 180°.

[0038] The gas nucleation medium can be inherently oleophobic (e.g., made of oleophobic fibers) and / or treated to become oleophobic using, for example, an oleophobic treatment compound. Typically, the oleophobic material is a fluorinated compound, such as a fluoropolymer having a high density of terminal CF3 side groups exposed to the surface. In certain embodiments, the gas nucleation medium or the oleophobic treatment compound (e.g., a fluorinated treatment compound) applied to the gas nucleation medium as a surface coating can be made of a perfluoropolymer, such as a perfluoroacrylate, a perfluorourethane, a perfluoroepoxy, a perfluorosilicone, a perfluoroalkane, a perfluorodioxolane, or a copolymer of these materials.

[0039] Although gas nucleation media made of inherently oleophobic materials can be used, a fluorine-containing treatment compound is typically coated on conventional filter media to render it oleophobic. The coating material can be, for example, an oleophobic polymer or another polymer that can be rendered oleophobic by a multi-step process. Typically, the fluorine-containing treatment compound dissolved or suspended in a liquid carrier (e.g., an organic solvent or water) is applied to conventional filter media by dipping or spraying.

[0040] Exemplary fluoropolymers include perfluoroacrylates dissolved in solvents, such as those available under the trade name FLUOROPEL series from Cytonix (Beltsville, Maryland), SRA450 or SRA451 from 3M Company (Maplewood, Minnesota), ADVAPEL 806 from Advanced Polymer Incorporated (Carlstadt, New Jersey); perfluorodioxolanes dissolved in solvents, such as those available under the trade name TEFLON AF from Chemours (Wilmington, Delaware); perfluoroacrylate emulsions suspended in water, such as those available under the trade name UNIDYNE from Daikin (Orangeburg, New York), CAPSTONE from Chemours (Wilmington, Delaware), TEFLON 806 from Huntsman (The Woodlands, New York). PHOBOL from PHOBOL, Woodlands, Texas, or ADVAPEL 734 from Advanced Polymers, Inc., Carlstadt, New Jersey; and perfluorourethanes suspended in water, such as those available from 3M Company, Maplewood, Minn., under the trade name SRC 220. Fluoropolymer coatings, such as perfluoroacrylate coatings from P2i, Savannah, Ga., can also be applied by a plasma polymerization process to render the gas nucleating medium oleophobic.

[0041] In certain embodiments, the gas nucleating media is prepared by applying a non-oleophobic coating to a conventional filter media and then modifying it to be oleophobic. For example, a polyol polymer can be applied to a conventional filter media and a perfluorosilane or perfluoroacyl chloride can be grafted onto the polymer. Alternatively, a polyamine can be applied to a conventional filter media and a perfluoroacrylate can be grafted onto the polymer.

[0042] The surface energy of a polymer material can be determined by preparing a Zisman plot with an appropriate fluid, for example, according to ASTM D7490-13. The surface energy of a material can also be determined using the Owens-Wendt method. The fibers in the gas nucleation medium can have a surface energy of at least 6 mJ / m 2 (millijoules per square meter), at least 10mJ / m 2 , at least 15mJ / m 2 , at least 20mJ / m 2 , or at least 40mJ / m 2 Fibers in a gas nucleation medium can have a surface energy of up to 400 mJ / m 2 , up to 300mJ / m 2 , up to 200mJ / m 2 , up to 150mJ / m 2 , up to 100mJ / m 2 , or up to 50mJ / m 2 surface energy.

[0043] The geometric configuration of the fibers in the gas nucleation medium may affect nucleation. For example, the presence of sharp edges or corners and surface roughness can improve nucleation. The configuration of the fiber intersections, the orientation angles of adjacent fibers, the orientation of the fiber surface relative to the flow direction, and the tortuosity of the flow path may also affect nucleation. According to some embodiments, the gas nucleation medium includes fibers with sharp edges or corners. For example, the fiber may have a cross-section that does not have a smooth shape (i.e., not circular or oval). The fiber cross-section may be polygonal or have an irregular shape with corners (e.g., a corner less than 180°, less than 120°, or less than 90°). The gas nucleation medium includes fibers with circular, star-shaped, square, rectangular, trifoliate, clover-shaped, or polygonal cross-sections. The cross-section may be constant or variable over the entire fiber length.

[0044] The surface roughness of the material can be determined using an atomic force microscope (AFM), a cross-sectional SEM or a transmission electron microscope (TEM) or a profilometer as the root mean square roughness. The measurement can be made on a fixed surface area (e.g., a square) having a size of half the fiber diameter. The fiber of the gas nucleation medium can have a surface roughness of at least 1 nm, at least 10 nm, at least 25 nm, at least 50 nm, or at least 100 nm. The fiber of the gas nucleation medium can have a surface roughness of up to 1000 nm, up to 500 nm, or up to 200 nm.

[0045] Surface roughness can also be characterized using various other parameters such as skewness, kurtosis, sharpness, etc. Surface features can exhibit a certain degree of asymmetry (e.g., showing steeper peaks or deep pits). Asymmetry can be expressed as the skewness measured using AFM, fiber cross-section SEM or a surface photometer. The skewness of the fiber can be at least -10, at least -8 or at least -6. The skewness of the fiber can be up to 6, up to 8 or up to 10.

[0046] Kurtosis is another measure of surface roughness, which indicates the degree of sharp angles of sharp features. Kurtosis can be measured using AFM, fiber cross-section SEM, or a profilometer. The fiber of the gas nucleation medium can have a kurtosis of at least -10, at least -8, or at least -6. The fiber of the gas nucleation medium can have a kurtosis of up to 6, up to 8, or up to 10. The combination of some surface roughness, skewness, and kurtosis can obtain favorable nucleation characteristics. For example, high roughness and high kurtosis can be beneficial to nucleation.

[0047] The sharpness or angle of the surface features can be expressed as the radius of curvature and measured using AFM, fiber cross-section SEM or profilometer. The radius of curvature can be up to 2 nm, up to 5 nm, up to 10 nm, up to 50 nm, up to 100 nm, or up to 500 nm.

[0048] It is believed that, to a certain extent, an increase in the number of fiber intersections can increase nucleation. A fiber intersection is understood to refer to a point of contact between two fibers. It is further believed that some ranges of orientation angles of adjacent fibers and the orientation of the fibers relative to the flow direction can be beneficial to nucleation. For example, the fibers within the gas nucleation medium can be randomly oriented so as to achieve a range of orientation angles. In some embodiments, adjacent fibers within the gas nucleation medium are not axially aligned with each other.

[0049] Aspects that affect the residence time or pressure differential of the fluid in the media may also affect nucleation. For example, face velocity, media sheet solidity, media sheet permeability, media sheet thickness, the Peclet number of the media (e.g., the ratio of advective transport rate to diffusive transport rate), the tortuosity of the flow path within the media, and the orientation (e.g., angle) of the media sheet relative to the main flow direction may all affect nucleation.

[0050] The face velocity of the fluid relative to the gas nucleation medium plate can be determined as the volume flow rate per unit surface area. The face velocity can be at least 0.01 fpm (feet per minute), at least 0.1 fpm, at least 0.5 fpm, at least 1 fpm, at least 5 fpm, or at least 10 fpm. The face velocity can be up to 100 fpm, up to 80 fpm, up to 50 fpm, or up to 25 fpm.

[0051] The solidity of a material is the inverse of the void space in the material (how much empty space there is in the material). The gas nucleation medium plate can have at least 5%, at least 10%, or at least 20% void space. The gas nucleation medium can have up to 98%, up to 90%, up to 75%, up to 50%, up to 40%, or up to 30% void space.

[0052] The permeability of the material may be expressed as Frazier permeability as measured by TAPPI T460, ASTM D737, or DIN 53887 (pressure differential set at 0.5 inches of water or 125 Pa). The gas nucleation media sheet may have a thickness of at least 1 ft. 3 / ft 2 / min (cubic feet per square foot per minute) (8L / m 2 / min (liters per square meter per minute)), at least 10ft 3 / ft 2 / min(80L / m 2 / min), or at least 50ft 3 / ft 2 / min(400L / m 2 / min) permeability. The gas nucleation media plate can have a permeability of up to 500 ft 3 / ft 2 / min(4010L / m 2 / min), up to 400ft 3 / ft 2 / min(3210L / m 2 / min), or up to 300ft 3 / ft 2 / min(2410L / m 2 / min) permeability.

[0053] Operating in accordance with ISO 16889 at appropriate face velocities, the gas nucleation media plates may have an initial clean pressure differential of at most 0.01 psi, at most 1 psi, or at most 100 psi.

[0054] The Peclet number indicates the ratio of the advective to diffusive transport rates of the medium and is calculated as the length (e.g., fiber diameter) multiplied by the velocity (e.g., face velocity) divided by the diffusion coefficient. The gas nucleation media plate can have a Peclet number of at least 0.05, at least 0.1, at least 0.5, at least 1, or at least 10. The gas nucleation media plate can have a Peclet number of up to 1000, up to 2500, up to 10,000, or up to 50,000.

[0055] The fluid flow path through the gas nucleation medium can be tortuous (e.g., twisted). The calculated average tortuosity (e.g., hydraulic tortuosity) of the flow path through the gas nucleation medium can be at least 0, at least 0.1, or at least 0.2. The calculated average tortuosity of the flow path through the gas nucleation medium can be up to 4, up to 3, up to 2, up to 1.5, up to 1, up to 0.8, up to 0.9, or up to 1.0.

[0056] The angle of the fiber relative to the flow stream can be determined using, for example, a CT scan of the medium as a weighted average of the angles of the fiber relative to the flow direction. The angle can be at least 0° (degrees), at least 10°, or at least 30°. The angle can be up to 90°, up to 80°, or up to 60°.

[0057] The stiffness of the fiber in the gas nucleation medium may also affect the flow characteristics and therefore may affect nucleation. For example, according to ASTM D790, the stiffness can be measured as the bending modulus of the fiber or base material. For non-polymer materials, the bending modulus is equal to Young's modulus. The fiber of the gas nucleation medium can have a bending modulus of at least 1 GPa (gigapascals), at least 10 GPa, or at least 50 GPa. The fiber of the gas nucleation medium can have a bending modulus of up to 500 GPa, up to 400 GPa, or up to 250 GPa.

[0058] The gas nucleation medium can have any suitable shape. The shape can be determined based on the positioning of the degasser in the system. In one embodiment, the gas nucleation medium defines a cylindrical shape. The gas nucleation medium can have any suitable thickness. The thickness of the gas nucleation medium can be measured in the direction of fluid flow. For example, in a cylindrical degasser, the thickness of the gas nucleation medium can be measured in a radial direction perpendicular to the central axis A. The gas nucleation medium can have a thickness of at least 0.01mm, at least 10mm, or at least 0.1mm. The gas nucleation medium can have a thickness of up to 5mm, up to 2mm, or up to 1mm. The gas nucleation medium can be pleated or wrapped. In either case (pleated or wrapped), the medium can have one layer or multiple layers. The medium can be repeatedly wrapped or stacked. When multiple layers are included, these layers can have the same composition and / or structure, or can be placed into a unique composition and / or structure in close contact.

[0059] Returning to the discussion of the preliminary filter media 116, in an embodiment, the preliminary filter media has a particulate filter media. The particulate filter media can be a media layer positioned upstream of the gas nucleation media. In some other embodiments, the preliminary filter media 116 is limited to a gas nucleation media configured to nucleate a gas in a fluid flow. In some such embodiments, the gas nucleation media is also configured to filter particles from the fluid flow. In some embodiments, the preliminary filter media has multiple layers. In some embodiments, the preliminary filter media is wrapped or stacked. In an embodiment, the preliminary filter media is constructed of pleated media. In an embodiment, the preliminary filter media is made of non-pleated media.

[0060] In some embodiments, the preliminary filter medium is combined with a growth medium layer downstream of the particle filter medium and / or the gas nucleation medium, but in some other embodiments, the growth medium can be omitted. The growth medium is described in detail in the following sections. The growth medium layer can be disposed adjacent to the gas nucleation medium. The growth medium can be around (e.g., in contact with) the gas nucleation medium. The growth medium can be arranged in the flow path of the fluid so that after flowing through the gas nucleation medium, the fluid flows through the growth medium. In contact with the gas nucleation medium, the growth medium layer can be disposed adjacent to the gas nucleation medium. Figure 1A In a consistent embodiment, the growth medium may form a cylinder coaxial with the gas nucleation medium and at least partially circumscribing the gas nucleation medium.

[0061] In some embodiments, the preliminary filter media 116 incorporates a porous baffle media, which is described in detail later in this application with particular reference to the primary filter stage 120 and the secondary filter stage 140. The porous baffle media can be a media layer. The porous baffle media can be the most downstream layer of the preliminary filter media 116.

[0062] Growth medium construction and materials

[0063] The growth medium can be disposed adjacent to or in abutment with the gas nucleation medium. The growth medium can be made of any suitable material capable of inducing gas cavity coalescence and / or growth. Without wishing to be bound by theory, it is believed that multiple aspects of the growth medium affect the effectiveness and efficiency of the medium-induced coalescence. For example, aspects that affect coalescence can include the chemical composition of the medium (e.g., fibers and adhesives); the surface energy of the medium; the oleophilicity / oleophobicity of the medium; the surface area of ​​the medium; the solidity of the medium sheet; the porosity of the medium sheet; the permeability of the medium sheet; the thickness of the medium sheet; the surface roughness; and the pressure difference across the medium. One or more of these characteristics can exhibit a gradient from the upstream side to the downstream side of the growth medium.

[0064] The chemical composition of the growth medium may affect aggregation and growth. The chemical composition of the growth medium may include the chemical composition of the fibers in the medium, and / or any adhesive or other components used in the medium. The fibers may include any suitable fiber material, including woven or nonwoven media made of one or more of the following: cellulose; regenerated cellulose (e.g., rayon); synthetic materials such as polyamides (e.g., nylon), polyesters, polyethersulfones (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF); glass; ceramics; or carbon fibers. In one embodiment, the growth medium is made of polyester, rayon, or a combination thereof, or includes polyester, rayon, or a combination thereof. The medium may include various adhesives, such as acrylic resins, phenolic resins, or epoxy resins.

[0065] Preferably, the growth medium has a suitable surface energy and oleophilicity / oleophobicity to induce gas cavity coalescence and / or growth, and release the formed gas cavity into the fluid flow (as opposed to being "trapped" to the surface of the fiber). According to an embodiment, the growth medium is oleophilic. In some embodiments, the growth medium exhibits an oleophilicity / oleophobicity gradient, wherein the upstream side of the medium is more oleophobic than the downstream side. In another embodiment, the upstream side is more oleophilic than the downstream side. The oleophobicity of the material can be expressed as the contact angle of an oil droplet on a single fiber in air. The growth medium can have a contact angle of at least 0°, at least 10°, at least 20°, or at least 30°. The growth medium can have a contact angle of up to 180°, up to 150°, up to 120°, up to 90°, or up to 60°. The growth medium can be inherently oleophilic (e.g., made of oleophilic fibers) and / or become oleophilic using, for example, an oleophilic treatment compound.

[0066] The fibers in the growth medium may have a strength of at least 6 mJ / m 2 , at least 20mJ / m 2 , at least 50mJ / m 2 , at least 75mJ / m 2, or at least 100mJ / m 2 The surface energy of the fibers in the growth medium can be as high as 400 mJ / m 2 , up to 350mJ / m 2 , up to 300mJ / m 2 , or up to 250mJ / m 2 surface energy.

[0067] The surface area of ​​the media and therefore the contact area between the media and the fluid can affect coalescence and growth. The surface area of ​​the fibers in the media is understood to refer to the surface area of ​​the media sheet (in m2) per unit of overall surface area. 2 Total surface area (including the surface area between fibers) (in m 2 The surface area of ​​the growth medium may be at least 0.1 m 2 Fiber / m 2 Medium, at least 1m 2 Fiber / m 2 Medium, at least 1.5m 2 Fiber / m 2 Medium, or at least 2m 2 Fiber / m 2 The surface area of ​​the growing medium can be up to 50m 2 Fiber / m 2 Medium, up to 30m 2 Fiber / m 2 Medium, up to 10m 2 Fiber / m 2 Medium, up to 6m 2 Fiber / m 2 Medium, or up to 4m 2 Fiber / m 2 medium.

[0068] The geometry of the fibers in the growth medium can affect coalescence and growth. For example, the presence of sharp edges or corners and surface roughness, the orientation of the fiber surface relative to the flow direction, the solidity, the permeability, and the pore size of the growth medium can be selected to increase the coalescence and growth of gas cavities and release the gas cavities into the fluid flow after they grow and / or coalesce.

[0069] The fiber cross-section of the fibers in the growth medium can be polygonal, or have an irregular shape with corners (e.g., corners less than 180°, less than 120°, or less than 90°). The growth medium can include fibers having a circular, star-shaped, square, rectangular, trilobal, clover-shaped, or polygonal cross-section. The cross-section can be constant or vary throughout the fiber length.

[0070] The fiber size of the fibers within the growth medium can vary between different fibers and along a given fiber. The fiber size can also vary along a gradient from the upstream side of the medium to the downstream side of the medium. The fibers within the growth medium can have a fiber size of at least 10 nm, at least 50 nm, or at least 100 nm. The fibers within the growth medium can have a fiber size of up to 500 μm, up to 100 μm, or up to 10 μm.

[0071] The angle of the fibers relative to the flow stream in the growth medium may be at least 0°, at least 10°, or at least 30°. The angle of the fibers in the growth medium may be up to 90°, up to 80°, or up to 60°.

[0072] The stiffness of the fibers in the growth medium may also affect flow characteristics and therefore may affect aggregation and / or growth. The fibers of the growth medium may have a flexural modulus of at least 1 GPa, at least 10 GPa, or at least 50 GPa. The fibers of the growth medium may have a flexural modulus of up to 500 GPa, up to 400 GPa, or up to 250 GPa.

[0073] The fibers within the growth medium may have a surface roughness of at least 1 nm, at least 10 nm, at least 25 nm, at least 50 nm, or at least 100 nm. The fibers within the growth medium may have a surface roughness of up to 1000 nm, up to 500 nm, or up to 200 nm. The fibers within the growth medium may have a skewness of at least -10, at least -8, or at least -6. The skewness of the fibers may be up to 6, up to 8, or up to 10. The fibers within the growth medium may have a kurtosis of at least -10, at least -8, or at least -6. The fibers within the growth medium may have a kurtosis of up to 6, up to 8, or up to 10. The sharpness or sharp angle of the surface features may be expressed as a radius of curvature and measured using an AFM, fiber cross-section SEM, or a profilometer. The sharpness of the fiber surface features may be up to 2 μm, up to 5 μm, or up to 10 μm.

[0074] The pores of the growth medium are understood to refer to holes (e.g., through holes) and cavities in the growth medium plate. The pore size of the growth medium can be determined by ASTM F316-03 or ASTM D6767. The pores of the growth medium can provide a flow path for the fluid to pass through the medium plate. The growth medium can have an average pore size of at least 0.5 μm, at least 1 μm, or at least 5 μm. The growth medium can have an average pore size of up to 5 μm, up to 10 μm, up to 20 μm, up to 100 μm, or up to 200 μm. The growth medium can have a maximum pore size of at least 1 μm, at least 5 μm, or at least 10 μm. The growth medium can have a maximum pore size of up to 10 μm, up to 20 μm, up to 100 μm, or up to 200 μm.

[0075] The growth medium can have at least 5%, at least 10%, or at least 20% void space. The growth medium can have up to 90%, up to 75%, up to 50%, up to 40%, or up to 30% void space. For example, the growth medium can include a woven or nonwoven medium having a porous structure.

[0076] The growth medium plate can have any suitable thickness. The thickness of the growth medium will affect the pressure difference at both ends of the medium plate. The thickness of the growth medium can be measured in the direction of fluid flow. For example, in a cylindrical degasser, the growth medium forms a coaxial cylinder that at least partially surrounds the gas nucleation medium, and the thickness of the growth medium can be measured in a radial direction perpendicular to the central axis A. The thickness can be measured according to TAPPI T411, ASTM D5729 or ASTM D5736. The growth medium can have a thickness of at least 0.01 mm, at least 0.02 mm, at least 0.05 mm, at least 0.1 mm, at least 0.5 mm, at least 1 mm, at least 2 mm, at least 3 mm, or at least 4 mm. The growth medium can have a thickness of up to 25 mm, up to 20 mm, up to 15 mm, or up to 10 mm.

[0077] Operating in accordance with ISO 16889 at appropriate face velocities, the growing media sheet may have a pressure differential of at most 0.01 psi, at most 1 psi, or at most 100 psi.

[0078] The growth medium can be set as a plurality of medium layers. A plurality of medium layers can be applied to (e.g., wrapped around or laminated to) the gas nucleation medium. The increase in the number of growth medium layers can improve the coalescence of the air cavity. However, the thickness of the growth medium (e.g., due to the number of medium layers) can also increase the pressure drop at both ends of the growth medium and the degasser as a whole. Therefore, the number of growth medium layers can be balanced to provide improved coalescence without excessively increasing the pressure drop at both ends of the degasser unit. The growth medium can be set to 2 or more layers, 3 or more layers, 4 or more layers, or 5 or more layers. The growth medium can be set to up to 20 layers, up to 15 layers, up to 12 layers, or up to 10 layers. In the embodiment where the growth medium includes a plurality of layers, unless otherwise indicated, the thickness of the growth medium can refer to the total thickness of the layer. The thickness of each growth medium plate can affect the number of wraps used, for example, thinner media can utilize more wraps. In one embodiment, the growth medium is composed of 5 to 10 (e.g., 7) non-woven medium layers.

[0079] return Figure 1A The primary filter stage 120 is downstream of the preliminary filter stage 110 and is configured to receive the filtered fluid flow produced by the preliminary filter stage 110. Figure 1C104 and air cavity aggregate stream 105. As used herein, a "liquid stream" will typically have a lower volume of entrained gas than an upstream fluid stream from which the liquid stream is separated. A "liquid stream" is a fluid stream of at least 75% liquid and no more than 25% gas by volume and more commonly at least 90% liquid and no more than 10% gas by volume. Typically, the liquid stream is at least 95% fluid and no more than 5% gas by volume. The primary filtration stage 120 has a primary fluid inlet 121, a primary fluid outlet 122, and a primary liquid outlet 123 downstream of the preliminary filtration stage 110. The primary fluid inlet 121 is configured to receive the filtered fluid stream from the preliminary filtration stage 110.

[0080] The primary filtration stage 120 is configured such that the air cavity focused flow 105 passes through a primary fluid outlet 122, and the first liquid flow 104 is configured to pass through a primary liquid outlet 123. The primary liquid outlet 123 may be connected to a primary liquid outlet such as Figure 1A The first liquid stream 104 is connected to a fluid tank 160 depicted in dashed lines in FIG. 1 , which is configured to receive the first liquid stream 104. The first liquid stream 104 can fall into the fluid tank, or in some embodiments, a tube, flow ramp, or nozzle can be used to direct the first liquid stream 104 into the fluid tank.

[0081] The primary filter stage 120 generally has a primary filter element 127 having a primary filter medium 124. The primary filter medium 124 includes an upstream side 125 and a downstream side 126. The primary filter medium 124 is configured to accommodate the flow of the first liquid stream 104 therethrough from the upstream side 125 to the downstream side 126. In various embodiments, the primary filter medium 124 does not accommodate the flow of the air cavity accumulation flow 105 therethrough, and therefore, the air cavity accumulation flow 105 bypasses the primary filter medium 124. In particular, the primary filter stage 120 is configured such that the air cavity accumulation flow 105 flows along (or across) the upstream side 125 of the primary filter medium 124 without flowing through the primary filter medium 124. The air cavity accumulation flow 105 flows axially along the length of the primary filter medium 124 that is generally parallel to the upstream side 125 of the primary filter medium 124.

[0082] In the present example, the primary filter medium 124 extends between a first end 128 and a second end 129. The degassing system 100 has a housing 130 that is spaced apart from an upstream side 125 of the primary filter medium 124 to define a primary fluid flow path 131 from the first end 128 toward the second end 129. A primary fluid inlet 121 is defined toward the first end 128 of the primary filter medium 124 (between the first end 128 of the primary filter medium 124 and the housing 130), and a primary fluid outlet 122 is defined on the second end 129 of the primary filter medium 124. Each of the primary fluid inlet 121 and the primary fluid outlet 122 is on the upstream side 125 of the primary filter medium 124. The primary fluid outlet 122 extends outwardly from the upstream side 125 of the primary filter medium 124. In particular, the primary fluid outlet 122 is defined by an opening between the housing 130 and a second end cap 133 of the primary filter element 127.

[0083] In various embodiments, the filtered fluid stream enters the primary filter stage 120 through the primary fluid inlet 121 on the first end 128 and travels along the primary fluid flow path 131 toward the second end 129 of the primary filter medium 124. The primary filter medium 124 is configured such that a portion of the liquid within the filtered fluid stream passes through the primary filter medium 124 to the primary liquid outlet 123, wherein the primary liquid outlet 123 extends outwardly from the downstream side 126 of the primary filter medium 124. The air cavities within the filtered fluid stream do not pass through the primary filter medium 124. The degassing system 100 is generally configured such that the filtered fluid stream sweeps along / across the upstream side 125 to prevent the air cavities from sticking to the primary filter medium 124 and blocking the liquid flow through the primary filter medium 124. Thus, the first liquid stream 104 passes through the primary filter medium 124, thereby being separated from the air cavity collection stream 105 on the upstream side 125 of the primary filter medium 124. The first liquid stream 104 then exits the degassing system 100 through the primary liquid outlet 123 , and the air cavity aggregate stream 105 then exits the degassing system 100 through the primary fluid outlet 122 .

[0084] Under normal operating conditions, the air cavity aggregate flow 105 may constitute up to 35% by volume of the filtered fluid flow. Thus, the first liquid flow 104 may constitute at least 65% by volume of the filtered fluid flow. Under normal operating conditions, the air cavity aggregate flow 105 may constitute at least 5% by volume of the filtered fluid flow. Thus, the first liquid flow 104 may constitute up to 95% by volume of the filtered fluid flow. "Normal operating conditions" refers to when the temperature of the hydraulic oil reaches a stable level (such as 140°F) at idle engine conditions. After initial startup, the fluid of the hydraulic system may be relatively cold and relatively viscous until the system warms up to normal operating conditions.

[0085] The primary filter medium 124 can have a variety of configurations. The primary filter medium 124 generally lacks a membrane. In the current example, the primary filter medium 124 is arranged in a tubular configuration so that the downstream side 126 defines a central passage extending from a first end 128 to a second end 129. A first end cap 132 is coupled to the first end 128 of the primary filter medium 124, and a second end cap 133 is coupled to the second end 129 of the primary filter medium 124. The first end cap 132 extends across the central passage, while the second end cap 133 defines an opening 134, i.e., the primary liquid outlet 123, that communicates with the central passage. Although the second end structure 135 and the first end cap 132 are depicted as separate components, in some embodiments, the second end structure 135 and the first end cap 132 form a single, integral component.

[0086] In various embodiments, the primary filter medium 124 has a porous baffle medium, which is described in more detail below. The porous baffle medium can form a layer. The porous baffle medium can be a pleated screen. In such embodiments, the primary filter medium 124 can be adjacent to one or more support screens configured to maintain the pleated arrangement of the primary filter medium 124. In an example, the primary filter medium 124 is a porous baffle medium sandwiched between two support screens. Such support screens, if used, generally do not affect the degassing performance of the primary filter medium 124. The porous baffle medium of the primary filter medium 124 can have a pore size in the range of 10 μm to 200 μm, wherein the pore size can be the average size of the openings of the screen forming the porous baffle medium. The porous baffle media may have a pore size in the range of 20-60 μm, 30-50 μm, 50-90 μm, 70-80 μm, or even 100-160 μm. In one example, the primary filter media 124 is a porous baffle media that is a screen having a screen opening of approximately 44 μm.

[0087] Porous Baffle Media Construction and Materials

[0088] The porous baffle media can have any suitable porous material defining openings or pores extending through the media. Without wishing to be bound by theory, it is believed that various aspects of the porous baffle media affect the effectiveness and efficiency of the media. For example, aspects that affect the efficiency of the porous baffle media can include pore size and pore shape, as well as the regularity or uniformity of the pore size, and the shape of the entire media; the chemical composition of the media; the oleophilicity / oleophobicity of the media; the surface roughness or smoothness of the media; and the direction / orientation of the media relative to the direction of flow. One or more of these characteristics can be different on the upstream side than the downstream side, or exhibit a gradient from the upstream side to the downstream side.

[0089] In some embodiments, the porous baffle medium comprises a woven or nonwoven material. The size of these openings can be uniform or non-uniform, i.e., including openings of various sizes. The pores of the porous baffle medium can also be referred to as screen openings, and should be understood to refer to holes (e.g., through holes) in the medium. The pore size of the porous baffle medium can be determined by ASTM E11 or by optical imaging. The porous baffle medium can include openings of 5 μm or greater, 10 μm or greater, 15 μm or greater, or 20 μm or greater. The porous baffle medium can include openings of 1 mm or less, 750 μm or less, 500 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, or 100 μm or less. In one example, the porous baffle medium includes openings of 10 μm to 120 μm, 15 μm to 100 μm, or 20 μm to 80 μm. In some embodiments, the openings of the porous baffle media are uniform in size (e.g., have a narrow pore size distribution). For example, in some embodiments, at least some of the openings, a majority of the openings, at least 90% of the openings, at least 95% of the openings, or at least 99% of the openings of the porous baffle media are within the size ranges specified herein, as determined by the total open area of ​​the porous baffle media. In one embodiment, all of the openings of the porous baffle media are within the size ranges specified herein.

[0090] The openings of the porous baffle medium can have any suitable shape. For example, the openings can be rectangular, square, rounded, oval, or any other suitable shape. The shape can be determined by observing the porous baffle medium from a direction perpendicular to the plane of the porous baffle medium. In some embodiments, the size of the openings of the porous baffle medium is uniform. For example, in some embodiments, at least some of the openings, most of the openings, at least 90% of the openings, at least 95% of the openings, or at least 99% of the openings of the porous baffle medium have the same shape (e.g., rectangular, square, rounded, oval, etc.).

[0091] The porous baffle medium 124 can be made of woven or nonwoven materials. For example, the porous baffle medium 124 can be made of a woven mesh. The woven mesh can have a wire diameter (or lateral dimension) of at least 0.01mm, at least 0.05mm, or at least 0.1mm. The woven mesh can have a wire diameter (or lateral dimension) of up to 10mm, up to 2mm, up to 1mm, or up to 0.5mm. In one embodiment, the porous baffle medium 124 includes a pleated material, such as a pleated woven mesh. The porous baffle medium 124 can be made of any suitable material. For example, the porous baffle medium can be made of a material with suitable oleophilicity / oleophobicity to promote further growth of the gas cavity and allow the gas cavity to pass through the medium. In some embodiments, the porous baffle medium or a portion of the porous baffle medium is oleophobic. According to some embodiments, at least one side of the porous baffle medium is oleophilic. In some embodiments, the porous baffle medium exhibits an oleophobic gradient, wherein the upstream side of the medium is more oleophobic than the downstream side. The oleophobicity of a material may be expressed as an oil rating measured according to AATCC TM 118. The porous baffle media may have an oil rating of at least 1, at least 1.5, or at least 2. The porous baffle media may have an oil rating of up to 10, up to 8, or up to 6.

[0092] For example, the porous baffle medium can be made of metal (such as stainless steel), or a woven or non-woven medium made of one or more of the following: cellulose; regenerated cellulose (e.g., rayon); synthetic materials such as polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF); glass; ceramic; or carbon fiber. In one embodiment, the porous baffle medium 124 is made of a woven metal mesh (such as a stainless steel mesh). In some embodiments, the fibers (e.g., metal fibers) are coated. A polymer or non-polymer coating, such as a resin, can be used. The porous baffle medium 124 can be arranged in a cylindrical shape.

[0093] The porous baffle medium can exhibit microtexture and macrotexture. Microtexture as used herein refers to the surface texture of the medium at the level of the individual fibers or filaments that make up the medium (for example, a change in size less than 1 mm). Microtexture can also be referred to as surface roughness. Macrotexture as used herein refers to the surface texture of the overall medium (for example, a change in size greater than 1 mm). The porous baffle medium can exhibit surface roughness. For example, the porous baffle medium can have a surface roughness of at least 1 nm, at least 10 nm, at least 25 nm, at least 50 nm, or at least 100 nm. The porous baffle medium can have a surface roughness of up to 1000 nm, up to 500 nm, or up to 200 nm. In some embodiments, the porous baffle medium has little or no macrotexture, that is, the porous baffle medium is "smooth", except that the porous baffle medium may be wrinkled.

[0094] Additional characteristics of the porous baffle media surface include skewness, kurtosis, and sharpness or sharp angles. The skewness of the fiber can be at least -10, at least -8, or at least -6. The skewness of the fiber can be up to 6, up to 8, or up to 10. The fibers of the porous baffle media can have a kurtosis of at least -10, at least -8, or at least -6. The fibers of the porous baffle media can have a kurtosis of up to 6, up to 8, or up to 10. Certain combinations of surface roughness, skewness, and kurtosis can obtain favorable capture characteristics. For example, high roughness and high peaks can be beneficial for capture. The fibers of the porous baffle media can have a radius of curvature that may be up to 2nm, up to 5nm, up to 10nm, up to 50nm, up to 100nm, or up to 500nm. The porous baffle media can have an initial cleaning pressure difference of at most 0.01psi, at most 1psi, or at most 100psi, according to ISO 16889, running at an appropriate face speed.

[0095] Return again Figure 1AIn some embodiments, the primary filter stage 120 has a primary filter media 124 that is limited to a porous baffle media. In such embodiments, there may be one or more porous baffle media layers. In some embodiments, the primary filter media 124 has a porous baffle media layer and a growth media layer, wherein the growth media is discussed in detail above. In some such embodiments, the porous baffle media layer is positioned downstream of the growth media layer. In some such embodiments, the porous baffle media layer is positioned upstream of the growth media layer. In some embodiments, the primary filter media 124 has a gas nucleation media layer, which is described in detail above. The gas nucleation media layer can be positioned upstream of the porous baffle media. In embodiments that also incorporate a growth media, the gas nucleation media layer can be positioned upstream of the growth media, and the growth media can be positioned upstream of the porous baffle media. Each of the media layers incorporated into the primary filter media 124 can be in direct contact, or in some embodiments, a gap can be formed between adjacent layers.

[0096] The secondary filter stage 140 is generally configured to receive the air cavity aggregate flow 105 from the primary filter stage 120 and separate the air cavity aggregate flow 105 into a second liquid flow 106 and a gas flow 107. The secondary filter stage 140 is Figure 1D 14. Secondary filter stage 140 may have a secondary filter element 143 having a secondary filter medium 142. Secondary filter medium 142 extends from a third end 146 to a fourth end 147 and has an upstream surface 144 and a downstream surface 145. Third end 146 of secondary filter medium 142 is coupled to base 141, and fourth end 147 of secondary filter medium 142 is coupled to open end cap 156.

[0097] The secondary filter stage 140 is configured to receive the air cavity collection flow 105 through a secondary fluid inlet 149, which in the current embodiment is the primary fluid outlet 122 of the primary filter stage 120. The secondary fluid inlet 149 is toward the third end 146 of the secondary filter medium 142. The second liquid flow 106 exits the secondary filter stage 140 through a secondary liquid outlet 145, which is the downstream surface 145 of the secondary filter medium 142. In various embodiments, the second liquid flow 106 is configured to flow into a fluid tank, similar to the first liquid flow 104. The second liquid flow 106 can fall into the fluid tank, or in some embodiments, a tube, flow ramp, or nozzle can be used to direct the second liquid flow 106 into the fluid tank.

[0098] The gas stream 107 exits the secondary filter stage 140 through the gas outlet 148 toward the fourth end 147 of the secondary filter medium 142. In various embodiments, the gas stream 107 can be in open communication with the surrounding environment, such as the surrounding environment within the hydraulic system that houses the degassing system 100. The surrounding environment within the hydraulic system can be at atmospheric conditions or pressurized, which is discussed below. In some embodiments, the gas stream 107 can be released into the atmosphere.

[0099] In the current example, the secondary filtration stage 140 can be considered as a settling tank, in which the air cavity aggregate flow 105 stays under ambient conditions to naturally separate the second liquid flow 106 and the gas flow 107. In the case where the degassing system 100 is contained in a fluid tank, a hydraulic system or other containing system, the ambient pressure can be at atmospheric pressure or higher. In the case where the ambient pressure is atmospheric pressure, the second liquid flow 106 and the gas flow 107 are separated at atmospheric pressure. The second liquid flow 106 and the gas flow 107 are separated without using a vacuum pump. The second liquid flow 106 is guided to the fluid tank at least partially under the action of gravity through the secondary filter medium 142. In the case where the ambient pressure is higher than the atmospheric pressure, the second liquid flow 106 and the gas flow 107 are separated under the action of gravity and the pressure in the tank. The pressure in the tank can be generally less than 10psi (69.0KPa) or less than 5psi (34.5KPa) higher than the atmospheric pressure. In some embodiments, the pressure in the tank can be about 7.25psi (50.0KPa) higher than the atmospheric pressure. In various embodiments, fluid flow from the secondary fluid inlet 149 through the secondary filter media 142 to the secondary liquid outlet 145 is at least partially driven by gravity. In various embodiments, fluid flow from the secondary fluid inlet 149 to the gas outlet 148 is driven by gravity.

[0100] In the current example, secondary filter stage 140 has a substantially impermeable base 141 and sidewalls constructed of secondary filter media 142. Although in the current embodiment, base 141 and second end cap 133 of primary filter element 127 are depicted as forming a single unitary structure, in some other embodiments, base 141 and second end cap 133 may be separate components.

[0101] In an example consistent with the current embodiment, the secondary filter medium 142 is arranged in a tubular configuration defining a cavity 150. The primary filter stage 120 is contained within the cavity 150 of the secondary filter medium 142. In particular, the primary filter element 127 and the housing 130 are contained in the cavity 150 of the secondary filter medium 142. In some alternative embodiments, the secondary filter stage 140 does not surround the primary filter stage 120. For example, in some embodiments, a tube or fluid connector can extend from the primary filter stage 120 to the secondary filter stage 140. The secondary filter medium 142 is constructed of materials generally consistent with the description above regarding the primary filter medium 124. Although in any particular system 100, the secondary filter medium 142 can be constructed of a different material and / or combination of materials than the primary filter medium 124.

[0102] Although system 100 is currently shown with preliminary filter stage 110, in some embodiments, preliminary filter stage 110 may be omitted or may be a component of an upstream system. In such embodiments, a conduit may fluidly couple the primary fluid outlet to the primary fluid inlet such that preliminary filter stage 110 is indirectly coupled to primary filter stage 120. In some embodiments such as currently depicted, preliminary filter stage 110 is directly coupled to primary filter stage 120. In the current embodiment, preliminary filter stage 110 is positioned above first end 128 of primary filter media 124, and therefore above primary fluid inlet 121. The following description of the preliminary filter stage 110 is a schematic diagram of a filter element that is provided in a plurality of embodiments. Figure 3 Another example is depicted where the preliminary filtration stage is positioned below the second end of the primary filter media.

[0103] In the current example, the housing 130 defines a portion of the preliminary filter stage 110 and the primary filter stage 120. In particular, the housing 130 is coupled to the first end structure 102 around the preliminary filter medium 116 and extends in an axial direction around the preliminary filter medium 116 and the primary filter medium 124. The portion of the housing 130 surrounding the preliminary filter medium 116 is generally parallel to the outer boundary 115 of the preliminary filter medium 116. The portion of the housing 130 surrounding the primary filter medium 124 generally tapers toward the second end 129 of the primary filter medium 124. In the current example, the housing 130 tapers radially inwardly toward the second end 129 of the primary filter medium 124. This configuration can encourage liquid to pass through the primary filter medium 124. In some other embodiments, the housing does not taper relative to the primary filter medium 124.

[0104] The housing 130 is generally constructed of a liquid-impermeable material. In some embodiments, the housing 130 is plastic, and in some other embodiments, the housing 130 is metal. The housing 130 can be a molded or machined material. In some embodiments, the housing 130 forms a single unitary structure with the first end structure 102, and in other embodiments, the housing 130 is a separate component that is sealably coupled to the first end structure 102.

[0105] The housing 130 also forms part of the secondary filter stage 140. In particular, the housing 130 is disposed within the cavity 150 of the secondary filter element 143 and forms an inner substantially cylindrical containment wall that, together with the secondary filter media 142 and the base 141, cumulatively defines a settling area 157 in the cavity 150. During operation, pressure caused by fluid flow of the air cavity collection flow 105 exiting the primary fluid outlet 122 keeps the air cavity collection flow 105 in the settling area 157 separated.

[0106] Figure 2 Depicted with Figure 1A Two test results (Example #1 and Example #2) comparing a conforming exemplary system to a commercially available deaerator system, which is a standard synthetic pleated filter element used as a baseline measurement ("Baseline"). The baseline pleated filter element is constructed of pleated synthetic filter media arranged about a central axis to form a tubular structure and is configured for radially outward fluid flow through the synthetic filter media from a central opening of the tubular structure. Figure 1A In a consistent exemplary system, the preliminary filter media is confined to a gas nucleation media layer, the primary filter media is confined to a porous baffle media layer, and the secondary filter media is confined to another porous baffle media layer. Each of the porous baffle media layers is sandwiched between support screens.

[0107] The degasser system is assembled in a tank that is constructed to simulate a hydraulic oil tank in a hydraulic system, where the returning hydraulic oil enters the tank and degasser from the top. During the test, the ambient pressure of the tank is equal to atmospheric pressure. Hydraulic oil is injected into the tank and aerated continuously for 1800 seconds. The air content (%) in the oil is measured and recorded throughout the test. The lower the percentage of air content in the oil, the more air is removed and therefore the better the degassing performance. As in Figure 2 As can be seen, the system consistent with the technology disclosed herein has significantly better performance than the baseline element, which means that the currently disclosed system is more effective in degassing the hydraulic fluid. It should be noted that the data from about 350 seconds to about 690 seconds associated with Example #1 is omitted here because of inaccuracies caused by execution errors in conducting the experiment during this time period.

[0108] Figure 3 2 is an exemplary degassing system 200 consistent with various embodiments. The degassing system 200 is generally configured to remove entrained air from a fluid flow. The degassing system 200 generally has a preliminary filtration stage 210, a primary filtration stage 220, and a secondary filtration stage 240.

[0109] The preliminary filtration stage 210 is generally configured to filter particles from a fluid stream. The preliminary filtration stage 210 is also configured to nucleate gases in the fluid stream. The preliminary filtration stage 210 has an inlet 212 for receiving the fluid stream and an outlet 214 for releasing the filtered fluid stream produced by the preliminary filtration stage 210.

[0110] The preliminary filter stage 210 has a preliminary filter medium 216 and defines a preliminary fluid flow path 218 from an inlet 212 to an outlet 214 and into and through the preliminary filter medium 216. In particular, in the current example, the preliminary filter stage 210 has a preliminary filter medium 216 surrounding a central opening 219 that is fluidly connected to the inlet 212. The first end structure 202 defines the inlet 212. The first end structure 202 is coupled to a first end 211 of the preliminary filter medium 216. The second end structure 235 is coupled to a second end 213 of the preliminary filter medium 216 and extends across the central opening 219 such that the preliminary fluid flow path 218 extends through the preliminary filter medium 216. In the current embodiment, the outlet 214 of the preliminary filter medium 216 may be an outer boundary 215 of the preliminary filter medium 216. The material and construction of the preliminary filter medium 216 may be generally the same as described above with respect to Figure 1A This is consistent with the discussion.

[0111] The primary filtration stage 220 is downstream of the preliminary filtration stage 210 and is configured to receive the filtered fluid flow generated by the preliminary filtration stage 210. The primary filtration stage 220 is configured to separate the filtered fluid flow into a first liquid flow 204 and an air cavity collection flow 205. The primary filtration stage 220 has a primary fluid inlet 221, a primary fluid outlet 222, and a primary liquid outlet 223 downstream of the preliminary filtration stage 210. The primary fluid inlet 221 is configured to receive the filtered fluid flow from the preliminary filtration stage 210. The primary filtration stage 220 is configured so that the air cavity collection flow 205 passes through the primary fluid outlet 222, and the first liquid flow 204 is configured to pass through the primary liquid outlet 223. The primary liquid outlet 223 may be in communication with a fluid tank 270 configured to receive the first liquid flow 204. The fluid tank 270 is at Figure 3 It is schematically indicated by a dotted line.

[0112] In the current embodiment, a fluid flow ramp 260 is coupled to the second end cap 233 around the primary fluid outlet 223. The fluid flow ramp 260 is configured to direct the first liquid stream 204 to the fluid tank 270. In some embodiments, the fluid flow ramp 260 forms a single, unitary structure with the second end cap 233, but in other embodiments, the fluid flow ramp 260 is a separate component coupled to the second end cap 233. The fluid flow ramp 260 extends radially outward from the second end cap 233 and also extends downward to allow the first liquid stream 204 to flow to the fluid tank under gravity assistance. In some embodiments, a flow tube can be in fluid communication with the primary liquid outlet to direct the liquid stream to the fluid tank.

[0113] The primary filter stage 220 generally has a primary filter element 227 having a primary filter medium 224. The primary filter medium 224 has an upstream side 225 and a downstream side 226. The primary filter medium 224 is configured to accommodate the flow of the first liquid stream 204 therethrough from the upstream side 225 to the downstream side 226. In various embodiments, the primary filter medium 224 does not accommodate the flow of the air cavity accumulation flow 205 therethrough, and therefore, the air cavity accumulation flow 205 bypasses the primary filter medium 224. In particular, the primary filter stage 220 is configured such that the air cavity accumulation flow 205 flows along the upstream side 225 of the primary filter medium 224 without flowing through the primary filter medium 224.

[0114] In the present example, the primary filter medium 224 extends between a first end 228 and a second end 229. The degassing system 200 has a housing 230 that is spaced apart from an upstream side 225 of the primary filter medium 224 to define a primary fluid flow path 231 from the first end 228 toward the second end 229. A primary fluid inlet 221 is defined toward the first end 228 of the primary filter medium 224 (between the first end 228 of the primary filter medium 224 and the housing 230), and a primary fluid outlet 222 is defined on the second end 229 of the primary filter medium 224. Each of the primary fluid inlet 221 and the primary fluid outlet 222 is on the upstream side 225 of the primary filter medium 224. The primary fluid outlet 222 extends outwardly from the upstream side 225 of the primary filter medium 224. In particular, the primary fluid outlet 222 is defined by an opening between the housing 230 and the second end 229 of the primary filter medium 224.

[0115] In various embodiments, the filtered fluid stream enters the primary filter stage 220 through the primary fluid inlet 221 on the first end 228 and travels along the primary fluid flow path 231 toward the second end 229 of the primary filter medium 224. The primary filter medium 224 is configured such that a portion of the liquid within the filtered fluid stream passes through the primary filter medium 224 to the primary liquid outlet 223, wherein the primary liquid outlet 223 extends outwardly from the downstream side 226 of the primary filter medium 224. The air cavities within the filtered fluid stream do not pass through the primary filter medium 224. The degassing system 200 is generally configured such that the filtered fluid stream sweeps across the upstream side 225 to prevent the air cavities from blocking the liquid stream through the primary filter medium 224. Thus, the first liquid stream 204 passes through the primary filter medium 224, thereby being separated from the air cavity aggregate stream 205 on the upstream side 225 of the primary filter medium 224. The first liquid stream 204 then exits the degassing system 200 through the primary liquid outlet 223 , and the air cavity aggregate stream 205 then exits the degassing system 200 through the primary fluid outlet 222 .

[0116] Under normal operating conditions, the air cavity aggregate flow 205 may constitute up to 35% by volume of the filtered fluid flow. Thus, the first liquid flow 204 may constitute at least 65% by volume of the filtered fluid flow. Under normal operating conditions, the air cavity aggregate flow 205 may constitute at least 5% by volume of the filtered fluid flow. Thus, the first liquid flow 204 may constitute up to 95% by volume of the filtered fluid flow.

[0117] The primary filter media 224 may be generally similar to the Figure 1A and Figure 1B 1. The discussion of the primary filter medium 124 is consistent. The primary filter medium 224 generally lacks a membrane. In the current example, the primary filter medium 224 is arranged in a tubular configuration so that the downstream side 226 defines a central passage 236 extending from a first end 228 to a second end 229. A first end cap 232 is coupled to the first end 228 of the primary filter medium 224, and a second end cap 233 is coupled to the second end 229 of the primary filter medium 224. The first end cap 232 extends across the central passage, while the second end cap 233 defines an opening 234, i.e., the primary liquid outlet 223, in communication with the central passage. In the current example, the first end cap 232 and the second end structure 235 are a single, unitary component, but other configurations are possible.

[0118] In various embodiments, the primary filter medium 224 is formed from a pleated screen. In such embodiments, the primary filter medium 224 may be adjacent to one or more support screens configured to maintain the pleated arrangement of the primary filter medium 224. In an example, the primary filter medium 224 is sandwiched between two support screens. Such support screens, if used, generally do not affect the degassing performance of the primary filter medium 224. The primary filter medium 224 may have a pore size in the range of 20 μm to 200 μm, where the pore size may be the size of the opening in the screen. The primary filter medium 224 may have a pore size in the range of 20 μm to 60 μm, 30 μm to 50 μm, 50 μm to 90 μm, 70 μm to 80 μm, or even 100 μm to 160 μm. Other materials may be used to construct the primary filter medium 224, such as the primary filter medium 224 described above with reference to the drawings. Figure 1A and Figure 1B described.

[0119] The secondary filter stage 240 is generally configured to receive the air cavity aggregate flow 205 from the primary filter stage 220 and separate the air cavity aggregate flow 205 into a second liquid flow 206 and a gas flow 207. The secondary filter stage 240 can have a secondary filter element 243 having a secondary filter medium 242. The secondary filter medium 242 extends from a third end 246 to a fourth end 247 and has an upstream surface 244 and a downstream surface 245. The third end 246 of the secondary filter medium 242 is coupled to the base, and the fourth end 247 of the secondary filter medium 242 is coupled to the open end cap 256.

[0120] The secondary filter stage 240 is configured to receive the air cavity collection flow 205 through a secondary fluid inlet 249, which is in fluid communication with the primary fluid outlet 222 of the primary filter stage 220. The secondary fluid inlet 249 surrounds the primary fluid outlet 222. In this example, the secondary fluid inlet 249 is toward the fourth end 247 of the secondary filter medium 242. The second liquid flow 206 exits the secondary filter stage 240 through the secondary liquid outlet 245, which is the downstream surface 245 of the secondary filter medium 242. The gas flow 207 exits the secondary filter stage 240 through the gas outlet 248. The gas outlet 248 can be defined as toward the fourth end 247 of the secondary filter medium 242. In the current example, the gas outlet 248 can be one or more openings defined by the fluid flow ramp 260. In various embodiments, the secondary filter stage 240 can be in open communication with the surrounding environment, such as the surrounding environment within the hydraulic system that houses the degassing system 200. The surrounding environment within the hydraulic system may be at atmospheric conditions or pressurized, as discussed above with reference to Figure 1A discuss.

[0121] In some embodiments, the gas stream 207 can be released into the atmosphere. In various embodiments, the second liquid stream 206 is configured to flow into the fluid tank 270, similar to the first liquid stream 204. The air cavity collection stream 205 can be left at ambient conditions to naturally separate the second liquid stream 206 and the gas stream 207. The second liquid stream 206 is directed into the fluid tank 270 through the secondary filter medium 242 at least partially under the action of gravity. In the case where the ambient pressure is higher than the atmospheric pressure, the second liquid stream 206 and the gas stream 207 are separated under the action of gravity and the pressure within the tank 270. In various embodiments, the fluid flow from the secondary fluid inlet 249 through the secondary filter medium 242 to the secondary liquid outlet 245 is at least partially driven by gravity. In various embodiments, the fluid flow from the secondary fluid inlet 249 to the gas outlet 248 is driven by gravity.

[0122] In the current example, the secondary filter stage 240 has a substantially impermeable base 241 and sidewalls constructed of secondary filter media 242. Although in the current embodiment, the base 241 and the first end structure 202 of the preliminary filter stage 210 are depicted as forming a single unitary structure, in some other embodiments, the base 241 and the first end structure 202 may be separate components.

[0123] In an example consistent with the current embodiment, the secondary filter medium 242 is arranged in a tubular configuration defining a cavity 250. The primary filter stage 220 is housed within the cavity 250 of the secondary filter medium 242. In particular, the primary filter element 227 and the housing 230 are housed in the cavity 250 of the secondary filter medium 242. In some alternative embodiments, the secondary filter stage 240 does not surround the primary filter stage 220, which is described above with reference to Figure 1A and Figure 1D Discussion. Figure 1A Consistent with the discussion of , the secondary filter media 242 can be constructed from materials and have a configuration.

[0124] Although the system is currently shown with a preliminary filtration stage 210, in some embodiments, the preliminary filtration stage 210 may be omitted or may be a component of the system upstream of the degassing system 200. In the current embodiment, the preliminary filtration stage 210 is positioned below the first end 228 of the primary filter media 224, and therefore below the primary fluid inlet 221.

[0125] In the current example, the housing 230 defines a portion of the preliminary filter stage 210 and the primary filter stage 220. In particular, the housing 230 is coupled to the first end structure 202 and the base 241 around the preliminary filter medium 216. The housing 230 extends in an axial direction around the preliminary filter medium 216 and the primary filter medium 224. The portion of the housing 230 surrounding the preliminary filter medium 216 is generally parallel to the outer boundary 215 of the preliminary filter medium 216. The portion of the housing 230 surrounding the primary filter medium 224 generally tapers toward the second end 229 of the primary filter medium 224. In the current example, the housing 230 tapers radially inward toward the second end 229 of the primary filter medium 224, but in some embodiments, the housing 230 does not taper. The housing 230 can be a single, unitary structure with the first end structure 202, and / or the base 241 or the housing 230 can be separate components. The housing 230 can be composed of the same components as described above with reference to Figure 1A The materials discussed are consistent with the structure.

[0126] The housing 230 also forms part of the secondary filter stage 240. In particular, the housing 230 is disposed within the cavity 250 of the secondary filter element 243 and forms an inner substantially cylindrical containment wall which, together with the secondary filter medium 242 and the base 241, cumulatively defines a settling area 257 in the cavity 250 in which the air cavity aggregate flow 205 can settle and separate into the second liquid flow 206 and the gas flow 207.

[0127] Figure 4 Another exemplary system 300 consistent with some embodiments is depicted. The system 300 is generally similar to the system 300 described above with reference to Figure 3 The system described is consistent, except that flow channel 360 is connected to the second end cap 333 of primary filter element 327 around primary liquid outlet 323 here.Flow channel 360 is configured to extend in fluid tank 370 to guide the first liquid stream 304 to the fluid tank. The gas stream 307 leaving the secondary filter stage 340 can be released in a generally upward direction, and the second liquid stream 306 leaving the secondary filter stage 340 is released into the fluid tank. Although in the current example, flow channel 360 is a closed tubular tube, in some other embodiments, flow channel 360 can be formed by the nozzle extending downward toward the inside of the fluid tank. In certain embodiments, another flow channel (such as a ramp, a pipe or a nozzle) can extend from the base 341 of the secondary filter stage 340 toward the inside of the fluid tank.

[0128] Figure 54 is a flow chart of an exemplary method 400 consistent with some embodiments. A filtered and nucleated fluid stream is generated 410. The filtered and nucleated fluid stream is separated into a first liquid stream and an air cavity collection stream 420. The first liquid is directed into a fluid tank 430. The air cavity collection stream is separated into a gas stream and a liquid stream 440. A second liquid is directed into a fluid tank 450.

[0129] A filtered and nucleated fluid stream 410 is produced by filtering particles in a fluid stream and nucleating gas cavities. Filtering particles and nucleating gas cavities can be achieved in a single step, such as described above with respect to a preliminary filtration stage. In particular, passing the fluid stream through a preliminary filter medium can filter particles in the fluid stream and nucleate gas cavities. Filtering particles and nucleating gas cavities can be achieved in multiple steps. For example, in some embodiments, particles can be filtered from a fluid stream to produce a filtered fluid stream, and then the filtered fluid stream can be passed through a nucleation medium that nucleates gas cavities in the filtered fluid stream. Other methods are also contemplated.

[0130] The filtered and nucleated fluid stream is separated into a first liquid stream and an air cavity collection stream 420. A primary filtration stage may be used to separate the filtered and nucleated fluid stream. In some embodiments, the filtered and nucleated fluid stream is swept along the upstream surface of the primary filter medium to separate the first liquid stream from the air cavity collection stream. The first liquid stream may pass through the primary filter medium. The air cavity collection stream may bypass the primary filter medium. The primary filter medium may be consistent with the primary filter medium discussed above.

[0131] The first liquid stream is directed into the fluid tank 430 by the methods discussed above. In some embodiments, the first liquid stream is directed into the fluid tank under the action of gravity. In some embodiments, the first liquid stream is directed into the fluid tank by using a nozzle, a tube, a flow ramp, or another structure. In some embodiments, the first liquid stream falls into the fluid tank from the primary liquid outlet.

[0132] The air cavity aggregate flow can be separated into a gas flow and a second liquid flow 450 by a variety of methods. The air cavity aggregate flow can be directed to a settling tank. The settling pipe can be consistent with the secondary filtration stage, as discussed herein. In addition, as discussed above, the settling tank can be constructed of a secondary filter medium. In various embodiments, the gas flow and the second liquid flow are separated from the air cavity aggregate flow 450 by naturally releasing the gas flow from the air cavity aggregate flow under atmospheric conditions. In various embodiments, the gas flow and the second liquid flow are separated from the air cavity aggregate flow 450 by naturally releasing the gas flow from the air cavity aggregate flow at an ambient pressure less than 10 psi above atmospheric pressure.

[0133] The second liquid stream is directed into the fluid tank 450 by the methods discussed above. In some embodiments, the second liquid stream is directed into the fluid tank under the action of gravity and ambient pressure. In some embodiments, the second liquid stream is directed into the fluid tank by using a nozzle, a tube, a flow ramp, or another structure. In some embodiments, the second liquid stream falls into the fluid tank from the secondary liquid outlet.

[0134] Description of Exemplary Embodiments

[0135] Embodiment 1. A degassing system comprising:

[0136] a primary filter element having a primary filter media extending between a first end and a second end, the primary filter media having an upstream side and a downstream side;

[0137] a housing spaced from an upstream side of the primary filter medium to define a primary fluid flow path from the first end toward the second end, wherein the system defines a primary fluid inlet between the first end of the primary filter medium and the housing, a primary fluid outlet at the second end of the primary filter medium extending outwardly from the upstream side of the primary filter medium, and a primary fluid outlet extending outwardly from the downstream side of the primary filter medium; and

[0138] A secondary filter element, the secondary filter element having a secondary filter medium, the secondary filter medium having an upstream surface and a downstream surface, the secondary filter medium extending from a third end to a fourth end, wherein the system defines a secondary fluid outlet that is the primary fluid outlet, a secondary fluid outlet that is the downstream surface of the secondary filter medium, and a gas outlet on the fourth end, wherein the secondary fluid inlet is toward the third end.

[0139] Embodiment 2. The system of any one of Embodiments 1 and 3 to 12, wherein the housing tapers toward the second end of the primary filter media.

[0140] Embodiment 3. The system of any one of embodiments 1-2 and 4-12, wherein the first end is configured to be positioned above the second end.

[0141] Embodiment 4. The system of any one of embodiments 1-3 and 5-12, wherein the first end is configured to be positioned below the second end.

[0142] Embodiment 5. The system of any one of embodiments 1 to 4 and 6 to 12, wherein the primary filter medium lacks a membrane.

[0143] Embodiment 6. The system of any one of embodiments 1 to 5 and 7 to 12, wherein the primary filter medium comprises a porous baffle medium defining a pore size range of 10 μm to 200 μm.

[0144] Embodiment 7. The system of any of Embodiments 1-6 and 8-12, wherein the primary filter media is arranged in a tubular configuration, wherein the downstream side defines a central passage extending from the first end to the second end.

[0145] Embodiment 8. The system of any of Embodiments 1-7 and 9-12, wherein the secondary filter media is arranged in a tubular configuration defining a cavity, and the primary filter element and the housing are disposed in the cavity.

[0146] Embodiment 9. The system of any one of Embodiments 1 to 8 and 10 to 12, further comprising a preliminary filtration stage upstream of the primary fluid inlet, wherein the preliminary filtration stage comprises a preliminary filter medium and defines a preliminary fluid flow path into and through the preliminary filter medium to the primary fluid inlet.

[0147] Embodiment 10. The system of any one of embodiments 1-9 and 11-12, wherein the preliminary filter medium is positioned vertically above the primary fluid inlet.

[0148] Embodiment 11. The system of any one of embodiments 1 to 10 and 12, wherein the fluid flow from the secondary fluid inlet to the secondary liquid outlet is driven by gravity.

[0149] Embodiment 12. The system of any one of Embodiments 1 to 11, wherein the fluid flow path from the secondary fluid inlet to the gas outlet is driven by gravity.

[0150] Embodiment 13. A degassing system comprising: a preliminary filtration stage configured to filter particles from a fluid stream and to nucleate gas in the fluid stream to produce a filtered fluid stream;

[0151] a primary filter stage downstream of the preliminary filter stage, the primary filter stage configured to separate the filtered fluid flow into a first liquid flow and an air cavity collection flow; and

[0152] A secondary filter stage is configured to receive the air cavity aggregate flow and separate the air cavity aggregate flow into a second liquid flow and a gas flow.

[0153] Embodiment 14. The degassing system of any one of Embodiments 13 and 15 to 23, wherein the gas flow is in open communication with the surrounding environment.

[0154] Embodiment 15. The degassing system of any one of embodiments 13 to 14 and 16 to 23, wherein the secondary filtration stage is a settling tank in open communication with the ambient environment.

[0155] Embodiment 16. The degassing system of any one of embodiments 13 to 15 and 17 to 23, wherein the settling tank has an impermeable base and sidewalls constructed of secondary filter media.

[0156] Embodiment 17. The degassing system of any one of embodiments 13 to 16 and 18 to 23, wherein the first liquid stream and the second liquid stream are configured to flow into a fluid tank.

[0157] Embodiment 18. The degassing system of any one of Embodiments 13 to 17 and 19 to 23, wherein the primary filtration stage comprises a primary filter medium, and the first liquid flow is configured to pass through the primary filter medium.

[0158] Embodiment 19. The degassing system of any one of embodiments 13 to 18 and 20 to 23, wherein the air cavity focus flow is configured to bypass the primary filter media.

[0159] Embodiment 20. The degassing system of any of Embodiments 13-19 and 21-23, wherein the primary filter media has an upstream side and a downstream side, and the air cavity focusing flow is configured to flow along the upstream side.

[0160] Embodiment 21. The degassing system of any one of Embodiments 13-20 and 22-23, wherein the primary filter media comprises a pleated screen.

[0161] Embodiment 22. The degassing system of any one of embodiments 13 to 21 and 23, wherein the air cavity aggregate flow is configured to constitute up to 35% by volume of the filtered fluid flow.

[0162] Embodiment 23. The degassing system of any one of Embodiments 13 to 22, wherein the air cavity aggregate flow is configured to constitute at least 5% by volume of the filtered fluid flow.

[0163] Embodiment 24. A method comprising:

[0164] filtering particles in a fluid stream and nucleating gas cavities in the fluid stream to produce a filtered and nucleated fluid stream;

[0165] separating the filtered and nucleated fluid stream into a first liquid stream and an air cavity collection stream;

[0166] directing a first liquid stream into a fluid tank;

[0167] separating the air cavity aggregate flow into a gas flow and a second liquid flow; and

[0168] A second liquid stream is directed into the fluid tank.

[0169] Embodiment 25. The method of any one of Embodiments 24 and 26 to 33, wherein separating the air cavity aggregate flow comprises directing the air cavity aggregate flow into a settling tank, wherein the settling tank is at atmospheric pressure.

[0170] Embodiment 26. The method of any one of embodiments 24-25 and 27-33, wherein the second liquid stream is directed into the fluid tank by gravity drive through a side wall of the settling tank, the side wall being constructed of the secondary filter media.

[0171] Embodiment 27. The method of any one of embodiments 24 to 26 and 28 to 33, wherein separating the gas flow from the air cavity aggregate flow comprises natural release of the gas flow under atmospheric conditions.

[0172] Embodiment 28. The method of any one of embodiments 24 to 27 and 29 to 33, wherein separating the air cavity aggregate flow comprises directing the air cavity aggregate flow into a settling tank, wherein the settling tank is at a pressure of less than 10 psi.

[0173] Embodiment 29. The method of any one of Embodiments 24 to 28 and 30 to 33, wherein separating the filtered and nucleated fluid stream comprises passing the filtered and nucleated fluid stream along an upstream surface of the primary filter medium.

[0174] Embodiment 30. The method of any one of Embodiments 24-29 and 31-33, wherein the first liquid stream passes through a primary filter medium.

[0175] Embodiment 31. The method of any one of embodiments 24 to 30 and 32 to 33, wherein the air cavity focus flow bypasses the primary filter media.

[0176] Embodiment 32. The method of any one of Embodiments 24 to 31 and 33, wherein the primary filter medium comprises a pleated screen.

[0177] Embodiment 33. The method of any one of Embodiments 24 to 32, wherein filtering the particles and nucleating the gas cavities comprises passing the fluid flow through a preliminary filter medium.

[0178] It should also be noted that, as used in this specification and the appended claims, the phrase "configured to" describes a system, device, or other structure that is configured to perform a specific task or adopt a specific configuration. The word "configured to" can be used interchangeably with similar words such as "arranged to", "constructed to", "made to", and the like.

[0179] All publications and patent applications in this specification indicate the level of ordinary technicians in the field to which this technology belongs. All publications and patent applications are incorporated herein by reference, and the extent of the citation is just as if each individual publication or patent application is clearly and individually indicated by reference. In the event of any inconsistency between the disclosure of this application and the disclosure of any document incorporated herein by reference, the disclosure of this application shall prevail.

[0180] This application is intended to cover adaptations or variations of the present subject matter.It is to be understood that the above description is intended to be illustrative and not restrictive, and that the claims are not limited to the illustrative embodiments as set forth herein.

Claims

1. A degassing system comprising: a primary filter element having a primary filter media extending between a first end and a second end, the primary filter media having an upstream side and a downstream side; a housing spaced from the upstream side of the primary filter medium to define a primary fluid flow path from the first end toward the second end, wherein the system defines a primary fluid inlet between the first end of the primary filter medium and the housing, a primary fluid outlet extending outwardly from the upstream side of the primary filter medium at the second end of the primary filter medium, and a primary fluid outlet extending outwardly from the downstream side of the primary filter medium; and A secondary filter element, the secondary filter element having a secondary filter medium, the secondary filter medium having an upstream surface and a downstream surface, the secondary filter medium extending from a third end to a fourth end, wherein the system defines a secondary fluid inlet which is the primary fluid outlet, a secondary liquid outlet which is the downstream surface of the secondary filter medium, and a gas outlet on the fourth end, wherein the secondary fluid inlet is toward the third end.

2. The degassing system of claim 1, wherein: The housing tapers toward the second end of the primary filter media.

3. The degassing system of claim 1, wherein: The first end is configured to be positioned above the second end.

4. The degassing system of claim 1, wherein: The first end is configured to be positioned below the second end.

5. The degassing system of claim 1, wherein: The primary filter media lacks a membrane.

6. The degassing system of claim 1, wherein: The primary filter media has a porous baffle media defining a pore size range of 10 μm to 200 μm.

7. The degassing system of claim 1, wherein: The primary filter media is arranged in a tubular configuration wherein the downstream side defines a central passage extending from the first end to the second end.

8. The degassing system of claim 1, wherein: The secondary filter media is arranged in a tubular configuration defining a cavity, and the primary filter element and the housing are disposed in the cavity.

9. The degassing system of claim 1, further comprising a preliminary filtration stage upstream of the primary fluid inlet, wherein: The preliminary filter stage includes a preliminary filter media and defines a preliminary fluid flow path into and through the preliminary filter media to the primary fluid inlet.

10. The degassing system of claim 9, wherein: The preliminary filter media is positioned vertically above the primary fluid inlet.

11. The degassing system of claim 1, wherein: Fluid flow from the secondary fluid inlet to the secondary fluid outlet is driven by gravity.

12. The degassing system according to any one of claims 1 to 11, wherein: The fluid flow path from the secondary fluid inlet to the gas outlet is driven by gravity.

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