Degassing system and method

Abstract

The degasser includes a gas nucleation medium and a porous barrier. The degasser may include a growth medium between the gas nucleation medium and the porous barrier. The degasser may be part of a system for removing gas from a fluid, the system including a tank with a fluid inlet and a fluid outlet and having a fluid flow path from the fluid inlet to the fluid outlet, the degasser being within the fluid flow path. A method for removing gas from a fluid includes passing the fluid through a degasser defining the fluid flow path.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 051,695, filed July 14, 2020, entitled "System and Method for Deaeration," the contents of which are incorporated herein by reference.

[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 that includes a housing having an inlet and a single outlet, a gas nucleation medium, and a porous barrier downstream of the gas nucleation medium, the gas nucleation medium and the porous barrier being disposed within the housing.

[0007] According to one embodiment, the degassing apparatus comprises a first element comprising a gas nucleation medium, the first element being an in-line filter; a second element downstream of the first element and in fluid communication with the first element, the second element comprising a porous barrier; and at least one of the first and second elements comprising a growth medium, the first and second elements being in a stacked configuration.

[0008] According to one embodiment, the degassing device comprises a cylindrical element comprising a gas nucleation medium and a porous barrier arranged cylindrically, the porous barrier being disposed downstream of and around the gas nucleation medium; a gap between the gas nucleation medium and the porous barrier; an end cap disposed at one end of the cylindrical element; an inlet formed in the end cap; an outlet in fluid communication with a hydraulic fluid tank; and a cylindrical extension of material extending coaxially from the upstream end of the cylindrical element.

[0009] The degasser may 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 and a fluid flow path from the fluid inlet to the fluid outlet, the degasser being in fluid communication with the fluid flow path.

[0010] 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 can be 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. [Brief explanation of the drawings]

[0011] [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 for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 2B] 2 is a schematic cross-sectional view of a degassing device for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 2C] 2 is a schematic cross-sectional view of a degassing device for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 2D] 2 is a schematic cross-sectional view of a degassing device for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 3A] 2A-2C are schematic diagrams of a nested degasser and a stacked degasser, respectively, for use in the hydraulic system of FIG. 1, according to an embodiment. [Figure 3B] 2A-2C are schematic diagrams of a nested degasser and a stacked degasser, respectively, for use in the hydraulic system of FIG. 1, according to an embodiment. [Figure 4A] FIG. 3B is a schematic diagram of a flow pattern of the nested degasser of FIG. 3A according to an embodiment. [Figure 4B] FIG. 3B is a schematic diagram of a flow pattern of the nested degasser of FIG. 3A according to an embodiment. [Figure 5A] FIG. 3C is a schematic diagram of a flow pattern of the stacked degasser of FIG. 3B according to an embodiment. [Figure 5B] FIG. 3C is a schematic diagram of a flow pattern of the stacked degasser of FIG. 3B according to an embodiment. [Figure 5C] FIG. 3C is a schematic diagram of a flow pattern of the stacked degasser of FIG. 3B according to an embodiment. [Figure 5D] FIG. 3C is a schematic diagram of a flow pattern of the stacked degasser of FIG. 3B according to an embodiment. [Figure 6A] 2 is a schematic diagram of a stacked degasser for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 6B] 2 is a schematic diagram of a stacked degasser for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 7A] 2 is a schematic diagram of a stacked degasser having nested components for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 7B] 2 is a schematic diagram of a stacked degasser having nested components for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 7C] 2 is a schematic diagram of a stacked degasser having nested components for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 7D] 2 is a schematic diagram of a stacked degasser having nested components for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 8A] 2 is a cross-sectional view of a pleated media degasser component for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 8B] 2 is a cross-sectional view of a pleated media degasser component for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 9] 2 is a schematic cross-sectional view of a deaerator unit for use in the hydraulic system of FIG. 1 according to an embodiment. [Figure 10] 1 is a graph of the data collection settings used in the examples. [Figure 11A] 1 is a graph showing the results of Example 1. [Figure 11B] 1 is a graph showing the results of Example 1. [Figure 11C] 1 is a graph showing the results of Example 1. [Figure 12A] 1 is a graph showing the results of Example 2. [Figure 12B] 1 is a graph showing the results of Example 2. [Figure 12C] 1 is a graph showing the results of Example 2. [Figure 13A] 1 is a graph showing the results of Example 3. [Figure 13B] 1 is a graph showing the results of Example 3. [Figure 13C] 1 is a graph showing the results of Example 3. [Figure 13D] 1 is a graph showing the results of Example 3. [Figure 14A]1 is a graph showing the results of Example 3. [Figure 14B] 1 is a graph showing the results of Example 3. [Figure 14C] 1 is a graph showing the results of Example 3. [Figure 14D] 1 is a graph showing the results of Example 3. [Figure 15A] 1 is a graph showing the results of Example 4. [Figure 15B] 1 is a graph showing the results of Example 4. [Figure 16A] 1 is a graph showing the results of Example 6. [Figure 16B] 1 is a graph showing the results of Example 6. [Figure 17A] 1 is a graph showing the results of Example 7. [Figure 17B] 1 is a graph showing the results of Example 7. [Figure 18] 1 is a graph showing the results of Example 8. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 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.

[0014] The terms "degass" and "degassing" are used herein to refer to the removal of air or other gases from a fluid.

[0015] The term "adjacent" is used herein to mean "next to." An "adjacent" feature may or may not be in contact with the adjacent feature. For example, "adjacent" features may be separated by a gap.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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 drawn 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 with or within smaller hydraulic tanks, such as those used in mobile hydraulic systems used on vehicles, e.g., excavators, loaders, and skid steer loaders, or for use in other systems with miniaturized hydraulic tanks. The devices and methods can also be advantageous because they can be configured to be retrofitted to existing hydraulic systems. One or more parts of the device may be conveniently removable and serviceable, at least due to its placement of the particles in-line.

[0029] 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.

[0030] 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 in FIG. 1 or may be located elsewhere in the system 1. For example, one or more components of the degasser 100 may be located in series along the return line 31. According to one embodiment, the degasser 100 is disposed in the flow path of hydraulic fluid flowing through or within the tank 10. For example, the degasser 100 may be disposed in the flow path of 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 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.

[0031] System 1 may include additional components such as additional tanks, lines, pumps, meters, controls, and the like.

[0032] 2A-2D are schematic cross-sectional views of a concentric nested degasser 100 according to the present disclosure. The degasser 100 includes a gas nucleation medium 110 disposed in a fluid flow path within the tank 10. The degasser 100 may further include 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.

[0033] The gas nucleation medium 110, growth medium 120, and / or porous barrier 130 may be arranged in a flow-through configuration within the flow channel. 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 over the medium in a direction parallel to the major surfaces of the medium.

[0034] 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 through a secondary inlet or opening 146 in the first end cap 141 into the gap 135 between the porous barrier 130 and the growth medium 120, as shown in FIG. 2D.

[0035] 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.

[0036] The growth medium 120 may be positioned 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 or a support structure for the gas nucleation medium 110. The growth medium 120 may be positioned 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.

[0037] 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. 2C. 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 2C, 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. The porous barrier 130 may form a cylinder coaxial with and at least partially circumscribing 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.

[0038] In some cases, it may be desirable to provide one or more components of the degassing apparatus 100 separate from the other components. Providing the components separately may allow for greater flexibility in component placement. For example, one or more components may be located outside the tank 10, while other components may be located inside the tank 10. The components may be independently positioned as an inside-to-outside flow or an outside-to-inside flow. Additionally, the components may be more easily serviceable or replaceable.

[0039] One or more of the components of the degassing apparatus 100 may be provided in a stacked configuration. The term "stacked" is used herein to distinguish it from a nested configuration. In a stacked configuration, fluid flows through and out of one component or element before entering the next. Stacked components may be separated by a gap or may be directly adjacent to one another, such that the outlet of one component forms the inlet of another. Stacked components may be physically stacked on top of one another. However, as used herein, the term "stacked" also includes embodiments in which the components or elements are not physically stacked but may be spatially separated either laterally and / or axially.

[0040] To illustrate the difference between a nested (sometimes called coaxial) configuration and a stacked configuration, simplified schematic diagrams including only the gas nucleation medium 110 and porous barrier 130 are shown in FIGS. 3A and 3B. In the nested configuration (FIG. 3A), the components of the degasser 100 (e.g., the gas nucleation medium 110 and the porous barrier 130) are nested within one another. The flow direction can be from inside to outside or from outside to inside. The nested components may be housed within a housing and may include shared end caps at both the top and bottom. The inner component (in this case, the gas nucleation medium 110) may serve as an inlet for the outer component (in this case, the porous barrier 130). In the stacked configuration (FIG. 3B), the components of the degasser 1000 may be separated into elements (e.g., a first element 200 and a second element 300, etc.). Each element may be configured independently of the others and may independently house one or more components, such as the gas nucleation medium 110, the growth medium 120, and / or the porous barrier 130. The elements may be axially aligned but spaced apart (e.g., not nested). There may or may not be gaps between the elements. The elements of the stacked degasser 1000 may be spatially separated in other ways, not necessarily axially aligned. One or more elements may be in-line while another one or more elements are disposed within a tank. The elements may be housed in separate housings, may be in a common housing, may have separate end caps, or may share end caps between elements. The flow direction may be independent, such as from inside to outside or from outside to inside, for each element. While cylindrical elements are shown here for illustrative purposes, the elements do not necessarily need to be housed in cylindrical housings. One or more elements may be housed within a tank without separate housings or may be arranged in a panel configuration.

[0041] Different flow configurations of the nested degasser 100 are shown in FIGS. 4A and 4B. The flow may be arranged as an inside-outside configuration (FIG. 4A) or an outside-inside configuration (FIG. 4B). Various flow configurations of the stacked degasser 1000 are shown in FIGS. 5A-5D. As can be seen, each element 200, 300, etc. may be independently arranged as an inside-outside or outside-inside configuration, allowing for great flexibility in design. In FIG. 5A, the first element 200 and the second element 300 are both arranged as an inside-outside configuration. In FIG. 5B, the first element 200 is arranged as an inside-outside configuration and the second element 300 is arranged as an outside-inside configuration. In FIG. 5C, the first element 200 is arranged as an outside-inside configuration and the second element 300 is arranged as an inside-outside configuration. In FIG. 5D, the first element 200 and the second element 300 are both arranged as an outside-inside configuration. Additionally, top-to-bottom and bottom-to-top flow configurations can also be considered separately for each element, adding even more variability.

[0042] Examples of various stacking configurations for a degassing apparatus 1000, including a gas nucleation medium 110, a growth medium 120, and a porous barrier 130, are shown in Figures 6A, 6B, and 7A-7C. Generally, as shown in Figure 6A, the components (gas nucleation medium 110, growth medium 120, and porous barrier 130) may be stacked. That is, the components are provided in separate elements 200, 300, and 400 that are not nested but are positioned one after the other. The general direction of fluid flow is indicated by the dotted arrows. However, any combination of inside-outside and outside-inside flow within each element (e.g., as shown in Figures 5A-5D) can be applied.

[0043] Each of the elements 200, 300, and 400 of the degasser 1000 may be positioned in-line (outside the tank 10), or one or more of the elements (e.g., elements 300 and 400) may be positioned inside the tank 10. Element 200 includes the gas nucleation medium 110, element 300 includes the growth medium 120, and element 300 includes the porous barrier 130. The elements 200, 300, and 400 may be housed in a common housing (e.g., housing 1010 as shown in FIG. 6A) or may be housed separately. The gas nucleation medium 110, growth medium 120, and porous barrier 130 may each be independently arranged in an inside-out or outside-in flow configuration. The degasser 1000 includes an inlet 1001 and an outlet 1002. The inlet 1001 may be formed in the housing 1010 or at the inlet of the gas nucleation medium 110. The outlet 1002 may be formed in the housing 1010 or may be formed in the outlet of the third element 400 .

[0044] The elements 200, 300, 300 of the degasser 1000 may be separated by one or more gaps, as shown in FIG. 6A, or two or all of the elements may be directly adjacent to one another. For example, as shown in FIG. 6B, the first element 200 of the degasser 1000, including the gas nucleation medium 110, is provided separately, while the second element 300 including the growth medium 120 and the third element 400 including the porous barrier 130 are directly adjacent to one another. Alternatively, the first element 200 including the gas nucleation medium 110 and the second element 300 including the growth medium 120 are directly adjacent to one another, while the third element 400 including the porous barrier 130 is provided separately. In each embodiment, one or more of the elements may be located in-line (outside of the tank 10), or one or more of the elements may be located inside the tank 10. Additionally, elements 200, 300, 400 may be housed separately or may be located within a common housing 1010. Elements 200, 300, 400 may also be independently arranged in an inside-to-outside flow or an outside-to-inside flow.

[0045] In some embodiments, one or more elements of the stacked degasser 1000 may include nested components. For example, as shown in FIG. 7A , the first element 200 of the degasser 1000 includes the gas nucleation medium 110, and the second element 300 includes the porous barrier 130 and the nested growth medium 120. The elements 200 and 300 may be housed separately or may be disposed within a common housing 1010. One or both elements may be disposed in-line (outside the tank 10), or one element may be disposed inside the tank 10. Additionally, the elements 200 and 300 may be disposed independently, with an inside-out flow or an outside-in flow. A replacement part for the first element 200 may include a unit having the gas nucleation medium 110. A replacement part for the second element 300 may include a unit having the growth medium 120 and the porous barrier 130.

[0046] In FIG. 7B, the first component 200 of the degassing apparatus 1000 includes a gas nucleation medium 110 nested with a growth medium 120, and the second component 300 includes a porous barrier 130. The components 200 and 300 may be housed separately or may be disposed within a common housing 1010. One or both components may be disposed in-line (outside the tank 10), or one may be disposed inside the tank 10. The components 200 and 300 may also be disposed independently, with inside-out or outside-in flow. A replacement component for the first component 200 may include a unit with the gas nucleation medium 110 and the growth medium 120. A replacement component for the second component 300 may include the porous barrier 130.

[0047] In FIG. 7C , the degassing apparatus 1000 includes two layers or stages of growth media 121 and 122. The first component 200 includes the first layer or stage of growth media 121 nested with the gas nucleation medium 110, and the second component 300 includes the second layer or stage of growth media 122 nested with the porous barrier 130. The components 200 and 300 may be housed separately or may be positioned within a common housing. One or both components may be positioned in-line (outside the tank 10), or one may be positioned inside the tank 10. The components 200 and 300 may also be independently positioned for inside-out flow or outside-in flow. Replacement components for the first component 200 may include a unit with the gas nucleation medium 110 and the growth medium 121. Replacement components for the second component 300 may include a unit with the growth medium 122 and the porous barrier 130.

[0048] In some embodiments, one or more of the elements of the degasser 1000 are disposed inside the tank 10. For example, as shown in FIG. 7D , the first element 200 may be in-line and the second element 300 may be disposed inside the tank. The first element 200 may include the gas nucleation medium 110, optionally the growth medium 120, and optionally the porous barrier 130. The components of the first element 200 may be in a nested configuration. The first element 200 may be disposed in an inside-out flow configuration as shown, or alternatively in an outside-in flow configuration. The porous barrier 130, or alternatively, the growth medium 120 and the porous barrier 130, may be disposed inside the tank 10. In some embodiments, the porous barrier 130 is formed by a strainer at the outlet 18 of the tank 10, as shown. Alternatively, the porous barrier 130 may be disposed at the inlet of the tank 10 or somewhere between the inlet and the outlet. The porous barrier 130 may have a cylindrical configuration or may have a flat plate or pleated panel configuration. A gap 135 may be formed inside the tank 10 between the growth medium 120 and the porous barrier 130. Replacement parts for the first element 200 may include a unit having the gas nucleation medium 110 and the growth medium 120.

[0049] In some embodiments, one or more of the gas nucleation medium, growth medium, and porous barrier are independently removable and replaceable. In some embodiments, two or more of the gas nucleation medium, growth medium, and porous barrier form a removable and replaceable unit. The replacement part may include a filter element configured to fit into the degasser. The replacement part may include two or more of the gas nucleation medium, growth medium, and porous barrier.

[0050] According to one embodiment, a filter element suitable for use in a degasser may be a replacement part. The filter element (e.g., a replacement part) may include a layer of gas nucleation medium and a layer of growth medium. The filter element (e.g., a layer of gas nucleation medium and a layer of growth medium) may form a cylindrical element. The filter element may further include end caps at the ends of the cylindrical element. The filter element may be a replacement part for one or more components of the degasser shown in Figures 2A-2D. The filter element may be a replacement part for one or more components or one or more elements 200, 300, 400 shown in Figures 3B and 5A-7D.

[0051] In some embodiments, such as those shown in FIGS. 6A-7C, the degasser 1000 may include only a single outlet. That is, the fluid (e.g., hydraulic oil) and gas bubbles exit the degasser 1000 (e.g., the degasser housing 1010) through the same outlet. In some embodiments, when at least the first element 200 is configured as an in-line degasser, the in-line degasser includes only a single outlet. The single outlet may connect the in-line degasser to the inlet of the tank 10, as shown in FIG. 7D. The tank 10 may house additional components of the degasser. In some embodiments, the degasser 1000 includes an additional outlet in the form of a gas release. One or more gas release holes (e.g., opening 146 shown in FIGS. 2D and 9) may be located at or near the top of the degasser 1000, such as at the top of the gap 135.

[0052] In embodiments, where two or more components are directly adjacent or nested, the components may optionally be separated by liners or support elements. In some embodiments, the liner of one component acts as support for an adjacent component. The elements may also include spacing (e.g., gaps 135) between and / or between the components.

[0053] When the degasser unit 100 is in use, a fluid flows through the gas nucleation medium 110. For example, in an inside-out flow configuration, the fluid flows into the open interior 144 of the gas nucleation medium 110, such as through the top inlet 101. By passing through the gas nucleation medium 110, at least some of the dissolved gas in the fluid may nucleate and form free air, such as a small gas cavity (a 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 coalesce in the growth medium 120. The growth and / or condensation forms a larger gas cavity (a second-stage gas cavity).

[0054] In embodiments including a gap 135 between the growth medium 120 and the porous barrier 130, the second-stage gas cavity may begin to rise upward in the gap 135. In some embodiments, the degassing apparatus 100 includes one or more gas release holes at the top of the gap 135. For example, the opening 146 (see FIGS. 2D and 9 ) in the first end cap 141 (e.g., the top end cap) may be used as a gas release hole. 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 coalesce upstream of the porous barrier 130 and rise upward in 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, enough pressure builds up to cause the gas pocket to break through the wetted 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, the gas cavity at the top of the gap may pass through the porous barrier as a large bubble and rise to the surface. If the degasser is submerged, the gas pocket may be large and buoyant enough to rise to the surface and escape from the surface. Once the gas pocket is cleared, the porous barrier 130 rewets, and the process can be repeated.

[0055] 2A-9, the gas nucleation medium 110 can be made of any suitable material capable of inducing gas nucleation. Without 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.

[0056] 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 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 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.

[0057] 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.

[0058] The pore size of a medium is understood to mean the size of individual pores in a sheet of the medium as determined by ASTM F316-03 or ASTM D6767. The 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. The 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, the pores in a gas nucleation medium may have an average pore size of 5 μm to 100 μm. The 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. The 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, the 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.

[0059] The chemical composition of the medium and its oleophilicity / oleophobicity are believed to affect nucleation. The chemical composition of the medium may 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 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 include 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), copolymers, or combinations thereof; glass; ceramic; or carbon fibers. In one embodiment, the filtration media used as the gas nucleation medium 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, as well as U.S. Patent Application Publication Nos. 2012 / 0234748 and 2017 / 0225105, each of which is incorporated herein by reference in its entirety. The media may include various binders, such as acrylic resins, phenolic resins, or epoxy resins.

[0060] 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°.

[0061] 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.

[0062] 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).

[0063] 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).

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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

[0075] 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.

[0076] 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.

[0077] 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°.

[0078] 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.

[0079] 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. Other configurations, such as a flat panel configuration, are possible. 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 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.

[0080] 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.

[0081] In some embodiments, the degassing device includes a growth medium. The growth medium may be adjacent to the gas nucleation medium or directly adjacent to the gas nucleation medium. The growth medium may be spaced (not adjacent) from the gas nucleation medium. The growth medium may be adjacent to the porous barrier or directly adjacent to the porous barrier. 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 to downstream side of the growth medium.

[0082] In some embodiments, the gas nucleation medium may exhibit bubble growth behavior. In such embodiments, a separate layer of growth medium may be excluded. 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 such an embodiment, the degasser does not include a growth medium. In one embodiment, the degasser includes gas nucleation with a pore size of 5 μm or more and does not include a growth medium.

[0083] 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.

[0084] 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 a composite material. The growth medium can be a composite of oleophilic and oleophobic components. The oleophobic component has an oleophobicity rating of one or more.

[0085] 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, or 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 / m 2The values ​​listed here are determined by ASTM D7490-13.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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°.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] The porous barrier downstream of the gas nucleation medium (and optionally 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 side of the growth medium.

[0099] 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.

[0100] 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.).

[0101] 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.

[0102] 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. Polymeric or non-polymeric coatings, such as resins, can be used. In some embodiments, the porous barrier 130 is disposed in a cylindrical shape downstream of the gas nucleation medium 110 and optional growth medium 120. In some embodiments, the porous barrier 130 is disposed in a cylindrical shape that at least partially surrounds (e.g., nests within) the gas nucleation medium 110 and / or growth medium 120. In one embodiment, the porous barrier 130 is arranged in a cylindrical shape that at least partially surrounds (e.g., nested with) the growth medium 120. The nested elements of the growth medium 120 and the porous barrier 130 may be in a stacked configuration with the gas nucleation medium 110. In some embodiments, the porous barrier 130 has another geometric configuration, such as a planar or substantially planar sheet or pleated sheet, or is composed of two or more planar or pleated sheets. The sheets or pleated sheets may be configured as panels. Such panel configurations may be disposed, for example, within the interior of the tank 10.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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 plane 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 also be sized to accommodate air pockets that may be formed by the condensed gas cavities. 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.

[0107] 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.

[0108] 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.

[0109] The degasser components may include pleated or non-pleated media. One or more of the gas nucleation medium 110, growth medium 120, and porous barrier 130 may be pleated. Components positioned directly adjacent to one another may be pleated together. In one embodiment, the gas nucleation medium is made of pleated media together with the growth medium. In another embodiment, the gas nucleation medium is made of pleated media together with the porous barrier (e.g., when the degasser does not include a growth medium). The pleated media may be arranged as a flat pane or as a cylinder. In one embodiment, the pleated media 61 is arranged cylindrically around the central opening 144, as shown in the cross-sectional view of FIG. 8A. In one embodiment, the pleated media is arranged with variable pleats, where the pleat depth varies throughout the component. The variable pleated media 62 may be arranged within a cylindrical housing, as shown in FIG. 8B.

[0110] In some embodiments, the degasser 100 includes a crown formed by an extension of material. In particular, in embodiments in which the nucleation medium 110, growth medium 120, and porous barrier 130 are arranged in a concentrically nested configuration, a cylindrical portion of the medium may extend beyond the top of the concentric circles to form a crown 133, as shown in FIG. 9 . The crown 133 is positioned outside the gas release 146. In other words, the crown 133 is positioned radially farther from the central axis A than the gas release 146. The crown may be axially aligned with the porous barrier. The crown 133 may be formed of any suitable material, including the same material as the porous barrier 130. The crown 133 may be an extension of the porous barrier 130 that extends beyond the nucleation medium 110 and growth medium 120. In some embodiments, the degasser 100 includes an end cap 141 having an inlet 101, the end cap 141 extending across the top of the degasser (e.g., across the top of the housing). The crown 133 may be a cylindrical piece of material (e.g., an extension of the porous barrier 130) that extends upward (upstream) from the end cap 141. The crown 133 may be secured to the end cap 141.

[0111] In one embodiment, the degasser 100 includes a cylindrical element formed of a gas nucleation medium 110 and a porous barrier 130 arranged in a cylindrical configuration, with the porous barrier 130 disposed downstream and surrounding the gas nucleation medium 110. A gap 135 may be disposed between the gas nucleation medium 110 and the porous barrier 130. The cylindrical element may also include a growth medium 120 disposed between the nucleation medium 110 and the porous barrier 130. The degasser 100 further includes an end cap disposed at one end of the cylindrical element, an inlet formed in the end cap, and an outlet in fluid communication with a hydraulic fluid tank. A cylindrical extension of material extends coaxially from the upstream end of the cylindrical element, forming a crown 133. The cylindrical element formed by the gas nucleation medium 110, optionally the growth medium 120, and the porous barrier 130 may have a first height H110. The crown 133 and cylindrical element may have a second height H130 greater than the first height such that a cylindrical extension of the material extends beyond the first height to form the crown 133.

[0112] 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. In one embodiment, a liner is disposed between the gas nucleation medium 110 and the growth medium 120. In one embodiment, the porous barrier 130 includes a liner disposed downstream thereof. In one embodiment, the porous barrier 130 includes a liner disposed upstream thereof. The liner of the porous barrier 130 may support the growth medium 120. 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 material, a tube, a line, etc.

[0113] The degassing apparatus 100 may include removable and / or serviceable components. For example, one or more of the elements 200, 300, 400, or one or more of the gas nucleation medium 110, growth medium 120, and 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 growth medium 120 are removable and / or serviceable. Any one of the gas nucleation medium 110, growth medium 120, or porous barrier 130 may be independently removable and / or serviceable, or two or more components may form a removable and / or serviceable unit. For example, the gas nucleation medium 110 and the growth medium 120 may form a removable and / or serviceable unit, or the growth medium 120 and the porous barrier 130 may form a removable and / or serviceable unit, or all three of the gas nucleation medium 110, the growth medium 120, and the porous barrier 130 may form a removable and / or serviceable unit. The serviceable unit 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 serviceable unit of the gas nucleation medium 110 and the growth medium 120 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 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.

[0114] 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.

[0115] 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.

[0116] A list of various aspects of the degassing device of the present disclosure is provided below.

[0117] According to a first aspect, a degassing device comprises a housing having an inlet and only one outlet, the one outlet being connectable to the inlet of a hydraulic fluid tank, a gas nucleation medium, and a porous barrier downstream of the gas nucleation medium, the gas nucleation medium and the porous barrier being disposed within the housing.

[0118] According to a second aspect, in the degassing apparatus of the first aspect, the gas nucleation medium and the porous barrier have a laminated structure.

[0119] According to embodiment 3, the degassing apparatus of embodiment 1 or 2 further comprises a growth medium disposed between the gas nucleation medium and the porous barrier.

[0120] According to a fourth embodiment, in the degassing apparatus of the third embodiment, the growth medium is in a layered configuration with the gas nucleation medium and the porous barrier.

[0121] According to embodiment 5, in the degassing apparatus of embodiment 3, the growth medium is nested with the gas nucleation medium.

[0122] According to embodiment 6, in the degassing apparatus of embodiment 3, the growth medium is nested with the porous barrier.

[0123] According to Example 7, in the degassing apparatus of any one of Examples 1 to 6, the gas nucleation medium is arranged in an inside-outside flow configuration and the porous barrier is arranged in an outside-inside flow configuration.

[0124] According to an eighth embodiment, in the degassing apparatus of any one of the first to sixth embodiments, the gas nucleation medium is arranged in an outside-to-inside flow configuration and the porous barrier is arranged in an inside-to-outside flow configuration.

[0125] According to a ninth aspect, a degassing apparatus includes a first element comprising a gas nucleation medium, the first element being an in-line filter, and a second element downstream of the first element and in fluid communication with the first element, the second element comprising a porous barrier, wherein at least one of the first and second elements comprises a growth medium, and the first and second elements are in a stacked configuration.

[0126] According to a tenth embodiment, in the degassing apparatus of the ninth embodiment, the first element comprises a gas nucleation medium and a growth medium, and the gas nucleation medium and the growth medium are nested.

[0127] According to an eleventh embodiment, in the degassing apparatus of any one of the ninth and tenth embodiments, the second element comprises a porous barrier and a growth medium, the porous barrier and the growth medium being nested.

[0128] According to a twelfth aspect, in the degassing device of any one of the ninth to eleventh aspects, the second element is disposed in the fluid tank.

[0129] According to aspect 13, in the degassing device of any one of aspects 9 to 12, the first element and the second element are configured in a counter-flow configuration, and the counter-flow configuration is selected from an inside-to-outside flow configuration and an outside-to-inside flow configuration.

[0130] According to a fourteenth aspect, in the degassing apparatus of any one of aspects 9 to 12, the first element and the second element are configured in the same flow configuration, and the flow configuration is selected from an inside-to-outside flow configuration and an outside-to-inside flow configuration.

[0131] According to a fifteenth aspect, in the degassing apparatus of any one of aspects 9 to 14, the first element is arranged in an inside-to-outside flow configuration.

[0132] According to a sixteenth embodiment, in the degassing apparatus of any one of the nine to fourteenth embodiments, the first element is arranged in an outside-to-inside flow configuration.

[0133] According to a seventeenth aspect, in the degassing apparatus of any one of aspects 9 to 16, the second element is arranged in an inside-to-outside flow configuration.

[0134] According to an eighteenth embodiment, in the degassing apparatus of any one of the nine to sixteenth embodiments, the second element is arranged in an outside-to-inside flow configuration.

[0135] According to Example 19, the degassing apparatus of any one of Examples 9-18 further comprises a gap between the growth medium and the porous barrier. The gap may 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 may have a width of 1 mm to 15 mm.

[0136] According to a twentieth aspect, the degassing device of the nineteenth aspect further includes a gas release hole extending from the gap to the outside of the degassing device.

[0137] According to embodiment 21, the degassing device comprises a cylindrical element having a gas nucleation medium and a porous barrier arranged cylindrically, the porous barrier being arranged downstream and around the gas nucleation medium; a gap between the gas nucleation medium and the porous barrier; an end cap arranged at one end of the cylindrical element; an inlet formed in the end cap; an outlet in fluid communication with a hydraulic fluid tank; and a cylindrical extension of material extending coaxially from the upstream end of the cylindrical element.

[0138] According to Example 22, the degassing apparatus of Example 21 further comprises a growth medium disposed between the gas nucleation medium and the gap.

[0139] According to a twenty-third aspect, in the degassing device of the twenty-first or twenty-second aspect, the housing includes a gas release hole extending from the gap through the end cap to the outside of the housing.

[0140] According to Aspect 24, in the degassing apparatus of any one of Aspects 1 to 23, the gas nucleation medium includes 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 include a combination of glass fiber and polyester.

[0141] According to Aspect 25, in the degassing apparatus of any one of Aspects 1 to 24, 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 50° to 120°. The oil contact angle can be measured using a microcontact angle meter by dropping oil on a single fiber in air.

[0142] According to Aspect 26, according to the degassing apparatus of any one of Aspects 1-25, 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.

[0143] According to Aspect 27, according to the degassing device of any one of Aspects 1 to 26, 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.

[0144] According to embodiment 28, according to the degassing apparatus of any one of embodiments 1 to 27, the growth medium is immediately adjacent to the gas nucleation medium.

[0145] According to Example 29, in the degassing device of any one of Examples 1 to 28, 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.

[0146] According to Aspect 30, in the degassing device of any one of Aspects 1 to 29, 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 include openings of a size of 10 μm to 120 μm, 15 μm to 100 μm, or 20 μm to 80 μm.

[0147] According to a thirty-first aspect, the degassing device according to any one of the first to thirty aspects further includes a liner.

[0148] According to a thirty-second embodiment, the degasser of any one of the first to thirty-first embodiments further includes a first end cap including an opening defining an inlet.

[0149] According to a thirty-third embodiment, the degassing device of any one of the first to thirty-second embodiments further includes a closed second end cap.

[0150] According to an embodiment 34, in the degassing device of embodiment 33, the second end cap comprises a bottom portion.

[0151] According to a thirty-fifth embodiment, in the degasser of any one of the first to thirty-fourth embodiments, the gas nucleation medium surrounds and defines an open degasser interior.

[0152] According to Example 36, in the degassing apparatus of any one of Examples 1 to 35, the gas nucleation medium and optionally the growth medium and the porous barrier form a cylindrical body.

[0153] According to a thirty-seventh aspect, according to the degassing apparatus of any one of the first to thirty-sixth aspects, 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 / m2 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

[0154] According to Example 38, in the degassing apparatus of any one of Examples 1 to 37, 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.

[0155] According to Aspect 39, in the degassing device of any one of Aspects 1 to 38, 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%.

[0156] According to Aspect 40, in the degassing device of any one of Aspects 1 to 39, the growth 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 growth medium may 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.

[0157] According to Example 41, according to the degassing apparatus of any one of Examples 1 to 40, 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.

[0158] According to Example 42, according to the degassing device of any one of Examples 1 to 41, the porous barrier comprises an oleophobic surface having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

[0159] According to Aspect 43, according to the degassing device of any one of Aspects 1 to 42, 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.

[0160] According to aspect 44, 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 degassing device according to any one of the preceding aspects in fluid communication with the fluid flow path.

[0161] According to an embodiment 45, in the system of embodiment 44, at least a portion of the degassing device is disposed within the tank along the fluid flow path.

[0162] According to embodiment 46, in the system of embodiment 44 or 45, at least a portion of the degasser is disposed in-line along the fluid inlet line in fluid communication with the fluid inlet of the tank.

[0163] According to a forty-seventh aspect, a method for removing gas from a fluid includes passing the fluid through a degasser defining a fluid flow path, the degasser comprising the degasser of any one of the first to forty-three aspects.

[0164] According to embodiment 48, in the method of embodiment 47, the fluid stream is forced or drawn through the degasser.

[0165] According to a forty-ninth aspect, a filter element suitable for use in the degasser of any one of the first to thirty-ninth aspects includes a layer of gas nucleation medium and a layer of growth medium.

[0166] According to embodiment 50, in the filter element of embodiment 49, the layer of gas nucleation medium and the layer of growth medium form a cylindrical element.

[0167] According to embodiment 51, the filter element of embodiment 50 further comprises end caps on the ends of the cylindrical element.

[0168] According to a fifty-second aspect, in the filter element of any one of the forty-ninth to fifty-first aspects, the filter element is a replacement part for a degassing device.

[0169] According to embodiment 53, a degasser replacement part includes a layer of gaseous nucleation medium and a layer of growth medium adjacent to the layer of gaseous nucleation medium.

[0170] According to embodiment 54, in the replacement part of embodiment 53, the gas nucleation medium and growth medium form a cylindrical element.

[0171] According to embodiment 55, the replacement part of embodiment 54 further comprises an end cap at an end of the cylindrical element. [Example]

[0172] 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.

[0173] 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.

[0174] The fluid was heated to a target temperature, such as 35±1.6° C. The fluid was aerated in an aeration circuit with an oil flow rate of 11.3 L / min under a pressure of 414 kPa and an air flow rate of 7.1 L / min. The aerated fluid was flowed into a deaerator at a flow rate of approximately 36 L / min. The deaerator was at ambient pressure.

[0175] 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). 2The 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.

[0176] 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.

[0177] 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).

[0178] Test Method. Air was continuously added to the hydraulic oil supplied to the tank 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 10. The maximum air addition value for each deaerator was determined by averaging the oil aeration (%) readings from 600 seconds to 1700 seconds. A lower maximum air addition 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." In the table, "Air addition compared to baseline" refers to the amount of air remaining in the oil compared to the baseline, which is normalized to 100%. A value less than 100% indicates better performance (less air remaining in the oil) than the baseline. "Air reduction from baseline" is the difference between the baseline (100%) and the air addition in the sample. A higher value indicates better performance.

[0179] The air entrainment measuring device was an AIR-X sensor from Delta Services Industriels (Froyennes, Belgium).

[0180] 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 11A-11C.

[0181] [Table 1]

[0182] Figure 11A 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 11B. 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 11C contrasts maximum average air entrainment (%) versus differential pressure.

[0183] 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 varying growth medium thicknesses were prepared by applying varying 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 12A-12C.

[0184] [Table 2]

[0185] FIG. 12A 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 FIG. 12B. 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 commercial Sample A and baseline Sample B. FIG. 12C contrasts maximum average air entrainment (%) versus differential pressure.

[0186] 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.

[0187] The term "elementary fiber surface area" is used herein to refer to the surface area of ​​a fiber per bulk media surface area.

[0188] 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.

[0189] 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

[0190] 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.

[0191] 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

[0192] 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. If the fibers are 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.

[0193] 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).

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] [Table 3]

[0201] The characteristics of the media tested are shown in Table 4.

[0202] [Table 4]

[0203] 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 13A-13D. 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 14A-14D.

[0204] 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.

[0205] 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.

[0206] [Table 5]

[0207] 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 15A. The average bubble size as a function of layers is shown in Figure 15B. 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.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] [Table 6]

[0213] Example 6 Various aspects of the growth layer were examined in Example 6.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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)

[0219] 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.

[0220] 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.

[0221] 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

[0222] 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.

[0223] 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.

[0224] [Table 7]

[0225] [Table 8]

[0226] 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 16A-16B, respectively.

[0227] 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.

[0228] 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%.

[0229] 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.

[0230] 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.

[0231] Test Procedure: The test procedure was the same as in Example 6 above.

[0232] 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.

[0233] Data Analysis. Screen performance was calculated as follows:

number

[0234] 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.

[0235] 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).

[0236] [Table 9]

[0237] 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.

[0238] 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.

[0239] The results of the tests are shown in Figure 17A. It was generally observed that as face velocity increased, the performance of the screen decreased.

[0240] 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.

[0241] The results of the test are shown in Figure 17B. 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.

[0242] Example 8 Sample devices of various configurations were prepared. Samples were prepared as described above for Examples 1 and 2, except where a different configuration is noted below. The degasser configurations are summarized in Table 10A below.

[0243] Each sample was equipped with a strainer at the outlet of the test tank. Sample A is the baseline. In Table 10A, CPP refers to cylindrical pleated pack. XP refers to Synteq-XP media used in product number P171846, available from Donaldson Company, Inc. (Minneapolis, MN). PN130 refers to 130 g / m² (130 g / m²) available from Precision Custom Coatings, LLC (Totowa, NJ). 2 The stainless steel screen had a nominal opening of 50 μm and a simple weave pattern.

[0244] The degassing devices were tested as described above in Examples 1 and 2. The gas reduction for each configuration was compared to the baseline. The results are shown in Table 10B and Figure 18. "Air entrainment compared to baseline" means the amount of air remaining in the oil compared to the baseline normalized to 100%. A number less than 100% represents better performance than the baseline (less air remaining in the oil). "Air reduction from baseline" is the difference between the baseline (100%) and the air entrainment in the sample. A higher number indicates better performance.

[0245] [Table 10]

[0246] [Table 11]

[0247] It was observed that different configurations of stages can result in different degassing performance. Nearly all samples performed better than the baseline (Sample A). Both single-element coaxial (e.g., nested) and dual-element stacked designs performed better than the baseline. Of the single-element coaxials, in-tank (Sample C in Example 2) and in-line (Sample H in Example 8) result in similar degassing performance. Adding a growth layer improves degassing performance, such as Samples G to H (Example 8) or Samples F to G (Example 8). Samples with outgassing (Samples B and C in Example 8) performed better than the equivalent sample without outgassing (Sample D in Example 1).

[0248] 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 for removing dissolved air from hydraulic fluid or oil, comprising: a housing having an inlet and only one outlet, said outlet being connectable to the inlet of a hydraulic fluid tank; a gas nucleation medium configured to induce gas nucleation in a fluid to form gas cavities, said gas nucleation medium having an elemental fiber surface area, as measured by the BET method, of 1 m 2 / m 2 to 100 m 2 / m 2 ; a porous barrier downstream of the gas nucleation medium, the porous barrier including openings in size between 10 μm and 1 mm; Equipped with the gas nucleation medium and porous barrier are disposed within the housing. Degassing device.

2. 10. The degasser of claim 1, wherein the gas nucleation medium and the porous barrier are in a laminated configuration.

3. 3. The degassing apparatus of claim 1 or 2, further comprising a growth medium disposed between the gas nucleation medium and the porous barrier, the growth medium having a surface energy of 6 mJ / m2 or greater, and optionally the growth medium being in a stacked configuration with the gas nucleation medium and the porous barrier, or the growth medium being in a nested configuration with the gas nucleation medium or the porous barrier, or both.

4. 4. The degassing apparatus of claim 1, wherein the gas nucleation medium is arranged in an inside-outside flow configuration and the porous barrier is arranged in an outside-inside flow configuration, or the gas nucleation medium is arranged in an outside-inside flow configuration and the porous barrier is arranged in an inside-outside flow configuration.

5. A degassing device for removing dissolved air from hydraulic fluid or oil, comprising: a first element comprising a gas nucleation medium configured to induce gas nucleation in a fluid to form a gas cavity, the gas nucleation medium having an elemental fiber surface area of ​​1 m 2 / m 2 to 100 m 2 / m 2 as measured by the BET method, the first element being an in-line filter; a second element downstream of and in fluid communication with the first element, the second element comprising a porous barrier containing openings of a size between 10 μm and 1 mm; At least one of the first and second elements comprises a growth medium that allows for the coalescence or growth or the coalescence and growth of gas cavities to be induced; Equipped with the first element and the second element have a laminated structure; Degassing device.

6. 6. The degasser of claim 5, further comprising a gap between the growth medium and the porous barrier, and optionally further comprising gas release holes extending from the gap to an exterior of the degasser.

7. A degassing device for removing dissolved air from hydraulic fluid or oil, comprising: a cylindrical element comprising a gas nucleation medium and a porous barrier arranged in a cylindrical shape, the gas nucleation medium configured to induce gas nucleation in a fluid to form gas cavities, the cylindrical element having an elemental fiber surface area of ​​1 m2 / m2 to 100 m2 / m2 as measured by the BET method, the porous barrier including openings of 10 μm to 1 mm in size, the cylindrical element arranged downstream of and around the gas nucleation medium; a gap between the gas nucleation medium and a porous barrier; an end cap disposed at one end of the cylindrical element; an inlet formed in the end cap; an outlet in fluid communication with the hydraulic fluid tank; and a cylindrical extension of material extending coaxially from the upstream end of said cylindrical element; A degassing device comprising:

8. 8. The degassing apparatus of claim 1, wherein the gas nucleation medium comprises a particulate filtration medium having an average pore size of 5 μm or greater as measured by ASTM F316; optionally, 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; optionally, the gas nucleation medium comprises an oleophobic material having an oil contact angle of at least 30° as measured by a microcontact angle tester using an oil drop on a single fiber in air; and optionally, the gas nucleation medium comprises an oleophobic material having an oleophobicity rating of 1 or greater as measured by AATCC Method 118.

9. 7. The degassing apparatus of any one of claims 3, 5, and 6, wherein the growth medium comprises a plurality of media layers, and optionally the growth medium comprises an oleophobic surface having an oleophobicity rating of 1 or more as measured by AATCC Method 118, and optionally the growth medium comprises a composite of an oleophilic component and an oleophobic component, and the oleophobic component has an oleophobicity rating of 1 or more as measured by AATCC Method 118.

10. 10. A degassing apparatus according to any one of claims 1 to 9, wherein the porous barrier comprises an oleophobic surface having an oleophobicity rating of 1 or more as measured by AATCC Method 118, optionally 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 more as measured by AATCC Method 118, and optionally wherein the porous barrier comprises openings with a size of less than 250 μm.

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