CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Patent Application No. 63/312,449, filed on February 22, 2022, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to filter assemblies. More specifically, the present disclosure relates to filter assemblies for dielectric fluid.

BACKGROUND

[0003] Data centers house information technology (IT) equipment for the purposes of storing, processing, and disseminating data and applications. IT equipment may include electronic devices, such as servers, storage systems, power distribution units, routers, switches, and firewalls.

[0004] IT equipment consumes electricity and produces waste heat as a byproduct. A data center housing many servers may require a dedicated IT cooling system to manage waste heat. If the waste heat is not removed from the data center, ambient temperature within the data center may rise above an acceptable threshold and temperature-induced performance throttling of electronic devices (e.g., microprocessors) may occur, which is undesirable.

[0005] Direct liquid cooling systems can be used to capture and remove waste heat from IT equipment. One form of direct liquid cooling is immersion cooling. In an immersion cooling system, an electronic device is immersed in a dielectric fluid. Waste heat from the electronic device is transferred to the dielectric fluid and then rejected outside the data center through a heat rejection system. Examples of immersion cooling systems include single-phase immersion cooling systems and two-phase immersion cooling systems.

[0006] Filtering the dielectric fluid is desirable to extend the useful life of the fluid and protect the IT equipment from exposure to contaminants or impurities that may be present in the fluid.

SUMMARY

[0007] In one aspect, a filter assembly for dielectric fluid may include a filter body having an inlet and an outlet. The filter assembly may include a first compartment located between the inlet and the outlet. The filter assembly may include a second compartment located between the first compartment and the outlet. The filter assembly may include a diffuser located between the inlet and the first compartment. The filter assembly may include a flow distributing structure located between the diffuser and the first compartment. The flow distributing structure is positioned along a centerline of the inlet and is configured to distribute dielectric fluid entering the filter assembly in at least two diverging directions. The filter assembly may include a carbon filter material in the first compartment. The carbon filter material may be contained in a removable packet or cartridge. The filter assembly may include an alumina filter material in the second compartment. The alumina filter material may be contained in a removable packet or cartridge. The flow distributing structure may be a hydrofoil. The flow distributing structure may include a fin or groove.

[0008] In another aspect, a filter assembly for dielectric fluid may include a filter body having an inlet and an outlet. The filter assembly may include a first compartment located between the inlet and the outlet. The first compartment may be configured to receive a first filter material. The filter assembly may include a second compartment located between the first compartment and the outlet. The second compartment may be configured to receive a second filter material. The filter assembly may include a flow distributing structure located between the inlet and the first compartment. The flow distributing structure may be intersected by a centerline of the inlet. The filter assembly may include a perforated plate located between the inlet and the first compartment. The filter assembly may include a diffuser located between the inlet and the first compartment. The flow distributing structure may be captured between the diffuser and the perforated plate. The filter assembly may include a perforated plate located between the first compartment and the second compartment. The filter assembly may include a perforated plate located between the second compartment and the outlet. The flow distributing structure may be a passive flow distributing structure having a wing shape.

[0009] In yet another aspect, a filter assembly for dielectric fluid may include a filter body having an inlet and an outlet. The filter assembly may include a first compartment located between the inlet and the outlet. The first compartment may include a first filter material. The filter assembly may include a second compartment located between the first compartment and the outlet. The second compartment may include a second filter material. A first gap may be provided between the first filter material and the second filter material. The filter assembly may include a flow distributing structure located between the inlet and the first compartment. An inlet flow pathway may intersect the flow distributing structure. The first filter material may include a carbon filter material, and the second filter material may include an alumina filter material. Alternately, the first filter material may include an alumina filter material, and the second filter material may include a carbon filter material. The first gap may be provided and maintained by a plurality of compression springs. A filter insert may be located between the first filter material and the plurality of compression springs. The filter assembly may include a perforated plate positioned between the first filter material and the second filter material. The perforated plate may include a recess, and a filter insert may be positioned in the recess. The filter insert may be sized to fit within and substantially cover the recess. The filter assembly may include a funnel located between the second compartment and the outlet. The filter assembly may include a perforated plate positioned between the second compartment and the funnel. The filter assembly may include a plurality of compression springs located between the second filter material and the perforated plate. The plurality of compression springs may provide and maintain a second gap within the filter assembly. [0010] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

BRIEF DESCRIPTION OF DRAWINGS

[0011] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention. In the following description, various embodiments are described with reference to the following drawings.

[0012] FIG. 1 shows a top perspective view of a filter assembly configured to filter dielectric fluid. [0013] FIG. 2 shows an exploded view of the filter assembly of FIG. 1 .

[0014] FIG. 2A shows an enlarged view of the perforated plate of FIG. 2.

[0015] FIG. 3 shows a top cross-sectional view of the filter assembly of FIG. 1 exposing a flow distributing structure, filter inserts, perforated plates, and a plurality of compression springs within the filter assembly.

[0016] FIG. 3A shows an exploded view of a portion of the filter assembly.

[0017] FIG. 4A shows a simplified flow field in the filter assembly of the FIG. 1 .

[0018] FIG. 4B shows a flow field in the filter assembly of FIG. 1 , as determined by a computational fluid dynamics model.

[0019] FIG. 5A shows a simplified flow field in the filter assembly of FIG. 1 without the flow distributing structure.

[0020] FIG. 5B shows a flow field in the filter assembly of FIG. 1 without the flow distributing structure, as determined by a computational fluid dynamics model.

[0021] FIG. 6A shows a flow distributing structure for use in the filter assembly of FIG. 1 .

[0022] FIG. 6B shows a flow distributing structure for use in the filter assembly of FIG. 1 .

[0023] FIG. 6C shows a flow distributing structure for use in the filter assembly of FIG. 1 . DETAILED DESCRIPTION

[0024] FIG. 1 shows a filter assembly 100. The filter assembly 100 may be configured to filter dielectric fluid. In some examples, the filter assembly 100 may be used to filter dielectric fluid in in an immersion cooling system, such as a single-phase or two-phase immersion cooling system. FIG. 2 shows an exploded view of the filter assembly 100. FIG. 3 shows a cross-sectional top view of the filter assembly 100, exposing components within the filter assembly 100.

[0025] The filter assembly 100 may include a filter body 150. The filter body 150 may include an inlet 110 and an outlet 115. The filter assembly 100 may be configured to receive dielectric fluid through the inlet 110. The dielectric fluid may then pass through one or more filter materials located within the filter body 150 and be expelled through the outlet 110. The filter assembly 100 may include one or more subcomponents, as described herein. Adjacent components may be joined by any suitable joining and sealing methods to provide liquid-tight connections. The filter assembly 100 may be disassembled to allow filter materials to be removed and replaced. As will be appreciated by reviewing the drawings and this disclosure, a first filter material may be removed from the filter assembly without disturbing a second filter material, and vice versa.

[0026] The filter assembly 100 may include a first compartment 101. The first compartment 101 may be configured to house a carbon filter material 119, as shown in FIGS. 3 and 3A. The carbon filter material 119 may be removable from the filter assembly 100 and replaceable. In one example, the carbon filter material 119 may be contained in a first filter packet. The first filter packet may be removable from the first compartment 101 and replaceable. In another example, the carbon filter material 119 may be in raw form. In yet another example, the carbon filter material may be stored in a cartridge. The carbon filter material 119 may be activated carbon. As used herein, the term “packet” may refer to a substantially flexible container made of one or more joined sheets of filter material. As used herein, the term “cartridge” may refer to a container that includes a combination of one or more rigid components (e.g., sheet metal) and one or more sections of filter material.

[0027] The filter assembly 100 may include a second compartment 102. The second compartment 102 may be configured to house an aluminum oxide (“alumina”) filter material 120, as shown in FIG. 3. The alumina filter material 120 may be removable from the filter assembly 100 and replaceable. In one example, the alumina filter material 120 may be contained in a second filter packet. The second filter packet may be removable from the second compartment 102 and replaceable.

[0028] The filter assembly 100 may include a diffuser 106 located proximate to the inlet 105. The diffuser 106 may serve as a front end of the filter body 150. As shown in FIG. 1 , the diffuser 106 may be located between the inlet 105 and the first compartment 101. The diffuser 106 may be configured to receive dielectric fluid from the inlet 110 and guide the dielectric fluid to the first compartment 101.

[0029] The filter assembly 100 may include a funnel 107 located proximate to the outlet 115. The funnel 107 may serve as a rear end of the filter body 150. As shown in FIGS. 2 and 3, the funnel 106 may be located between the second compartment 102 and the outlet 110. The funnel 107 may be attached (e.g., removably fastened) to the second compartment 102. The funnel 107 may collect dielectric fluid that is exiting the second compartment and direct the fluid to the outlet 110. [0030] The filter assembly 100 may include a passive flow distributing structure 200. The flow distributing structure 200 may be, for example, a hydrofoil, fin, or protrusion. The flow distributing structure 200 may be located in an inlet stream of dielectric fluid flowing from the inlet 105 to the first compartment 101. As shown in FIG. 3, the flow distributing structure 200 may be positioned along a centerline 130 of the inlet 105 and be configured to distribute fluid entering the filter assembly 100 in at least two diverging directions, as shown in FIGS. 4A and 4B. An inlet flow pathway may be collinear with the centerline 130 and may intersect the flow distributing structure 200.

[0031] FIG. 4A shows a simplified flow field 121 in which the flow distributing structure 200 serves to distribute the flow of dielectric fluid substantially equally across an entryway of the first compartment 101. FIG. 4B shows the flow field 121 , as determined by a computational fluid dynamics model, that reveals more complex flow behavior than FIG. 4A, particularly near the outlet 110. However, the flow field 121 in FIG. 4B confirms the beneficial effect of the flow distributing structure 200 in distributing the dielectric fluid more evenly across the entryway of the first compartment 101. By doing so, a larger percentage of the carbon filter material 119 is utilized to filter the dielectric fluid, which may improve efficiency and extend the useful life of the carbon filter material.

[0032] By contrast, FIG. 5A shows a simplified flow field 122 in a filter assembly without a flow distributing structure. The dielectric fluid enters the inlet 105 and proceeds along a flow field 122 that is concentrated in a central region of the carbon filter material. FIG. 5B shows the flow field 122 as determined by a computational fluid dynamics model, revealing a more complex flow behavior, but confirming that only a small percentage of the carbon filter material 120 participates in filtering the dielectric fluid.

[0033] By providing improved flow distribution across the carbon filter material 119, as shown in FIGS. 4A and 4B, the performance of the filter assembly 100 may be improved. It is therefore desirable to provide a flow distributing structure 200 near the inlet 105 of the filter assembly 100 to improve flow distribution within the filter assembly 100 and more effectively utilize the carbon filter material 119 provided therein.

[0034] FIG. 6A shows an example of a flow distributing structure 200 for use in the filter assembly 100. The flow distributing structure 200 may have a wing shape. In the examples shown in FIGS. 6A-6C, the flow distributing structure 200 may have a truncated wing shape. The flow distributing structure 200 may include a leading edge 205. The flow distributing structure 200 may include a first plurality of grooves 210 formed in a first end surface. The flow distributing structure 200 may include a second plurality of grooves 215 formed in a second end surface.

[0035] FIG. 6B shows an example of a flow distributing structure 200 for use in the filter assembly 100. The flow distributing structure 200 may include a leading edge 205. The flow distributing structure 200 may include a plurality of fins 220 extending outward from a side surface.

[0036] FIG. 6C shows an example of a flow distributing structure 200 for use in the filter assembly 100. The flow distributing structure 200 may include a leading edge 205. The flow distributing structure 200 may include a plurality of grooves 225 formed in a side surface. The grooves 225 may extend from the side surface to the leading edge 205 and encircle the flow distributing structure 200.

[0037] As shown in FIGS. 2 and 2A, the filter assembly 100 may include a perforated plate 109 located between the first compartment 101 and the second compartment 102. The perforated plate 109 may include a plurality of perforations 113 (i.e., openings) that allow dielectric fluid to flow through the first perforated plate 109. The perforated plate 109 may include a recess 118 (see FIG. 2A) configured to receive a filter insert 114, as shown in FIG. 3A. The filter insert 114 may be sized to fit in and substantially cover the recess 118. In some examples, the filter insert 114 may be cut from a sheet of filter material. As shown in FIG. 2A, the perforated plate 109 may have a surrounding flange 111 with a groove 112 formed therein. The groove 112 may be configured to receive a sealing member, such as an O-ring 112, that provides a liquid-tight seal between the perforated plate 109 the second compartment 102. Similarly, an opposing side of the perforated plate 109 may include a groove containing a sealing member that is configured to provide a liquid-tight seal between the perforated plate and the first compartment 101. As shown in FIG. 3, when installed, the filter insert 114 may be positioned between the perforated plate 109 and the alumina filter material 120.

[0038] As shown in FIG. 3A, the filter assembly 100 may include a filter insert 114 positioned between the carbon filter material 119 and the perforated plate 109. One or more compression springs 117 may be positioned between the filter insert 114 and the perforated plate 109. The compression springs 117 may serve to provide separation (i.e., a gap 160) between the carbon filter material 119 and the perforated plate 109, which may improve flow through the perforated plate 109 and/or keep the carbon filter material 119 in an intended location in the first compartment

101. When the filter assembly 100 is dry, the gap 160 may be filled with air. When the filter assembly 100 is in use (i.e., wet), the gap 160 may be filled with dielectric fluid. The compression springs 117 may have suitable stiffness to maintain the gap 160 even as fluid pressure and flow rate varies within the filter assembly 100 during use.

[0039] As shown in FIG. 2, the filter assembly 100 may include a perforated plate 122 located between the diffuser 106 and the first compartment 101. As shown in FIG. 3, a filter insert 114 may be located between the perforated plate 122 and the carbon filter material 119. As shown in FIG. 2, the flow distributing structure 200 may be positioned between the perforated plate 122 and the inlet 105. More specifically, the flow distributing structure 200 may be positioned between the perforated plate 122 and the diffuser 106. The flow distributing structure 200 may be attached to the perforated plate 122. In another example, the flow distributing structure 200 may be held in place (e.g., captured) between the diffuser 106 and the perforated plate 122.

[0040] As shown in FIG. 2, the filter assembly 100 may include a perforated plate 123 between the second compartment 102 and the funnel 107. The perforated plate 123 may include a plurality of perforations. As shown in FIG. 3, the filter assembly 100 may include a filter insert 114 positioned between the alumina filter material 120 and the perforated plate 124. A plurality of compression springs 117 may be provided between the filter insert 114 and the perforated plate 124. The compression springs 117 may serve to provide separation (i.e., a gap 161) between the alumina filter material 120 and the perforated plate 124, which may improve flow through the perforated plate 124 and/or keep the alumina filter material 120 in an intended location in the second compartment 102. When the filter assembly 100 is dry, the gap 161 may be filled with air. When the filter assembly 100 is wet, the gap 161 may be filled with dielectric fluid.

[0041] In the examples shown and described above, the carbon filter material 119 may be located in the first compartment 101 , and the alumina filter material 120 may be located in the second compartment 102. In another example, the alumina filter material 120 may be located in the first compartment 101 , and the carbon filter material 120 may be located in the second compartment

102.

[0042] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments, therefore, are to be considered in all respects illustrative rather than limiting the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.