Grooved porous media gas trap for terrestrial and microgravity environments.

Abstract

To provide a gas trap assembly that can inhibit damage to a pump or failure of a system.SOLUTION: A gas trap assembly includes: a base connector housing including an inflow port and an outflow port; a reservoir fluidly connecting the inflow port to the outflow port; and a grooved porous medium located within the reservoir. The grooved porous medium includes a plurality of grooves and is composed of a material having a plurality of pores of a selected size. The grooved porous medium fluidly divides the reservoir into two portions in such a way that a working fluid flowing from the inflow port to the outflow port must flow through the plurality of grooves and the plurality of pores of the grooved porous medium. The plurality of grooves and the plurality of pores are configured to prevent gas from passing through the grooved porous medium.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The subject matter disclosed herein relates generally to the field of evaporators, and more particularly to gas traps for terrestrial and microgravity environments.

[0002] In a single-phase flow loop, a liquid-phase working fluid circulates through the system for various purposes. Due to corrosion, material compatibility, and several other reasons, gases may be generated within the system and enter the liquid stream of the working fluid. If the generated gas enters the suction side of the pump, it can damage the pump or cause the system to fail. Summary of the Invention [Means for solving the problem]

[0003] According to one embodiment, a gas trap assembly is provided. The gas trap assembly includes a base connector housing including an inlet port and an outlet port, a reservoir fluidly connecting the inlet port to the outlet port, and a grooved porous medium disposed within the reservoir. The grooved porous medium is composed of a material including a plurality of grooves and having a plurality of pores of a selected size. The grooved porous medium fluidically divides the reservoir into two portions such that working fluid flowing from the inlet port to the outlet port must pass through the grooves and pores of the grooved porous medium. The grooves and pores are configured to prevent gas from passing through the grooved porous medium.

[0004] In addition to or as an alternative to one or more of the above features, further embodiments may include each of the plurality of grooves being defined as being formed by two opposing sidewalls that form a base and an apex with an apex angle measured between the two opposing sidewalls at the apex, wherein the working fluid in each of the plurality of grooves moves from the base to the apex and the gas in each of the plurality of grooves moves from the apex to the base.

[0005] In addition to or as an alternative to one or more of the above features, further embodiments may include each of the plurality of grooves being formed by two opposing sidewalls, the two opposing sidewalls forming a base and an apex with an apex angle opposite the base.

[0006] In addition to or in the alternative to one or more of the above features, further embodiments may include a central tube circumferentially surrounded by a grooved porous medium, with two opposing side walls and each of the plurality of grooves extending from a radially inner side of the grooved porous medium disposed proximate the central tube to a radially outer side of the grooved porous medium.

[0007] In addition to or as an alternative to one or more of the above features, further embodiments may include the apex angle on the radially inner side being equivalent to the apex angle on the radially outer side.

[0008] In addition to or as an alternative to one or more of the above features, further embodiments may include the apex angle remaining constant along each of the plurality of grooves from the radially inner side to the radially outer side.

[0009] In addition to or as an alternative to one or more of the above features, further embodiments may include the apex angle on the radially inner side being greater than the apex angle on the radially outer side.

[0010] In addition to or in place of one or more of the above features, further embodiments may include the apex angle decreasing along each of the plurality of grooves from the radially inner side to the radially outer side.

[0011] In addition to or as an alternative to one or more of the above features, further embodiments may include the apex angle on the radially inner side being smaller than the apex angle on the radially outer side.

[0012] In addition to or as an alternative to one or more of the above features, further embodiments may include an apex angle that increases along each of the plurality of grooves from the radially inner side to the radially outer side.

[0013] In addition to or in the alternative to one or more of the above features, further embodiments may include the apex angle being less than or equal to two times the sum of the angles less than 90° minus the solid-liquid contact angle of the working fluid.

[0014] In addition to or in the alternative to one or more of the above features, further embodiments may include the reservoir further comprising a tubular housing, a reservoir dome, and a filter housing sandwiched between the reservoir dome and the tubular housing, wherein the grooved porous media is disposed within the tubular housing.

[0015] In addition to or as an alternative to one or more of the above features, further embodiments may include the base connector housing further including a fluid passage fluidly connected to the inlet of the inlet port. The gas trap assembly further includes a transfer tube fluidly connecting the fluid passage to the central tube.

[0016] In addition to or as an alternative to one or more of the above features, further embodiments may include the central tube being fluidly connected to a gas storage space within the reservoir dome.

[0017] In addition to or as an alternative to one or more of the above features, further embodiments may include the transfer tube being disposed within and separated from an internal cavity of the transfer housing, the internal cavity being separated from the gas storage space by a grooved porous medium.

[0018] According to another embodiment, a component assembly for a gas trap assembly is provided. The component assembly includes a central tube and a grooved porous medium circumferentially surrounding the central tube. The grooved porous medium is constructed from a material containing a plurality of grooves and a plurality of pores of a selected size. The plurality of grooves and the plurality of pores are configured to prevent gas from passing through the grooved porous medium.

[0019] In addition to or as an alternative to one or more of the above features, further embodiments may include each of the plurality of grooves being defined as being formed by two opposing sidewalls that form a base and an apex with an apex angle measured between the two opposing sidewalls at the apex, wherein the working fluid in each of the plurality of grooves moves from the base to the apex and the gas in each of the plurality of grooves moves from the apex to the base.

[0020] In addition to or as an alternative to one or more of the above features, further embodiments may include each of the plurality of grooves being formed by two opposing sidewalls, the two opposing sidewalls forming a base and an apex with an apex angle opposite the base.

[0021] In addition to or as an alternative to one or more of the above features, further embodiments may include the grooved porous media further comprising a radially inner side of the grooved porous media disposed proximate the central tube and a radially outer side of the grooved porous media, wherein each of the two opposing sidewalls and the plurality of grooves extends from the radially inner side to the radially outer side.

[0022] In addition to or as an alternative to one or more of the above features, further embodiments may include the apex angle on the radially inner side being equivalent to the apex angle on the radially outer side.

[0023] The foregoing features and elements may be combined in various non-exclusive combinations unless otherwise specified. These features and elements and their operation will become more apparent in light of the following description and accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and not limiting. [Brief explanation of the drawings]

[0024] The following description should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numbered alike. [Figure 1] FIG. 1 is an isometric view of a gas trap assembly according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the gas trap assembly of FIG. 1 according to one embodiment of the present disclosure. [Figure 3] FIG. 2 is a cross-sectional isometric view of the gas trap assembly of FIG. 1 according to one embodiment of the present disclosure. [Figure 4] FIG. 2 is an isometric view of a grooved porous media for use in the gas trap assembly of FIG. 1 according to one embodiment of the present disclosure. [Figure 5] FIG. 2 is an isometric view of unfluted porous media previously used in prior designs of the gas trap assembly of FIG. 1. [Figure 6] FIG. 5 is a schematic diagram of the dimensions of the grooved porous media of FIG. 4 according to one embodiment of the present disclosure. [Figure 7] FIG. 5 is a schematic diagram of liquid and gas movement within the grooves of the grooved porous media of FIG. 4 according to one embodiment of the present disclosure. [Figure 8] FIG. 10 is a diagram of a groove with a constant apex angle according to one embodiment of the present disclosure. [Figure 9] FIG. 10 is a diagram of a groove having an apex angle that increases radially outward, according to one embodiment of the present disclosure. [Figure 10] FIG. 10 is a diagram of a groove having a radially outward decreasing apex angle according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0025] A detailed description of one or more embodiments of the disclosed apparatus and methods is presented herein by way of example, and not limitation, with reference to the drawings.

[0026] In a single-phase flow loop, a liquid-phase working fluid circulates through the system for various purposes. Due to corrosion, material compatibility, and various other reasons, gases may be generated within the system and enter the liquid flow of the working fluid. If the generated gas enters the suction side of the pump, it can damage the pump or cause the system to fail.

[0027] In a gravity field, gas bubbles flowing with the liquid flow can coalesce at high points in the flow loop due to buoyancy forces. The locations where the bubbles accumulate can be identified with reasonable accuracy. However, in a microgravity field, the gas bubbles flow with the liquid flow and can be anywhere. The embodiments disclosed herein aim to separate the gas from the liquid flow and confine the gas to a known location in both terrestrial and microgravity fields.

[0028] Referring now to FIG. 1 , an isometric view of a gas trap assembly 100 is illustrated, according to one embodiment of the present disclosure. The gas trap assembly 100 includes a base connector housing 110, a reservoir 130, and a vent and sampling port 120. The base connector housing 110 includes an inlet port 112 and an outlet port 116. The outlet port 116 may be located opposite the inlet port 112. The reservoir 130 fluidly connects the inlet port 112 to the outlet port 116. The reservoir 130 is sandwiched between the inlet port 112 and the outlet port 116, allowing a working fluid 200 to flow from the inlet port 112 through the reservoir 130 to the outlet port 116. The reservoir 130 is comprised of a tubular housing 136, a reservoir dome 132, and a filter housing 140. The filter housing 140 is sandwiched between the reservoir dome 132 and the tubular housing 136, as illustrated in FIG. 1 . The vent and sampling port 120 is attached to the reservoir dome 132. The tubular housing 136 is attached to the base connector housing 110. The filter housing 140 is attached to the tubular housing 136, and the reservoir dome 132 is attached to the filter housing 140.

[0029] With continuing reference to FIG. 1 , and now with reference to FIGS. 2 and 3 , a cross-sectional view of a gas trap assembly 100 is illustrated in accordance with one embodiment of the present disclosure. The base connector housing 110 includes an inlet 113 disposed within an inlet port 112, allowing a working fluid 200 to enter the gas trap assembly 100. The working fluid 200 may be accompanied by gas 210 in the form of bubbles. The inlet 113 is fluidly connected to a fluid passage 115 disposed within the base connector housing 110. The fluid passage 115 may include a right-angle bend, as illustrated in FIGS. 2 and 3 , thereby fluidly connecting the inlet 113 to a transfer tube, which is disposed at 90° relative to one another. The fluid passage 115 is fluidly connected to a transfer tube 134 disposed within a tubular housing 136. The transfer tube 134 is attached to the fluid passage 115 to form a sealed connection 117. The working fluid 200 flows from the fluid passage 115 in the base connector housing 110 to the transfer tube 134 in the tubular housing 136. The transfer tube 134 is fluidly connected to the central tube 142. The working fluid 200 flows from the transfer tube 134 to the central tube 142 and then to the gas storage space 138 in the reservoir dome 132. The working fluid 200 and the gas 210 are forced to flow in opposite directions and through the grooved porous media 150. In other words, the working fluid 200 and the gas 210 are forced to turn 180 degrees upon leaving the central tube 142 in order to reach the grooved porous media 150.

[0030] At this stage, the gas 210 is separated from the working fluid 200 by the grooved porous medium 150. The gas 210 is prevented from passing through the grooved porous medium 150 and is stored in the gas storage space 138 and occasionally vented through the vent and sampling port 120. The vent and sampling port 120 may be normally closed during operation, but can be opened for liquid sampling of the working fluid 200 or venting of the gas 210.

[0031] The grooved porous medium 150 is configured to separate the gas 210 from the working fluid 200 by creating a physical separation between the incoming and outgoing liquid streams, as discussed further herein.

[0032] In a terrestrial field (e.g., a gravity field), the bubbles of gas 210 move in a direction D1 opposite to the gravity field direction G1 due to buoyancy effects. The gravity field direction G1 points toward the base in Figures 2 and 3, and the trapped gas 210 in the gas storage space 138 moves away from the grooved porous medium 150 toward the vent and sampling port 120, allowing this gas to be vented whenever necessary.

[0033] In a microgravity environment, the distribution of the gas 210 bubbles is random. The gas 210 bubbles may be forced against the surface of the grooved porous medium 150 by the momentum of the liquid flow. To avoid accumulation of the gas 210 bubbles on the surface of the grooved porous medium 150 adjacent to the gas storage space 138, the gas 210 bubbles are vented from the grooved porous medium 150 as discussed herein with reference to FIG. 7 .

[0034] The working fluid 200 travels through the grooved porous medium 150 and into the internal cavity 139 within the tubular housing 136. As shown in Figures 2 and 3, the transfer tube 134 is disposed within the internal cavity 139 but is separate from it. The only fluid path between the internal cavity and the tube 134 is through the grooved porous medium 150. The transfer tube 134 passes through the center of the internal cavity 139. The internal cavity 139 is separated from the gas storage space 138 of the reservoir dome 132 by the grooved porous medium 150.

[0035] The internal cavity 139 of the tubular housing 136 is fluidly connected to the internal cavity 119 of the base connector housing 110. The working fluid 200 flows from the internal cavity 139 of the tubular housing 136 to the internal cavity 119 of the base connector housing 110. The internal cavity 119 of the base connector housing 110 is fluidly connected to an outlet 111 of the base connector housing 110 located at the outlet port 116. The working fluid 200 flows from the internal cavity 119 of the base connector housing 110 through the outlet 111 and exits the gas trap assembly 100.

[0036] 4 and 5, with continuing reference to Figures 1-3, an isometric view of a grooved porous medium 150 according to an embodiment of the present disclosure is illustrated in Figure 4, along with an isometric view of an ungrooved porous medium 150a used in a prior design of a gas trap assembly. As illustrated in Figure 5, the ungrooved porous medium 150a is flat and therefore does not offer the same advantages as the grooved porous medium 150, as discussed herein.

[0037] The grooved porous medium 150 circumferentially surrounds the central pipe 142. The grooved porous medium 150 and the central pipe 142 may form a component assembly for the gas trap assembly 100. The grooved porous medium 150 is circular in shape and includes a radially inner side 154 and a radially outer side 156 disposed adjacent to the central pipe 142. The grooved porous medium 150 extends from the radially inner side 154 disposed adjacent to the central pipe 142 to the radially outer side 156. The grooved porous medium 150 includes a plurality of grooves 152. The grooved porous medium 150 is constructed from a material having a plurality of pores for passing particles of a selected size. The grooved porous medium 150 may be constructed from a metal sintered powder, a multi-layer screen mesh, felt, or any other similar material known to one skilled in the art. The pores have a pore size. The pore size may range from a few micrometers to several hundred micrometers. The grooved porous medium 150 fluidly divides the reservoir 130 into two portions (e.g., before the grooved porous medium 150 and after the grooved porous medium 150) such that the working fluid 200 flowing from the inlet port 112 to the outlet port 116 must flow through the multiple grooves 152 and multiple pores of the grooved porous medium 150.

[0038] Each of the grooves 152 has the same shape as the other grooves 152 and is directly adjacent to its neighboring groove 152. Furthermore, each of the grooves 152 is formed by two opposing sidewalls 151, such as a first opposing sidewall 151 and a second opposing sidewall 151. The two opposing sidewalls 151 taper toward each other to form a base 153 and an apex 155. Advantageously, the grooves 152 provide the grooved porous medium 150 with an increased surface area, which allows the grooved porous medium 150 to filter the working fluid 200 more quickly than the non-grooved porous medium 150a. Advantageously, the grooved porous medium 150 also allows the working fluid 200 to flow through the grooved porous medium 150 with a lower pressure drop.

[0039] When a gas-rich liquid (e.g., working fluid 200 and gas 210) flows into the grooved porous media 150, only gas 210 bubbles smaller than the pore size of the grooved porous media 150 can flow through. Gas 210 bubbles larger than the pore size are blocked and stored in the gas storage space 138. Controlling the pore size of the grooved porous media 150 controls the size of the gas 210 bubbles that flow into the suction pump, which is fluidly connected to the outlet 111 of the outlet port 116. To prevent the gas 210 bubbles from leaking around the grooved porous media 150, the interfaces between the grooved porous media 150 and the inner wall of the filter housing 140 and between the grooved porous media 150 and the central tube 142 are created so that the maximum allowable gap is smaller than the pore size of the grooved porous media 150.

[0040] 6 and 7, with continuing reference to FIGS. 1-5, schematic diagrams of grooves 152 according to embodiments of the present disclosure are illustrated. In a microgravity environment, working fluid 200 moves from base 153 toward apex 155, and gas 210 is pushed from apex 155 toward base 153 by working fluid refilling groove 152 toward apex 155 when half of apex angle 250 is less than the difference between a right angle (i.e., 90°) and the solid-liquid contact angle. Solid-liquid contact angles can vary for different liquids and thus depend on the type of working fluid 200 utilized. The disclosed embodiments may be applicable to any solid-liquid pair as long as the liquid can "wet" the solid material, in other words, as long as the solid-liquid contact angle is less than 90°.

[0041] The apex 155 has an apex angle 250 measured between the two opposing sidewalls 151. In one embodiment, the apex angle 250 is equal to a selected angle of 2β, where β is less than 90° minus the liquid-solid contact angle. In other words, the selected angle of 2β is equal to 2×((β<90)−liquid-solid contact angle). In other words, the selected angle 2β is less than or equal to twice the sum of the angles less than 90° minus the liquid-solid contact angle of the working fluid 200. That is, the apex angle 250 is defined such that for a fluid flow of working fluid 200 and gas 210 moving through one of the channels 140 in a microgravity environment where one portion of the fluid flow is in a liquid phase (e.g., working fluid 200) and another portion of the fluid flow is in a gas phase (e.g., gas), the liquid phase (e.g., working fluid 200) portion of the fluid flow within a particular groove 152 moves from the base 153 to the apex 155 within the particular groove 152, and the gas phase (e.g., gas) portion of the fluid flow within a particular groove 152 moves from the apex 155 to the base 153 within the particular groove 152.

[0042] With continuing reference to Figures 1-7, and now referring to Figures 8, 9, and 10, an apex angle 250 of a grooved porous media 150 according to an embodiment of the present disclosure is illustrated.

[0043] Apex angle 250 is measured between two opposing sidewalls 151 at apex 155. Opposing sidewalls 151 and each of the plurality of grooves 152 extend from a radially inner side 154 to a radially outer side 156.

[0044] In one embodiment, as illustrated in Figure 8, the apex angle 250 at the radially inner side 154 may correspond to the apex angle 250 at the radially outer side 156. In Figure 8, the apex angle 250 at the radially inner side 154 corresponds to 2β, and the apex angle 250 at the radially outer side 156 corresponds to 2β. In Figure 8, the apex angle 250 remains constant or unchanged along the groove 152 from the radially inner side 154 to the radially outer side 156.

[0045] 9 and 10, the apex angle 250 at the radially inner side 154 may not be equal to the apex angle 250 at the radially outer side 156. The apex angle 250 may vary in size along the groove 152 from the radially inner side 154 to the radially outer side 156.

[0046] In one embodiment, as shown in Figure 9, the apex angle 250 at the radially inner side 154 may be smaller than the apex angle 250 at the radially outer side 156. In Figure 9, the apex angle 250 at the radially inner side 154 corresponds to 2α, and the apex angle 250 at the radially outer side 156 corresponds to 2β. In Figure 9, the apex angle 250 increases in size along the groove 152 from the radially inner side 154 to the radially outer side 156.

[0047] In one embodiment, as shown in Figure 10, the apex angle 250 at the radially inner side 154 may be greater than the apex angle 250 at the radially outer side 156. In Figure 10, the apex angle 250 at the radially inner side 154 corresponds to 2β, and the apex angle 250 at the radially outer side 156 corresponds to 2γ. In Figure 10, the apex angle 250 decreases in size along the groove 152 from the radially inner side 154 to the radially outer side 156.

[0048] Technical effects and advantages of the features described herein include utilizing grooved porous media to filter gas bubbles from a working fluid in both microgravity and terrestrial environments.

[0049] A detailed description of one or more embodiments of the disclosed apparatus and methods is presented herein by way of example, and not limitation, with reference to the drawings.

[0050] The term "about" is intended to include the degree of error associated with measurement of the particular quantity based on equipment available at the time of filing.

[0051] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0052] While the present disclosure has been described with reference to exemplary embodiment(s), those skilled in the art will recognize that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope of the present disclosure. Therefore, it is not intended that the present disclosure be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the disclosure, but rather that the present disclosure will include all embodiments falling within the scope of the appended claims.

Claims

1. a base connector housing having an inlet port and an outlet port; a reservoir fluidly connecting the inlet port to the outlet port; a fluted porous medium disposed within the reservoir, the fluted porous medium comprising a plurality of channels and constructed from a material having a plurality of pores of a selected size; a central pipe circumferentially surrounded by the grooved porous medium, the grooved porous medium fluidly divides the reservoir into two portions such that working fluid flowing from the inlet port to the outlet port must flow through the plurality of grooves and the plurality of pores of the grooved porous medium; the plurality of grooves and the plurality of pores are configured to prevent gas from passing through the grooved porous medium; each of the plurality of grooves is formed by two opposing sidewalls that form a base and an apex with an apex angle measured between the two opposing sidewalls at the apex; the two opposing side walls and each of the plurality of grooves extend from a radially inner side of the grooved porous medium disposed adjacent to the central pipe to a radially outer side of the grooved porous medium; The reservoir comprises: a tubular housing; a reservoir dome having a gas storage space for storing gas separated from the working fluid by the grooved porous medium, the reservoir dome being connected to a vent and a sampling port; a filter housing sandwiched between the reservoir dome and the tubular housing; the grooved porous medium is disposed within the filter housing so as to be disposed adjacent to the gas storage space; Gas trap assembly.

2. The working fluid in each of the plurality of grooves moves from the base to the apex, The gas trap assembly of claim 1 , wherein the gas in each of the plurality of grooves is defined to travel from the apex to the base.

3. 2. The gas trap assembly of claim 1, wherein the apex angle on the radially inner side is equal to the apex angle on the radially outer side.

4. 2. The gas trap assembly of claim 1, wherein the apex angle remains constant along each of the plurality of grooves from the radially inner side to the radially outer side.

5. 2. The gas trap assembly of claim 1, wherein the apex angle on the radially inner side is greater than the apex angle on the radially outer side.

6. 2. The gas trap assembly of claim 1, wherein the apex angle decreases along each of the plurality of grooves from the radially inner side to the radially outer side.

7. 2. The gas trap assembly of claim 1, wherein the apex angle on the radially inner side is smaller than the apex angle on the radially outer side.

8. 2. The gas trap assembly of claim 1, wherein the apex angle increases along each of the plurality of grooves from the radially inner side to the radially outer side.

9. 2. The gas trap assembly according to claim 1, wherein the apex angle is equal to or less than two times the sum of an angle smaller than 90 degrees minus a solid-liquid contact angle of the working fluid.

10. the base connector housing further comprising a fluid passageway fluidly connected to the inlet of the inlet port; The gas trap assembly of claim 1 , further comprising a transfer tube fluidly connecting the fluid passage to the central tube.

11. The gas trap assembly of claim 10 , wherein the central pipe is fluidly connected to a gas storage space within the reservoir dome.

12. 12. The gas trap assembly of claim 11, wherein the transfer tube is disposed within and separated from an internal cavity of the tubular housing, the internal cavity being separated from the gas storage space by the grooved porous media.

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