Degassing system and method

Abstract

The present invention provides a degassing device for degassing hydraulic fluids. [Solution] A gas nucleation medium 110 configured to induce gas nucleation in a fluid so as to form a gas cavity, wherein when measured by the BET method, 1 m 2 / m 2 100m from 2 / m 2 The degassing device comprises a gas nucleating medium having a basic fiber surface area, and a porous barrier 130 downstream of the gas nucleating medium, the porous barrier including a woven mesh having openings ranging in size from 10 μm to 1 mm. Preferably, the gas nucleating medium and the porous barrier form a cylindrical element further including a first end cap 141 including an inlet and a closed second end cap 142.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority granted to U.S. Provisional Patent Application No. 63 / 051,695, filed on 14 July 2020, entitled “System and Method for Deaeration,” the contents of which are incorporated herein by reference.

[0002] This application relates to a fluid degassing system and method. [Background technology]

[0003] Various fluid-based systems can benefit from removing air from the fluid (e.g., degassing). In particular, systems where the same fluid remains in the system for extended periods can accumulate air. For example, in hydraulic systems where the fluid circulates multiple times, air can accumulate in the fluid, potentially degrading system performance.

[0004] Hydraulic systems, particularly hydraulic machinery, rely on hydraulic fluids to perform their tasks. Common examples of hydraulic systems include hydraulic machinery, hydraulic drive systems, hydraulic transmission systems, hydraulic brakes, and others. Because hydraulic fluids typically remain in the system for extended periods and undergo periods of high and low pressure, air can accumulate within the fluid. Air in the fluid can exist in various forms, such as dissolved air and free air. Free air can include entrained air and bubbles. The presence of air can cause cavitation in pumps, leading to symptoms such as increased wear and noise of components 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 systems and methods for degassing fluids. Furthermore, it would be desirable to provide systems and methods for degassing hydraulic fluids that are compatible with hydraulic systems. [Overview of the project] [Means for solving the problem]

[0006] A degassing apparatus is provided in accordance with the principles of this disclosure. The degassing apparatus includes a housing having an inlet and a single outlet, a gas nucleating medium, and a porous barrier downstream of the gas nucleating medium. The gas nucleating medium and the porous barrier are located inside the housing.

[0007] According to one embodiment, the degassing device comprises a first element which is an inline filter and includes a gas nucleating medium, a second element which is downstream of the first element and in fluid communication with the first element and includes a porous barrier, and at least one of the first and second elements which includes a growth medium, wherein the first and second elements are in a laminated configuration.

[0008] According to one embodiment, the degassing device is a cylindrical element comprising a cylindrically arranged gas nucleating medium and a porous barrier, wherein the porous barrier comprises a cylindrical element arranged downstream and around the gas nucleating medium; a gap between the gas nucleating medium and the porous barrier; an end cap located 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] A degasser may be part of a system for removing gas (e.g., air) from a fluid, and this system includes a tank having a fluid inlet and a fluid outlet, and a fluid passage from the fluid inlet to the fluid outlet, with the degasser being in fluid communication with the fluid passage.

[0010] A method is provided for removing a gas (e.g., air) from a fluid. This method involves passing the fluid through a degasser. The degasser defines a fluid flow path and includes a gas nucleating medium placed in the fluid flow path. A growth medium may be placed in the fluid flow path downstream of the gas nucleating medium. A porous barrier is placed in the fluid flow path downstream of the growth medium. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic flowchart of a hydraulic system according to one embodiment. [Figure 2A] This is a schematic cross-sectional view of a degasser for use in a hydraulic system according to an embodiment shown in Figure 1. [Figure 2B] This is a schematic cross-sectional view of a degasser for use in a hydraulic system according to an embodiment shown in Figure 1. [Figure 2C] This is a schematic cross-sectional view of a degasser for use in a hydraulic system according to an embodiment shown in Figure 1. [Figure 2D] This is a schematic cross-sectional view of a degasser for use in a hydraulic system according to an embodiment shown in Figure 1. [Figure 3A] These are schematic diagrams of a nested degasser and a stacked degasser, respectively, for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 3B] These are schematic diagrams of a nested degasser and a stacked degasser, respectively, for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 4A] This is a schematic diagram of the flow pattern of the nested degassing apparatus shown in Figure 3A according to an embodiment. [Figure 4B] This is a schematic diagram of the flow pattern of the nested degassing apparatus shown in Figure 3A according to an embodiment. [Figure 5A] This is a schematic diagram of the flow pattern of the stacked degassing apparatus shown in Figure 3B according to an embodiment. [Figure 5B] This is a schematic diagram of the flow pattern of the stacked degassing apparatus shown in Figure 3B according to an embodiment. [Figure 5C] This is a schematic diagram of the flow pattern of the stacked degassing apparatus shown in Figure 3B according to an embodiment. [Figure 5D] This is a schematic diagram of the flow pattern of the stacked degassing apparatus shown in Figure 3B according to an embodiment. [Figure 6A] This is a schematic diagram of a stacked degassing device for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 6B] This is a schematic diagram of a stacked degassing device for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 7A] This is a schematic diagram of a stacked degassing device having nested components for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 7B] This is a schematic diagram of a stacked degassing device having nested components for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 7C] This is a schematic diagram of a stacked degassing device having nested components for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 7D] This is a schematic diagram of a stacked degassing device having nested components for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 8A] This is a cross-sectional view of a pleated medium, a component of a degassing device for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 8B] This is a cross-sectional view of a pleated medium, a component of a degassing device for use in the hydraulic system shown in Figure 1 according to an embodiment. [Figure 9] This is a schematic cross-sectional view of a degassing device unit for use in the hydraulic system shown in Figure 1, according to an embodiment. [Figure 10] This is a graph of the data acquisition settings used in the example. [Figure 11A] This is a graph showing the results of Example 1. [Figure 11B] This is a graph showing the results of Example 1. [Figure 11C] This is a graph showing the results of Example 1. [Figure 12A] This is a graph showing the results of Example 2. [Figure 12B] This is a graph showing the results of Example 2. [Figure 12C] This is a graph showing the results of Example 2. [Figure 13A] This is a graph showing the results of Example 3. [Figure 13B] This is a graph showing the results of Example 3. [Figure 13C] This is a graph showing the results of Example 3. [Figure 13D] This is a graph showing the results of Example 3. [Figure 14A]This is a graph showing the results of Example 3. [Figure 14B] This is a graph showing the results of Example 3. [Figure 14C] This is a graph showing the results of Example 3. [Figure 14D] This is a graph showing the results of Example 3. [Figure 15A] This is a graph showing the results of Example 4. [Figure 15B] This is a graph showing the results of Example 4. [Figure 16A] This is a graph showing the results of Example 6. [Figure 16B] This is a graph showing the results of Example 6. [Figure 17A] This is a graph showing the results of Example 7. [Figure 17B] This is a graph showing the results of Example 7. [Figure 18] This is a graph showing the results of Example 8. [Modes for carrying out the invention]

[0012] This disclosure relates to a system and method for removing gases such as air from a fluid. The system and method of this disclosure are particularly useful for removing air (e.g., degassing) from a fluid used in a recirculation system such as a hydraulic system.

[0013] The term "fluid" is used in this disclosure to describe a substance in the liquid phase. Fluids may contain dissolved or mixed gaseous compounds.

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

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

[0016] The term "directly adjacent" is used here to mean that a feature is in contact with an adjacent feature. The term "directly adjacent" may also be used to indicate the absence of an intervening feature.

[0017] As used herein, the term “substantially” is synonymous with “significantly” and can be understood to modify the following term by at least approximately 75%, at least approximately 90%, at least approximately 95%, or at least approximately 98%. As used herein, the term “substantially not” is synonymous with “significantly not” and can be understood to have the opposite meaning of “substantially” and to modify the following term by 25% or less, 10% or less, 5% or less, or 2% or less.

[0018] In the context of mesh size, hole diameter, fiber diameter, or wire diameter, the term “nominal” is used here to refer to the stated or reported mesh or hole dimensions of commercially available products.

[0019] The unit "psi" is used here to refer to pounds of force per square inch. 1 psi is equivalent to approximately 6900 pascals, or about 6.9 kPa.

[0020] References to standard methods (e.g., ASTM, TAPPI, AATCC, etc.) refer to the most current available version of that method at the time of filing this disclosure, unless otherwise specified.

[0021] The term "approximately" is used here in conjunction with a number to include the normal variation in measurements that would be expected by those skilled in the art, and is understood to mean the same as "approximately," covering a typical tolerance, such as ±5% of the stated value.

[0022] Words such as "a," "an," and "the" are not intended to refer to a single entity, but rather to include a general class for which specific examples may be used for illustrative purposes.

[0023] The words “a,” “an,” and “the” are interchangeable with the term “at least one.” The phrases “at least one of” and “including at least one of” that follow a list refer to any one item in the list, or any combination of two or more items in the list.

[0024] As used herein, the term "or" is used in its ordinary sense, including "and / or," unless the content explicitly indicates otherwise. The term "and / or" means one or all of the listed elements, or any combination of two or more of the listed elements.

[0025] Enumerating a numerical range by an endpoint includes all numbers within that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, and others, or 10 or less includes 10, 9.4, 7.6, 5, 4.3, 2.9, 1.62, 0.3, and others). If a range of values ​​is "maximum" a specific value or "at least" a specific value, that value is included within the range.

[0026] The terms “preferred” and “preferred” refer to embodiments that may provide a particular benefit under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the enumeration of one or more preferred embodiments does not mean that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of this disclosure, including the claims.

[0027] According to some embodiments, gas can be removed from a fluid by inducing gas nucleation and releasing the gas. Nucleation can be induced by bringing a fluid into contact with a material that provides gas nucleation sites. Gas nucleation can form free gas cavities. Gas cavities can be further grown and / or aggregated in one, two, or more stages to increase their size, thereby increasing their buoyancy and increasing the rate at which the gas rises in the fluid. The terms “gas cavity” and “bubble” are used interchangeably here.

[0028] Certain types of vehicles, such as excavators, loaders, skid steer loaders, and similar vehicles, include on-board hydraulic systems. There is a desire to improve hydraulic systems, particularly to reduce the size of the hydraulic fluid tank, for various reasons, including the need to improve efficiency. However, smaller tanks can exacerbate air problems in hydraulic fluids (e.g., oil) because they reduce the residence time of the fluid within the tank. Short residence times can prevent air from escaping the fluid before it is drawn again from the tank. The apparatus and methods of this disclosure may be advantageous due to their ability to remove air, including dissolved air, small air cavities, and impurities, from hydraulic fluids or fluids such as oil. These apparatus and methods may be further advantageous due to their ability to be miniaturized for use with or within smaller hydraulic tanks, or in other systems with smaller hydraulic tanks, such as those used in mobile hydraulic systems in vehicles, e.g., excavators, loaders, and skid steer loaders. These apparatus and methods may also be advantageous because they can be configured to be added to existing hydraulic systems. One or more components of the device may be conveniently removable and serviceable, at least for their in-line particle arrangement.

[0029] Figure 1 shows a schematic diagram of the hydraulic system 1 according to this disclosure. The hydraulic system 1 includes a tank 10 for containing hydraulic fluid. The system 1 also includes a pump 20 for transferring fluid from the tank 10 to one or more hydraulic applications 30. Examples of hydraulic applications 30 include hydraulic machinery, hydraulic drive systems, hydraulic transmission systems, hydraulic brakes and similar devices. The fluid flows from the tank 10 to the pump 20 via an output line 11, and from the pump 20 to the hydraulic applications 30 via an output line 21. The pump 20 pressurizes the fluid, and therefore the fluid in the output line 21 is under a higher pressure than the fluid in the tank 10 or the output line 11. The pressurized fluid can be used to perform work in the hydraulic applications. The fluid can return from the hydraulic applications 30 to the tank via a return line 31.

[0030] System 1 includes a degasser 100. The degasser 100 is constructed to remove at least a portion of gases dissolved and / or trapped in the hydraulic fluid. The degasser 100 may be positioned within the tank 10 as shown in Figure 1, or it may be located elsewhere in System 1. For example, one or more components of the degasser 100 may be arranged in series along the return line 31. According to one embodiment, the degasser 100 is positioned in the flow path of the hydraulic fluid flowing through or inside the tank 10. For example, the degasser 100 may be positioned in the flow path of the fluid discharged from the return line 31 to the tank 10. The direction of flow may be from top to bottom as shown in Figure 1, where the fluid from the return line 31 flows into the tank 10 from above. At least a portion of the fluid from the return line 31 can enter the degasser 100.

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

[0032] Schematic cross-sectional views of the concentric nesting degasser 100 according to this disclosure are shown in Figures 2A to 2D. The degasser 100 includes a gas nucleating medium 110 placed in the fluid flow path within the tank 10. The degasser 100 may further include a growth medium 120 downstream of the gas nucleating medium 110. A porous barrier 130 may be placed downstream of the gas nucleating medium 110 and / or the growth medium 120.

[0033] The gas nucleating medium 110, the growth medium 120, and / or the porous barrier 130 may be arranged in a through-flow configuration within the flow channel. In some embodiments, at least one of the layers of the gas nucleating medium 110, the growth medium 120, and / or the porous barrier 130 is arranged in a cross-flow configuration. The term “through-flow configuration” is used here to refer to a configuration in which the fluid flows through the medium. The term “cross-flow configuration” is used here to refer to a configuration in which the fluid flows over the medium in a direction parallel to the main surface of the medium.

[0034] The degasser 100 may have an open interior 144 with an inlet 101 for receiving the flow of incoming fluid. The inlet 101 may be defined as the opening of a first end cap 141. The particular inlet 101 shown is configured as an upper inlet, which is an opening to the open interior 144. Alternative inlet arrangements, positions, and orientations are possible. For example, the inlet 101 may be located at the bottom or side of the degasser 100. However, the illustrated upper inlet is convenient and advantageous. The inlet 101 may include features for connecting the degasser 100 to 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), discharge, overflow, return flow, and similar. Such additional or alternative flow paths may flow back to the tank 10. In one embodiment, a case drain flow 152 flows into the degasser 100. For example, the case drain flow 152 may flow through the secondary inlet or opening 146 of the first end cap 141 into the gap 135 between the porous barrier 130 and the growth medium 120, as shown in Figure 2D.

[0035] The gas nucleating medium 110 may define the open interior 144 such that the gas nucleating medium 110 at least partially surrounds the open interior 144. The gas nucleating medium 110 may be positioned within a fluid channel such that at least a portion of the fluid entering the open interior 144 flows through the gas nucleating medium 110. In the illustrated example, the gas nucleating medium 110 is cylindrically positioned around the open interior 144. The cylindrical shape may have an open upper part including an inlet 101 and a closed lower part defined by a second end cap 142.

[0036] The growth medium 120 may be positioned adjacent to the gas nucleating medium 110. The growth medium 120 may be directly adjacent to (e.g., in contact with) the gas nucleating medium 110 or the support structure of the gas nucleating medium 110. The growth medium 120 may be positioned within a fluid channel such that the fluid flows through the growth medium 120 after flowing through the gas nucleating medium 110. The growth medium 120 may be coaxial with the gas nucleating medium 110 and form a cylinder that at least partially circumscribes it.

[0037] The degassing device 100 may further include a porous barrier 130 defining the opening 131. The porous barrier 130 may be positioned adjacent to the growth medium 120, as shown in Figures 2A and 2B. In some embodiments, the degassing device 100' is similar to the degassing device 100 of Figure 2A in another aspect, and includes a gas nucleating medium 110 and a porous barrier 130, but does not include the growth medium, as shown in Figure 2C. In some embodiments, the porous barrier 130 is adjacent to the growth medium 120 or the gas nucleating medium 110, but not directly adjacent (e.g., not in contact), leaving a gap 135 between the porous barrier 130 and the growth medium 120, or between the porous barrier 130 and the gas nucleating medium 110, as shown in Figures 2A and 2C, respectively. In some embodiments, the porous barrier 130 is directly adjacent to the growth medium 120, as shown in Figure 2B, so that there is no gap between the porous barrier 130 and the growth medium 120. The porous barrier 130 is coaxial with the growth medium 120 and the gas nucleating medium 110 and can form a cylinder that at least partially circumscribes them. In some embodiments, the gas nucleating medium 110, the growth medium 120, and the porous barrier 130 define a cylindrical body. A first end (e.g., the top) of the cylindrical body may be partially closed by a first end cap 141. A second end (e.g., the 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 device 100 separately from other components. Providing components separately may increase flexibility in component arrangement. For example, one or more components may be located outside the tank 10, while other components are located inside the tank 10. Components may be arranged independently as an inside-to-outflow or outside-to-insideflow. Furthermore, components may be more easily serviceable or replaceable.

[0039] One or more of the components of the degassing device 100 may be provided in a stacked configuration. Here, the term “stacked” is used to distinguish it from a nested configuration. In a stacked configuration, a fluid flows through one component or element and out of it before flowing into the next component or element. Stacked components may be separated by gaps, or they may be directly adjacent to one another such that the outlet of one component forms the inlet of another. Stacked components can be physically stacked on top of each other. However, as used herein, the term “stacked” also includes embodiments in which the components or elements are not physically stacked but are spatially separated in either the lateral and / or axial directions.

[0040] To illustrate the difference between a nested (sometimes called coaxial) configuration and a stacked configuration, simplified schematic diagrams including only the gas nucleating medium 110 and the porous barrier 130 are shown in Figures 3A and 3B. In the nested configuration (Figure 3A), the components of the degasser 100 (e.g., the gas nucleating medium 110 and the porous barrier 130) are arranged nested to one another. The flow direction may be from inside to outside or from outside to inside. The nested components may be housed inside a housing and may include shared end caps at both the top and bottom. The inner component (in this case, the gas nucleating medium 110) may function as an inlet for the outer component (in this case, the porous barrier 130). In the stacked configuration (Figure 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 is configured independently of the others and may independently house one or more components, for example, a gas nucleating medium 110, a growth medium 120, and / or a porous barrier 130. The elements may be aligned axially but spaced apart axially (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, in that they do not need to be aligned axially, and one or more elements may be arranged in line while another one or more elements are arranged in a tank. The elements may be housed in separate housings or in a common housing, and may have separate end caps or share end caps among the elements. The flow direction may be independently arranged for each element as inside to outside or outside to inside. Although 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 in a tank without separate housings or arranged in a panel configuration.

[0041] Different flow configurations of the nested degasser 100 are shown in Figures 4A and 4B. The flow may be arranged as an inside-to-out type (Figure 4A) or an outside-to-inside type (Figure 4B). Various flow configurations of the stacked degasser 1000 are shown in Figures 5A to 5D. As can be seen, each element 200, 300, etc., can be arranged independently as an inside-to-outside type or an outside-to-inside type, providing a great degree of design freedom. In Figure 5A, the first element 200 and the second element 300 are both arranged as an inside-to-outside type. In Figure 5B, the first element 200 is arranged as an inside-to-outside type, and the second element 300 is arranged as an outside-to-inside type. In Figure 5C, the first element 200 is arranged as an outside-to-inside type, and the second element 300 is arranged as an inside-to-outside type. In Figure 5D, the first element 200 and the second element 300 are both arranged as an outside-to-inside type. Furthermore, the arrangement of flows from top to bottom and bottom to top can be considered separately for each element, adding even more variability.

[0042] Examples of various stacked configurations of the degasser 1000, which includes a gas nucleating medium 110, a growth medium 120, and a porous barrier 130, are shown in Figures 6A, 6B, and 7A-7C. Generally, the components (gas nucleating medium 110, growth medium 120, and porous barrier 130) may be stacked, as shown in Figure 6A. That is, the components are provided not as nested but as separate elements 200, 300, 400 arranged in succession. The general direction of fluid flow is indicated by dotted arrows. However, any combination of inside-to-outside and outside-to-inside flow in each element (for example, as shown in Figures 5A-5D) can be applied.

[0043] Each of the elements 200, 300, and 400 of the degasser 1000 may be arranged inline (or outside the tank 10), or one or more of the elements (e.g., 300 and 400) may be arranged inside the tank 10. Element 200 includes a gas nucleating medium 110, element 300 includes a growth medium 120, and element 300 includes a porous barrier 130. Elements 200, 300, and 400 may be housed in a common housing (e.g., a housing 1010 as shown in Figure 6A), or they may be housed separately. Each of the gas nucleating medium 110, the growth medium 120, and the porous barrier 130 may be arranged independently in an inside-to-outside or outside-to-inside 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 nucleating medium 110. The outlet 1002 may be formed in the housing 1010 or at the outlet of the third element 400.

[0044] The elements 200, 300, and 300 of the degasser 1000 may be separated by one or more gaps, as shown in Figure 6A, or two or all of the elements may be directly adjacent to each other. For example, as shown in Figure 6B, the first element 200 of the degasser 1000, which includes the gas nucleating medium 110, is provided separately, while the second element 300, which includes the growth medium 120, and the third element 400, which includes the porous barrier 130, are directly adjacent to each other. Alternatively, the first element 200 having the gas nucleating medium 110 and the second element 300 having the growth medium 120 are directly adjacent to each other, while the third element 400 having the porous barrier 130 is provided separately. In each embodiment, one or more of the elements may be arranged inline (outside the tank 10), or one or more of the elements may be arranged inside the tank 10. Furthermore, elements 200, 300, and 400 may be housed separately or arranged inside a common housing 1010. Elements 200, 300, and 400 may also be arranged independently 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 Figure 7A, the first element 200 of the degasser 1000 includes a gas nucleating medium 110, and the second element 300 includes a porous barrier 130 and a nested growth medium 120. The elements 200 and 300 may be housed separately or located inside a common housing 1010. One or both elements may be located inline (outside the tank 10), or one element may be located inside the tank 10. The elements 200 and 300 may also be located independently in an inside-to-outflow or outside-to-insideflow configuration. A replacement part for the first element 200 may include a unit having the gas nucleating 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 Figure 7B, the first element 200 of the degasser 1000 includes a growth medium 120 and a nested gas nucleating medium 110, and the second element 300 includes a porous barrier 130. The elements 200 and 300 may be housed separately or located inside a common housing 1010. One or both of the elements may be located inline (outside the tank 10), or one of the elements may be located inside the tank 10. The elements 200 and 300 may also be located independently in an inside-to-outflow or outside-to-insideflow configuration. Replacement parts for the first element 200 may include a unit comprising the gas nucleating medium 110 and the growth medium 120. Replacement parts for the second element 300 may include the porous barrier 130.

[0047] In Figure 7C, the degasser 1000 includes two layers or stages of growth media 121 and 122. The first element 200 includes a first layer or stage of growth media 121 nested with gas nucleating medium 110, and the second element 300 includes a second layer or stage of growth media 122 nested with a porous barrier 130. The elements 200 and 300 may be housed separately or arranged inside a common housing. One or both elements may be arranged inline (outside the tank 10), or one element may be arranged inside the tank 10. The elements 200 and 300 may also be arranged independently as an inside-to-outflow or outside-to-insideflow. Replacement parts for the first element 200 may include a unit having gas nucleating medium 110 and growth media 121. Replacement parts for the second element 300 may include a unit having growth media 122 and porous barrier 130.

[0048] In some embodiments, one or more elements of the degasser 1000 are located inside the tank 10. For example, as shown in Figure 7D, the first element 200 may be inline, and the second element 300 may be located inside the tank. The first element 200 may include a gas nucleating medium 110, optionally a growth medium 120, and optionally a porous barrier 130. The components of the first element 200 may be arranged in a nested configuration. The first element 200 may be arranged in an inside-to-outward flow as shown, or alternatively in an outside-to-inward flow. The porous barrier 130, or alternatively the growth medium 120 and the porous barrier 130, may be located 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 located at the inlet of the tank 10, or somewhere between the inlet and the outlet. The porous barrier 130 may have a cylindrical structure, or it may have a flat plate or pleated panel structure. The 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 a gas nucleating medium 110 and a 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 a 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 nucleating medium and a layer of growth medium. The filter element (e.g., the layer of gas nucleating medium and the layer of growth medium) may form a cylindrical element. The filter element may further include an end cap at the end of the cylindrical element. The filter element may be a replacement part for one or more components of the degasser shown in Figures 2A to 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 to 7D.

[0051] In some embodiments, such as those shown in Figures 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 arranged as an inline degasser, the inline degasser includes only a single outlet. The single outlet may connect the inline degasser to the inlet of the tank 10, as shown in Figure 7D. The tank 10 may house further components of the degasser. In some embodiments, the degasser 1000 includes additional outlets in the form of gas releases. One or more gas release holes (e.g., openings 146 shown in Figures 2D and 9) may be located above or near the degasser 1000, such as above 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, a liner of one component functions as a support for an adjacent component. The elements may also include spacing between components and / or between elements (e.g., gap 135).

[0053] When the degassing unit 100 is in use, the fluid flows through the gas nucleating medium 110. For example, in an inside-to-outside flow configuration, the fluid flows into the open interior 144 of the gas nucleating medium 110, for example, through the upper inlet 101. By passing through the gas nucleating medium 110, at least some of the dissolved gas in the fluid nucleates, potentially forming free air such as small gas cavities (first-stage gas cavities). As the fluid further passes through the growth medium 120 downstream of the gas nucleating medium 110, more gas may be released from the solution and added to the existing gas cavities, causing them to grow. The gas cavities may also coalesce in the growth medium 120. Growth and / or aggregation form larger gas cavities (second-stage gas cavities).

[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 degasser 100 includes one or more gas release holes at the top of the gap 135. For example, an opening 146 in the first end cap 141 (e.g., the upper end cap) (see Figures 2D and 9) 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 generated by the growth medium. The porous barrier 130 may act to hold the gas cavity within the gap 135, preventing the gas cavity from prematurely diffusing into the fluid in the tank 10. While not wishing to be constrained by theory, it is conceivable that the porous barrier may cause the gas cavity to grow and / or aggregate further upstream of the porous barrier 130, rising upward in the gap 135. If the porous barrier 130 is wet, a gas pocket (larger gas cavity) may form above the gap 135 from rising condensed gas. When the gas pocket becomes large enough, enough pressure accumulates for the gas pocket to break through the wet porous barrier 130. As the gas breaks through the porous barrier, it may dry out the adjacent areas of the porous barrier, allowing the air pocket to escape. However, even if that area of ​​the porous barrier remains submerged and wet, the gas cavity above the gap may pass through the porous barrier as a large bubble and float to the surface. If the degasser is submerged, the gas pocket may be large enough and buoyant to float to the surface and escape from the surface. Once the gas pocket is gone, the porous barrier 130 is re-wetted, and the process may be repeated.

[0055] Returning to Figures 2A-9, the gas nucleation medium 110 can be made from any suitable material capable of inducing gas nucleation. While we do not wish to be constrained by theory, it is thought that several aspects of the gas nucleation medium influence the effectiveness and efficiency of the medium inducing nucleation, based on the influence of those aspects on the chemical and physical interactions between the medium and the fluid and the gas in the fluid. Aspects that may influence nucleation include, for example, the following: surface area of ​​the fibers in the medium; accessible surface area; fiber size (e.g., diameter or cross-sectional dimensions); medium pore size; presence of sharp edges or corners; surface roughness; chemical composition of the medium (e.g., fibers and binder); lipophilicity / oleophobicity of the medium; presence and number of fiber crossings; orientation angle of adjacent fibers; orientation relative to the direction of flow; curvature of the flow path; solidity of the medium sheet; permeability of the medium sheet; thickness of the medium sheet; residence time of the fluid in the medium; pecule number of dissolved gases from the fluid to the medium (e.g., ratio of advection velocity to diffusion velocity); and differential pressure between the sheet and individual fibers.

[0056] For example, media with appropriate (accessible) surface area, fiber size, and media pore diameter are considered beneficial for nucleation efficiency. The accessible surface area of ​​the fibers can be measured as the basic fiber surface area of ​​the media, which is the area that the fluid can access (e.g., contact). 2 m² per unit bulk surface area of ​​media sheet 2 It is understood that this refers to the total surface area in square meters (including the surface area within pores and between fibers). The basic fiber surface area of ​​the medium can be determined by Branauer-Emmett-Teller (BET) analysis or from the Carmen-Kozeny relation (described in detail in Examples 3 and 4 below). The bulk surface area of ​​the medium sheet is understood to refer to the area calculated as the length × width of the medium sheet (in the case of pleated mediums, the width can be calculated using the height and number of pleats). The basic fiber surface area of ​​a gas nucleating medium, when measured by either the BET method or the Carmen-Kozeny method, is 1 m². 2 / m 2 Over 1.5m 2 / m 2 Over 2m 2 / medium m 2 Above, 5 m 2 / medium m 2 Above, 10 m 2 / medium m 2 Above, 25 m 2 / m 2 Above, 50 m 2 / m 2 Above, or 100 m 2 / m 2 It can be above. When the surface area of the gas nucleation medium is measured by either the BET method or the Carmen-Kozeny method, 200 m 2 / m 2 Below, 150 m 2 / m 2 Below, 100 m 2 / m 2 Below, 50 m 2 / m 2 Below, 30 m 2 / m 2 Below, 10 m 2 / m 2 Below, 6 m 2 / m 2 Below, or 4 m 2 / m 2 It can be below. In one embodiment, when the basic fiber surface area of the gas nucleation medium is measured by the BET method, 1 m 2 / m 2 Above, 2 m 2 / m 2 Above, 5 m 2 / m 2 Above. In one embodiment, when the basic fiber surface area of the gas nucleation medium is measured by the BET method, 100 m 2 / m 2 Below, 50 m 2 / m 2 Below, 20 m 2 / m 2 Below. In one embodiment, when the fiber surface area of the gas nucleation medium is measured by the BET method, 1 to 75 m 2 / m 2 It is. In one embodiment, when the basic fiber surface area of the gas nucleation medium is measured by the BET method, 5 to 50 m 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 That concludes the explanation. In one embodiment, the basic fiber surface area of ​​the gas nucleating medium was 200 m² when measured by the Carmen-Kozeny method. 2 / m 2 Below, 100m 2 / m 2 Below, 50m 2 / m 2 Below, 20m 2 / m 2 The following applies: In one embodiment, the basic fiber surface area of ​​the gas nucleating medium is 5 to 75 m², as measured by the Carmen-Kozeny method. 2 / m 2 In one embodiment, the basic fiber surface area of ​​the gas nucleating medium is 10 to 50 m², as measured by the Carmen-Kozeny method. 2 / m 2 That is the case.

[0057] Fiber size is used here to refer to the diameter or cross-sectional dimension of the fibers in the medium. The diameter or cross-sectional dimension of the fibers can be determined optically for larger fibers and using a scanning electron microscope (SEM) for smaller fibers. The fiber size of fibers in a gas nucleation medium can vary from fiber to fiber and along a given fiber. Fiber size can also vary along a gradient, from the upstream side of the medium to the downstream side. Fibers in a gas nucleation medium may have fiber sizes of at least 10 nm (nanometers), at least 50 nm, or at least 100 nm. Fibers in a gas nucleation medium may have fiber sizes of up to 10 μm (micrometers) or up to 100 μm.

[0058] The pore size of the medium is understood to mean the size of individual pores in the medium sheet, as determined by ASTM F316-03 or ASTM D6767. Pores in a gas nucleating medium may have an average pore size of 0.5 μm or more, 1 μm or more, or 5 μm or more. Pores in a gas nucleating medium may have an average pore size of 5 μm or less, 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, pores in a gas nucleating medium may have an average pore size of 5 μm to 100 μm. Pores in a gas nucleating medium may have a maximum pore size of 1 μm or more, 5 μm or more, or 10 μm or more. Pores in a gas nucleating medium may have a maximum pore size of 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, pores in a gas nucleating 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 lipophilic / oleophobic properties are thought to influence 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 binder or other components used in the medium. Fibers may include any suitable fibrous material, including woven or nonwoven media made from organic or inorganic materials or combinations thereof. The medium may include a variety of structures combining different materials, such as core-and-sheath structures, side-by-side structures, underwater island structures, and others. Fibers may contain two or more material components within a single fiber, including a single material component or a mixture of materials. For example, fibrous materials may include one or more of the following: cellulose; regenerated cellulose (e.g., rayon); synthetic materials such as polyamides, polyesters, polyethersulfones (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), copolymers or combinations thereof; glass; ceramics; or carbon fibers. In one embodiment, the filtration medium used as a gas nucleating medium is made of microglass and synthetic fibers. Examples of suitable filtration mediums 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 Publication Nos. 2012 / 0234748 and 2017 / 0225105, each incorporated herein in its entirety by reference. The medium may include various binders such as acrylic resins, phenolic resins, or epoxy resins.

[0060] Preferably, the gas nucleating medium has lipophilic / oleophobic properties suitable for inducing nucleation and releasing the formed gas cavities into the fluid flow (as opposed to being "trapped" on the fiber surface). In one embodiment, the gas nucleating medium is oleophobic. The oleophobicity (oil repellency) of the medium can 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 higher. A gas nucleating medium may have an oleophobicity rating of 1 or higher, 2 or higher, 3 or higher, 4 or higher, 5 or higher, or 6 or higher. A gas nucleating medium may have an oleophobicity rating of 8 or lower, 7 or lower, 6 or lower, 5 or lower, or 4 or lower. In one embodiment, the gas nucleating 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 distributing bubbles or oil droplets onto the fiber and measuring the contact angle using, for example, a micro-contact angle instrument (e.g., the MCA-3 instrument available from Kyowa Interface Science Co., Ltd. (Niiza, Japan)). Gas nucleating media may have an oil contact angle of at least 30°, at least 50°, at least 70°, at least 90°, or at least 120°. Gas nucleating media may have an oil contact angle of up to 120° and up to 150°.

[0061] Gas nucleating media can be inherently oleophobic (e.g., they can be made from oleophobic fibers) and / or can be treated to be oleophobic using, for example, an oleophobic treatment compound. Generally, oleophobic materials are fluorochemicals such as fluoropolymers in which a high density of terminal CF3 pendant groups is exposed on the surface. In certain embodiments, the gas nucleating media, or the oleophobic treatment compound (e.g., a fluorochemical treatment compound) applied as a surface coating to the gas nucleating media, can be made from perfluoropolymers such as perfluoroacrylates, perfluorourethanes, perfluoroepoxys, perfluorosilicones, perfluoroalkanes, perfluorodioxolanes, or copolymers of these materials.

[0062] While gas nucleation media made from inherently oleophobic materials can be used, typically, a fluorochemical-treated compound is coated onto a conventional filtration medium to make it oleophobic. The coating material may be, for example, an oleophobic polymer, or another polymer that can be made oleophobic through a multi-step process. Typically, the fluorochemical-treated compound, dissolved or suspended in a liquid carrier (e.g., an organic solvent or water), is applied to the conventional filtration medium by immersion or spraying. Alternatively, the coating can be applied through the gas phase using a process such as chemical vapor deposition (CVD).

[0063] Exemplary fluoropolymers include: perfluoroacrylates dissolved in solvent, such as the 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 solvent, such as TEFLON AF from Chemors (Wilmington, DE); perfluoroacrylate emulsions suspended in water, such as UNIDYNE from Daikin (Orangeburg, NY), CAPSTONE from Chemors (Wilmington, DE), PHOBOL from Huntsman (The Woodlands, TX), or ADVAPEL 734 from Advanced Polymer Incorporated (Carlstadt, NJ); and 3M Perfluorourethane suspended in water, such as the one available from Company (Maplewood, MN) under the trade name SRC220. The gas nucleating medium can also be made oleophobic by applying a fluoropolymer coating via a plasma polymerization process, such as a perfluoroacrylate coating from P2i (Savannah, GA).

[0064] In certain embodiments, the gas nucleating medium is prepared by applying a non-oleophobic coating to a conventional filtration medium and then modifying it to be oleophobic. For example, a polyalcohol polymer can be applied to a conventional filtration medium and perfluorosilane or perfluoroacryloxide can be grafted onto this polymer. Alternatively, a polyamine can be applied to a conventional filtration medium and perfluoroacrylate can be grafted onto this polymer.

[0065] The surface energy of a polymer material can be determined, for example, by creating a Zisman plot using a suitable fluid according to ASTM D7490-13. The surface energy of the material may also be determined using the Owens-Wendt method. The fiber in a gas nucleating medium has a surface energy of 6 mJ / m 2 (Millijoules per square meter) or more, 10 mJ / m 2 More than 15mJ / m 2 More than 20mJ / m 2 Above 40 mJ / m 2 It can have a surface energy of the above. The fibers in the gas nucleation medium have a surface energy of 400 mJ / m 2 Below, 300mJ / m 2 Below, 200mJ / m 2 Below, 150mJ / m 2 Below, 100mJ / m 2 The following, or 50 mJ / m 2 The following surface energies may be present. For example, fibers in a gas nucleating medium may have a surface energy of 10 mJ / m 2 From 200 mJ / m 2 It may have a surface energy of . The values ​​listed here are determined by ASTM D7490-13.

[0066] The geometric configuration of fibers in a gas nucleating medium can influence 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 fiber surfaces relative to the flow direction, and the curvature of the flow path can also influence nucleation. According to some embodiments, the gas nucleating medium includes fibers having sharp edges or corners. For example, fibers may have cross-sections that do not have a smooth shape (e.g., neither circular nor elliptical). The cross-section of a fiber may be polygonal or have an irregular shape with corners (e.g., corners less than 180°, less than 120°, or less than 90°). The gas nucleating medium includes fibers having circular, star-shaped, square, rectangular, trefoil, clover-shaped, or polygonal cross-sections. The cross-section may be constant or vary throughout the length of the fiber.

[0067] The surface roughness of a material can be determined as root mean square roughness using atomic force microscopy (AFM), cross-sectional scanning electron microscopy (SEM), or transmission electron microscopy (TEM), or a surface profile analyzer. Measurements can be performed on a fixed surface area, e.g., a square, with dimensions equal to half the fiber diameter. Fibers of a gas nucleation medium may have 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 a gas nucleation medium may have surface roughness of 1000 nm or less, 500 nm or less, or 200 nm or less. For example, fibers of a gas nucleation medium may have surface roughness ranging from 10 nm to 500 nm. The values ​​listed here are determined by a surface profile analyzer.

[0068] Surface roughness can also be characterized using various other parameters such as skewness, kurtosis, and others. These surface features may indicate a degree of asymmetry (e.g., steeper peaks or deeper pits). Asymmetry can be expressed as skewness measured using AFM, fiber cross-sectional SEM, or a surface profile analyzer. Fiber skewness can be greater than -10, greater than -8, or greater than -6. Fiber skewness can be less than or equal to 6, less than or equal to 8, or less than or equal to 10. For example, fiber skewness can range from -8 to 8. The values ​​listed here are determined by the surface profile analyzer.

[0069] Kurtosis is another measure of surface roughness, indicating the degree of sharpness of sharp features. Kurtosis can be measured using AFM, fiber cross-sectional SEM, or surface profile analyzers. Fibers in gas nucleating media may have a kurtosis of at least -10, -8, or -6. Fibers in gas nucleating media may have a kurtosis of 6 or less, 8 or less, or 10 or less. For example, the kurtosis of a fiber may range from -8 to 8. Certain combinations of surface roughness, strain, and kurtosis may yield favorable nucleation properties. For example, high roughness and high kurtosis may be beneficial for nucleation. The values ​​listed here are determined by surface profile analyzers.

[0070] An increase in the number of fiber crossings is thought to potentially increase nucleation to some extent. A fiber crossing is understood to mean a point of contact between two fibers. Furthermore, it is thought that certain angles of orientation of adjacent fibers, and certain ranges of angles of orientation of fibers relative to the flow direction, may be beneficial for nucleation. For example, fibers in a gas nucleating medium may be oriented randomly so that a certain range of orientation angles is achieved. In some embodiments, adjacent fibers in a gas nucleating medium are not aligned axially with each other.

[0071] Aspects that affect the residence time or differential pressure of the fluid in the medium can also affect nucleation. For example, surface velocity, medium sheet solids fraction, medium sheet permeability, medium sheet thickness, Peclet number of dissolved gas from the fluid to the medium (e.g., the ratio of convective transport velocity to diffusive transport velocity), degree of bend of the flow path in the medium, and orientation (e.g., angle) of the medium sheet with respect to the main flow direction can affect nucleation.

[0072] The surface velocity of the fluid with respect to the gas nucleation medium sheet can be determined as the volumetric flow rate per bulk medium surface area. The surface velocity can be 0.01 cm / second or more, 0.1 cm / second or more, 0.5 cm / second or more, 1.0 cm / second or more, or 5.0 cm / second or more. There is no desirable upper limit for the surface velocity, but in practice, the surface velocity can be 50 cm / second or less, 20 cm / second or less, or 10 cm / second 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. The gas nucleation medium sheet can have a solids fraction of 5% or more, 10% or more, or 20% or more. The gas nucleation medium sheet 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 filter medium is defined as the volumetric flow rate of air passing through a specified filter medium area at a specified pressure drop. The method for measuring air permeability is ASTM D737 - 04. The gas nucleation medium sheet is 1 ft 3 / min / ft 2 or more (at a pressure of 125 Pa and 0.305 m 3 / min / m 2 or more), 10 ft 3 / min / ft 2 or more (at a pressure of 125 Pa and 3.05 mm 3 / min / m 2 or more), or 50 ft 3 / min / ft 2 or more (at a pressure of 125 Pa and 15.2 m 3 / min / m 2It may have breathability as described above. The gas nucleation media sheet has a water column of 0.5 inches and 500 ft 3 / min / ft 2 or less (152 m / min / m at 125 Pa 3 or less), a water column of 0.5 inches and 400 ft 2 / min / ft 3 or less (123 m / min / m at 125 Pa 2 or less), or a water column of 0.5 inches and 300 ft 3 / min / ft 2 or less (91.4 m / min / m at 125 Pa 3 or less) and may have permeability. For example, the gas nucleation media sheet may have a permeability of 0.5 m / min / m to 100 m / min / m at 125 Pa 2 from 3 / min / m 2 [[ID=2s]]to 3 / min / m 2 .[[ID=3s]]

[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, in accordance with ISO 16889 performed at an appropriate face velocity, for example, 0.5 cm / sec

[0076] The Peclet number indicates the ratio of the convective transport rate to the diffusive transport rate of dissolved gas from the fluid to the medium, and is calculated by dividing the length (e.g., fiber diameter) × velocity (e.g., face velocity) by the diffusion coefficient. The gas nucleation media sheet may have a Peclet number of 0.05 or more, 0.1 or more, 0.5 or more, 1 or more, or 10 or more. The gas nucleation media sheet may have a Peclet number of 1000 or less, 2500 or less, 10,000 or less, or 50,000 or less. For example, the gas nucleation media sheet may have a Peclet number from 0.5 to 10,000

[0077] <0OO0532>​​​​The angle of the fibers relative to the flow stream can be determined, for example, by using a CT (Computed Tomography) scan of the medium, as the weight average of the fiber angles relative to the flow direction. The angle can be greater than or equal to 0°, greater than or equal to 10°, or greater than or equal to 30°. The angle can be less than or equal to 90°, less than or equal to 80°, or less than or equal to 60°. For example, the angle can range from 10° to 80°.

[0078] The stiffness of fibers in a gas nucleating medium can also affect flow properties and, therefore, nucleation. Stiffness can be measured, for example, as the flexural modulus of the fiber or base material, according to ASTM D790. For non-polymeric materials, the flexural modulus is equal to Young's modulus. Fibers in a gas nucleating medium may have a flexural modulus of 1 GPa (gigapascals) or more, 10 GPa or more, or 50 GPa or more. Fibers in a gas nucleating medium may have a flexural modulus of 500 GPa or less, 400 GPa or less, or 250 GPa or less. For example, fibers in a gas nucleating medium may have a flexural modulus ranging from 10 GPa to 400 GPa.

[0079] The gas nucleating medium can have any suitable shape. The shape may be determined based on the position of the degasser in the system. In one embodiment, the gas nucleating medium is defined as cylindrical. Other configurations are also possible, such as a planar panel configuration. The thickness of the filter medium sheet can be measured using a suitable caliper thickness gauge, such as one using a foot with a diameter of 2.87 cm and a pressure of 1.5 psi. The thickness of the filter medium sheet can be measured according to the TAPPI T411 test method. The gas nucleating medium can have any suitable thickness. The thickness of the gas nucleating medium can be measured in the direction of fluid flow. For example, in a cylindrical degasser, the thickness of the gas nucleating medium can be measured in the radial direction perpendicular to the central axis A. The gas nucleating medium may have a thickness of 0.01 mm or more, 0.1 mm or more, or 0.5 mm or more. The gas nucleating medium may have a thickness of 5 mm or less, 2 mm or less, or 1 mm or less. For example, the gas nucleating medium may have a thickness from 0.1 mm to 2 mm. The gas nucleating medium can be pleated or rolled. In either case (pleated or rolled), the medium can have one or more layers. The medium can be repeatedly rolled or stacked. If multiple layers are involved, the layers can have the same composition and / or structure, each with a unique composition and / or structure, and can be arranged in close contact.

[0080] In some embodiments, the gas nucleating medium includes a filtration medium. In one embodiment, the gas nucleating medium is made of a particulate filtration medium. In some embodiments, the gas nucleating medium has multiple layers. In some embodiments, the gas nucleating medium is rolled or stacked. In one embodiment, the gas nucleating medium is made of a pleated medium. In one embodiment, the gas nucleating medium is made of a non-pleated medium.

[0081] In some embodiments, the degasser includes a growth medium. The growth medium may be located adjacent to the gas nucleating medium, or directly adjacent to the gas nucleating medium. The growth medium may be located at a distance from the gas nucleating medium (not adjacent). The growth medium may be located adjacent to the porous barrier, or directly adjacent to the porous barrier. The growth medium can be made of any suitable material capable of inducing aggregation and / or growth of the gas cavity. While we do not wish to be bound by theory, it is believed that several aspects of the growth medium influence the effectiveness and efficiency of the medium inducing aggregation. For example, aspects influencing aggregation may include the chemical composition of the medium (e.g., fibers and binder); the surface energy of the medium; the lipophilicity / oleophobicity of the medium; the basic fiber surface area of ​​the medium; the solidity of the medium sheet; the average pore size of the medium; the maximum pore size of the medium; the permeability of the medium sheet; the thickness of the medium sheet; the surface roughness; and the differential pressure across the medium. One or more of these properties may indicate a gradient from upstream to downstream 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, gas nucleation mediums having pore sizes 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 pore sizes of 4 μm or more, 5 μm or more, 6 μm or more, or 8 μm or more. In such one embodiment, the degasser does not include the growth medium. In one embodiment, the degasser includes gas nucleation with pore sizes of 5 μm or more, but does not include the growth medium.

[0083] The chemical composition of the growth medium can affect aggregation and growth. The chemical composition of the growth medium may include the chemical composition of the fibers in the medium and / or the chemical composition of any binder or other components used in the medium. The fibers may include any suitable fibrous material, including woven or nonwoven media made from one or more of the following: cellulose; regenerated cellulose (e.g., rayon); polyamide (e.g., nylon); synthetic materials such as polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF); glass; ceramic; or carbon fibers. In one embodiment, the growth medium is made from or contains polyester, rayon, or a combination thereof. The medium may contain various binders such as acrylic resins, phenolic resins, or epoxy resins.

[0084] Preferably, the growth medium has appropriate surface energy and oleophilicity / oleophobicity to induce the aggregation and / or growth of gas cavities and release the formed gas cavities into the fluid flow (as opposed to being "trapped" on the fiber surface). According to one embodiment, the growth medium is lipophilic. 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 another embodiment, the upstream side is more lipophilic than the downstream side. The oleophobicity rating (oil repellency) of the medium can be measured according to AATCC method 118 (e.g., 118-2013). The growth medium may have an oleophobicity rating of 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more. The growth 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 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. A growth medium may have an oil contact angle of 0° or greater, 10° or greater, 20° or greater, or 30° or greater. A growth medium may have an oil contact angle of 150° or less, 120° or less, 90° or less, or 60° or less. A growth medium may be inherently lipophilic (e.g., made from lipophilic fibers) and / or may be treated to become oleophobic using, for example, an oleophobic treatment compound. A growth medium may be constructed from a composite material. A growth medium may be a composite of lipophilic and oleophobic components. The oleophobic component may have one or more oleophobic ratings.

[0085] The 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 Above, or 100 mJ / m 2 It can have a surface energy of 400 mJ / m². The fibers in the growth medium have a surface energy of 400 mJ / m². 2 Below, 350mJ / m 2 Below, 300mJ / m 2 The following, or 250 mJ / m³ 2 The following surface energies may be present. For example, the fibers in the growth medium may have a surface energy of 20 mJ / m 2 From 350 mJ / m 2It may have a surface energy of . The values ​​listed here are determined by ASTM D7490-13.

[0086] The basic fiber surface area of ​​the medium, and therefore the contact area between the medium and the fluid, can affect aggregation and growth. The basic fiber surface area of ​​the medium is m 2 m² per unit bulk surface area of ​​media sheet 2 It is understood to mean the total surface area of ​​the unit (including the surface area between fibers). The basic fiber surface area of ​​the growth medium is 1 m². 2 / m 2 Over 1.5m 2 / m 2 Over 1.6m 2 / m 2 or more, or 2m 2 / m 2 It may exceed this. The basic fiber surface area of ​​the growth medium is up to 200 m². 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 This is possible. For example, the basic fiber surface area of ​​the growth medium is 1.5 m². 2 / m 2 50m from 2 / m 2 It is possible. The values ​​listed here are determined by the Carmen-Kozeny method.

[0087] The geometric configuration of fibers in the growth medium can affect aggregation and growth. For example, the presence of sharp edges or corners, surface roughness, orientation of the fiber surface relative to the flow direction, solidity, permeability, and pore size of the growth medium may be selected to improve the 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-section of the fibers in the growth medium may be polygonal or have an irregular shape with corners (e.g., corners less than 180°, less than 120°, or less than 90°). The growth medium may contain fibers having circular, star-shaped, square, rectangular, trefoil, clover-shaped, or polygonal cross-sections. The cross-section may be constant or vary throughout the length of the fiber.

[0089] The fiber size of fibers within the growth medium can vary from fiber to fiber and along a given fiber. Fiber size can also vary along a gradient, from the upstream to the downstream side of the medium. Fibers within the growth medium may have fiber sizes of 10 nm or more, 50 nm or more, or 100 nm or more. Fibers within the growth medium may have fiber sizes of 500 μm or less, 100 μm or less, or 10 μm or less. For example, fibers within the growth medium may have fiber sizes ranging from 50 nm to 100 μm.

[0090] The angle of the fiber relative to the flow stream in the growth medium may be 0° or greater, 10° or greater, or 30° or greater. The angle of the fiber in the growth medium may be 90° or less, 80° or less, or 60° or less. For example, the angle may be between 10° and 80°.

[0091] The stiffness of the fibers in the growth medium can also affect the flow properties and, therefore, affect aggregation and / or growth. The fibers in the growth medium may have a flexural modulus of 1 GPa or more, 10 GPa or more, or 50 GPa or more. The fibers in the growth medium may have a flexural modulus of 500 GPa or less, 400 GPa or less, or 250 GPa or less. For example, the fibers in the growth medium may have a flexural modulus between 10 GPa and 400 GPa.

[0092] 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. 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, fibers in the growth medium may have a surface roughness from 10 nm to 500 nm. Fibers in the growth medium may have a strain of -10 or more, -8 or more, or -6 or more. The strain of the fibers may be 6 or less, 8 or less, or 10 or less. For example, the strain of the fibers may be from -8 to 8. 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 surface profile measuring instrument.

[0093] Pores in a medium are understood to mean holes (e.g., through holes) and cavities within the sheet of medium. Pore diameters can be determined by ASTM F316-03 or ASTM D6767. Pores in a medium can provide pathways for fluids through the sheet of medium. A growing medium may have an average pore diameter of 0.5 μm or more, 1 μm or more, or 5 μm or more. A growing medium may have an average pore diameter of 5 μm or less, 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, pores in a growing medium may have an average pore diameter of 5 μm to 100 μm. A growing medium may have a maximum pore diameter of 1 μm or more, 5 μm or more, or 10 μm or more. Pores in a growing medium may have a maximum pore diameter of 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. For example, pores in the growth medium can have a maximum pore diameter ranging from 5 μm to 200 μm. The values ​​listed here are determined according to ASTM F316-03.

[0094] The growth medium may have a solid content 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 growth medium may have a solid content 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 growth medium may have a solid content of 2% to 20% or 2% to 9% at 1.5 psi. The growth medium may include a woven or nonwoven medium having a porous structure.

[0095] The growth medium sheet may have any suitable thickness. The thickness of the growth medium affects the differential pressure across the medium sheet. The thickness of the growth medium may be measured in the direction of fluid flow. For example, in a cylindrical degasser, the growth medium forms a coaxial cylinder that at least partially surrounds the gas nucleating medium, and the thickness of the growth medium may be measured radially perpendicular to the central axis A. The thickness of the filtration medium sheet can be measured using a suitable caliper thickness gauge, such as one using a foot with a diameter of 2.87 cm and a pressure of 1.5 psi. The thickness of the filtration medium sheet can be measured according to the TAPPI T411 test method. The growth medium 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, 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. The growth medium 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 growth medium sheet may have a differential pressure of 0.01 psi or less, 1 psi or less, or 100 psi or less, according to ISO 16889, which is performed at an appropriate surface speed, e.g., 0.5 cm / sec.

[0097] The growth medium may be provided as multiple medium layers. Multiple layers of medium may be applied on top of a gas nucleation medium (e.g., wrapped or laminated). Increasing the number of growth medium layers may improve the aggregation of the gas cavity. However, increasing the thickness of the growth medium (e.g., by increasing the number of medium layers) may also increase the pressure drop across the growth medium and the entire degasser. Furthermore, a high pressure drop may limit the amount of gas that the nucleation phase can release, resulting in nucleation occurring later in the growth phase and smaller bubbles being released downstream of the growth phase. Therefore, the number of growth medium layers can be balanced to provide improved aggregation 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 individual growth medium sheets can affect the number of turns used. For example, thinner medium may utilize more turns. In one embodiment, the growth medium consists of 5 to 10 layers (e.g., 7 layers) of medium.

[0098] The porous barrier downstream of the gas nucleation medium (and optionally the growth medium) may contain any suitable porous material defining openings or pores extending through the barrier. While we do not wish to be bound by theory, several aspects of the porous barrier are thought to influence its effectiveness and efficiency. For example, aspects influencing the efficiency of the porous barrier may include: pore size and shape, and the regularity or uniformity of pore size and shape throughout the barrier; the chemical composition of the barrier; the oleophilicity / oleophobicity of the barrier; the surface roughness or smoothness of the barrier; and the direction / orientation of the barrier relative to the flow direction. One or more of these properties may differ upstream and downstream, or may exhibit a gradient from upstream to downstream of the growth medium.

[0099] In some embodiments, the porous barrier comprises a woven or nonwoven material. The openings can be of uniform size or non-uniform, including openings of various sizes. The pores of the porous barrier are sometimes called screen openings and are understood to mean holes in the barrier (e.g., through holes). The pore size can be determined by ASTM E11 or optical imaging. The porous barrier may include openings of sizes 5 μm or larger, 10 μm or larger, 15 μm or larger, or 20 μm or larger. The porous barrier may 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 10 μm to 250 μm, 15 μm to 200 μm, or 20 μm to 150 μm. In some embodiments, the openings of the porous barrier are of uniform size (e.g., a narrow pore size distribution). For example, in some embodiments, as determined by the total opening area of ​​the porous barrier, at least some openings, most openings, at least 90% of openings, at least 95% of openings, or at least 99% of openings of the porous barrier are within the size range specified herein. The values ​​stated herein are determined by optical imaging. In one embodiment, substantially all openings of the porous barrier are within the size range specified herein.

[0100] The openings of a porous barrier can have any suitable shape. For example, the openings may be rectangular, square, circular, elliptical, or any other suitable shape. The shape can be determined by viewing the porous barrier from a direction perpendicular to the plane of the porous barrier. In some embodiments, the openings of the porous barrier are uniform in shape. For example, in some embodiments, at least some openings, most openings, at least 90% of openings, at least 95% of openings, or at least 99% of openings of the porous barrier have the same shape (e.g., rectangular, square, circular, elliptical, etc.).

[0101] The porous barrier 130 can be made of woven or nonwoven material. For example, the porous barrier 130 can be made of woven mesh. The woven mesh may 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 may 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 may have a wire diameter (or cross-sectional dimension) from 0.05 mm to 2 mm. In one embodiment, the porous barrier 130 includes 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 may be made of a material having appropriate lipophilic / oleophobicity to promote further growth of gas cavities and allow 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 lipophilic. In some embodiments, the porous barrier exhibits an oleophobic 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 the AATCC method 118. The porous barrier may have an oleophobicity rating of 1 or higher, 1.5 or higher, or 2 or higher. The porous barrier may have an oleophobicity rating of 8 or lower, or 6 or lower. The porous barrier may be constructed from composite materials. The porous barrier may be a composite of lipophilic and oleophobic components. The oleophobic component has an oleophobicity rating of 1 or higher.

[0102] For example, the porous barrier 130 may be made from a woven or nonwoven medium made from one or more of the following: metal such as stainless steel, or synthetic materials such as cellulose; regenerated cellulose (e.g., rayon); polyamide, polyester, polyethersulfone (PES), polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF); glass; ceramic; or carbon fibers. In one embodiment, the porous barrier 130 is made from a woven metal mesh such as stainless steel mesh. In some embodiments, fibers (e.g., metal fibers) are coated. Polymer or nonpolymer coatings such as resins can be used. In some embodiments, the porous barrier 130 is arranged in a cylindrical shape downstream of the gas nucleation medium 110 and the optionally selected growth medium 120. In some embodiments, the porous barrier 130 is arranged in a cylindrical shape that at least partially surrounds (e.g., nested with) the gas nucleation medium 110 and / or the growth medium 120. In one embodiment, the porous barrier 130 is arranged in a cylindrical shape that at least partially surrounds the growth medium 120 (for example, nested with it). The nested growth medium 120 and the elements of the porous barrier 130 may be stacked with the gas nucleating 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 sheet or pleated sheet may be configured as a panel. Such a panel configuration may be arranged, for example, inside a tank 10.

[0103] Porous barriers may exhibit microtexture and macrotexture. Microtexture is used here to refer to the surface texture of the barrier at the level of individual fibers or wires that make up the barrier (e.g., variations in size less than 1 mm). Microtexture is sometimes called surface roughness. Macrotexture is used here to refer to the surface texture of the entire barrier (e.g., variations in size greater than 1 mm). Porous barriers 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 from 10 nm to 500 nm. In some embodiments, the porous barrier has little to 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 strain, kurtosis, and radius of curvature. The strain of the fibers may be at least -10, -8, or -6. The strain of the fibers may be 6 or less, 8 or less, or 10 or less. The fibers of the porous barrier may have a kurtosis of -10 or more, -8 or more, or -6 or more. The fibers of the porous barrier may have a kurtosis of 6 or less, 8 or less, or 10 or less. Certain combinations of surface roughness, strain, and kurtosis may yield favorable capture properties. For example, high roughness and high kurtosis may be beneficial for capture. The fibers of the porous barrier may have a radius of curvature of 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, which is performed at an appropriate face velocity, e.g., 0.5 cm / sec.

[0106] The porous barrier may be positioned substantially perpendicular to the direction of flow. For example, the porous barrier may be cylindrical with a cylindrical wall coaxial with the nucleating medium. In some embodiments, the porous barrier includes a pleated material in which the pleat planes are angled with respect to the direction of flow. The degasser 100 may include a gap 135 between the gas nucleating 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 sized appropriately to accommodate the condensed gas cavity (second-stage gas cavity) from the growth medium 120. The gap 135 may be sized to fit into an air pocket that may be formed by the condensed gas cavity. The gap 135 may be positioned so that the condensed gas cavity (second-stage gas cavity) can gather and further condense (third-stage gas cavity). Thus, the gap 135 may be considered a second growth stage in some respects.

[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 longer or shorter than the axial length of the gas nucleation medium 110. In one embodiment, the axial length of the porous barrier 130 is shorter than the axial length of the gas nucleation medium 110.

[0108] The gap 135 may extend axially from a first end cap 141 to a second end cap 142 that determines the axial length of the gap 135. The gap 135 may have a width measured as the radial distance between the gas nucleating 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 tank wall. The gap 135 may be uniform in size along its axial length, or one end may be wider than the other. For example, the gap 135 may be constructed to be wider at the bottom and narrower at the top, or narrower at the bottom and wider at the 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 may 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 may have a width of 4 mm to 20 mm. In some embodiments in which the gap 135 extends from the growth medium 120 to the wall of the tank, the size of the gap may 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 components of the degasser 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 that are directly adjacent to each other may be pleated together. In one embodiment, the gas nucleation medium is made of a medium pleated together with the growth medium. In another embodiment, the gas nucleation medium is made of a medium pleated together with the porous barrier (for example, 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 a central opening 144, as shown in the cross-sectional view of Figure 8A. In one embodiment, the pleated media is arranged with variable pleats, the depth of which varies throughout the component. The variable pleated media 62 may be arranged in a cylindrical housing, as shown in Figure 8B.

[0110] In some embodiments, the degasser 100 includes a crown formed by an extension of the material. In particular, in embodiments in which the nucleating medium 110, the growth medium 120, and the porous barrier 130 are arranged in a concentric, nested configuration, the cylindrical portion of the medium may extend beyond the concentric apex to form a crown 133, as shown in Figure 9. The crown 133 is located outside the gas outlet 146. In other words, the crown 133 is positioned radially away from the central axis A than the gas outlet 146. The crown may be axially aligned with the porous barrier. The crown 133 may be formed from any suitable material, including from the same material as the porous barrier 130. The crown 133 may be an extension of the porous barrier 130 that extends beyond the nucleating medium 110 and the 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 (for example, across the top of the housing). The crown 133 may be a cylindrical piece of material (for example, an extension of the porous barrier 130) extending upward (upstream) from the end cap 141. The crown 133 may be fixed to the end cap 141.

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

[0112] The degassing device 100 may include additional elements. For example, the degassing device 100 may include one or more support liners. Such liners may be positioned adjacent to or between the gas nucleating medium 110, the growth medium 120, and / or the porous barrier 130, or any combination thereof. In one embodiment, the liner is positioned between the gas nucleating medium 110 and the growth medium 120. In one embodiment, the porous barrier 130 includes a liner positioned downstream thereof. In one embodiment, the porous barrier 130 includes a liner positioned upstream thereof. The liners of the porous barrier 130 may support the growth medium 120. The degassing device 100 may further include one or more of the following: housing elements, support elements, mounting elements, end caps, seals, filling materials, tubes, lines, etc.

[0113] The degassing device 100 may include removable and / or serviceable parts. For example, one or more of the elements 200, 300, 400, or one or more of the gas nucleating 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 nucleating medium 110 and growth medium 120 are removable and / or serviceable. Any one of the gas nucleating medium 110, growth medium 120, or porous barrier 130 may be separately removable and / or serviceable, or two or more parts may form a removable and / or serviceable unit. For example, the gas nucleating 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 nucleating 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 nucleating medium 110 and the growth medium 120. The porous barrier 130 may be permanently attached to a first end cap 141 and / or a 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 nucleating medium 110 and the growth medium 120 may be detachably and securely coupled to the frame. Once the degassing device 100 is assembled, the end caps of the maintainable units of the gas nucleating medium 110 and the growth medium 120 may be adjacent to the first and second end caps 141, 142, and may include a seal such as an O-ring between adjacent end caps. Adjacent end caps may be axially aligned with one or more end caps that include a lip to restrict the movement of the adjacent end caps.

[0114] The degasser 100 is configured to be mounted in various orientations, for example, with its central axis A oriented vertically as shown, or with its central axis A oriented horizontally. When the degasser 100 is mounted in series, such as in the return line 31, the horizontal orientation may be advantageous. In the horizontal orientation, the gas nucleating medium 110, the growth medium 120, and the porous barrier 130 can be arranged in a non-cylindrical shape, such as a planar shape.

[0115] In a preferred embodiment, the degasser 100 is positioned vertically inside the tank 10 (axis A is vertical or substantially vertical). The degasser 100 can be positioned 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 may be submerged, partially submerged, or at least occasionally completely above the fluid level in the tank. For example, the tank 10 may be a hydraulic fluid tank for a hydraulic system, where the fluid level in the tank 10 changes during the operation of the hydraulic system. The degasser 100 can be mounted on or near the top of the tank such that the degasser 100 is occasionally, at least occasionally, or always partially submerged in the hydraulic fluid.

[0116] A list of various embodiments of the degassing apparatus of this disclosure is provided below.

[0117] According to the first embodiment, the degassing device comprises a housing having an inlet and a single outlet, the single outlet being connectable to the inlet of a hydraulic fluid tank, a gas nucleating medium, and a porous barrier downstream of the gas nucleating medium, the gas nucleating medium and the porous barrier being located within the housing.

[0118] According to Embodiment 2, in the degassing apparatus of Embodiment 1, the gas nucleation medium and the porous barrier are in a laminated configuration.

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

[0120] According to Embodiment 4, in the degassing apparatus of Embodiment 3, the growth medium is configured in a layered structure with a gas nucleation medium and a porous barrier.

[0121] According to Embodiment 5, in the degassing apparatus of Embodiment 3, the growth medium has a nested configuration with the gas nucleation medium.

[0122] According to Embodiment 6, in the degassing apparatus of Embodiment 3, the growth medium has a porous barrier and a nested configuration.

[0123] According to Embodiment 7, in any one of Embodiments 1 to 6, the gas nucleating medium is arranged in an inside-to-outside flow configuration, and the porous barrier is arranged in an outside-to-inside flow configuration.

[0124] According to embodiment 8, in any one of embodiments 1 to 6, the gas nucleating 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 embodiment 9, the degassing device comprises a first element which is an inline filter and is equipped with a gas nucleating medium, and a second element which is downstream of the first element and in fluid communication with the first element and includes a porous barrier, wherein at least one of the first and second elements is equipped with a growth medium, and the first and second elements are in a laminated configuration.

[0126] According to embodiment 10, in the degassing apparatus of embodiment 9, the first element comprises a gas nucleation medium and a growth medium, and the gas nucleation medium and the growth medium are nested together.

[0127] According to embodiment 11, in the degassing apparatus of embodiment 9 or 10, the second element comprises a porous barrier and a growth medium, and the porous barrier and the growth medium are nested together.

[0128] According to embodiment 12, in any one of the degassing devices of embodiments 9 to 11, the second element is placed inside a fluid tank.

[0129] According to embodiment 13, in any one of embodiments 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 embodiment 14, in any one of embodiments 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 embodiment 15, in any one of embodiments 9 to 14, the first element is arranged in an inside-to-outside flow configuration.

[0132] According to embodiment 16, in any one of embodiments 9 to 14, the first element is arranged in an outside-to-inside flow configuration.

[0133] According to embodiment 17, in any one of embodiments 9 to 16, the second element is arranged in an inside-to-outside flow configuration.

[0134] According to embodiment 18, in any one of embodiments 9 to 16, the second element is arranged in an outside-to-inside flow configuration.

[0135] According to embodiment 19, any one of embodiments 9 to 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 a width of 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 embodiment 20, the degassing device of embodiment 19 further comprises a gas discharge hole extending from the gap to the outside of the degassing device.

[0137] According to embodiment 21, the degassing device is a cylindrical element comprising a cylindrically arranged gas nucleating medium and a porous barrier, wherein the porous barrier is arranged downstream and around the gas nucleating medium; a gap between the gas nucleating medium and the porous barrier; an end cap located 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 embodiment 22, the degassing apparatus of embodiment 21 further comprises a growth medium disposed between the gas nucleation medium and the gap.

[0139] According to embodiment 23, in the degassing device of embodiment 21 or 22, the housing is provided with a gas release hole that extends from a gap through an end cap to the outside of the housing.

[0140] According to Embodiment 24, in any one of Embodiments 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 embodiment 25, in any one of embodiments 1 to 24, the gas nucleating medium comprises an oleophobic material having an oil contact angle of at least 30°, at least 50°, at least 70°, at least 90°, or at least 120°; or up to 120°, or up to 150°. The gas nucleating medium may have an oil contact angle of 50° to 120°. The oil contact angle can be measured by dropping oil onto a single fiber in air using a micro-contact angle meter.

[0142] According to embodiment 26, according to any one degassing apparatus of embodiments 1 to 25, the gas nucleating medium includes an oleophobic material having an oleophobicity rating of 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more; or 8 or less, 7 or less, 6 or less, 5 or less, or 4 or less. The gas nucleating medium may have an oleophobicity rating of 2 to 8 or 3 to 8.

[0143] According to embodiment 27, according to any one degassing apparatus of embodiments 1 to 26, the growth medium includes multiple medium layers. The growth medium may include two or more layers, three or more layers, four or more layers, or five or more layers; or up to 20, up to 15, up to 12, or up to 10 layers. The growth medium may include 2 to 15 layers or 4 to 10 layers. The growth medium may include 7 layers.

[0144] According to embodiment 28, in any one of the degassing devices of embodiments 1 to 27, the growth medium is directly adjacent to the gas nucleating medium.

[0145] According to embodiment 29, according to any one of embodiments 1 to 28, the growth 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 growth medium may include a combination of regenerated cellulose fibers and polyester.

[0146] According to embodiment 30, in any one of embodiments 1 to 29, the porous barrier has 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 may 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 embodiment 31, the degassing device described in any one of embodiments 1 to 30 further comprises a liner.

[0148] According to embodiment 32, any one of embodiments 1 to 31 of the degassing device further comprises a first end cap having an opening that defines an inlet.

[0149] According to embodiment 33, any one of embodiments 1 to 32 further comprises a closed second end cap.

[0150] According to embodiment 34, in the degassing device of embodiment 33, the second end cap is provided with a bottom.

[0151] According to embodiment 35, in any one of the degassing apparatuses of embodiments 1 to 34, the gas nucleating medium encloses and defines the open interior of the degassing apparatus.

[0152] According to embodiment 36, in any one of embodiments 1 to 35, the gas nucleating medium, optionally the growth medium, and the porous barrier form a cylindrical body.

[0153] According to embodiment 37, according to any one degassing apparatus of embodiments 1 to 36, the gas nucleation medium is measured by the Carmen-Kozeny method and is 1 m 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 Above 50m 2 / m 2 or more, or 100m 2 / m 2 Above; 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 The following, or 4m 2 / m 2 The basic fiber surface area is as follows: The gas nucleation medium, when measured by the Carmen-Kozeny method, is 1 m 2 / m 2 ~100m 2 / m 2 or 5m 2 / m 2 ~50m 2 / m 2 It may have the following basic fiber surface area.

[0154] According to embodiment 38, according to any one degassing apparatus of embodiments 1 to 37, the gas nucleating medium has an average pore diameter of 0.5 μm or more, 1 μm or more, or 5 μm or more, as measured by ASTM F316; or 5 μm or less, 10 μm or less, 20 μm or less, 100 μm or less, or 200 μm or less. The pores in the gas nucleating medium may have an average pore diameter of 5 μm to 100 μm or 30 μm or less, as measured by ASTM F316.

[0155] According to embodiment 39, according to any one degassing device of embodiments 1 to 38, the growth medium has a solid content of 2% or more, 4% or more, 5% or more, 6% or more, 10% or more, or 20% or more at 1.5 psi; 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 may have a solid content of 2% to 20% or 2% to 9% at 1.5 psi.

[0156] According to embodiment 40, using any one of the degassing devices of embodiments 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 according to 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 according to the TAPPI T411 test method.

[0157] According to embodiment 41, according to any one of the degassing devices of embodiments 1 to 40, the growth medium comprises a composite of lipophilic and oleophobic components, and the oleophobic components have an oleophobicity rating of 1 or higher when measured by the AATCC method 118.

[0158] According to embodiment 42, with respect to any one of the degassing devices of embodiments 1 to 41, the porous barrier includes an oleophobic surface having an oleophobicity rating of 1 or more when measured by the AATCC method 118.

[0159] According to embodiment 43, according to any one of the degassing devices of embodiments 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 higher when measured by the AATCC method 118.

[0160] According to embodiment 44, the system for removing gas from a fluid comprises a tank having a fluid inlet and a fluid outlet, and a fluid passage from the fluid inlet to the fluid outlet; and a degassing device according to any one of the preceding embodiments that is in fluid communication with the fluid passage.

[0161] According to embodiment 45, in the system of embodiment 44, at least a portion of the degassing device is arranged in 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 degassing device is arranged inline along a fluid inlet line that is in fluid communication with the fluid inlet of the tank.

[0163] According to embodiment 47, a method for removing gas from a fluid includes passing the fluid through a degasser that defines a fluid flow path, the degasser comprising one of the degassers of embodiments 1 to 43.

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

[0165] According to embodiment 49, a filter element suitable for use in any one of embodiments 1 to 39 comprises 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 an end cap at the end of the cylindrical element.

[0168] According to embodiment 52, in any one of the filter elements of embodiments 49 to 51, the filter element is a replacement part for the degassing device.

[0169] According to embodiment 53, the replacement part of the degassing device comprises a layer of gas nucleating medium and a layer of growth medium adjacent to the layer of gas nucleating medium.

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

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

[0172] Examples 1 and 2 We tested various aspects of degassing devices configured for use with hydraulic fluid. We tested the performance of the degassing devices against a baseline including commercially available degassing devices and devices without degassing.

[0173] Test System. To test the performance of the degasser, pressurized air was used to saturate the hydraulic fluid with air. The test was performed using HY-GARD® hydraulic / transmission fluid, available from Deere & Company (Moline, IL). The degasser was mounted in a tank constructed to simulate the hydraulic fluid tank of a hydraulic system. Here, return hydraulic fluid enters the tank and degasser from above. During the test, the tank was placed under ambient pressure. The air-saturated oil was circulated through a system including a degasser tank housing the degasser under test. The air-saturated oil was pumped into the degasser and the air removal efficiency was measured.

[0174] The fluid was heated to a target temperature of 35±1.6℃. The fluid was aerated in an aeration circuit with an oil flow rate of 11.3 L / min and an air flow rate of 7.1 L / min under a pressure of 414 kPa. The aerated fluid was then flowed into a degasser at a certain flow rate or approximately 36 L / min. The degasser was operated at ambient pressure.

[0175] Sample preparation. Degassing and filtration elements (samples C-H) were constructed coaxially with a 0.5 cm gap between the growth medium and the screen barrier, as shown in Figure 2A. The elements were sized to target the medium surface velocity for each 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 medium was pleated EN0799037 hydraulic medium available from Donaldson Company, Inc. (Minneapolis, MN), used in part numbers P171846 and P171579. The growth medium was PN-130 (130 g / m³) manufactured by Precision Custom Coatings, LLC (Totowa, NJ). 2The medium was a wound needle-punched polyester / rayon blend nonwoven fabric, such as ). The screen barrier consisted of a simple woven screen with pleats. The nucleating medium and screen barrier were supported by support wires.

[0176] A commercially available degasser (comparative example, sample A) was miniaturized to match the flow capacity of the test system. In the commercially available degasser, the flow enters from the bottom, bends, and passes radially outward through the particulate medium from the inside to the outside. The particulate medium is surrounded by a cylindrical metal shell (downstream of the particulate medium). The cylindrical metal shell has a rectangular opening in the lower third of the shell, and a single layer of stainless steel screen is fitted inside the opening so that all the flow passes through the screen. The screen was estimated to have an opening of approximately 2 mm. It was observed that all small bubbles and many large bubbles passed through the screen without agglomerating. The screen provided an outward and slightly upward flow through the rectangular opening.

[0177] The baseline (Sample B) included only the particle filter and no degassing equipment. The particle filter used as the baseline was the K041774 filter, available from Donaldson Company, Inc. (Minneapolis, MN).

[0178] Test Method. Air was continuously mixed into the hydraulic fluid supplied to the tank for 1800 seconds. The oil-air mixture (%) was measured and recorded throughout the test. A schematic of the data acquisition settings used in Examples 1 and 2 is shown in Figure 10. The maximum air mixture value for each degasser was determined by averaging the oil-air mixture (%) readings from 600 seconds to 1700 seconds. A lower maximum air mixture value indicates that more air was removed and therefore improved degassing performance. Samples were tested against a baseline that did not include the commercially available degasser designated as "Sample A" and the degasser designated as "Sample B". In the table, "Air Mixture Compared to the Baseline" means the amount of air remaining in the oil compared to the baseline normalized to 100%. Values ​​less than 100% indicate better performance than the baseline (less air remaining in the oil). "Air Reduction from the Baseline" is the difference between the air mixture in the sample and the baseline (100%). A higher value indicates better performance.

[0179] The air inclusion measurement device was an AIR-X sensor from Delta Services Industrials (Froyennes, Belgium).

[0180] Example 1 Sample devices were prepared by varying the mesh opening size of the porous barrier while maintaining a constant nucleation and growth stage. The growth medium was prepared using a 7-layer (winding) medium. As shown in Table 1 below, the nominal mesh opening sizes of samples C to F ranged from 20 μm to 125 μm. The degassing device was tested as described above. The results, including the differential pressure across the degassing device, are shown in Table 1 and Figures 11A to 11C.

[0181] [Table 1]

[0182] Figure 11A shows data plots of oil-air contamination (%) results for various samples. Figure 11B shows the improvement in maximum mean air contamination (%) compared to the baseline sample B. It was observed that smaller mesh opening sizes in the porous barrier yielded better degassing results than larger sizes. Sample C showed a 61% reduction in maximum mean air contamination, while Sample D showed a 22% reduction, and Samples E and F showed a 15% reduction. Furthermore, each of Samples C-F was observed to be superior to the commercially available Sample A and the baseline Sample B. Figure 11C compares maximum mean air contamination (%) with differential pressure.

[0183] Example 2 Sample apparatuses C, G, and H were prepared as follows: while maintaining a constant mesh opening size for the nucleation medium and porous barrier, they were prepared with varying thicknesses of growth medium by applying different numbers of layers of growth medium. As shown in Table 2 below, sample C had the same thickness of growth medium as in 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 apparatus was tested as described above. The results, including the differential pressure across the degassing apparatus, are shown in Table 2 and Figures 12A-12C.

[0184] [Table 2]

[0185] Figure 12A is a data plot of the oil-air contamination (%) results for various samples. Figure 12B shows the improvement in maximum mean air contamination (%) compared to the baseline sample B. It was observed that thicker growth media resulted in better degassing results. Sample C showed a 61% reduction in maximum mean air contamination compared to the baseline, while sample G achieved a 46% reduction and sample H achieved a 27% reduction. Furthermore, it was observed that samples C, G, and H each outperformed the commercially available sample A and the baseline sample B. Figure 12C compares maximum mean air contamination (%) with differential pressure.

[0186] Examples 3-5 Sample preparation. A media hand sheet was prepared by dispersing fibers in water and then formed in an ADIRONDACK FORMAX 12''×12'' stainless steel sheet mold, available from Adirondack Machine Corp. (Hudson Falls, NY). Specific details of the finished material (furnish) are provided in Example 3 below. The media tested was 71 mm². 2 It was cut to fit the media holder with its effective area. The test media was immersed in the test oil and placed in the series media housing.

[0187] The term "basic fiber surface area" is used here to refer to the surface area of ​​the fiber per unit of bulk medium surface area.

[0188] Surface area analysis. The surface area of ​​the medium can be determined by Branauer-Emmett-Teller (BET) analysis or by the Carmen-Kozeny relation. Examples 3 and 4 used the Carmen-Kozeny relation.

[0189] BET analysis: 1m media sample 2 m per bulk surface area 2 The basic fiber surface area of ​​a unit medium can be determined from the surface area per unit mass using ISO 9277 and the basic dry weight of the medium as determined by ASTM D646 by the following relationship:

number

[0190] Low surface area materials (for example, fiber surface area of ​​1 m²) 2 For materials with a high surface area (e.g., fiber surface area of ​​1 m²), BET measurement is preferably performed using krypton gas. 2 If the BET measurement is greater than / g, it is preferable to perform the measurement using nitrogen gas. If the basic fiber surface area of ​​only one layer of the media composite is measured, that layer is removed from the composite and its mass and basic weight are used for the calculation.

[0191] Carmen-Kozeny method: The specific surface area of the media can be calculated based on the Carmen-Kozeny relationship, where the pressure drop of the fluid flowing through the solid porous material is calculated based on an equation derived by combining Darcy's law and Poiseuille's law when modeling the flow of fluid through a packed bed of spheres. The general form of the equation is as follows:

Number

Number

[0192] The fibers used in the most typical filter media, including the examples here, have a large aspect ratio of 100 to 1000, so the end surface area can be considered negligible and the surface area of the fiber can be regarded as the surface area of a single long fiber or cylinder. Next, the specific surface area of the media can be calculated based on the total mass of the filter media sample and the density of the material. When the fibers are made of multiple materials, the mass fraction weighted density is used. The identification of the fiber materials and their mass fractions can be determined by methods known to those skilled in the art. The surface area is reported as the specific surface area of the basic fiber according to the Carmen-Kozeny method. When the specific surface area of the basic fiber is measured for only a single layer of the media composite, that layer is removed from the composite before testing.

[0193] Test Procedure: To test the performance of the nucleating medium, a nucleation test bench was constructed from a tank connected to an air supply source via 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 medium test housing that also incorporated a bypass loop. Both the housing tubing and the bypass were connected to a CANTYVISION camera, which in turn connected to a collection flask positioned on a digital mass scale. Images acquired from the video recording of the CANTYVISION camera were analyzed using CANTYVISION intelligent analysis software to record and analyze the nucleation function of the medium sheet under test. The CANTYVISION camera 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 mix air into the hydraulic fluid by bubbling. The tank pressure was maintained at 25 psi to mix air into the oil. After mixing air into the oil, excess free air was released from the oil.

[0195] To conduct the nucleation test, air-mixed hydraulic fluid from a tank was flowed through the test medium while adjusting the tank pressure to drive the flow at the desired experimental surface velocity, which was 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 and the National Institutes of Health). The following routine was applied uniformly to all experiments for the last 1000 frames captured for each experiment.

[0197] The images were cropped to remove experimental artifacts such as window walls and circular objects that are not bubbles, as needed. The images were converted to 8-bit grayscale images. The images were converted to black and white images using the "Otsu" automatic thresholding algorithm (described in Otsu, N., A Threshold Selection Method from Gray-Level Histograms, 9 IEEE Transactions on Systems, Man, and Cybernetics 62 (1979)), where black was set as the background color. The contours of unfilled objects in the images were filled using a "fill holes" routine, and then a "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 divide overlapping objects. These processed images were then used to create images with an area of ​​at least 1203 μm². 2 , roundness (4*area / [π*principal_axis 2 Bubbles with a ferret diameter of 0.95 (defined as ) were counted. The volume of the bubbles was estimated from the ferret diameter of the bubbles. The ferret diameter is defined as the longest distance between any two points along the choice boundary (also known as the maximum caliper). In the nucleation stage, the term “bubble diameter” refers to the ferret diameter.

[0198] Pore ​​size measurement. The pore size of the medium can be measured using an automated air permeable porometer, such as one manufactured by Porous Materials, Inc. (Ithaca, NY). In these examples, the porous material 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 a silicone liquid 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 medium samples were tested in monolayer configurations. Medium samples were prepared from microglass fibers and two-component polyester sheaths / cores, according to Table 3 below. The two-component polyester fibers were ADVANSA 271P, available from Advansa GmbH in Germany, with a nominal average diameter of 14 μm and a nominal average length of 6 mm. Various drying techniques, including ovens and sheet dryers, and compression were used to produce samples with varying thicknesses and solidity. Airflow ovens are known to produce structures with lower solidity than sheet dryers.

[0200] [Table 3]

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

[0202] [Table 4]

[0203] The average air volume per frame (proportional to the total air released) and the average bubble diameter were determined as functions of the average pore diameter, the basic fiber surface area, the solids fraction of the media measured at 1.5 psi, and the media thickness. The basic fiber surface area was determined by the Carmen-Kozeny method. The parameters showing trends are shown in the figures. Data comparing the average air volume per frame with the average pore diameter, the total nucleation surface area, the solids fraction of the media measured at 1.5 psi, and the media thickness are shown in FIGS. 13A - 13D. Data comparing the average bubble diameter with the average pore diameter, the basic fiber surface area, the solids fraction of the media measured at 1.5 psi, and the media thickness are shown in FIGS. 14A - 14D.

[0204] ANOVA analysis was performed to determine the most important regressors for the average air volume per frame. Based on this analysis, more air is released as the basic fiber surface area increases and the average pore diameter decreases. A similar ANOVA analysis was performed to determine the most important regressors for the average bubble diameter. Based on this analysis, the average bubble diameter increases as the average pore diameter increases. The average bubble diameter decreases as the basic fiber surface area increases.

[0205] Example 4 In another example, 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 from 1 to 8.

[0206] [Table 5]

[0207] The average air volume per frame (proportional to the total air released) and the 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 leveled off, but the average bubble size continued to decrease.

[0208] Example 5 In another example, a media hand sheet was manufactured by a wet-laid process involving the dispersion of 200 mg of a sheath / core two-component polyester fiber (ADVANSA 271P) with a nominal average diameter of 14 μm and a nominal average length of 6 mm in water, and then molded on a circular stainless steel sheet mold with a diameter of 90 mm. The dried media hand sheet patches were fused at 115°C.

[0209] Samples of media hand sheets were coated to make them oleophobic. The oleophobic coating was applied by dipping screen samples by hand 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 oleophobic coated media was compared with that of uncoated media, such as those 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 the total released air. After the oleophobic treatment, the average bubble diameter decreased.

[0212] [Table 6]

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

[0214] Sample preparation. The medium hand sheet was prepared by dispersing fibers in water and then molded in an ADIRONDACK FORMAX 12''×12'' stainless steel sheet mold, available from Adirondack Machine Corp. (Hudson Falls, NY). Specific details of the finished material are shown in Table 7 below. The medium tested was 12.9 cm². 2 It was cut to fit the media holder with its effective area. The test media was placed in the series media housing.

[0215] Test Procedure: To test the performance of the growth medium, a test bench was constructed and used, and a medium sample containing small bubbles (nominal average diameter 600 μm) in oil was challenged, and the medium's ability to grow bubbles was monitored. The bench was constructed to monitor the size and number of bubbles both upstream and downstream of the test medium sample.

[0216] The test bench included an oil storage tank, a gear pump to regulate the oil flow from the tank, a pressure gauge, and a line connecting the oil storage tank to the test cell. A flow meter placed on the line was used to determine the face velocity of the oil in the medium within the test cell. A 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 bubble challenge upstream of the test medium. The test cell was constructed of transparent acrylic to allow image capture on both the upstream and downstream sides 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 on both the upstream and downstream sides of the test medium.

[0217] To conduct the test, the oil flow was first initiated, and once the oil filled the test cell, the 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 short period, the image capture was repeated.

[0218] Image data processing. Images were processed in the same manner as in Examples 3 and 4 (nucleation stage) across all experiments (20 frames per experiment) until the application of the "watershed" routine. Next, the processed images were used to process areas with an area of ​​at least 10,000 μm². 2 (23.42 μm / pixel), roundness (4π * area / perimeter) 2 We counted bubbles with a value of 0.5 (as defined). The volume of the bubbles was calculated from the bubble area using the following conditions: If the ferret diameter of the bubble is greater 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 considered the ferret diameter, and the volume of the bubble is calculated as a typical sphere.

[0220] The difference in calculation methods stems from the fact that visual inspection of bubbles larger than approximately 3 mm suggests that these large bubbles are actually clusters of bubbles, which artificially gives them a larger volume when calculated in ferret diameter.

[0221] Data analysis. Performance was evaluated using the growth performance parameter D50. D50 is defined as the median of the calculated bubble volume, i.e., 50% of the number of bubbles are below this size.

number

[0222] If the performance improvement rate for D50 is 0%, it is interpreted as no improvement in performance. A rate below 0% is interpreted as insufficient bubble growth performance, and a rate above 0% is interpreted as an improvement in bubble growth.

[0223] Tests and Results. Various growth medium samples were tested to evaluate the effect of the medium structure. The medium samples were composites of rayon and two-component polyester fibers (ADVANSA 271P) with a nominal average diameter of 14 μm and a nominal average length of 6 mm in sheath / core configuration. The design variables for the finished material are shown in Table 7 and were mixed to create various medium samples. The parameters of the finished material were modified to target various medium properties shown in Table 8.

[0224] [Table 7]

[0225] [Table 8]

[0226] The rate of increase in D50 was determined as a function of the solidity of the medium, the thickness of the medium, and the fiber size. The results are shown in Figures 16A and 16B, respectively.

[0227] It should be noted that solidity and thickness are not independent of each other. To prepare a medium with a higher solidity, the medium was compressed, thereby reducing its thickness. It may be difficult to distinguish the effects attributable to solidity and thickness. However, it has been observed that decreasing solidity while increasing thickness results in better growth performance.

[0228] Benefits in growth performance were observed at thicknesses exceeding 1 mm. Furthermore, benefits in growth performance were observed at solidity percentages of 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 in Example 7 for the porous barrier stage. Such aspects included the size of the openings, the chemical properties of the surface, the face velocity, and the size of the bubbles reaching the upstream porous barrier.

[0230] Sample preparation. Various screens were obtained from commercial sources. Screen samples were prepared on a 12.9 cm² screen. 2 The media holder was cut to fit its effective area. The screen sample was placed inside a series 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 volume of the bubbles was estimated from the ferret diameter of the bubbles. In this document, the ferret diameter is referred to as the "bubble diameter" in relation 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 on the screen. Performance below 0% is interpreted as insufficient performance, performance above 0% but below 100% is interpreted as a moderate increase in size, performance above 100% but below 250% is interpreted as a significant improvement in size, and performance above 250% is interpreted as a substantial improvement in size.

[0235] Tests and Results. The screens were plain weave stainless steel screens. Various screens were tested with different properties, as shown in Table 9 below, along with the application of 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] The bubble challenges were classified into either "coarse" (average nominal ferret diameter 550 μm) or "fine" (average nominal ferret diameter 350 μm). To maintain similar upstream bubble challenge sizes, the airflow rate was adjusted to account for changes in face velocity.

[0239] The test results are shown in Figure 17A. In general, it was observed that the screen performance deteriorated as the face velocity increased.

[0240] The effect of oleophobic surface treatment on screen performance was also tested. 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 of the samples was tested by the AATC118 method. All treated samples had an oleophobicity rating of at least 6.

[0241] The test results are shown in Figure 17B. At lower face speeds of 0.5 cm / sec and with oleophobic treatment, screen performance was observed to improve, particularly with respect to fine bubbles.

[0242] Example 8 Sample apparatuses with various configurations were prepared. The samples were prepared as described above for Examples 1 and 2, unless a different configuration is described below. The configurations of the degassing apparatuses 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 packs. XP refers to Synteq-XP medium used in product number P171846, available from Donaldson Company, Inc. (Minneapolis, MN). PN130 refers to 130 g / m², available from Precision Custom Coatings, LLC (Totowa, NJ). 2 This refers to a polyester / rayon blend needle-punched nonwoven fabric medium. The stainless steel screen had a nominal opening of 50 μm and a simple weave pattern.

[0244] The degassing apparatus was tested as described above in Examples 1 and 2. The gas reduction of each configuration was compared to a baseline. The results are shown in Table 10B and Figure 18. "Air contamination compared to the baseline" refers to the amount of air remaining in the oil compared to a baseline normalized to 100%. Values ​​less than 100% indicate better performance than the baseline (less air remaining in the oil). "Air reduction from the baseline" is the difference between the baseline (100%) and the air contamination in the sample. A higher value indicates better performance.

[0245] [Table 10]

[0246] [Table 11]

[0247] It was observed that various configurations of the stages could result in varying degassing performance. Almost 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 coaxial designs, those in a tank (Sample C in Example 2) and in-line (Sample H in Example 8) yielded similar degassing performance. Adding a growth layer improved degassing performance, such as from Sample G to H (Example 8) or from Sample F to G (Example 8). Samples with gas release (Samples B and C in Example 8) performed better than their equivalent sample without gas release (Sample D in Example 1).

[0248] All references and publications cited herein are expressly incorporated in their entirety by reference unless they would directly contradict this disclosure. While specific embodiments have been illustrated and described herein, it will be understood by those skilled in the art that various alternative and / or equivalent implementations can be substituted for the specific embodiments illustrated and described without departing from the scope of this disclosure. This disclosure is not intended to be unduly limited by the exemplary embodiments and examples described herein, and such examples and examples are presented merely as illustrations; the scope of this disclosure is intended to be limited only by the claims described herein.

Claims

1. A housing having an inlet and a single outlet, wherein the single outlet is connectable to the inlet of a hydraulic fluid tank, A gas nucleation medium and The porous barrier downstream of the gas nucleation medium and Equipped with, The gas nucleating medium and the porous barrier are arranged within the housing. Degassing device.

2. The degassing apparatus according to claim 1, wherein the gas nucleation medium and the porous barrier are in a laminated configuration.

3. The degassing apparatus according to claim 1 or 2, further comprising a growth medium disposed between the gas nucleating medium and the porous barrier.

4. The degassing apparatus according to claim 3, wherein the growth medium is laminated with the gas nucleating medium and the porous barrier.

5. The degassing apparatus according to claim 3, wherein the growth medium is nested with the gas nucleation medium.

6. The degassing apparatus according to claim 3, wherein the growth medium has a nested configuration with the porous barrier.

7. The degassing apparatus according to any one of claims 1 to 6, wherein the gas nucleating medium is arranged in an inside-to-outward flow configuration, and the porous barrier is arranged in an outside-to-inward flow configuration.

8. The degassing apparatus according to any one of claims 1 to 6, wherein the gas nucleating medium is arranged in an outside-to-inside flow configuration, and the porous barrier is arranged in an inside-to-outside flow configuration.

9. A first element comprising a gas nucleation medium, the first element being an inline filter, A second element located downstream of the first element and in fluid communication with the first element, the second element comprising a porous barrier, At least one of the first and second elements comprising a growth medium and Equipped with, The first and second elements are arranged in a laminated configuration. Degassing device.

10. The degassing apparatus according to claim 9, wherein the first element comprises a gas nucleation medium and a growth medium, and the gas nucleation medium and the growth medium are nested together.

11. The degassing apparatus according to claim 9 or 10, wherein the second element comprises a porous barrier and a growth medium, and the porous barrier and the growth medium are nested together.

12. The degassing apparatus according to any one of claims 9 to 11, wherein the second element is disposed inside a fluid tank.

13. The degassing device according to any one of claims 9 to 12, wherein 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.

14. The degassing device according to any one of claims 9 to 12, wherein 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.

15. The degassing device according to any one of claims 9 to 14, wherein the first element is arranged in an inside-to-outside flow configuration.

16. The degassing device according to any one of claims 9 to 14, wherein the first element is arranged in an outer-to-inner flow configuration.

17. The degassing device according to any one of claims 9 to 16, wherein the second element is arranged in an inside-to-outside flow configuration.

18. The degassing device according to any one of claims 9 to 16, wherein the second element is arranged in an outer-to-inner flow configuration.

19. The degassing apparatus according to any one of claims 9 to 18, further comprising a gap between the growth medium and the porous barrier.

20. The degassing apparatus according to claim 19, further comprising a gas discharge hole extending from the gap to the outside of the degassing apparatus.

21. A cylindrical element comprising a gas nucleating medium arranged in a cylindrical shape and a porous barrier, wherein the porous barrier is arranged downstream and around the gas nucleating medium. The gap between the gas nucleation medium and the porous barrier, An end cap is positioned at one end of the cylindrical element. An opening formed in the end cap, The outlet that is in fluid communication with the hydraulic fluid tank, and A cylindrical extension of the material that extends coaxially from the upstream end of the aforementioned cylindrical element. A degassing device equipped with the following features.

22. The degassing apparatus according to claim 21, further comprising a growth medium disposed between the gas nucleating medium and the gap.

23. The degassing device according to claim 21 or 22, wherein the housing is provided with a gas release hole extending from the gap through the end cap to the outside of the housing.

24. The degassing apparatus according to any one of claims 1 to 23, wherein the gas nucleation medium comprises a particle filtration medium having an average pore size of 5 μm or more as measured by ASTM F316.

25. The degassing apparatus according to any one of claims 1 to 24, wherein the gas nucleating 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.

26. The degassing apparatus according to any one of claims 1 to 25, wherein the gas nucleation medium includes an oleophobic material having an oil contact angle of at least 30°, which is measured by dropping oil onto a single fiber in air using a micro-contact angle measuring instrument.

27. The degassing apparatus according to any one of claims 1 to 26, wherein the gas nucleation medium includes an oleophobic material having an oleophobicity rating of 1 or more when measured by the AATCC method 118.

28. The degassing apparatus according to any one of claims 3 to 27, wherein the growth medium comprises a plurality of medium layers.

29. The degassing apparatus according to any one of claims 3 to 28, wherein the growth medium is directly adjacent to the gas nucleating medium or the support structure of the gas nucleating medium.

30. The degassing apparatus according to any one of claims 3 to 29, wherein the growth medium includes an oleophobic surface having an oleophobicity rating of 1 or more when measured by the AATCC method 118.

31. The degassing apparatus according to any one of claims 3 to 30, wherein the growth medium comprises a composite of lipophilic and oleophobic components, and the oleophobic components have an oleophobicity rating of 1 or more when measured by the AATCC method 118.

32. The degassing apparatus according to any one of claims 1 to 31, wherein the porous barrier includes an oleophobic surface having an oleophobicity rating of 1 or more when measured by the AATCC method 118.

33. The degassing apparatus according to any one of claims 1 to 32, wherein the porous barrier comprises a composite of an oleophilic component and an oleophobic component, and the oleophobic component has an oleophobicity rating of 1 or more when measured by the AATCC method 118.

34. The degassing apparatus according to any one of claims 1 to 33, wherein the porous barrier has an opening of less than 250 μm in size.

35. The degassing apparatus according to any one of claims 1 to 34, wherein the porous barrier provides a mutually supportive structure with the gas nucleation medium or growth medium.

36. The degassing apparatus according to any one of claims 3 to 35, wherein one or more of the gas nucleating medium, the growth medium, or the porous barrier are configured in a cylindrical shape.

37. The degassing apparatus according to any one of claims 3 to 36, wherein one or more of the gas nucleating medium, the growth medium, or the porous barrier are configured in a planar panel configuration.

38. The degassing apparatus according to any one of claims 3 to 37, wherein one or more of the gas nucleating medium, growth medium, and porous barrier are independently removable and replaceable.

39. The degassing apparatus according to any one of claims 3 to 38, wherein two or more of the gas nucleating medium, growth medium, and porous barrier form a removable and replaceable unit.

40. A system for removing gas from a fluid, A tank having a fluid inlet and a fluid outlet, and a fluid flow path from the fluid inlet to the fluid outlet, A degassing device according to any one of claims 1 to 39 that is in fluid communication with the fluid passage, A system equipped with these features.

41. The system according to claim 40, wherein at least a portion of the degassing device is arranged in the tank along the fluid flow path.

42. The system according to claim 40 or 41, wherein at least a portion of the degassing device is arranged inline along a fluid inlet line that is in fluid communication with the fluid inlet of the tank.

43. A method for removing gas from a fluid, A method comprising passing the fluid through a degasser that defines a fluid flow path, wherein the degasser includes a degasser according to any one of claims 1 to 39.

44. The method according to claim 43, wherein the fluid flow is forcibly passed through the degassing device or drawn through the degassing device.

45. A layer of gas nucleation medium, Layers of growth media and A filter element suitable for use in a degassing apparatus according to any one of claims 1 to 39, comprising:

46. The filter element according to claim 45, wherein the layer of gas nucleation medium and the layer of growth medium form a cylindrical element.

47. The filter element according to claim 46, further comprising an end cap at the end of the cylindrical element.

48. The filter element according to any one of claims 45 to 47, wherein the filter element is a replacement part for the degassing device.

49. A layer of gas nucleation medium, A growth medium layer adjacent to the gas nucleation medium layer and Replacement parts for a degassing device.

50. The replacement part according to claim 49, wherein the gas nucleation medium and growth medium form a cylindrical element.

51. The replacement part according to claim 50, further comprising an end cap at the end of the cylindrical element.

Images