System and method for deaeration

Abstract

To provide a deaerator for removing air from a fluid used in a recirculation system such as a hydraulic system.SOLUTION: A deaerator 100 includes: a gas nucleating media 110 configured to induce nucleation of a gas in a fluid to form a gas cavity, the gas nucleating media having a base fiber surface area of at least 10 m2 / m2, as measured by the Carmen-Kozeny method, and an average pore size of 30 μ m or less, as measured by ASTM F316; a pore barrier 130 downstream of the gas nucleating media, the pore barrier comprising openings of a size of 250 μm or less; and a gap 135 between the gas nucleating media and the pore barrier.SELECTED DRAWING: Figure 2C

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 798,272, filed January 29, 2019, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE INVENTION This application relates to a system and method for degassing a fluid. [Background technology]

[0003] Various systems that utilize fluids can benefit from the removal of air (e.g., degassing) from the fluid. Air can accumulate within the fluid, especially in systems where the same fluid remains within the system for an extended period of time. For example, in systems where the fluid circulates multiple times, such as hydraulic systems, air can accumulate within the fluid, reducing system performance.

[0004] Hydraulic systems, particularly hydraulic machines, rely on hydraulic fluid to perform work. Common examples of hydraulic systems include hydraulic machines, hydraulic drive systems, hydraulic transmission systems, hydraulic brakes, and others. Because hydraulic fluids typically reside within a system for extended periods and experience periods of high and low pressure, air can accumulate within the fluid. Air within a fluid can exist in various forms, such as dissolved air or free air. Free air can include entrained air and bubbles. The presence of air can cause pump cavitation, with symptoms such as increased component wear and noise, or a decrease in the fluid's bulk modulus, reducing the efficiency and controllability of the hydraulic system.

[0005] It would be desirable to provide a system and method for degassing a fluid.It would further be desirable to provide a system and method for degassing a hydraulic fluid that is compatible with hydraulic systems. Summary of the Invention [Means for solving the problem]

[0006] In accordance with the principles of the present disclosure, a degasser is provided. The degasser includes a gas nucleation medium. A growth medium can be disposed adjacent to the gas nucleation medium. A porous barrier is disposed adjacent to the growth medium. The degasser can be part of a system for removing gas (e.g., air) from a fluid, the system including a tank having a fluid inlet and a fluid outlet, the tank having a fluid flow path from the fluid inlet to the fluid outlet, the degasser being within the fluid flow path.

[0007] A method for removing gas (e.g., air) from a fluid is provided. The method includes passing the fluid through a degasser. The degasser defines a fluid flow path and includes a gas nucleation medium disposed in the fluid flow path. A growth medium is disposed in the fluid flow path downstream of the gas nucleation medium. A porous barrier is disposed in the fluid flow path downstream of the growth medium.

[0008] A system for removing gas from a fluid is provided. The system includes a tank having a fluid inlet and a fluid outlet, the tank having a fluid flow path from the fluid inlet to the fluid outlet, and a degasser. The system includes a gas nucleation medium. A growth medium can be disposed adjacent to the gas nucleation medium. A porous barrier is disposed adjacent to the growth medium.

[0009] The degasser can include a gas nucleation medium, a porous barrier adjacent to the gas nucleation medium, and a gap between the gas nucleation medium and the porous barrier. The porous barrier can have openings of a size of 250 μm or less. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic flow diagram of a hydraulic system according to one embodiment. [Figure 2A] 2 is a schematic cross-sectional view of a degassing device used in the hydraulic system of FIG. 1 according to an embodiment. [Figure 2B] 2 is a schematic cross-sectional view of a degassing device used in the hydraulic system of FIG. 1 according to an embodiment. [Figure 2C] 2 is a schematic cross-sectional view of a degassing device used in the hydraulic system of FIG. 1 according to an embodiment. [Figure 2D] 2 is a schematic cross-sectional view of a degassing device used in the hydraulic system of FIG. 1 according to an embodiment. [Figure 3] 2 is a schematic cross-sectional view of a degassing device used in the hydraulic system of FIG. 1 according to an embodiment. [Figure 4] 1 is a graph of the data collection settings used in the examples. [Figure 5A] 1 is a graph showing the results of Example 1. [Figure 5B] 1 is a graph showing the results of Example 1. [Figure 5C] 1 is a graph showing the results of Example 1. [Figure 6A] 1 is a graph showing the results of Example 2. [Figure 6B] 1 is a graph showing the results of Example 2. [Figure 6C] 1 is a graph showing the results of Example 2. [Figure 7A] 1 is a graph showing the results of Example 3. [Figure 7B] 1 is a graph showing the results of Example 3. [Figure 7C] 1 is a graph showing the results of Example 3. [Figure 7D] 1 is a graph showing the results of Example 3. [Figure 8A] 1 is a graph showing the results of Example 3. [Figure 8B] 1 is a graph showing the results of Example 3. [Figure 8C] 1 is a graph showing the results of Example 3. [Figure 8D] 1 is a graph showing the results of Example 3. [Figure 9A] 1 is a graph showing the results of Example 4. [Figure 9B] 1 is a graph showing the results of Example 4. [Figure 10A] 1 is a graph showing the results of Example 6. [Figure 10B] 1 is a graph showing the results of Example 6. [Figure 11A] 1 is a graph showing the results of Example 7. [Figure 11B] 1 is a graph showing the results of Example 7. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure relates to systems and methods for removing gases, such as air, from fluids. The systems and methods of the present disclosure are particularly useful for removing air (e.g., degassing) from fluids used in recirculating systems, such as hydraulic systems.

[0012] The term "fluid" is used in this disclosure to describe a substance that is in the liquid phase. A fluid may have gas compounds dissolved or entrained in it.

[0013] The terms "degass" and "degassing" are used herein to refer to the removal of air or other gases from a fluid.

[0014] The term "adjacent" is used herein to mean "next to." An "adjacent" feature may or may not touch the adjacent feature. For example, "adjacent" features may be separated by a gap.

[0015] The term "directly adjacent" is used herein to mean in contact with adjacent features. The term "directly adjacent" may also be used to indicate the absence of intervening features.

[0016] As used herein, the term "substantially" has the same meaning as "significantly" and can be understood to modify the following term by at least about 75%, at least about 90%, at least about 95%, or at least about 98%. As used herein, the term "not substantially" has the same meaning as "not significantly" and can be understood to have the opposite meaning of "substantially," i.e., modifying the following term by 25% or less, 10% or less, 5% or less, or 2% or less.

[0017] The term "nominal" in the context of mesh size, pore size, fiber diameter, or wire diameter is used herein to refer to the stated or reported mesh or pore dimensions of a commercially available product.

[0018] The unit "psi" is used herein to refer to pounds-force per square inch. 1 psi is equivalent to approximately 6900 Pascals, or approximately 6.9 kPa.

[0019] References to standard methods (e.g., ASTM, TAPPI, AATCC, etc.) refer to the latest available version of the method at the time of the filing of this disclosure, unless otherwise specified.

[0020] The term "about" is used herein in conjunction with numerical values ​​to include normal variations in measurements expected by one of ordinary skill in the art, and is understood to have the same meaning as "approximately," covering typical tolerances, such as ±5% of the stated value.

[0021] Words such as "a," "an," and "the" are not intended to refer to only a single entity, but include general classes for which specific examples may be used for illustration.

[0022] The words "a," "an," and "the" are used interchangeably with the term "at least one." The phrases "at least one of" and "including at least one of," followed by a list, refer to any one item in the list, and any combination of two or more items in the list.

[0023] As used herein, the term "or" is generally used in its ordinary sense, including "and / or," unless the context clearly dictates otherwise. The term "and / or" refers to one or all of the listed elements or a combination of any two or more of the listed elements.

[0024] The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.; or 10 or less includes 10, 9.4, 7.6, 5, 4.3, 2.9, 1.62, 0.3, etc.). When a range of values ​​is "up to" a particular value or "at least" a particular value, then that value is included within the range.

[0025] The words "preferred" and "preferably" refer to embodiments that may offer certain benefits, under particular circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present disclosure, including the claims.

[0026] According to some embodiments, gas may be removed from a fluid by inducing gas nucleation and allowing the gas to escape. Nucleation may be induced by contacting the fluid with a material that provides nucleation sites for the gas. Gas nucleation may result in the formation of free gas cavities. The gas cavities may further grow and / or coalesce in one or more stages to increase the size of the gas cavities, thereby increasing their buoyancy and increasing the rate at which the gas rises within the fluid. The terms "gas cavities" and "gas bubbles" are used interchangeably herein.

[0027] Certain types of vehicles, such as excavators, loaders, skid steer loaders, and the like, include on-board hydraulic systems. For various reasons, including improved efficiency, there is a desire to improve hydraulic systems, particularly to reduce the size of hydraulic fluid tanks. However, smaller tanks can exacerbate the problem of air in hydraulic fluids (e.g., oil) due to shorter fluid residence times within the tank. Short residence times can prevent air from escaping from the fluid before it is withdrawn from the tank again. The disclosed devices and methods can be advantageous due to their ability to remove air, including dissolved air, small air cavities, and entrained air, from fluids, such as hydraulic fluid or oil. The devices and methods can be further advantageous due to their ability to be miniaturized for use within smaller hydraulic tanks, such as those used within mobile hydraulic systems used on vehicles, e.g., excavators, loaders, and skid steer loaders, or for use within other systems with small hydraulic tanks.

[0028] A schematic diagram of a hydraulic system 1 according to the present disclosure is shown in FIG. 1. Hydraulic system 1 includes a tank 10 for containing hydraulic fluid. System 1 also includes a pump 20 that transfers fluid from tank 10 to one or more hydraulic applications 30. Examples of hydraulic applications 30 include hydraulic machines, hydraulic drive systems, hydraulic transmission systems, hydraulic brakes, and the like. Fluid flows from tank 10 to pump 20 via output line 11 and from pump 20 to hydraulic application 30 via output line 21. Pump 20 applies pressure to the fluid; therefore, the fluid in output line 21 is under a higher pressure than the fluid in tank 10 or output line 11. The pressurized fluid may be used to perform work in the hydraulic application. Fluid may return from hydraulic application 30 to the tank via return line 31.

[0029] System 1 includes a degasser 100. The degasser 100 is configured to remove at least a portion of gas dissolved and / or trapped in the hydraulic fluid. The degasser 100 may be positioned within the tank 10 as shown, or may be located elsewhere in the system 1. For example, the degasser 100 may be located inline along the return line 31. According to one embodiment, the degasser 100 is disposed in the flow path of the hydraulic fluid flowing through or within the tank 10. For example, the degasser 100 may be disposed in the flow path of the fluid draining from the return line 31 to the tank 10. The flow direction may be from top to bottom, as shown in FIG. 1, where the fluid from the return line 31 flows into the tank 10 from above. At least a portion of the fluid from the return line 31 may enter the degasser 100.

[0030] System 1 may include additional components such as additional tanks, lines, pumps, meters, controls, and the like.

[0031] 2A-2D show schematic cross-sectional views of a degassing apparatus 100 according to the present disclosure. The degassing apparatus 100 includes a gas nucleation medium 110 disposed in a fluid flow path within the tank 10. The degassing apparatus 100 further includes a growth medium 120 downstream of the gas nucleation medium 110. A porous barrier 130 may be disposed downstream of the gas nucleation medium 110 and / or the growth medium 120.

[0032] The gas nucleation medium 110, growth medium 120, and / or porous barrier 130 may be arranged in a flow-through configuration within the flow path. In some embodiments, at least one of the layers of the gas nucleation medium 110, growth medium 120, and / or porous barrier 130 is arranged in a cross-flow configuration. The term "flow-through configuration" is used herein to refer to an arrangement in which fluid flows through the medium. The term "cross-flow configuration" is used herein to refer to an arrangement in which fluid flows across (or over) the medium.

[0033] The degasser 100 may have an open interior 144 with an inlet 101 for receiving an incoming fluid flow. The inlet 101 may be defined as an opening in the first end cap 141. The particular inlet 101 shown is configured as a top inlet that opens into the open interior 144. Alternative inlet arrangements, locations, and orientations are possible. For example, the inlet 101 may be located on the bottom or side of the degasser 100. However, the top inlet shown is convenient and advantageous. The inlet 101 may include features for coupling the degasser 100 with the tank 10 and directing the fluid flow into the open interior 144. The degasser 100 may further include additional or alternative flow paths, such as case drain flow (excess flow from the pump), waste flow, overflow, return flow, and the like. Such additional or alternative flow paths may flow back to the tank 10. In one embodiment, a case drain flow 152 is channeled into the degasser 100. For example, case drain flow 152 can be channeled into gap 135 between porous barrier 130 and growth medium 120 through secondary inlet 146 in first end cap 141, as shown in FIG. 2D.

[0034] The gas nucleation medium 110 may define an open interior 144 such that the gas nucleation medium 110 at least partially surrounds the open interior 144. The gas nucleation medium 110 may be disposed within a fluid flow path such that at least a portion of the fluid entering the open interior 144 flows through the gas nucleation medium 110. In the illustrated example, the gas nucleation medium 110 is disposed in a cylindrical shape around the open interior 144. The cylinder may have an open top including the inlet 101 and a closed bottom defined by a second end cap 142.

[0035] A layer of growth medium 120 may be disposed adjacent to the gas nucleation medium 110. The growth medium 120 may be directly adjacent to (e.g., in contact with) the gas nucleation medium 110. The growth medium 120 may be disposed within a fluid flow path such that the fluid flows through the gas nucleation medium 110 and then through the growth medium 120. The growth medium 120 may be coaxial with the gas nucleation medium 110 and form a circumscribing cylinder at least partially therearound.

[0036] The degasser 100 may further include a porous barrier 130 defining an opening 131. The porous barrier 130 may be positioned adjacent to the growth medium 120, as shown in FIGS. 2A and 2B. In some embodiments, the degasser 100′ is otherwise similar to the degasser 100 of FIG. 2A and includes a gas nucleation medium 110 and a porous barrier 130, but does not include a growth medium, as shown in FIG. 3. In some embodiments, the porous barrier 130 is adjacent to, but not directly adjacent to (e.g., not in contact with), the growth medium 120 or the gas nucleation medium 110, leaving a gap 135 between the porous barrier 130 and the growth medium 120 or between the porous barrier 130 and the gas nucleation medium 110, as shown in FIGS. 2A and 3, respectively. In some embodiments, the porous barrier 130 is directly adjacent to the growth medium 120, such that there is no gap between the porous barrier 130 and the growth medium 120, as shown in FIG. 2B. In some embodiments, the porous barrier 130 is formed by a strainer at the outlet 18 of the tank 10, as shown in FIG. 2C. In such embodiments, a gap 135 may be formed between the growth medium 120 and the porous barrier 130 at the outlet 18. The porous barrier 130 may form a cylinder coaxial with and at least partially circumscribed around the growth medium 120 and the gas nucleation medium 110. In some embodiments, the gas nucleation medium 110, the growth medium 120, and the porous barrier 130 define a cylindrical body. A first end (e.g., top) of the cylindrical body may be partially closed by a first end cap 141. A second end (e.g., bottom) of the cylindrical body may be closed by a closed second end cap 142.

[0037] When the degassing apparatus 100 is in use, a fluid is flowed into the open interior 144 through the top inlet 101. After the fluid enters the open interior 144, it may pass through the gas nucleation medium 110. The gas nucleation medium 110 may cause at least some dissolved gas in the fluid to nucleate and form free air, such as a small gas cavity (first-stage gas cavity). As the fluid further passes through the growth medium 120 downstream of the gas nucleation medium 110, more gas may come out of solution and add to the existing gas cavity, causing the gas cavity to grow. The gas cavities may also merge in the growth medium 120. Growth and / or condensation may form a larger gas cavity (second-stage gas cavity). The second-stage gas cavity may begin to rise upward in the gap 135 between the growth medium 120 and the porous barrier 130. In some embodiments, the opening 131 in the porous barrier 130 may be generally smaller in size than the second-stage gas cavity created by the growth medium. The porous barrier 130 may act to retain the gas cavity within the gap 135, preventing it from prematurely diffusing into the fluid within the tank 10. Without wishing to be bound by theory, it is believed that the porous barrier may cause the gas cavity to further grow and / or condense upstream of the porous barrier 130 and rise upward within the gap 135. If the porous barrier 130 is wet, a gas pocket (larger gas cavity) may form at the top of the gap 135 from the rising condensed gas. If the gas pocket becomes large enough, sufficient pressure builds up to cause the gas pocket to break through the wet porous barrier 130. When the gas breaks through the porous barrier, it may dry the porous barrier in adjacent areas, allowing the air pocket to escape. However, even if that area of ​​the porous barrier remains submerged and wet, gas cavities at the top of the gap may pass through the porous barrier as large bubbles and rise to the surface. If the degasser is submerged, the gas pockets may be large and buoyant enough to rise to the surface and escape from the surface. Once the gas pockets are cleared, the porous barrier 130 will rewet and the process can be repeated.

[0038] 2A-2D and 3, the gas nucleation medium 110 can be made of any suitable material capable of inducing gas nucleation. While not wishing to be bound by theory, it is believed that several aspects of a gas nucleation medium affect the effectiveness and efficiency of the medium in inducing nucleation based on their effect on the chemical and physical interactions of the medium 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 medium; the accessible surface area; the fiber size (e.g., diameter or cross-sectional dimension); the medium pore size; the presence of sharp edges or corners; the surface roughness; the chemical composition of the medium (e.g., fibers and binder); the oleophilicity / oleophobicity of the medium; the presence and number of fiber crossovers; the orientation angle of adjacent fibers; their orientation relative to the direction of flow; the tortuosity of the flow path; the solids fraction of the media sheet; the permeability of the media sheet; the thickness of the media sheet; the residence time of the fluid in the media; the Peclet number (e.g., the ratio of advective to diffusive transport rates) of the dissolved gas from the fluid to the media; and the differential pressure of the sheet and individual fibers.

[0039] For example, media with appropriate (accessible) surface area, fiber size, and media pore size are believed to be beneficial to nucleation efficiency. The accessible surface area of ​​a fiber can be measured as the basic fiber surface area of ​​the media, which is the area that a fluid can access (e.g., contact), m 2 m per unit of media sheet bulk surface area 2 The term "basic surface area" is understood to mean the total surface area (including intrapore and interfiber surface area) in square meters. The elemental fiber surface area of ​​the media can be determined by Branauer-Emmett-Teller (BET) analysis or from the Carmen-Kozeny relationship (explained in detail in Examples 3 and 4 below). The bulk surface area of ​​a media sheet is understood to mean the area calculated as the length times the width of the media sheet (for pleated media, the pleat height and number of pleats may be used to calculate the width). The elemental fiber surface area of ​​a gas nucleation media, as measured by either the BET method or the Carmen-Kozeny method, is understood to mean the area calculated as the length times the width of the media sheet. 2 / m 2 Over 1.5m 2 / m 2Over 2m 2 / medium 2 More than 5m 2 / medium 2 More than 10m 2 / medium 2 Over 25m 2 / m 2 Over 50m 2 / m 2 or more, or 100m 2 / m 2 The surface area of ​​the gas nucleation medium can be greater than 200 m as measured by either the BET or Carmen-Kozeny method. 2 / m 2 Below, 150m 2 / m 2 Below, 100m 2 / m 2 Below, 50m 2 / m 2 Below 30m 2 / m 2 Below, 10m 2 / m 2 Below, 6m 2 / m 2 or less, or 4m 2 / m 2 In one embodiment, the base fiber surface area of ​​the gas nucleation medium can be less than 1 m2 as measured by the BET method. 2 / m 2 Over 2m 2 / m 2 More than 5m 2 / m 2 In one embodiment, the gas nucleation medium has an elemental fiber surface area of ​​100 m2 or more as measured by the BET method. 2 / m 2 Below, 50m 2 / m 2 Below, 20m 2 / m 2 In one embodiment, the fiber surface area of ​​the gas nucleation medium is from 1 to 75 m as measured by the BET method. 2 / m 2 In one embodiment, the gas nucleation medium has an elemental fiber surface area of ​​5 to 50 m as measured by the BET method. 2 / m 2In one embodiment, the basic fiber surface area of ​​the gas nucleation medium is 1 m2 as measured by the Carmen-Kozeny method. 2 / m 2 More than 5m 2 / m 2 or more, or 10m 2 / m 2 In one embodiment, the gas nucleation medium has an elemental fiber surface area of ​​200 m2 or greater as measured by the Carmen-Kozeny method. 2 / m 2 Below, 100m 2 / m 2 Below, 50m 2 / m 2 Below, 20m 2 / m 2 In one embodiment, the gas nucleation medium has an elemental fiber surface area of ​​5 to 75 m as measured by the Carmen-Kozeny method. 2 / m 2 In one embodiment, the gas nucleation medium has an elemental fiber surface area of ​​10 to 50 m as measured by the Carmen-Kozeny method. 2 / m 2 is.

[0040] Fiber size is used herein to refer to the diameter or cross-sectional dimension of the fibers in the medium. Fiber diameter or cross-sectional dimension may be determined optically for larger fibers or using SEM for smaller fibers. Fiber size of fibers in a gas nucleation medium may vary from fiber to fiber and along a given fiber. Fiber size may also vary along a gradient from the upstream side of the medium to the downstream side of the medium. Fibers in a gas nucleation medium may have a fiber size of at least 10 nm (nanometers), at least 50 nm, or at least 100 nm. Fibers in a gas nucleation medium may have a fiber size of up to 10 μm (micrometers) or up to 100 μm.

[0041] Media pore size is understood to mean the size of individual pores in a media sheet as determined by ASTM F316-03 or ASTM D6767. Pores in a gas nucleation medium may have an average pore size of 0.5 μm or more, 1 μm or more, or 5 μm or more. Pores in a gas nucleation medium may have an average pore size of 5 μm or less, 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, pores in a gas nucleation medium may have an average pore size of 5 μm to 100 μm. Pores in a gas nucleation medium may have a maximum pore size of 1 μm or more, 5 μm or more, or 10 μm or more. Pores in a gas nucleation medium may have a maximum pore size of 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, pores in a gas nucleation medium may have a maximum pore size of 5 μm to 200 μm. The values ​​listed here are determined by ASTM F316-03.

[0042] The chemical composition of the media and its oleophilicity / oleophobicity are believed to affect nucleation. The chemical composition of the media may include the chemical composition of the fibers in the media and / or the chemical composition of any binders or other components used in the media. The fibers may include any suitable fibrous material, including woven or nonwoven media made from organic or inorganic materials or combinations thereof. The media may include various structures combining different materials, such as core-and-sheath structures, side-by-side structures, islands-in-the-sea structures, and others. The fibers may contain a single material component or two or more material components within a single fiber, including a mixture of materials. For example, the fibrous material may include one or more of 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 fibers. In one embodiment, the filtration media used as gas nucleation media is made of microglass and synthetic fibers. Examples of suitable filtration 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. Patent Application Publication Nos. 2012 / 0234748 and 2017 / 0225105. The media can include various binders, such as acrylic resins, phenolic resins, or epoxy resins.

[0043] Preferably, the gas nucleation medium has suitable oleophilic / oleophobic properties to induce nucleation and release the formed gas cavities into the fluid stream (as opposed to being "trapped" on the surface of the fiber). In one embodiment, the gas nucleation medium is oleophobic. The oleophobicity rating (oleorepellency) of the medium may be measured according to AATCC Method 118 (e.g., 118-2013) using KAYDOL White Mineral Oil from Sonnerborn LLC (Petrolia, PA). The oleophobicity range based on this test is 0 to 8, with a rating of 0 meaning the medium is not oleophobic. An oleophobic medium has a rating of 1 or greater. The gas nucleation medium may have an oleophobicity rating of 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 6 or greater. The gas nucleation medium may have an oleophobicity rating of 8 or less, 7 or less, 6 or less, 5 or less, or 4 or less. In one embodiment, the gas nucleation medium has an oleophobicity rating of 2 to 8 or 3 to 8. The oleophobicity of a material can also be expressed as the contact angle of an oil droplet on a single fiber in air, which can be measured by dispensing air bubbles or oil droplets onto the fiber and measuring the contact angle using, for example, a microcontact angle meter (e.g., an MCA-3 meter available from Kyowa Interface Science Co., Ltd., Niiza, Japan). The gas nucleation medium can have an oil 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 an oil contact angle of up to 120°, or up to 150°.

[0044] The gas nucleation medium can be inherently oleophobic (e.g., made of oleophobic fibers) and / or can be treated to be oleophobic, for example, using an oleophobic treatment compound. Typically, the oleophobic material is a fluorochemical, such as a fluoropolymer, with a high density of terminal CF3 pendant groups exposed on its surface. In certain embodiments, the gas nucleation medium, or the oleophobic treatment compound (e.g., a fluorochemical treatment compound) applied as a surface coating to the gas nucleation medium, can be made from a perfluoropolymer, such as a perfluoroacrylate, perfluorourethane, perfluoroepoxy, perfluorosilicone, perfluoroalkane, perfluorodioxolane, or copolymers of these materials.

[0045] Although gas nucleation media made from inherently oleophobic materials can be used, typically, a fluorochemical treatment compound is coated onto conventional filtration media to make it oleophobic. The coating material can be, for example, an oleophobic polymer or another polymer that can be made oleophobic through a multi-step process. Typically, the fluorochemical treatment compound, dissolved or suspended in a liquid carrier (e.g., organic solvent or water), is applied to conventional filtration media by dipping or spraying. Alternatively, the coating can be applied through the gas phase using processes such as chemical vapor deposition (CVD).

[0046] Exemplary fluoropolymers include: perfluoroacrylates dissolved in solvents, such as those available under the tradenames FLUOROPEL series from Cytonix (Beltsville, MD), SRA 450 or SRA451 from 3M Company (Maplewood, MN), and ADVAPEL 806 from Advanced Polymer Incorporated (Carlstadt, NJ); perfluorodioxolanes dissolved in solvents, such as those available under the tradenames TEFLON AF from Chemours (Wilmington, DE); perfluoroacrylate emulsions suspended in water, such as those available under the tradenames UNIDYNE from Daikin (Orangeburg, NY), CAPSTONE from Chemours (Wilmington, DE), PHOBOL from Huntsman (The Woodlands, TX), or ADVAPEL 734 from Advanced Polymer Incorporated (Carlstadt, NJ); and 3M and perfluorourethane suspended in water, such as that available under the trade name SRC220 from Company (Maplewood, MN). The gas nucleation medium can also be made oleophobic by applying a coating of fluoropolymer via a plasma polymerization process, such as a perfluoroacrylate coating from P2i (Savannah, GA).

[0047] In certain embodiments, the gas nucleation medium is prepared by applying a non-oleophobic coating to a conventional filtration medium and then modifying it to become oleophobic. For example, a polyalcohol polymer can be applied to the conventional filtration medium and a perfluorosilane or perfluoroacyl chloride can be grafted onto the polymer. Alternatively, a polyamine can be applied to the conventional filtration medium and a perfluoroacrylate can be grafted onto the polymer.

[0048] The surface energy of a polymeric material can be determined by constructing a Zisman plot using an appropriate fluid, for example, according to ASTM D7490-13. The surface energy of a material may also be determined using the Owens-Wendt method. Fibers in a gas nucleation medium exhibit a surface energy of 6 mJ / m 2 (millijoules per square meter) or more, 10mJ / m 2 More than 15mJ / m 2 More than 20mJ / m 2 or more than 40mJ / m 2 The fibers in the gas nucleation medium may have a surface energy of 400 mJ / m or more. 2 Below, 300mJ / m 2 Below, 200mJ / m 2 Below, 150mJ / m 2 Below, 100mJ / m 2 or less, or 50mJ / m 2 For example, a fiber in a gas nucleation medium may have a surface energy of 10 mJ / m 2 to 200 mJ / m 2 The values ​​listed here are determined by ASTM D7490-13.

[0049] The geometric configuration of fibers in a gas nucleation medium can affect nucleation. For example, the presence of sharp edges or corners and surface roughness can improve nucleation. The configuration of fiber intersections, the orientation angle of adjacent fibers, the orientation of the fiber surface relative to the direction of flow, and the tortuosity of the flow path can also affect nucleation. According to some embodiments, a gas nucleation medium includes fibers with sharp edges or corners. For example, the fibers can have a cross-section that is not smooth (e.g., not circular or elliptical). The cross-section of the fiber can be polygonal or have an irregular shape with corners (e.g., corners less than 180°, less than 120°, or less than 90°). The gas nucleation medium includes fibers with circular, star-shaped, square, rectangular, trilobe, clover-shaped, or polygonal cross-sections. The cross-section can be constant or vary throughout the length of the fiber.

[0050] The surface roughness of a material can be determined as the root-mean-square roughness using atomic force microscopy (AFM), cross-sectional SEM or transmission electron microscopy (TEM), or a profilometer. Measurements can be performed on a fixed surface area, e.g., a square, with a dimension half the fiber diameter. Fibers of gas nucleation media can have a surface roughness of 1 nm or more, 10 nm or more, 25 nm or more, 50 nm or more, or 100 nm or more. Fibers of gas nucleation media can have a surface roughness of 1000 nm or less, 500 nm or less, or 200 nm or less. For example, fibers of gas nucleation media can have a surface roughness of 10 nm to 500 nm. The values ​​listed herein are determined by a profilometer.

[0051] Surface roughness can also be characterized using various other parameters, such as skewness, kurtosis, etc. These surface features may indicate a degree of asymmetry (e.g., exhibiting sharper peaks or deeper pits). Asymmetry can be expressed as skewness measured using AFM, fiber cross-section SEM, or a surface profilometer. The skewness of a fiber can be -10 or greater, -8 or greater, or -6 or greater. The skewness of a fiber can be 6 or less, 8 or less, or 10 or less. For example, the skewness of a fiber can be -8 to 8. The values ​​listed here are determined by a surface profilometer.

[0052] Kurtosis is another measure of surface roughness, indicating the sharpness of sharp features. Kurtosis may be measured using an AFM, fiber cross-section SEM, or surface profilometer. Fibers of gas nucleation media may have a kurtosis of at least -10, -8, or -6. Fibers of gas nucleation media may have a kurtosis of 6 or less, 8 or less, or 10 or less. For example, the kurtosis of the fibers may be between -8 and 8. Certain combinations of surface roughness, kurtosis, and kurtosis may result in favorable nucleation properties. For example, high roughness and high kurtosis may be beneficial for nucleation. The values ​​listed here are determined by a surface profilometer.

[0053] It is believed that increasing the number of fiber crossings may increase nucleation to some extent. Fiber crossings are understood to mean contact points between two fibers. Furthermore, it is believed that several ranges of the angle of orientation of adjacent fibers and the angle of fiber orientation relative to the direction of flow may be beneficial for nucleation. For example, the fibers in the gas nucleation medium may be randomly oriented to achieve a range of orientation angles. In some embodiments, adjacent fibers in the gas nucleation medium are not axially aligned with each other.

[0054] Aspects that affect the residence time or differential pressure of the fluid in the media can also affect nucleation. For example, face velocity, media sheet solids fraction, media sheet permeability, media sheet thickness, Peclet number (e.g., ratio of convective to diffusive transport rates) of dissolved gases from the fluid to the media, tortuosity of flow paths within the media, and orientation (e.g., angle) of the media sheet relative to the main flow direction can affect nucleation.

[0055] The face velocity of the fluid relative to the gas nucleation media sheet may be determined as the volumetric flow rate per bulk media surface area. The face velocity may be 0.01 cm / sec or greater, 0.1 cm / sec or greater, 0.5 cm / sec or greater, 1.0 cm / sec or greater, or 5.0 cm / sec or greater. There is no desirable upper limit to the face velocity, but in practice the face velocity may be 50 cm / sec or less, 20 cm / sec or less, or 10 cm / sec or less.

[0056] The solids fraction of a porous material is the ratio of the volume of solids to the total volume of the porous material. Gas nucleation media sheets can have a solids fraction of 5% or more, 10% or more, or 20% or more. Gas nucleation media sheets can have a solids fraction of 98% or less, 90% or less, 75% or less, 50% or less, 40% or less, or 30% or less.

[0057] The air permeability of a filtration media is defined as the volumetric air flow rate through a specified area of ​​filtration media at a specified pressure drop. The method for measuring air permeability is ASTM D737-04. Gas nucleation media sheets are designed to withstand 1 ft2 of air at 0.5 inches of water. 3 / min / ft 2 or more (0.305m at 125Pa 3 / min / m 2 or more), 10 ft at 0.5 inches of water 3 / min / ft 2 or more (3.05 mm at 125 Pa 3 / min / m 2 or more), or 50 ft at 0.5 inches of water 3 / min / ft 2 or more (15.2m at 125Pa 3 / min / m 2The gas nucleation media sheet can have a permeability of 500 ft at 0.5 inches of water. 3 / min / ft 2 Below (152m at 125Pa 3 / min / m 2 (less than 0.5 inches of water at 400 ft 3 / min / ft 2 Below (123m at 125Pa 3 / min / m 2 or less), or 300 ft at 0.5 inches of water 3 / min / ft 2 Below (91.4m at 125Pa 3 / min / m 2 For example, the gas nucleation media sheet may have a permeability of 0.5 m at 125 Pa or less. 3 / min / m 2 100m from 3 / min / m 2 The permeability may be

[0058] The gas nucleation media sheet may have an initial clean differential pressure of 0.01 psi or less, 1 psi or less, or 100 psi or less according to ISO 16889 run at a suitable face velocity, for example, 0.5 cm / sec.

[0059] The Peclet number indicates the ratio of the advective to diffusive transfer rates of a dissolved gas from a fluid to a medium and is calculated as the length (e.g., fiber diameter) times the velocity (e.g., face velocity) divided by the diffusion coefficient. Gas nucleation media sheets can have Peclet numbers of 0.05 or greater, 0.1 or greater, 0.5 or greater, 1 or greater, or 10 or greater. Gas nucleation media sheets can have Peclet numbers of 1000 or less, 2500 or less, 10,000 or less, or 50,000 or less. For example, gas nucleation media sheets can have Peclet numbers of 0.5 to 10,000.

[0060] The angle of the fibers relative to the flow stream can be determined, for example, using a CT (computer-aided tomography) scan of the medium as a weighted average of the angle of the fibers relative to the direction of flow. The angle can be 0° (degrees) or greater, 10° or greater, or 30° or greater. The angle can be 90° or less, 80° or less, or 60° or less. For example, the angle can be between 10° and 80°.

[0061] The stiffness of the fibers in the gas nucleation medium can also affect flow characteristics and therefore nucleation. Stiffness can be measured as the flexural modulus of the fiber or base material, for example, according to ASTM D790. For non-polymeric materials, the flexural modulus is equivalent to Young's modulus. The fibers of the gas nucleation medium can have a flexural modulus of 1 GPa (gigapascal) or more, 10 GPa or more, or 50 GPa or more. The fibers of the gas nucleation medium can have a flexural modulus of 500 GPa or less, 400 GPa or less, or 250 GPa or less. For example, the fibers of the gas nucleation medium can have a flexural modulus of 10 GPa to 400 GPa.

[0062] The gas nucleation medium may have any suitable shape. The shape may be determined based on the location of the degasser within the system. In one embodiment, the gas nucleation medium defines a cylindrical shape. The thickness of the filtration media sheet may be measured using a suitable caliper thickness gauge, such as one using a 2.87 cm diameter foot at 1.5 psi pressure. The thickness of the filtration media sheet may be measured in accordance with TAPPI T411 test method. The gas nucleation medium may have any suitable thickness. The thickness of the gas nucleation medium may be measured in the direction of fluid flow. For example, in a cylindrical degasser, the thickness of the gas nucleation medium may be measured in a radial direction perpendicular to the central axis A. The gas nucleation medium may have a thickness of 0.01 mm or more, 0.1 mm or more, or 0.5 mm or more. The gas nucleation medium may have a thickness of 5 mm or less, 2 mm or less, or 1 mm or less. For example, the gas nucleation medium may have a thickness of 0.1 mm to 2 mm. The gas nucleation medium can be pleated or rolled. In either case (pleated or rolled), the medium can have one layer or multiple layers. The medium can be repeatedly rolled or stacked. When multiple layers are included, the layers can have the same composition and / or structure of a unique composition and / or structure that can be placed in intimate contact.

[0063] In some embodiments, the gas nucleation medium comprises a filtration medium. In one embodiment, the gas nucleation medium is made of a particulate filtration medium. In some embodiments, the gas nucleation medium has multiple layers. In some embodiments, the gas nucleation medium is rolled or stacked. In one embodiment, the gas nucleation medium is made of pleated media. In one embodiment, the gas nucleation medium is made of non-pleated media.

[0064] The growth medium may be positioned adjacent to or directly adjacent to the gas nucleation medium. The growth medium may be made of any suitable material capable of inducing coalescence and / or growth of gas cavities. Without wishing to be bound by theory, it is believed that several aspects of the growth medium affect the effectiveness and efficiency of the medium in inducing coalescence. For example, aspects that affect coalescence may include the chemical composition of the medium (e.g., fibers and binder); the surface energy of the medium; the oleophilicity / oleophobicity of the medium; the basic fiber surface area of ​​the medium; the solids fraction of the media sheet; the average pore size of the media; the maximum pore size of the media; the permeability of the media sheet; the thickness of the media sheet; the surface roughness; and the differential pressure across the media. One or more of these properties may exhibit a gradient from the upstream side to the downstream side of the growth medium. In some embodiments, the gas nucleation medium may exhibit bubble growth behavior. In such embodiments, a separate layer of growth medium may be omitted. For example, a gas nucleation medium having a pore size of 4 μm or more, 5 μm or more, 6 μm or more, or 8 μm or more may exhibit bubble growth behavior. In one embodiment, the gas nucleation medium has a pore size of 4 μm or more, 5 μm or more, 6 μm or more, or 8 μm or more. In one such embodiment, the degasser does not contain a growth medium. In one embodiment, the degasser contains gas nucleation with a pore size of 5 μm or more and does not contain a growth medium.

[0065] The chemical composition of the growing medium can affect aggregation and growth. The chemical composition of the growing medium can include the chemical composition of the fibers in the medium and / or the chemical composition of any binders or other components used in the medium. The fibers can include any suitable fibrous material, including woven or nonwoven media made from one or more of cellulose; regenerated cellulose (e.g., rayon); synthetic materials such as polyamide (e.g., nylon), polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF); glass; ceramic; or carbon fibers. In one embodiment, the growing medium is made from or includes polyester, rayon, or a combination thereof. The medium can include various binders, such as acrylic resins, phenolic resins, or epoxy resins.

[0066] Preferably, the growth medium has the appropriate surface energy and oleophilicity / oleophobicity to induce aggregation and / or growth of gas cavities and release the formed gas cavities into the fluid flow (as opposed to being "trapped" on the surface of the fiber). According to one embodiment, the growth medium is oleophilic. In some embodiments, the growth medium exhibits an oleophilicity / oleophobicity gradient, with the upstream side of the medium being more oleophobic than the downstream side. In other embodiments, the upstream side is more oleophilic than the downstream side. The oleophobicity rating (oleorepellency) of the medium can be measured according to AATCC Method 118 (e.g., 118-2013). The growth medium can have an oleophobicity rating of 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 6 or greater. The growth medium can have an oleophobicity rating of 8 or less, 7 or less, 6 or less, 5 or less, or 4 or less. In one embodiment, the growth medium has an oleophobicity rating of 2 to 8 or 3 to 8. The oleophobicity of a material can also be expressed as the contact angle of an oil droplet on a single fiber in air. The growth medium can have an oil contact angle of 0° or more, 10° or more, 20° or more, or 30° or more. The growth medium can have an oil contact angle of 150° or less, 120° or less, 90° or less, or 60° or less. The growth medium can be inherently oleophilic (e.g., made from oleophilic fibers) and / or can be treated to be oleophobic, for example, using an oleophobic treatment compound. The growth medium can be constructed from composite materials. The growth medium can be a composite of oleophilic and oleophobic components. The oleophobic component has an oleophobicity rating of one or more.

[0067] Fiber in the growth medium is 6 mJ / m 2 More than 20mJ / m 2 More than 50mJ / m 2 More than 75mJ / m 2 or more than 100mJ / m 2 The fibers in the growth medium may have a surface energy of 400 mJ / m 2 Below, 350mJ / m 2 Below, 300mJ / m 2 or less, or 250mJ / m 2 For example, the fibers in the growth medium may have a surface energy of 20 mJ / m 2 to 350 mJ / m2 The values ​​listed here are determined by ASTM D7490-13.

[0068] The basic fiber surface area of ​​the media, and therefore the contact area between the media and the fluid, can affect aggregation and growth. The basic fiber surface area of ​​the media is m 2 m per unit of media sheet bulk surface area 2 is understood to mean the total surface area of ​​the unit (including the surface area between the fibers). The basic fiber surface area of ​​the growing medium is 1 m 2 / m 2 Over 1.5m 2 / m 2 Over 1.6m 2 / m 2 or more, or 2m 2 / m 2 The base fiber surface area of ​​the growing medium can be up to 200 m 2 / m 2 , up to 50m 2 / m 2 , up to 30m 2 / m 2 , up to 10m 2 / m 2 , up to 6m 2 / m 2 , or up to 4m 2 / m 2 For example, the basic fiber surface area of ​​the growing medium can be 1.5 m 2 / m 2 50m from 2 / m 2 The values ​​given here are determined by the Carmen-Kozeny method.

[0069] The geometric configuration of the fibers in the growth medium can affect aggregation and growth. For example, the presence of sharp edges or corners and surface roughness, the orientation of the fiber surfaces relative to the direction of flow, the solids fraction, permeability, and pore size of the growth medium can be selected to enhance aggregation and growth of gas cavities and to release the gas cavities into the fluid flow after they have grown and / or aggregated.

[0070] The fiber cross-sections of the fibers in the growth medium can be polygonal or have irregular shapes with corners (e.g., corners less than 180°, less than 120°, or less than 90°). The growth medium can include fibers with round, star-shaped, square, rectangular, trilobe, cloverleaf, or polygonal cross-sections. The cross-section can be constant or vary throughout the length of the fiber.

[0071] The fiber size of the fibers within the growth medium can vary from fiber to fiber 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 10 nm or more, 50 nm or more, 100 nm or more. The fibers within the growth medium can have a fiber size of 500 μm or less, 100 μm or less, or 10 μm or less. For example, the fibers within the growth medium can have a fiber size of 50 nm to 100 μm.

[0072] The angle of the fibers relative to the flow stream in the growth medium can be 0° or greater, 10° or greater, or 30° or greater. The angle of the fibers in the growth medium can be 90° or less, 80° or less, or 60° or less. For example, the angle can be between 10° and 80°.

[0073] The stiffness of the fibers in the growth medium can also affect flow properties and therefore aggregation and / or growth. The fibers of the growth medium can have a flexural modulus of 1 GPa or more, 10 GPa or more, or 50 GPa or more. The fibers of the growth medium can have a flexural modulus of 500 GPa or less, 400 GPa or less, or 250 GPa or less. For example, the fibers of the growth medium can have a flexural modulus of 10 GPa to 400 GPa.

[0074] The fibers in the growth medium may have a surface roughness of 1 nm or more, 10 nm or more, 25 nm or more, 50 nm or more, or 100 nm or more. The fibers in the growth medium may have a surface roughness of 1000 nm or less, 500 nm or less, or 200 nm or less. For example, the fibers in the growth medium may have a surface roughness of 10 nm to 500 nm. The fibers in the growth medium may have a skewness of -10 or more, -8 or more, or -6 or more. The skewness of the fibers may be 6 or less, 8 or less, or 10 or less. For example, the skewness of the fibers may be -8 to 8. The fibers in the growth medium may have a kurtosis of 6 or less, 8 or less, or 10 or less. The values ​​listed here are determined by a profilometer.

[0075] Pores of a medium are understood to mean holes (e.g., through-holes) and cavities in a sheet of medium. Pore size may be determined by ASTM F316-03 or ASTM D6767. Pores of a medium may provide a flow path for a fluid through a sheet of medium. The growth medium may have an average pore size of 0.5 μm or more, 1 μm or more, or 5 μm or more. The growth medium may have an average pore size of 5 μm or less, 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, the pores in the growth medium may have an average pore size of 5 μm to 100 μm. The growth medium may have a maximum pore size of 1 μm or more, 5 μm or more, or 10 μm or more. The pores in the growth medium may have a maximum pore size of 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, the pores in the growth medium may have a maximum pore size of 5 μm to 200 μm. The values ​​listed here are determined by ASTM F316-03.

[0076] The growing medium may have a percent solids of 2% or more, 4% or more, 5% or more, 6% or more, 10% or more, or 20% or more at 1.5 psi. The growing medium may have a percent solids of 90% or less, 75% or less, 50% or less, 40% or less, 30% or less, 20% or less, 15% or less, 10% or less, 9% or less, or 8% or less at 1.5 psi. For example, the growing medium may have a percent solids of 2% to 20%, or 2% to 9% at 1.5 psi. The growing medium may comprise a woven or nonwoven medium having a porous structure.

[0077] The growth media sheet may have any suitable thickness. The thickness of the growth media affects the pressure differential across the media sheet. The thickness of the growth media may be measured in the direction of fluid flow. For example, in a cylindrical degasser, the growth media forms a coaxial cylinder at least partially surrounding the gas nucleation medium, and the thickness of the growth media may be measured in a radial direction perpendicular to the central axis A. The thickness of the filtration media sheet may be measured using an appropriate caliper thickness gauge, such as one using a 2.87 cm diameter foot at 1.5 psi pressure. The thickness of the filtration media sheet may be measured in accordance with the TAPPI T411 test method. The growth media may have a thickness of 0.01 mm or more, 0.02 mm or more, 0.05 mm or more, 0.1 mm or more, 0.5 mm or more, 0.8 mm or more, 1 mm or more, 2 mm or more, 3 mm or more, or 4 mm or more. The growth media may have a thickness of 25 mm or less, 20 mm or less, 15 mm or less, or 10 mm or less. For example, the growth medium may have a thickness of 0.1 mm to 20 mm or 0.8 mm to 10 mm.

[0078] The growing media sheet can have a differential pressure of 0.01 psi or less, 1 psi or less, or 100 psi or less according to ISO 16889 run at an appropriate face velocity, for example, 0.5 cm / sec.

[0079] The growth medium may be provided as multiple layers of media. Multiple layers of media may be applied (e.g., wrapped or stacked) on the gas nucleation medium. Increasing the number of layers of growth medium may improve cohesion of the gas cavities. However, increasing the thickness of the growth medium (e.g., by increasing the number of layers of media) may also increase the pressure drop across the growth medium and the entire degasser. Furthermore, a high pressure drop may limit the gas that the nucleation stage can release, resulting in nucleation occurring later in the growth stage and the release of smaller bubbles downstream of the growth stage. Therefore, the number of layers of growth medium can be balanced to provide improved cohesion without excessively increasing the pressure drop across the degasser unit. The growth medium may be provided as two or more, three or more, four or more, or five or more layers. The growth medium may be provided as up to 20, up to 15, up to 12, or up to 10 layers. In embodiments where the growth medium includes multiple layers, the thickness of the growth medium may refer to the total thickness of the layers, unless otherwise specified. The thickness of the individual growing media sheets can affect the number of wraps used. For example, thinner media may utilize more wraps. In one embodiment, the growing media is comprised of 5 to 10 layers (e.g., 7 layers) of media.

[0080] The porous barrier downstream of the growth medium may comprise any suitable porous material that defines openings or pores extending through the barrier. Without wishing to be bound by theory, it is believed that several aspects of the porous barrier affect the effectiveness and efficiency of the barrier. For example, aspects that affect the efficiency of a porous barrier may include: pore size and shape, and the regularity or uniformity of pore size and shape throughout the barrier; chemical composition of the barrier; oleophilicity / oleophobicity of the barrier; surface roughness or smoothness of the barrier; and orientation / orientation of the barrier relative to the direction of flow. One or more of these properties may differ between the upstream and downstream sides or may exhibit a gradient from the upstream to downstream sides of the growth medium.

[0081] In some embodiments, the porous barrier comprises a woven or nonwoven material. The openings can be uniform in size or nonuniform, including openings of various sizes. The pores of the porous barrier are sometimes referred to as screen openings, and are understood to mean holes (e.g., through-holes) in the barrier. Pore size can be determined by ASTM E11 or optical imaging. The porous barrier can include openings of sizes 5 μm or more, 10 μm or more, 15 μm or more, or 20 μm or more. The porous barrier can include openings of sizes 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 barrier includes openings of sizes between 10 μm and 250 μm, 15 μm and 200 μm, or 20 μm and 150 μm. In some embodiments, the openings of the porous barrier are uniform in size (e.g., have a narrow pore size distribution). For example, in some embodiments, at least some, a majority, at least 90%, at least 95%, or at least 99% of the openings in the porous barrier are within the size ranges specified herein, as determined by the total open area of ​​the porous barrier. The values ​​recited herein are determined by optical imaging. In one embodiment, substantially all of the openings in the porous barrier are within the size ranges specified herein.

[0082] The openings in the porous barrier can have any suitable shape. For example, the openings can be rectangular, square, circular, oval, or any other suitable shape. The shape can be determined by viewing the porous barrier in a direction perpendicular to the plane of the porous barrier. In some embodiments, the openings in the porous barrier are uniform in shape. For example, in some embodiments, at least some openings, a majority of openings, at least 90% of the openings, at least 95% of the openings, or at least 99% of the openings in the porous barrier have the same shape (e.g., rectangular, square, circular, oval, etc.).

[0083] The porous barrier 130 can be made of a woven or nonwoven material. For example, the porous barrier 130 can be made of a woven mesh. The woven mesh can have a wire diameter (or cross-sectional dimension) of 0.01 mm or more, 0.05 mm or more, or 0.1 mm or more. The woven mesh can have a wire diameter (or cross-sectional dimension) of 10 mm or less, 2 mm or less, 1 mm or less, or 0.5 mm or less. For example, the woven mesh can have a wire diameter (or cross-sectional dimension) of 0.05 mm to 2 mm. In one embodiment, the porous barrier 130 comprises a pleated material, such as a pleated woven mesh. The porous barrier 130 can be made of any suitable material. For example, the porous barrier can be made of a material with appropriate oleophilic / oleophobic properties to promote further growth of gas cavities and allow the gas cavities to pass through the barrier. In some embodiments, the porous barrier or a portion of the porous barrier is oleophobic. According to some embodiments, at least one side of the porous barrier is oleophilic. In some embodiments, the porous barrier exhibits an oleophobicity gradient, with the upstream side of the barrier being more oleophobic than the downstream side. The oleophobicity of a material can be expressed as an oleophobicity rating measured according to AATCC Method 118. The porous barrier can have an oleophobicity rating of 1 or greater, 1.5 or greater, or 2 or greater. The porous barrier can have an oil rating of 8 or less, or 6 or less. The porous barrier can be constructed from a composite material. The porous barrier can be a composite of an oleophilic component and an oleophobic component. The oleophobic component has an oleophobicity rating of 1 or greater.

[0084] For example, the porous barrier 130 may be made from a metal such as stainless steel, or a woven or nonwoven medium made from one or more of 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 barrier 130 is made from a woven metal mesh, such as stainless steel mesh. In some embodiments, the fibers (e.g., metal fibers) are coated. Polymer or non-polymer coatings, such as resins, can be used. The porous barrier 130 may be arranged in a cylindrical shape, at least partially surrounding the gas nucleation medium 110 and the growth medium 120.

[0085] A porous barrier may exhibit microtexture and macrotexture. Microtexture is used herein to refer to the surface texture of the barrier at the level of the individual fibers or wires that make up the barrier (e.g., referring to variations less than 1 mm in size). Microtexture is sometimes referred to as surface roughness. Macrotexture is used herein to refer to the surface texture of the entire barrier (e.g., referring to variations greater than 1 mm in size). A porous barrier may exhibit surface roughness. For example, a porous barrier may have a surface roughness of 1 nm or more, 10 nm or more, 25 nm or more, 50 nm or more, or 100 nm or more. A porous barrier may have a surface roughness of 1000 nm or less, 500 nm or less, or 200 nm or less. For example, a porous barrier may have a surface roughness of 10 nm to 500 nm. In some embodiments, the porous barrier has little or no macrotexture, i.e., the porous barrier is "smooth," except that the porous barrier may be pleated.

[0086] Additional properties of the porous barrier surface include skewness, kurtosis, and radius of curvature. The skewness of the fibers can be at least -10 or greater, -8 or greater, or -6 or greater. The skewness of the fibers can be 6 or less, 8 or less, or 10 or less. The fibers of the porous barrier can have a kurtosis of -10 or greater, -8 or greater, or -6 or greater. The fibers of the porous barrier can have a kurtosis of 6 or less, 8 or less, or 10 or less. Certain combinations of surface roughness, skewness, and kurtosis can result in favorable capture properties. For example, high roughness and high kurtosis can be beneficial for capture. The fibers of the porous barrier can have a radius of curvature that can be up to 2 nm, up to 5 nm, up to 10, up to 50, up to 100, or up to 500 nm.

[0087] The porous barrier may have an initial clean differential pressure of 0.01 psi or less, 1 psi or less, or 100 psi or less according to ISO 16889 run at a suitable face velocity, for example, 0.5 cm / sec.

[0088] The porous barrier may be positioned approximately perpendicular to the direction of flow. For example, the porous barrier may be cylindrical with a cylindrical wall coaxial with the nucleation medium. In some embodiments, the porous barrier comprises a pleated material with the planes of the pleats angled relative to the direction of flow. The degassing apparatus 100 may include a gap 135 between the gas nucleation medium 110 and the porous barrier 130, or between the growth medium 120 and the porous barrier 130, as shown. The gap 135 may be appropriately sized to accommodate condensed gas cavities (second-stage gas cavities) from the growth medium 120. The gap 135 may be positioned to allow the condensed gas cavities (second-stage gas cavities) to gather and further condense (third-stage gas cavities). Thus, the gap 135 may be considered, in some respects, a second growth stage.

[0089] The porous barrier 130 may have an axial length equal to the axial length of the gas nucleation medium 110. Alternatively, the porous barrier 130 may have an axial length that is greater than or less than the axial length of the gas nucleation medium 110. In one embodiment, the axial length of the porous barrier 130 is less than the axial length of the gas nucleation medium 110.

[0090] The gap 135 may extend axially from the first end cap 141 to the second end cap 142, defining the axial length of the gap 135. The gap 135 may have a width measured as the radial distance between the gas nucleation medium 110 and the porous barrier 130, or between the growth medium 120 and the porous barrier 130. In some embodiments, the gap 135 extends from the growth medium 120 to the wall of the tank. The gap 135 may be uniformly sized along its axial length, or may be wider at one end than the other. For example, the gap 135 may be constructed to be wider at its bottom and narrower at its top, or narrower at its bottom and wider at its top. The gap 135 may have a width of 0.5 mm or more, 1 mm or more, 1.5 mm or more, 2 mm or more, 2.5 mm or more, or 4 mm or more. The width of the gap 135 can be 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, or 5 mm or less. For example, the gap can have a width of 4 mm to 20 mm. In some embodiments where the gap 135 extends from the growth medium 120 to the wall of the tank, the size of the gap can be larger, for example, up to 10 m (meters), up to 5 m, up to 1 m, up to 50 cm (centimeters), up to 25 cm, or up to 10 cm.

[0091] The degasser 100 may include additional elements. For example, the degasser 100 may include one or more support liners. Such liners may be disposed adjacent to or between the gas nucleation medium 110, the growth medium 120, and / or the porous barrier 130, or any combination thereof. The degasser 100 may further include one or more of a housing element, a support element, a mounting element, an end cap, a seal, a potting compound, tubing, a line, and the like.

[0092] The degassing apparatus 100 may include removable and / or serviceable components. For example, one or more of the gas nucleation medium 110, the growth medium 120, and the porous barrier 130 may be independently removable and / or serviceable, or may form a removable and / or serviceable unit. In one embodiment, the gas nucleation medium 110 and the growth medium 120 are removable and / or serviceable. For example, the gas nucleation medium 110 and the growth medium 120 may form a removable and / or serviceable unit. The serviceable unit of the gas nucleation medium 110 and the growth medium 120 may optionally include separate end caps attached to the gas nucleation medium 110 and the growth medium 120. The porous barrier 130 may be permanently attached to the first end cap 141 and / or the second end cap 142. The porous barrier 130 and the first end cap 141 and / or the second end cap 142 may form a frame. In some embodiments, the gas nucleation medium 110 and growth medium 120 serviceable units may be removably and sealingly coupled to the frame. When the degassing apparatus 100 is assembled, the end caps of the gas nucleation medium 110 and growth medium 120 serviceable units may abut the first and second end caps 141, 142 and may include seals, such as O-rings, between adjacent end caps. Adjacent end caps may be axially aligned with one or more of the end caps including a lip that limits movement of the adjacent end cap.

[0093] The degasser 100 is configured so that it can be mounted in various orientations, for example, with the central axis A oriented vertically as shown, or with the central axis A oriented horizontally. A horizontal orientation may be advantageous when the degasser 100 is mounted in series, such as in the return line 31. In a horizontal orientation, the gas nucleation medium 110, growth medium 120, and porous barrier 130 may be arranged in a non-cylindrical shape, such as a planar shape.

[0094] In a preferred embodiment, the degasser 100 is positioned inside the tank 10 in a vertical position (axis A is vertical or substantially vertical). The degasser 100 can be located below (e.g., directly below) the inlet to the tank 10. For example, the degasser 100 can be attached to the inlet where the return line 31 discharges fluid into the tank 10. The degasser 100 can be submerged, partially submerged, or, at least sometimes, completely above the fluid level of the tank. For example, the tank 10 can be a hydraulic fluid tank for a hydraulic system, where the fluid level in the tank 10 changes during operation of the hydraulic system. The degasser 100 can be attached at or near the top of the tank such that the degasser 100 is occasionally, at least sometimes, or always partially submerged in hydraulic fluid.

[0095] A list of various aspects of the degassing device of the present disclosure is provided below.

[0096] According to a first embodiment, a degasser includes a gas nucleation medium; a growth medium adjacent to the gas nucleation medium; and a porous barrier adjacent to the growth medium.

[0097] In Example 2, the degassing apparatus of Example 1 further comprises a gap between the growth medium and the porous barrier. The gap can have a width of 0.5 mm or more, 1 mm or more, 1.5 mm or more, 2 mm or more, or 2.5 mm or more; or 50 cm or less, 20 cm or less, 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, or 5 mm or less. The gap can have a width from 1 mm to 15 mm.

[0098] In Example 3, the degassing apparatus of Example 1 or Example 2, wherein the gas nucleation medium comprises a particulate filtration medium.

[0099] In Example 4, according to the degassing device of any one of Examples 1 to 3, the gas nucleation medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, ceramic, carbon fiber, or a combination thereof. The gas nucleation medium may comprise a combination of glass fiber and polyester.

[0100] In Example 5, according to the degassing apparatus of any one of Examples 1-4, the gas nucleation medium comprises an oleophobic material having an oil contact angle of at least 30°, at least 50°, at least 70°, at least 90°, or at least 120°; or at most 120°, or at most 150°. The gas nucleation medium can have an oil contact angle of from 50° to 120°.

[0101] In Aspect 6, according to the degassing apparatus of any one of Aspects 1-5, the gas nucleation medium comprises an oleophobic material having an oleophobicity rating of 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 6 or greater; or 8 or less, 7 or less, 6 or less, 5 or less, or 4 or less. The gas nucleation medium can have an oleophobicity rating of 2 to 8 or 3 to 8.

[0102] In Example 7, according to the degassing device of any one of Examples 1-6, the growing medium comprises multiple layers of media. The growing medium can comprise 2 or more, 3 or more, 4 or more, or 5 or more layers; or up to 20, up to 15, up to 12, or up to 10 layers. The growing medium can comprise 2 to 15 layers, or 4 to 10 layers. The growing medium can comprise 7 layers.

[0103] In an eighth embodiment, according to the degassing apparatus of any one of the first to seventh embodiments, the growth medium is immediately adjacent to the gas nucleation medium.

[0104] In an embodiment 9, according to the degassing device of any one of embodiments 1 to 8, the growing medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, ceramic, carbon fiber, or a combination thereof. The growing medium may comprise a combination of regenerated cellulose fiber and polyester.

[0105] In a tenth embodiment, according to the degassing device of any one of the first to ninth embodiments, the porous barrier includes an opening that forms the outlet.

[0106] In an eleventh embodiment, according to the degassing device of any one of the first to tenth embodiments, the porous barrier comprises openings of a size 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. The porous barrier can comprise openings of a size of 10 μm to 120 μm, 15 μm to 100 μm, or 20 μm to 80 μm.

[0107] In an embodiment 12, the degassing device of the embodiment 11 further comprises a liner.

[0108] In a thirteenth aspect, the degassing device of any one of the first to twelfth aspects further comprises a first end cap including an opening defining an inlet.

[0109] In an embodiment 14, the degassing device of any one of embodiments 1 to 13 further comprises a closed second end cap.

[0110] In Example 15, the degassing device of Example 14, wherein the second end cap includes a bottom portion.

[0111] In Example 16, according to the degasser of any one of Examples 1-15, the gas nucleation medium surrounds and defines the open degasser interior.

[0112] In Example 17, according to the degassing apparatus of any one of Examples 1 to 16, the gas nucleation medium, the growth medium, and the porous barrier form a cylindrical body.

[0113] In an eighteenth embodiment, according to the degassing apparatus of any one of the first to seventeenth embodiments, the gas nucleation medium has a viscosity of 1 m 3 as measured by the Carmen-Kozeny method. 2 / m 2 Over 1.5m 2 / m 2 Over 2m 2 / medium 2 More than 5m 2 / medium 2 More than 10m 2 / medium 2 Over 25m 2 / m 2 Over 50m 2 / m 2 or more, or 100m 2 / m 2 or more; or 200m 2 / m 2 Below, 150m 2 / m 2 Below, 100m 2 / m 2 Below, 50m 2 / m 2 Below 30m 2 / m 2 Below, 10m 2 / m 2 Below, 6m 2 / m 2 or less, or 4m 2 / m 2 The gas nucleation medium has a base fiber surface area of ​​1 m as measured by the Carmen-Kozeny method. 2 / m 2 ~100m 2 / m 2 or 5m 2 / m 2 ~50m 2 / m 2 may have an underlying fiber surface area of

[0114] In Example 19, according to the degassing apparatus of any one of Examples 1-18, the gas nucleation medium has an average pore size of 0.5 μm or more, 1 μm or more, or 5 μm or more; or 5 μm or less, 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less, as measured by ASTM F316. The pores in the gas nucleation medium can have an average pore size of 5 μm to 100 μm, or 30 μm or less, as measured by ASTM F316.

[0115] In Example 20, according to the degassing apparatus of Example 13, the first end cap includes a direct inlet to the gap between the growth medium and the porous barrier.

[0116] In Aspect 21, according to the degassing device of any one of Aspects 1-20, the growth medium has a percent solids at 1.5 psi of 2% or more, 4% or more, 5% or more, 6% or more, 10% or more, or 20% or more; or 90% or less, 75% or less, 50% or less, 40% or less, 30% or less, 20% or less, 15% or less, 10% or less, 9% or less, or 8% or less. The growth medium can have a percent solids at 1.5 psi of 2% to 20%, or 2% to 9%.

[0117] In Aspect 22, according to the degassing device of any one of Aspects 1 to 21, the growing medium has a thickness of 0.01 mm or more, 0.02 mm or more, 0.05 mm or more, 0.1 mm or more, or 0.5 mm or more, 0.8 mm or more, 1 mm or more, 2 mm or more, 3 mm or more, or 4 mm or more, as measured in accordance with the TAPPI T411 test method; or 25 mm or less, 20 mm or less, 15 mm or less, or 10 mm or less. The growing medium can have a thickness of 0.1 mm to 20 mm or 0.8 mm to 10 mm, as measured in accordance with the TAPPI T411 test method.

[0118]

[0023] In Example 23, the degassing apparatus of any one of Examples 1-22, the growth medium comprises a complex of an lipophilic component and an lipophobic component, wherein the lipophobic component has an lipophobicity rating of 1 or greater as measured by AATCC Method 118.

[0119] In Example 24, the degassing apparatus of any one of Examples 1-23, the porous barrier comprises an oleophobic surface having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

[0120] In Example 25, the degassing device of any one of Examples 1-24, the porous barrier comprises a composite of an oleophilic component and an oleophobic component, wherein the oleophobic component has an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

[0121] According to embodiment 26, a system for removing gas from a fluid includes a tank having a fluid inlet and a fluid outlet, the tank having a fluid flow path from the fluid inlet to the fluid outlet; and a degasser within the fluid flow path.

[0122] In Example 27, according to the system of Example 26, the degasser includes a gaseous nucleation medium; a growth medium downstream of the gaseous nucleation medium; and a porous barrier downstream of the gaseous nucleation medium.

[0123] In Example 28, according to the system of Examples 26 or 27, the degassing device comprises a gap between the growth medium and the porous barrier.

[0124] In Example 29, according to the system of any one of Examples 26-28, the gas nucleation medium comprises a particulate filtration medium.

[0125] In example 30, according to the system of any one of examples 26-29, the gas nucleation medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, or a combination thereof. The gas nucleation medium can comprise a combination of glass fiber and polyester.

[0126] In Example 31, according to the system of any one of Examples 26-30, the gas nucleation medium comprises an oleophobic material having an oil contact angle of at least 30°, at least 50°, at least 70°, at least 90°, or at least 120°; or up to 120°, or up to 150°. The gas nucleation medium can have an oil contact angle of from 50° to 120°.

[0127] In Example 32, according to the system of any one of Examples 26-31, the gas nucleation medium comprises an oleophobic material having an oleophobicity rating of 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 6 or greater; or 8 or less, 7 or less, 6 or less, 5 or less, or 4 or less. The gas nucleation medium can have an oleophobicity rating of 2 to 8 or 3 to 8.

[0128] In example 33, according to the system of any one of examples 26-32, the growing medium comprises multiple media layers. The growing medium can comprise 2 or more, 3 or more, 4 or more, or 5 or more layers; or up to 20, up to 15, up to 12, or up to 10 layers. The growing medium can comprise 2 to 15 layers, or 4 to 10 layers. The growing medium can comprise 7 layers.

[0129] In example 34, according to the system of any one of examples 26 to 33, the growing medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, ceramic, carbon fiber, or a combination thereof. The growing medium can comprise a combination of regenerated cellulose fiber and polyester.

[0130] In Example 35, according to the system of any one of Examples 26-34, the growth medium is immediately adjacent to the gas nucleation medium.

[0131] In Example 36, according to the system of any one of Examples 26-35, the porous barrier comprises openings of a size 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. The porous barrier can comprise openings of a size of 10 μm to 250 μm, 15 μm to 200 μm, or 20 μm to 150 μm.

[0132] In an embodiment 37, according to the system of any one of embodiments 26 to 36, the degasser includes a liner.

[0133] In Example 38, according to the system of any one of Examples 26-37, the degasser includes a first end cap including an opening defining the degasser inlet.

[0134] In Example 39, according to the system of any one of Examples 26-38, the degasser includes a closed second end cap.

[0135] In Example 40, according to the system of any one of Examples 26-39, the closed second end cap includes a bottom portion.

[0136] In Example 41, according to the system of any one of Examples 26-40, the gas nucleation medium surrounds and defines the open degasser interior.

[0137] In Example 42, according to the system of any one of Examples 26-41, the gas nucleation medium, the growth medium, and the porous barrier form a cylindrical body.

[0138] In Example 43, according to the system of any one of Examples 26-42, the gas nucleation medium and growth medium are disposed within the fluid flow channel in a flow-through configuration.

[0139] According to aspect 44, a method for removing gas from a fluid includes passing the fluid through a degasser defining a fluid flow path, the degasser including the degasser of any one of aspects 1 to 25. The fluid may include oil. The fluid may include hydraulic fluid.

[0140] In Example 45, according to the method of Example 44, the method includes removing at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, or at least 60% of the air in the fluid compared to a baseline without the degasser.

[0141] According to embodiment 46, the degassing device includes a gas nucleation medium, a porous barrier adjacent to the growth medium, the porous barrier including openings of a size 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, and a gap between the gas nucleation medium and the porous barrier. The porous barrier can include openings of a size of 10 μm to 120 μm, 15 μm to 100 μm, or 20 μm to 80 μm.

[0142] In Example 47, the degassing apparatus of Example 46, wherein the gas nucleation medium comprises a particulate filtration medium.

[0143] In Example 48, according to the degassing device of Examples 46 or 47, the gas nucleation medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, ceramic, carbon fiber, or a combination thereof. The gas nucleation medium can comprise a combination of glass fiber and polyester.

[0144] In Example 49, according to the degassing device of any one of Examples 46-48, the gas nucleation medium comprises an oleophobic material having an oil contact angle of at least 30°, at least 50°, at least 70°, at least 90°, or at least 120°; or at most 120°, or at most 150°. The gas nucleation medium can have an oil contact angle of from 50° to 120°.

[0145] In example 50, according to the degassing device of any one of examples 46-49, the gas nucleation medium comprises an oleophobic material having an oleophobicity rating of 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 6 or greater; or 8 or less, 7 or less, 6 or less, 5 or less, or 4 or less. The gas nucleation medium can have an oleophobicity rating of 2 to 8 or 3 to 8.

[0146] In embodiment 51, according to the degassing device of any one of embodiments 46 to 50, the gap is 0.5 mm or more, 1 mm or more, 1.5 mm or more, 2 mm or more, 2.5 mm or more, or 4 mm or more; or 25 mm or less, 20 mm or less, 15 mm or less, 10 mm or less, or 5 mm or less. The gap can be from 4 mm to 20 mm.

[0147] In Example 52, the degasser of any one of Examples 46-51 further includes a liner.

[0148] In Example 53, the degasser of any one of Examples 46-52 further comprises a first end cap including an opening defining an inlet.

[0149] In Example 54, the degasser of any one of Examples 46-53 further includes a closed second end cap.

[0150] In Example 55, according to the degasser of any one of Examples 46-54, the gas nucleation medium surrounds and defines the open degasser interior.

[0151] In Example 56, according to the degassing apparatus of any one of Examples 46 to 55, the gas nucleation medium and the porous barrier form a cylindrical body.

[0152] In Example 57, according to the degassing apparatus of any one of Examples 46-56, the gas nucleation medium has an average pore size of 0.5 μm or more, 1 μm or more, or 5 μm or more; or 5 μm or less, 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less, as measured by ASTM F316. The pores in the gas nucleation medium can have an average pore size of 5 μm to 100 μm, or 30 μm or less, as measured by ASTM F316. [Example]

[0153] Examples 1 and 2 Various aspects of the degasser configured for use with hydraulic fluid were tested. The performance of the degasser was tested against a commercially available degasser and a baseline that did not include a degasser.

[0154] Test System. To test the performance of the deaerator, hydraulic fluid was saturated with air using pressurized air. Tests were performed using HY-GARD™ hydraulic / transmission fluid available from Deere & Company (Moline, IL). The deaerator was assembled into a tank constructed to simulate a hydraulic system's hydraulic fluid tank, where return hydraulic fluid enters the tank and deaerator from above. During testing, the tank was under ambient pressure. Air-saturated oil was circulated through a system that included a deaerator tank housing the deaerator being tested. The air-saturated oil was pumped through the deaerator, and the air removal efficiency was measured.

[0155] The fluid was heated to a target temperature, such as 35±1.6°C, and the flow rate was approximately 36 L / min at a pressure of 414 kPa. Air was flowed into the aeration chamber at 7.1 L / min.

[0156] Sample Preparation. Degassing filter elements (Samples C-H) were constructed coaxially with a 0.5 cm gap between the growth media and screen barrier, as shown in Figure 2A. The elements were sized to target media face velocities per stage: 30 cm / min for the nucleation stage, 130 cm / min for the growth stage, and 30 cm / min for the screen barrier stage. The nucleation media was pleated EN0799037 hydraulic media available from Donaldson Company, Inc. (Minneapolis, MN) used in part numbers P171846 and P171579. The growth media was PN-130 (130 g / m) manufactured by Precision Custom Coatings, LLC (Totowa, NJ). 2 The nucleation media was a wound, needle-punched polyester / rayon blend nonwoven fabric such as a PET film. The screen barrier consisted of a pleated, simple woven screen. The nucleation media and screen barrier were supported by support wires.

[0157] A commercially available degasser (comparison example, Sample A) was scaled down to match the flow capacity of the test system. In the commercial degasser, the flow enters from the bottom, bends, and passes radially outward through the particulate media from the inside to the outside. The particulate media is enclosed in a cylindrical metal shell (downstream of the particulate media). The cylindrical metal shell has a rectangular opening in the lower third of the shell, and a single layer of stainless steel screen is attached to the inside of the opening, allowing all flow to pass through the screen. The screen was estimated to have an opening of approximately 2 mm. All small bubbles and many larger bubbles were observed to pass through the screen without agglomeration. The screen provided an outward, slightly upward flow through the rectangular opening.

[0158] The baseline (Sample B) contained only a particulate filter and no degasser. The particulate filter used as the baseline was a K041774 filter available from Donaldson Company, Inc. (Minneapolis, MN).

[0159] Test Method. Hydraulic oil supplied to the tank was continuously aerated for 1800 seconds. Oil aeration (%) was measured and recorded throughout the test. The data collection setup used in Examples 1 and 2 is outlined in Figure 4. The maximum aeration value for each deaerator was determined by averaging the oil aeration (%) readings from 600 seconds to 1700 seconds. A lower maximum aeration value indicates more air removed and therefore improved deaerator performance. Samples were tested against a commercially available deaerator, designated "Sample A," and a baseline without a deaerator, designated "Sample B."

[0160] The air entrainment measuring device was an AIR-X sensor from Delta Services Industriels (Froyennes, Belgium).

[0161] Example 1 Sample devices were prepared by varying the mesh opening size of the porous barrier while keeping the nucleation and growth stages constant. Growth media were prepared with seven layers (rolls) of media. As shown in Table 1 below, the nominal mesh opening sizes for Samples C-F ranged from 20 μm to 125 μm. The degassing devices were tested as described above. The results, including the differential pressure across the degassing devices, are shown in Table 1 and Figures 5A-5C.

[0162] [Table 1]

[0163] Figure 5A is a data plot of oil aeration (%) results for various samples. The improvement in maximum average air entrainment (%) relative to baseline Sample B is shown in Figure 5B. It was observed that smaller mesh opening sizes in the porous barrier provided better degassing results than larger sizes. Sample C had a 61% reduction in maximum average air entrainment, compared to 22% for Sample D and 15% for Samples E and F. Additionally, each of Samples C-F was observed to be superior to the commercial Sample A and baseline Sample B. Figure 5C contrasts maximum average air entrainment (%) versus differential pressure.

[0164] Example 2 Sample devices C, G, and H were prepared as follows: the mesh opening size of the nucleation medium and porous barrier were kept constant, while various growth medium thicknesses were prepared by applying various numbers of layers of growth medium. As shown in Table 2 below, Sample C had the same thickness of growth medium as Example 1 (7 layers of medium), Sample G had half the thickness of growth medium (3 layers of medium), and Sample H had no growth medium. The degassing devices were tested as described above. The results, including the differential pressure across the degassing devices, are shown in Table 2 and Figures 6A-6C.

[0165] [Table 2]

[0166] Figure 6A is a data plot of oil aeration (%) results for various samples. The improvement in maximum average air entrainment (%) relative to baseline Sample B is shown in Figure 6B. It was observed that thicker growth media resulted in better degassing results. Sample C's maximum average air entrainment reduction was 61% of baseline, while Sample G achieved a 46% reduction in maximum average air entrainment and Sample H achieved a 27% reduction. Furthermore, Samples C, G, and H were each observed to outperform the commercial Sample A and baseline Sample B. Figure 6C contrasts maximum average air entrainment (%) versus differential pressure.

[0167] Examples 3 to 5 Sample Preparation. Media handsheets were prepared by dispersing fibers in water and then formed in an ADIRONDACK FORMAX 12" x 12" stainless steel sheet mold available from Adirondack Machine Corp. (Hudson Falls, NY). Specific details of the furnishings are provided below in Example 3. The media tested were 71 mm 2 The test media was immersed in the test oil and placed in the in-line media housing.

[0168] The term "elementary fiber surface area" is used herein to refer to the surface area of ​​a fiber per bulk media surface area.

[0169] Surface Area Analysis. The surface area of ​​the media can be determined by Branauer-Emmett-Teller (BET) analysis or from the Carmen-Kozeny relationship. Examples 3 and 4 used the Carmen-Kozeny relationship.

[0170] BET analysis: 1 m of media sample 2 m per bulk surface area 2 The basic fiber surface area of ​​a unit of media can be determined from the surface area per unit mass using ISO 9277 and the media dry basis weight as determined by ASTM D646 by the following relationship:

number

[0171] Low surface area materials (e.g., fiber surface area of ​​1 m 2 For high surface area materials (e.g., fiber surface areas of 1 m or less), BET measurements are preferably performed using krypton gas. 2 / g), the BET measurement is preferably performed using nitrogen gas. If the basis fiber surface area of ​​only a single layer of a media composite is to be measured, that layer is removed from the composite and the mass and basis weight of the layer are used in the calculation.

[0172] Carmen-Kozeny Method: The fundamental fiber surface area of ​​a medium can be calculated based on the Carmen-Kozeny relation, where the pressure drop of a fluid flowing through a solid porous material is calculated based on an equation derived by combining Darcy's law and Poiseuille's law when modeling fluid flow through a packed bed of spheres. The general form of the equation is:

number

number

[0173] Because the fibers used in most typical filtration media, including those used in the examples herein, have large aspect ratios of 100 to 1000, the surface area of ​​the ends can be considered negligible, and the surface area of ​​the fiber can be considered that of a single long fiber or cylinder. The base fiber surface area of ​​the media can then be calculated based on the total mass of the filtration media sample and the density of the materials. For fibers made from multiple materials, a mass fraction-weighted density is used. The identity of the fiber materials and their mass fractions can be determined by methods known to those skilled in the art. Surface area is reported as the base fiber surface area according to the Carmen-Kozeny method. If the base fiber surface area is measured on only a single layer of a media composite, that layer is removed from the composite before testing.

[0174] Test Procedure. To test the performance of the nucleation media, a nucleation test bench was constructed from a tank connected to an air supply through a series of valves and piping. The air supplied to the tank was controlled by two different pressure control valves to maintain a specific pressure within the tank. The tank was connected to a media test housing that also incorporated a bypass loop. Both the housing tubing and the bypass led to a CANTYVISION camera, which in turn led to a collection flask positioned above a digital mass scale. Images obtained from the CANTYVISION camera's video recording were analyzed using CANTYVISION intelligent analysis software to record and analyze the nucleation function of the media sheet being tested. CANTYVISION cameras and software are available from JM Canty, Inc. (Buffalo, NY).

[0175] At the start of the test, the tank was filled with approximately 1.5 gallons of test oil. An airflow loop was created through the tank to aerate the hydraulic oil by bubbling. To aerate the oil, the tank pressure was maintained at 25 psi. After aeration, excess free air was allowed to escape from the oil.

[0176] To conduct the nucleation test, aerated hydraulic oil from the tank was flowed through the test medium while the tank pressure was adjusted to drive the flow at the desired experimental face velocity, as observed by recording data from the scale. The test was run for 7 minutes. The oil flow was imaged at 5 frames per second using a CANTYVISION camera, and the data was processed using CANTYVISION software to calculate the average air volume and average bubble diameter per video frame.

[0177] Image data processing. Image processing was performed using IMAGEJ software (available from the U.S. Department of Health and Human Services, National Institutes of Health). The following routine was applied uniformly across all experiments to the last 1000 frames captured per experiment.

[0178] Images were cropped, if necessary, to a region that eliminated experimental artifacts, such as window walls and circular objects that were not bubbles. Images were converted to 8-bit grayscale images. The "Otsu" autothreshold algorithm (described in Otsu, N., "A Threshold Selection Method from Gray-Level Histograms," 9 IEEE Transactions on Systems, Man, and Cybernetics 62 (1979)) was applied to convert the images to black-and-white images, where black was set as the background color. The contours of unfilled objects in the images were filled using a "hole-fill" routine, and then the "watershed" routine (described in Soille, P. and Vincent, L., "Determining Watersheds in Digital Pictures via Flooding Simulations," 1360 Proc. SPIE 240 (1990)) was applied to detect and segment overlapping objects. These processed images were then used to separate images of at least 1203 μm in area. 2 , roundness (4*area / [π*principal_axis 2 Bubbles with a diameter (defined as [Diameter]) of 0.95 were counted. The volume of the bubbles was estimated from the ferret diameter of the bubble. The ferret diameter is defined as the longest distance (also known as the maximum caliper) between any two points along the selected boundary. During the nucleation stage, the term "bubble diameter" refers to the ferret diameter.

[0179] Pore ​​Size Measurement. The pore size of the media can be measured using an automated air permeability porometer, such as that manufactured by Porous Materials, Inc. (Ithaca, NY). In these examples, Porous Materials model number APP-1200-AEXSC was used with CAPWIN software. The test type was capillary flow porometry, dry-up / wet-up, the test fluid was silicone fluid with a fluid surface tension of 20.1 dynes / cm, and the effective test size of the sample was 1 cm in diameter.

[0180] Example 3 Various nucleation media samples were tested in a single-layer configuration. Media samples were prepared from microglass fiber and sheath / core bicomponent polyester according to Table 3 below. The bicomponent polyester fiber was ADVANSA 271P, available from Advansa GmbH, Germany, with a nominal average diameter of 14 μm and a nominal average length of 6 mm. Various drying techniques and compression, including ovens and sheet dryers, were used to create various thicknesses and solids percentages in the samples. Airflow ovens are known to create structures with lower solids percentages than sheet dryers.

[0181] [Table 3]

[0182] The characteristics of the media tested are shown in Table 4.

[0183] [Table 4]

[0184] The average air volume per frame (proportional to the total air released) and average bubble diameter were determined as a function of average pore size, elemental fiber surface area, media solids fraction measured at 1.5 psi, and media thickness. The elemental fiber surface area was determined by the Carmen-Kozeny method. Trended parameters are shown in the figures. Data comparing the average air volume per frame to average pore size, total nucleation surface area, media solids fraction measured at 1.5 psi, and media thickness are shown in Figures 7A-7D. Data comparing the average bubble diameter to average pore size, elemental fiber surface area, media solids fraction measured at 1.5 psi, and media thickness are shown in Figures 8A-8D.

[0185] An ANOVA analysis was performed to determine the most significant regressors for the average air volume per frame. Based on this analysis, the more air released, the greater the base fiber surface area, and the smaller the average pore size. A similar ANOVA analysis was performed to determine the most significant regressors for the average bubble diameter. Based on this analysis, the average bubble diameter increases as the average pore size increases. The average bubble diameter decreases as the base fiber surface area increases.

[0186] Example 4 In another example, the media samples from Example 3 were stacked into a multi-layer media sample. The media properties of the media samples used for layering are shown in Table 5. The multi-layer media sample included media samples 1-8.

[0187] [Table 5]

[0188] The average air volume per frame (proportional to the total air released) and average bubble diameter were determined as a function of the number of layers. The average air volume per frame as a function of layers is shown in Figure 9A. The average bubble size as a function of layers is shown in Figure 9B. Initially, it was observed that as the number of layers increased, the average air volume per frame increased and the average bubble size decreased. As the number of layers increased, the average air volume per frame plateaued, while the average bubble size continued to decrease.

[0189] Example 5 In another example, media handsheets were produced by a wet-laid process by dispersing 200 mg of sheath / core bicomponent polyester fiber (ADVANSA 271P) with a nominal average diameter of 14 μm and a nominal average length of 6 mm in water, and then forming it on a 90 mm diameter circular stainless steel sheet mold. The dried media handsheet patch was fused at 115°C.

[0190] Media handsheet samples were coated to be oleophobic. The oleophobic coating was applied by hand dipping the screen swatches into a 5% aqueous solution of DAIKIN UNIDYNE TG-5502, obtained from Daikin America Inc. (Orangeburg, NY). The samples were dried in an oven at 120°C for 10 minutes. The oleophobic-treated media had an oleophobicity rating of at least 6 when tested by AATCC Method 118.

[0191] The nucleation performance of the oleophobic coated media was compared to uncoated media as in Examples 3 and 4. The average air generation rate was calculated by summing the volumes of all individual bubbles during the experiment and dividing by the length of the experiment in seconds.

[0192] The results are shown in Table 6. It was observed that the oleophobic treatment increased the air generation rate and total released air. After the oleophobic treatment, the average air bubble diameter decreased.

[0193] [Table 6]

[0194] Example 6 Various aspects of the growth layer were examined in Example 6.

[0195] Sample Preparation. Media handsheets were prepared by dispersing the fibers in water and then formed in an ADIRONDACK FORMAX 12" x 12" stainless steel sheet mold available from Adirondack Machine Corp. (Hudson Falls, NY). Specific details of the finished material are provided in Table 7 below. The media tested were 12.9 cm 2 The test media was placed in the in-line media housing.

[0196] Test Procedure. To test the performance of the growth media, a test bench was constructed and used to challenge media samples with small air bubbles (nominal average diameter 600 μm) in oil and monitor the media's ability to grow the bubbles. The bench was constructed so that the size and number of bubbles could be monitored both upstream and downstream of the test media sample.

[0197] The test bench included an oil storage tank, a gear pump to regulate oil flow from the tank, a pressure gauge, and a line connecting the oil storage tank to the test cell. A flow meter placed in the line was used to determine the oil face velocity in the medium within the test cell. An air bubble injection fitting was installed in series immediately before the test cell. Air injection was controlled by a series of flow meters and pressure regulators to create a consistent air bubble challenge upstream of the test medium. The test cell was constructed of clear acrylic to allow image capture both upstream and downstream of the test medium. A return line ran from the test cell back to the oil storage tank. A Nikon D90 camera was mounted on a vertical slide rail and used to capture image sequences both upstream and downstream of the test medium.

[0198] To conduct the test, oil flow was initiated. Once the oil filled the test cell, the air bubble injector was turned on. After a steady state was reached, a series of images were captured on both the upstream and downstream sides of the test medium. After a period of time, the image capture was repeated.

[0199] Image data processing. Images were processed as in Examples 3 and 4 (nucleation stage) across all experiments (20 frames per experiment) up to the application of the "watershed" routine. The processed images were then used to generate images of at least 10,000 μm in area. 2 (23.42μm / pixel), circularity (4π*area / perimeter 2 Bubbles with a diameter (defined as 0.5) of 0.5 were counted. The volume of the bubbles was calculated from the bubble area using the following condition: If the ferret diameter of the bubble is larger than 3 mm, the diameter is estimated from the bubble area as follows: Volume = π / (7.5*10 8 )*([area] / π) (3 / 2)

[0200] Otherwise, if the ferret diameter is 3 mm or less, the diameter is taken as the ferret diameter and the volume of the bubble is calculated as a typical sphere.

[0201] The difference in calculation methods is due to the fact that visual inspection of bubbles larger than approximately 3 mm suggests that these larger bubbles are actually clusters of bubbles, which gives an artificially large volume when calculated in ferret diameters.

[0202] Data Analysis. Performance was evaluated using the growth performance parameter D50. D50 is defined as the median calculated bubble volume, i.e., 50% of the bubble population falls below this size.

number

[0203] A D50 performance increase of 0% is interpreted as no performance improvement, less than 0% is interpreted as poor bubble growth performance, and more than 0% is interpreted as improved bubble growth.

[0204] Testing and Results. Various growth media samples were tested to evaluate the effect of media construction. The media samples were composites of rayon and a sheath / core bicomponent polyester fiber (ADVANSA 271P) with a nominal average diameter of 14 μm and a nominal average length of 6 mm. The design variables for the finished material are listed in Table 7 and were mixed to create the various media samples. The finished material parameters were varied to target various media properties, as listed in Table 8.

[0205] [Table 7]

[0206] [Table 8]

[0207] The rate of increase in D50 was determined as a function of media solids fraction, media thickness, and fiber size, and the results are shown in Figures 10A-10B, respectively.

[0208] It should be noted that solid fraction and thickness are not independent of each other. To prepare media with higher solid fraction, the media was compressed, thereby reducing thickness. It can be difficult to distinguish between effects due to solid fraction and thickness. However, it has been observed that decreasing solid fraction with increasing thickness leads to better growth performance.

[0209] It has been observed that benefits in growth performance are obtained at thicknesses greater than 1 mm. Additionally, benefits in growth performance are observed at solids fractions less than 7.5%, and especially less than 9%.

[0210] Example 7 Various aspects of the woven stainless steel screen and other variables were tested for the porous barrier stage in Example 7. Such aspects included the size of the openings, the surface chemistry, the face velocity, and the size of the air bubbles reaching the upstream porous barrier.

[0211] Sample Preparation. Various screens were obtained from commercial sources. Screen samples were prepared using 12.9 cm 2 The screen sample was placed in the in-line test cell.

[0212] Test Procedure: The test procedure was the same as in Example 6 above.

[0213] Image data processing. Image processing was performed as in Examples 3-5 above. The bubble volume was estimated from the ferret diameter of the bubble. The ferret diameter is referred to as the "bubble diameter" in this document with respect to the screen barrier stage.

[0214] Data Analysis. Screen performance was calculated as follows:

number

[0215] Screen performance is the percentage difference between the average of the 10 largest downstream bubbles compared to the average of the 10 largest upstream bubbles for each test.

[0216] A performance of 0% is interpreted as no change in bubble volume at the screen, less than 0% is interpreted as poor performance, greater than 0% but less than 100% is interpreted as a moderate increase in size, greater than 100% but less than 250% is interpreted as a significant improvement in size, and greater than 250% is interpreted as a significant size improvement.

[0217] Testing and Results. The screens were stainless steel plain weave screens. Various screens were tested with various properties as shown in Table 9 below, along with the application of an oleophobic treatment. The screens were obtained from McMaster-Carr (Elmhurst, Illinois).

[0218] [Table 9]

[0219] Screen samples were run at different face velocities of 0.5 cm / sec, 1.25 cm / sec, and 5.0 cm / sec to test the effect of face velocity on screen performance.

[0220] Bubble challenges were classified as either "coarse," with a mean nominal ferret diameter of 550 μm, or "fine," with a mean nominal ferret diameter of 350 μm. To maintain a similar upstream bubble challenge size, the airflow rate was adjusted to account for changes in face velocity.

[0221] The results of the tests are shown in Figure 11 A. In general, it was observed that as face velocity increased, the performance of the screen decreased.

[0222] The effect of oleophobic surface treatment on the performance of the screens was also tested. The screens were treated with trichloro(1H,1H,2H,2H-perfluorooctyl)silane (available from Millipore Sigma, St. Louis, MO) using chemical vapor deposition. Briefly, the screens were placed under vacuum for at least 10 minutes, and the treatment chemical was applied to the screen in vapor form. After treatment, the oleophobicity ratings of the samples were tested by the AATC118 method. All treated samples had an oleophobicity rating of at least 6.

[0223] The results of the test are shown in Figure 11B. At the lower face velocity of 0.5 cm / sec and with the oleophobic treatment, it was observed that the screen performance improved, especially with respect to fine bubbles.

[0224] All references and publications cited herein are expressly incorporated by reference in their entirety into this disclosure, except to the extent that they may directly contradict the present disclosure. While specific embodiments have been illustrated and described herein, those skilled in the art will recognize that various alternative and / or equivalent implementations may be substituted for the specific embodiments illustrated and described without departing from the scope of the present disclosure. It is understood that the present disclosure is not intended to be unduly limited by the exemplary embodiments and examples set forth herein, and that such examples and embodiments are presented merely as examples, and that the scope of the present disclosure is intended to be limited only by the claims set forth herein.

Claims

1. A degassing device comprising: a gas nucleation medium; a growth medium adjacent to the gas nucleation medium; a porous barrier adjacent to the growth medium; A degassing device comprising:

2. The degassing apparatus of claim 1 further comprising a gap between the growth medium and the porous barrier.

3. 3. The degasser of claim 1 or 2, wherein the gas nucleation medium comprises a particulate filtration medium.

4. 4. The degasser of claim 1, wherein the gas nucleation medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, ceramic, carbon fiber, or a combination thereof.

5. A degasser according to any one of claims 1 to 4, wherein the gas nucleation medium comprises an oleophobic material having an oil contact angle of at least 30°.

6. 6. The degasser of any one of claims 1 to 5, wherein the gas nucleation medium comprises an oleophobic material having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

7. The degasser of any one of claims 1 to 6, wherein the growth medium comprises multiple media layers.

8. A degasser according to any one of claims 1 to 7, wherein the growth medium is immediately adjacent to the gas nucleation medium.

9. 9. The degasser of any one of claims 1 to 8, wherein the growth medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, ceramic, carbon fiber, or a combination thereof.

10. A degasser according to any one of claims 1 to 9, wherein the porous barrier comprises an opening forming an outlet.

11. A degasser according to any one of claims 1 to 10, wherein the porous barrier comprises openings of a size of 250 μm or less.

12. The degasser of any one of claims 1 to 11, further comprising a liner.

13. A degasser according to any one of claims 1 to 12, further comprising a first end cap including an opening defining an inlet.

14. A degasser according to any one of claims 1 to 13, further comprising a closed second end cap.

15. 15. The degasser of claim 14, wherein the second end cap comprises a bottom.

16. A degasser according to any one of claims 1 to 15, wherein the gas nucleating medium surrounds and defines an open degasser interior.

17. A degassing apparatus according to any one of claims 1 to 16, wherein the gas nucleation medium, the growth medium and the porous barrier form a cylindrical body.

18. The nucleation medium has a thickness of at least 10 m as measured by the Carmen-Kozeny method. ２ / m ２ A degasser according to any one of claims 1 to 17, having an elemental fibre surface area of

19. A degasser according to any one of the preceding claims, wherein the nucleation medium has an average pore size of less than or equal to 30 μm as measured by ASTM F316.

20. 14. The degasser of claim 13, wherein the first end cap includes an inlet that leads directly into a gap between the growth medium and the porous barrier.

21. 21. The degasser of any one of claims 1 to 20, wherein the growing medium has a solids percentage of 9% or less at 1.5 psi.

22. A degassing apparatus according to any one of the preceding claims, wherein the growth medium has a thickness of 0.8 mm or more.

23. 23. The degasser of any one of claims 1 to 22, wherein the growth medium comprises a complex of an oleophilic component and an oleophobic component, the oleophobic component having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

24. A degasser according to any one of claims 1 to 23, wherein the porous barrier comprises an oleophobic surface having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

25. 25. A degasser according to any one of the preceding claims, wherein the porous barrier comprises a composite of an oleophilic component and an oleophobic component, the oleophobic component having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

26. 1. A system for removing gas from a fluid, comprising: a tank including a fluid inlet and a fluid outlet, the tank having a fluid flow path from the fluid inlet to the fluid outlet; The degassing device according to any one of claims 1 to 25. A system including:

27. 1. A method for removing gas from a fluid, comprising: A method comprising passing the fluid through a degasser defining a fluid flow path, the degasser comprising the degasser of any one of claims 1 to 25.

28. A degassing device comprising: a gas nucleation medium; a porous barrier adjacent to the gas nucleation medium, the porous barrier comprising openings of a size of 250 μm or less; a gap between the gas nucleation medium and the porous barrier; A degassing device comprising:

29. 30. The degasser of claim 28, wherein the degasser does not include a growth medium between the gas nucleation medium and the porous barrier.

30. 30. The degasser of claim 28 or 29, wherein the gas nucleation medium comprises a particulate filtration medium.

31. 31. The degasser of any one of claims 28 to 30, wherein the gas nucleation medium comprises cellulose, regenerated cellulose, polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), glass, ceramic, carbon fiber, or a combination thereof.

32. A degasser according to any one of claims 28 to 31, wherein the gas nucleation medium comprises an oleophobic material having an oil contact angle of at least 30°.

33. 33. The degasser of any one of claims 28 to 32, wherein the gas nucleation medium comprises an oleophobic material having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

34. A degassing apparatus according to any one of claims 28 to 33, wherein the gap is in the range of from 4 mm to 20 mm.

35. A degasser according to any one of claims 28 to 34, further comprising a liner.

36. A degasser according to any one of claims 28 to 35, further comprising a first end cap including an opening defining an inlet.

37. A degasser according to any one of claims 28 to 36, further comprising a closed second end cap.

38. A degasser according to any one of claims 28 to 37, wherein the gas nucleation medium surrounds and defines an open degasser interior.

39. A degasser according to any one of claims 28 to 38, wherein the gas nucleation medium and the porous barrier form a cylindrical body.

40. A degasser according to any one of claims 28 to 39, wherein the gas nucleation medium has an average pore size of 5 μm or greater as measured by ASTM F316.

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