Coalescing filter element and filter assembly therefore

Abstract

A coalescing filter element provides an integrated filter element with a three stage design with a hydrophobic or hydrophilic coalescing layer. A coalescing filter element comprises: a) At least one particulate filtration layer; b) A coalescing layer promoting coalescing of water particles, wherein the coalescing layer is downstream of the at least one particulate filtration layer relative to the flow of fluid through the element; c) An annular coalescing space downstream of the coalescing layer; d) A sump in a lower portion of the filter element in fluid communication with the annular coalescing space; and e) A hydrophobic layer downstream of the annular coalescing space, wherein fluid being cleaned by the element flows through the hydrophobic layer. The coalescing layer may be a hydrophobic or a hydrophilic coalescing layer. A filter assembly will include the coalescing filter element of the present invention.

Claims

1. A coalescing filter element comprising a) At least one particulate filtration layer; b) A coalescing layer promoting coalescing of water particles, wherein the coalescing layer is downstream of the at least one particulate filtration layer relative to the flow of fluid through the element; c) An annular coalescing space downstream of the coalescing layer; d) A sump in a lower portion of the filter element in fluid communication with the annular coalescing space; e) A hydrophobic layer downstream of the annular coalescing space, wherein fluid being cleaned by the element flows through the hydrophobic layer, wherein the filter element is an inside out flow design, and wherein the filter element includes a lower end cap and an intermediate end cap on opposite sides of the sump, wherein the filter element includes an upper end cap and wherein each of the particulate filtration layers and the coalescing layer extend between the upper end cap and the intermediate end cap, wherein the hydrophobic layer downstream of the annular coalescing space extends between the upper end cap and the lower end cap, and further including a spacing support tube between the annular coalescing space and the hydrophobic layer which is downstream of the annular coalescing space.

2. The coalescing filter element according to claim 1 wherein the coalescing layer promoting coalescing of water particles is formed as a hydrophobic material.

3. The coalescing filter element according to claim 2 wherein the coalescing layer is formed in annular corrugated pack with the at least one particulate filter layer.

4. The coalescing filter element according to claim 1 wherein the coalescing layer promoting coalescing of water particles is formed as a hydrophilic material.

5. A coalescing filter assembly comprising: At least one filter housing; An end cap for each filter housing; and a Coalescing filter element in at least one filter housing, the coalescing filter element including a) At least one particulate filtration layer; b) A coalescing layer promoting coalescing of water particles, wherein the coalescing layer is downstream of the at least one particulate filtration layer relative to the flow of fluid through the element; c) An annular coalescing space downstream of the coalescing layer; d) A sump in a lower portion of the filter element in fluid communication with the annular coalescing space; e) A hydrophobic layer downstream of the annular coalescing space, wherein fluid being cleaned by the element flows through the hydrophobic layer, wherein the coalescing filter element is an inside out flow design, wherein the coalescing filter element includes a lower end cap and an intermediate end cap on opposite sides of the sump, wherein the coalescing filter element includes an upper end cap and wherein each of the particulate filtration layers and the coalescing layer extend between the upper end cap and the intermediate end cap, wherein in the coalescing filter element the hydrophobic layer downstream of the annular coalescing space extends between the upper end cap and the lower end cap, and wherein in the coalescing filter element a spacing support tube is between the annular coalescing space and the hydrophobic layer which is downstream of the annular coalescing space.

6. The coalescing filter assembly according to claim 5 wherein in the coalescing filter element the coalescing layer promoting coalescing of water particles is formed as a hydrophobic material.

7. The coalescing filter assembly according to claim 6 wherein in the coalescing filter element the coalescing layer is formed in annular corrugated pack with the at least one particulate filter layer.

8. The coalescing filter assembly according to claim 5 wherein in the coalescing filter element the coalescing layer promoting coalescing of water particles is formed as a hydrophilic material.

9. The coalescing filter assembly according to claim 5 wherein two filter housing are provided coupled in series with a particulate filter element located in an upstream housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a schematic section view of a hydrophobic coalescing filter element according to one embodiment of the present invention;

(2) FIG. 1B is an enlarged view of the hydrophobic coalescing filter element of FIG. 1A;

(3) FIG. 2A is a schematic section view of a hydrophilic coalescing filter element according to one embodiment of the present invention;

(4) FIG. 2B is an enlarged view of the hydrophilic coalescing filter element of FIG. 2A;

(5) FIG. 3 is a schematic plan section view which is partially exploded of the hydrophobic media layer of the hydrophobic coalescing filter element of FIGS. 1A and 1B;

(6) FIGS. 4A-D are front, side, top and bottom views of an inline bulk fuel coalescing filter assembly using the coalescing filter elements of the present invention;

(7) FIGS. 5A-B are side and top views of a diesel skid filter assembly with a coupled pre-filter assembly and using the coalescing filter elements of the present invention; and

(8) FIG. 6 is a side view of an inline bulk fuel coalescing filter assembly using the coalescing filter elements of the present invention.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) This invention is directed to a cost effective, efficient, coalescing filter element and coalescing filter assembly. The invention provides an integrated filter element with a three stage design with a hydrophobic or hydrophilic coalescing layer.

(10) It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent.

(11) For the purposes of this specification, unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

(12) Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

(13) FIGS. 1A and B are schematic section views of a hydrophobic coalescing filter element 10 according to one embodiment of the present invention which provides a three stage, single element design with a hydrophobic coalescing layer. The coalescing element features a particulate filtration layer, coalescing layer and separation layer within one element.

(14) The element 10 is an inside-out flow design where fluid enters the element 10, via inlet 12 in the bottom end cap 14 and along centering tube 16, through the inner core and flows through each layer before it exits around the perimeter of the element 10. The primary application of this element 10 is for liquid-liquid separation of a dispersed phase, water, and a continuous phase, hydrocarbon oil or fuel oil.

(15) Summary Of Operation

(16) For simplicity sakes, the continuous/dispersed phase mixture will be referred to as the mixture. The dispersed phase will be referred to as water and the continuous phase will be referred to as fuel. The mixture enters the coalescing element 10 through the inlet 12, in FIGS. 1A and B, in the lower end cap 14 and extends along centering tube 16 to enter the pleated pack 18. The centering tube 12 aligns the inner diameters of the bottom end cap 14 and the middle end cap 20 and defines the space of the sump 22.

(17) The pleated pack 18 and outer support wrap 26 extends between upper end cap 24 and the intermediate end cap 20. The pleated pack 18 is shown in greater detail in FIG. 3. The pleated pack 18 is formed of an inner or upstream mesh support 28, an adjacent scrim layer 30, a pre-filter media layer 32 and a main filter media layer 34. Adjacent the filter media or main layer 34 is a layer of hydrophobic material 36 followed by a downstream supporting mesh 38. A circular support wrap 26 surround the pleat pack 18 and extend between the upper end cap 24 and the intermediate end cap 20.

(18) The mixture first passes through pleated particulate filtration layers 32 and 34 of FIG. 3. These particulate filtration layers can be formed of conventional particulate filtration media and will retain contaminates that would otherwise collect on the coalescing layer 36 and prematurely degrade its performance. Both the particulate filtration layers 32 and 34 and the coalescing layer 36 are located within one pleated media pack 18.

(19) Next, following the particulate filter layers 32 and 34, the mixture encounters the coalescing layer 36. The coalescing layer 36 in this embodiment is a hydrophobic material which repels smaller water droplets causing them to build on the surface rather than pass through. As these water droplets build up on the surface of the hydrophobic material 36 they will contact each other and combine together. These water droplets will eventually become big enough to be pushed through by the fluid velocity.

(20) Once through, the coalesced water drops will enter the gravity separation space 39 adjacent support tube 40 which can also be described as forming an annular coalescing flow channel 39. The layer 40 extends from end cap 24 to lower end cap 14 as shown in FIGS. 1A and B. Since the larger water droplets have a higher specific gravity than the fuel, gravity will cause the larger coalesced droplets to fall downward in channel 39 to the sump region 22 of the element 10 between the lower end cap 14 and the intermediate end cap 20.

(21) Coalesced water in the sump region 22 will then be allowed to flow out the element 10 through drain holes 42 in lower end cap 11.

(22) Finally, any water droplets located in the gravity separation region 39 defined by layer or support tube 40 will be impeded from exiting the element 10 through the perimeter by a hydrophobic separation layer 44. The separation layer 44 is made of a hydrophobic material. Exiting through the perimeter of the element 10 through outer support wrap or layer 46 will be clean fuel with un-dissolved water removed. The separation layer 44 is formed between an outer mesh support layer 46, also called an outer wrap or outer tube, and an inner support tube or layer 40 which all extend between the lower end cap 14 and the upper end cap 24. The support tubes or layers 40 and 46 are perforated support tubes providing support to the element 10 and protection of the separation layer 44. The separation support layer assembly thus includes a perforated support tube 40 that prevents the separation layer 44 from contacting the coalescing region 39 between layer 40 and the layer 26 which could decrease the gravity separation region effective area or allow for “wicking” of water droplets through the separation layer 46 and out the perimeter of the element 10. Particulate Filtration/Coalescing Layer Support Wrap 26 includes a perforated wrap and provides support to the particulate filtration/coalescing layer 18.

(23) FIGS. 2A and B are schematic section views of a hydrophilic coalescing filter element 50 according to one embodiment of the present invention which provides a three stage, single element design with a hydrophilic coalescing layer. The coalescing element 50 features a particulate filtration layer, coalescing layer and separation layer within one element 50.

(24) The element 50 is also an inside-out flow design where fluid enters the element 50 through the inner core and flows through each layer before it exits around the perimeter of the element. The primary application of this element 50 is also for liquid-liquid separation of a dispersed phase, water, and a continuous phase, hydrocarbon oil or fuel oil. The element 50 is analogous to element 10 discussed above and common components are identified with common reference numerals and are described in detail above.

(25) Summary Of Operation

(26) For simplicity sakes, the continuous/dispersed phase mixture will again be referred to as the mixture. The dispersed phase will be referred to as water and the continuous phase will be referred to as fuel.

(27) The mixture enters the coalescing element 50 through the inlet 12 of lower end cap 14 and through centering tube 16. The mixture first passes through pleated particulate filtration layer 52 and associated support tube 54. This particulate filtration layer 52 retain contaminates that would otherwise collect on the coalescing layer 56 and degrade its performance. The filtration layer operates analogously to layers 32 and 34 of pack 18 of element 10 above.

(28) Next the mixture encounters the coalescing layer 56. The coalescing layer 56 is a hydrophilic material which attracts smaller water droplets causing them to be absorbed. As these water droplets build up within the hydrophilic material of layer 56 they will contact each other and combine together. These water droplets will eventually become big enough to be pushed through by the fluid velocity.

(29) Once through, the coalesced water drops will enter the gravity separation area 39 between layer 56 and layer 40. Since the larger water droplets have a higher specific gravity than the fuel, gravity will cause the coalesced droplets to fall downward in channel 39 to the sump region 22 of the element 50.

(30) Coalesced water in the sump region 22 will then be allowed to flow out the element 50 through drain holes 42. Finally, any water droplets located in the gravity separation region 39 between layer 56 and layer 40 will be impeded from exiting the element 50 through the perimeter by a separation layer 44. The separation layer 44 as noted above is made of a hydrophobic material. Exiting through the perimeter of the element 50 will be clean fuel with un-dissolved water removed.

(31) The main difference between the embodiments of FIGS. 1a and b and 2a and b is the use of hydrophilic material 56 rather than hydrophobic material 36 in pack 18 and the associated change in the method of operation. Additionally a support tube 26 formed as a perforated tube provides support to the particulate filtration/coalescing layer pack 18 in the embodiment of FIGS. 1A and B and particulate filter layer 52 is separate from the hydrophilic material 56 in the embodiment of FIGS. 2A and B. The embodiment of FIG. 1 could include the separate particulate filter configuration of FIG. 2 while the construction of FIG. 2 could be combined into a pack construction analogous to FIG. 1.

(32) FIGS. 4A-D are front, side, top and bottom views of an inline bulk fuel coalescing filter assembly 60 using one of the coalescing filter elements 10 and/or 50 of the present invention. The coalescing filter assembly 60 includes a filter housing 62 and end cap. The end cap 64 may be easily formed as a K9™ brand end cap available from the assignee of the present application. The assembly 60 utilizes the three-phase element construction for high efficiency, single-pass removal of un-dissolved water in diesel fuels. The assembly 60 can be can be upstream (suction side) or downstream (pressure side) of transfer pumps to protect expensive, vital engine components against failures caused by water contaminated fuel. The coalescing filter assembly 60 can separate emulsified or finely dispersed water from fuel and allows for use in single-pass fuel dispensing or multi-pass reservoir clean-up and continuous maintenance. In operation the assembly 60 has greater than 99.5% efficiency at removing un-dissolved water in a single pass.

(33) The details can be summarized in the following specification listing for the assembly 60: Flow rating of Up to 70 gpm (265 L/min) for ULSD15; Max. Operating Pressure: 100 psi (7 bar); 45 psi (3 bar) with water sight gauge; Min. Yield Pressure: 400 PSI (27.6 bar) without sight gauge; Temperature range: −20° F. to 165° F. (−29° C. to 74° C.); and Weight: 155 Lbs. (77 kg).

(34) FIGS. 5A-B are side and top views of a diesel skid filter assembly 70 with a coupled pre-filter assembly 72 and an assembly 60 using the coalescing filter elements 10 or 50 of the present invention. The assembly 70 of FIGS. 5A and B couples two assemblies 72 and 60 in series with the first assembly 72 using a particulate filter element (not shown, but available from the assignee). The K9™ modular end caps 64 allow for easy coupling of the two assemblies 72 and 60 in series. The second downstream assembly 60 uses the three stage coalescing filter element 50 or 10 of the invention.

(35) FIG. 6 is a side view of an inline bulk fuel coalescing filter assembly 80 using the coalescing filter elements 50 or 10 of the present invention in a slightly different embodiment. Namely the inlet to the assembly 80 is through the upper end cap 82 for this assembly and is illustrated to show the modifications of the present invention. The operating parameters of this assembly 80, for comparison, are as follows: Flow rating of Up to 16 gpm (60 L/min) for ULSD15; Max. Operating Pressure: 100 psi (7 bar); Min. Yield Pressure: 400 PSI (27.6 bar); Temperature range: −20° F. to 165° F. (−29° C. to 74° C.); and Weight: 19 lbs (8.6 kg).

(36) The preferred embodiments described above are illustrative of the present invention and not restrictive hereof. It will be obvious that various changes may be made to the present invention without departing from the spirit and scope of the invention. The precise scope of the present invention is defined by the appended claims and equivalents thereto.