SEPARATOR ARRANGEMENT FOR GAS/LIQUID SEPARATION HAVING INTEGRAL GROUNDING ARRANGEMENT ; APPARATUS AND METHOD This application is being filed as a PCT International Patent Application in the name of Donaldson Company, Inc., a U.S. national corporation and resident, (Applicant for all countries except US) and Brian Read, a U.S. resident and GB citizen (Applicant for US only), on 17 December 2003, designating all countries. Field of the Invention The present disclosure relates to gas/liquid separation. The disclosure particularly concerns serviceable separator arrangements for use in conducting gas/liquid separation. It also concerns apparatus and systems in which such separators are used, methods of operation and separation and methods of assembly. A particular, useful, application is as an air/oil separator for air compressors.
Background A variety of equipment types and systems utilize gas/liquid separation assemblies. Examples include: compressors and compressed air systems; and, industrial mist collectors. In general, such assemblies include a removable and replaceable (i.e., serviceable) separator unit, construction or arrangement. In some assemblies, a single serviceable separator element is used as the separator element construction. In general, operation involves directing a gas/liquid flow through the separator unit, i.e., through the various serviceable separator elements. Within the separator unit, liquid coalescing and drainage occurs. As a result, an entrained liquid concentration, within the gas stream, is reduced. Periodically, the serviceable elements are removed and replaced. In some systems, the serviceable elements include media pack components attached to a mounting plate assembly having a mounting flange. When installed, the mounting flange is trapped between a sidewall and a top cover, of a pressure vessel. Sealing between the mounting flange and the pressure vessel (and top cover), is generally provided by gasket material positioned on opposite surfaces
of the mounting flange. In some systems, the gasket material electrically insulates the serviceable separator element from the pressure vessel and top cover. To accommodate for this, in some instances conductive staples are driven through the gasket material to provide for electrical contact among: the mounting plate assembly; the pressure vessel; and, the top cover.
Summary of the Invention According to the present disclosure, a gas/liquid separator element is provided. The element generally includes a mounting plate assembly having a mounting flange section and a media pack mounting section. The mounting flange section comprises an electrically conductive material and has first and second opposite sides. The mounting flange section further includes an axially directed conductive portion thereon. Preferably the axially directed conductive portion is integral with a remainder of the mounting flange section. The gas/liquid separator element further includes a gasket arrangement. The gasket arrangement is preferably a compressible electrically insulating material positioned on opposite sides of the mounting plate assembly, as first and second gasket members. The integral axially directed conductive portion is sized to project outwardly from opposite sides of the mounting plate assembly, in the same general direction of the gaskets. The arrangement is configured so that when the gaskets are compressed during use, the integral, axially directed, conductive portion of the mounting flange section comes into electrically conductive (grounding) contact with equipment in which the gas/liquid separator element is positioned in use. A variety of arrangements are possible for the integral, axially directed, conductive portion. In one example shown, the mounting flange section is a generally planar annular ring; and, the integral, axially directed, conductive portion includes: a bead in that annular ring directed in one axial direction, and an edge of the annular ring directed in an opposite direction. A variety of materials can be utilized for the gasket arrangement.
Preferably a mold-in-place gasket arrangement is used. One example would be a thixotropic bead applied to opposite surfaces of the mounting flange section. An example of useable thixotropic material would be a compressible polyurethane bead.
In certain, preferred, arrangements, the non-compressed state of this gasket material is approximately twice as thick, axially, as a thickness of the direction of axial projection of the integral, axially directed, conductive portion in the same direction. Also provided are descriptions of gas/liquid separator assemblies, including a gas/liquid separator element according to the description. Further methods of assembly in use are provided.
Brief Description of the Drawings Fig. 1 is a top plan view of a gas/liquid separator assembly. Fig. 2 is a cross-sectional view taken along line A- A, Fig. 1, with the assembly depicted showing a serviceable separator element having a prior art shaped mounting plate assembly sealed therein. Fig. 3 is a fragmentary enlarged view of a portion of Fig. 2. Fig. 4 is a cross-sectional view taken along line A- A, Fig. 1, depicting the gas/liquid separation assembly with a serviceable separator element having a mounting plate assembly according to an embodiment of the present disclosure, mounted therein. Fig. 5 is an enlarged fragmentary view of a portion of the assembly depicted in Fig. 4. Fig. 6 is a cross-sectional view of a gas/liquid separator element component of the serviceable gas/liquid separator element depicted in Fig. 4. Fig. 7 is a mounting plate and seal combination, for the element of Fig. 6. Fig. 8 is a cross-sectional view of an alternate, useable, mounting plate assembly component, to the mounting plate assembly component depicted in the element of Fig. 6. Fig. 9 is a cross-sectional view analogous to Fig. 8, depicting the component of Fig. 8 with a mold-in-place sealing gasket thereon.
Detailed Description
I. General Background A component of typical of gas/liquid separator arrangements of the type of concern herein, is a removable and replaceable, i.e., serviceable, separator arrangement. The removable and replaceable (i.e., serviceable) separator arrangement generally includes at least one gas/liquid separator element (or separator element) that, in time (due to operation of the gas/liquid separator assembly) is removed and replaced during a servicing operation; hence the term "serviceable." Typically, each serviceable separator element includes a media pack, through which the gasses are passed. Each media pack typically includes layers or stages of media for conduct of coalescing and drain steps. Components of the media pack are typically mounted on a mounting flange arrangement. The mounting flange arrangement allows the serviceable separator element to be appropriately positioned in a gas/liquid separator assembly or arrangement, for use. Herein, gas/liquid separator assemblies or separator elements will be characterized or classified as either "in-to-out flow" or "out-to-in flow," depending on whether, in use, during gas flow through the media pack of each separator element, gas flow is directed from outside the serviceable separator element arrangement to an interior; or, from an interior of the serviceable separator element to an exterior. While the techniques described herein can be applied to either or both; many typical applications will be in association with out-to-in flow arrangements. Thus, the examples depicted in the drawings depict out-to-in flow arrangements. The principles described herein, with respect to gas/liquid separation, can be applied in many arrangements, with one type of typical application being as a gas/oil (specifically air/oil) separator for a compressor arrangement. Such an apparatus is generally adapted for operation with internal pressures on the order of at least about 60 psi (i.e., at least about 4.2 kilograms/sq. cm.), typically at least about 80 psi (i.e., at least about 5.6 kilograms/sq. cm.). Examples of use would be with compressors about 25 hp and up. Herein, some particular arrangements for air/oil separation in compressor systems are shown. The techniques and principles described herein can
be applied in a variety of systems, and in a variety of sizes, for use with a wide variety of equipment types and sizes (for example a variety of compressors). In some instances, the techniques described herein can be applied in other applications of gas/liquid separation; for example: in mist collector arrangements (air/liquid separators), such as industrial mist collectors; or, in air/water separators in compressed gas systems. Issues of application, relate to adaptation of the various techniques described herein, to such assemblies.
II. The Assembly of Figs. 1-3; Described in Use With a Conventional, Prior Art, Mounting Plate Assembly in a Serviceable Separator Element In Figs. 1-3, a gas/liquid separator assembly useable as an air/oil separator is depicted. The particular gas/liquid separator assembly depicted is shown used, in Figs. 2 and 3, with a serviceable separator element having a prior art mounting plate assembly. (The term "serviceable," as used herein, meaning a component intended to be removable and replaceable with respect to a remainder of the assembly.) The reference number 1, Fig. 1, generally designates a gas/liquid separator assembly. The view of Fig. 1, is a top view. The view in Fig. 2, is a cross- sectional view along line A- A, Fig. 1, and depicts a side cross-sectional view. Referring to Figs. 1 and 2, the assembly 1 includes a pressure vessel
4 comprising: a bottom part 4a having a sidewall construction 5; and, a top cover 6. For the particular assembly shown, the sidewall construction 5 comprises a cylindrical sidewall section 8 with a rounded bottom 9. The top cover 6 is secured in place by bolts 11. Typically, there are 6-12 bolts tightened to more than 50 ft-lbs. (more than 6.5 kg-meters). For the particular assembly shown there are eight such bolts arranged in a circular pattern. Referring to Fig. 2, the bolts 11 secure top cover 6 in place, by engagement of the bolts 11 with nut plate or ring 12. For the particular assembly 1 depicted, the top cover 6 includes a central aperture 15 therethrough. As will be apparent from the following description, central aperture 15 is an air or gas flow exit aperture from the assembly 1. Also extending through top cover 6 is a pressure tap 16, control port 17 and a scavenge port 18 (Fig. 1).
Referring to Fig. 1, assembly 1 includes a gas/liquid inlet 21. The gas/liquid inlet 21 provides a port in flow communication with interior 22 of pressure vessel 4, for introduction therein of a gas/liquid mixture to be separated. Referring to Fig. 2, interior 22 of pressure vessel 4 is divided into an upper region 24 and a lower region 25, by central divider 26. The central divider 26 is imperforate, except for central air flow aperture 29. Central aperture 29 is surrounded by a downwardly directed shroud 30; i.e., shroud 30 projects into lower region 25. Shroud 30 is preferably imperforate, and defines an open lower end 31. For the preferred arrangement shown, shroud 30 is cylindrical around central longitudinal axis 33 of vessel 4, although alternate shapes and locations for shroud 30 are possible. Mounted within upper section 24 of interior 22, is serviceable separator element 35. Serviceable separator element 35 is configured for out-to-in flow, for reasons apparent from the following. During operation, a gas/liquid mixture (typically an air/oil mixture from a compressor system), is directed into interior 22 through air/oil inlet 21, Fig. 1; in this instance into bottom region 25. The gas/liquid mixture is directed into a preferred flow pattern, in this instance in part around shroud 30. For the particular arrangement shown, the flow pattern would be counter-clockwise, when viewed downwardly from the view point of Fig. 1, although alternate flow patterns can be accommodated. A certain portion of the oil carried in the liquid, will drain directly down into lower sump 38, shown in Fig. 2 with an oil level at 38a. The air, after preseparation within lower region 25, will pass under shroud 30, and upwardly into upper region 24, by passage through opening 31 and through opening 29, defined by shroud 30. The air is then directed through the serviceable separator element 35 in the general direction of arrows 39. While passing through the separator 35, further separation of gas and liquid occurs, with separated liquid draining into upper sump 40. For an out-to-in flow element as shown, the upper sump 40 is positioned within an interior 35a of serviceable separator element 35. Liquid can be scavenged from upper sump 40, by a draw tube (not shown) extended through scavenge port 18, Fig. 1. The separated gasses (under pressure) can then escape from serviceable separator element 35, by passage through an open end or outflow aperture 45 of the element 35 and then outwardly from assembly 1 through air flow aperture 15.
The serviceable separator element 35 depicted includes a media pack 50 and a mounting plate assembly 51. The mounting plate assembly 51 includes mounting flange section 55 and media pack mounting section 56. In addition, the mounting plate assembly 51 defines outflow aperture 45. Typically, the mounting plate assembly 51 is formed from a conductive metal, for example electrogalvanized steel. All or a portion of the media pack 50 can be attached or secured at an appropriate location on the media pack mounting section 56 using, for example, an appropriate adhesive or potting agent. The particular mounting plate assembly 51 depicted in Fig. 2, is of a conventional configuration, similar to that shown in PCT publication WO 99/47211, the complete disclosure of which is incorporated herein by reference. Referring to Fig. 3, the mounting flange section 55 for the particular example shown is generally planar and shaped as an annular ring, with opposite sides 55 a, 55b. Referring to Fig. 2, serviceable separator element 35 is removeably mounted with interior 22, by trapping mounting flange section 55 between top cover 6 and a remainder 4a of the pressure vessel 4, in this instance plate 12. This is shown in an enlarged view, in Fig. 3. For the particular serviceable separator element 35 depicted in Fig. 2, the media pack 50 is secured to the mounting plate assembly 51, at end 50a of the media pack 50. At an opposite end 50b of the media pack, end cap 52 is provided, including central sump 40 formed therein. End cap 52 may comprise a metal piece, or a plastic molded piece. The particular arrangement shown, utilizes a metal end cap for end cap 52, secured to end 50b and media pack 50 by an appropriate adhesive or potting agent. Still referring to Fig. 3, a seal is needed between the mounting flange section 55 and each of the top plate 6 and plate 12, in order to ensure appropriate maintenance of the environment within pressure vessel 4. For the assembly 1 as shown, in Fig. 3, the seal is provided by the presence of gasket rings 61, 62 positioned on opposite sides 55a, 55b of mounting flange section 55, respectively. Gasket rings of the type used for gasket rings 61, 62 are typically pre- made by being cut from a sheet compressed fiber material. Example of a useable gasket materials are commercially available under the trade designations Klinger
4401 and Klinger 4201 from Thermoseal, Inc., Sidney, OH 45365. Such gaskets usually comprise Kevlar fibers or similar material. Typical such gaskets are about 0.06 inches (1.5 mm.) thick (non- compressed). The gaskets are typically adhered to the flange section 55 using a liquid adhesive, or the gaskets are coated on one face with the pressure sensitive adhesive (psa). The gaskets usually do not compress in thickness very much when the mounting plate assembly 51 is installed in assembly 1, during use. Typical gasket materials such as Klinger 4401 and 4201, are electrically insulating. As a result, referring to Fig. 3 and Fig, 2, when operably installed, the mounting plate assembly 51 of the serviceable separator element 35 is electrically insulated from both the top cover 6 and the remainder of the pressure vessel 4, by the gasket rings 61, 62. In many instances, it is required that the mounting plate assembly 51 be electrically grounded to a remainder of the gas/liquid separator assembly 1. To accommodate this, in separator elements such as element 35 sometimes electrically conductive staples are driven through each of the gasket rings 61, 62, and into electrical connection with the mounting plate assembly 51, at spaced locations around mounting flange section 55. Typically, each staple is driven through one of the gaskets into contact with the mounting flange section, in a region of the gaskets centrally positioned between the outside edges 61a, 62a and the inside edges 61b, 62b, of each gasket (61, 62). Such staples are usually about 0.5 inch to 1 inch wide (1.25 - 2.54 cm). It is desirable to avoid the need for such pre-made gaskets, if possible. A reason is that the pre-made gaskets provide a cost issue, especially since specifically sized and configured gaskets may be needed for different serviceable separator elements. In addition, it is desirable to replace the staple operation. A portion of the teachings of the present disclosure, concern alternate gasket arrangements and/or electrically conductive assembly arrangements, to provide for avoidance of the types of gasket/stapler arrangements previously used. These techniques are described herein below, in connection with Figs. 4-8. Before turning attention to these figures, additional features relating to the assembly of Figs. 1-3, are described. Referring to Fig. 2, vessel 4 includes a fill port 70, for ensuring an appropriate oil level, for example at start up. In addition, a lower drain 71 is
positioned in a lower sump 38. Also a site glass 72 is provided, for viewing the oil level 39. The pressure vessel 4 may be provided with various taps for control systems and monitoring. For the particular arrangement shown, a pressure relief tap 73 and temperature probe port 74 are shown. In addition, a control port 75 and a pressure tap 76 are shown. In general, gas/liquid separators of the type of concern here are provided with one of two types of gas inlet arrangements. A first, generally referred to herein as a tangential gas inlet, is a gas inlet which has a center line directed generally tangentially with respect to the rounded or cylindrical outside wall 8 of the vessel 4. Inlet 21 is a tangential inlet. A second type of gas inlet, not shown in the figures, is generally referred to herein as a "radial" or "radially directed" inlet. Such an inlet would generally be directed toward central longitudinal axis 33 of the assembly 1. No radial inlet is depicted herein, however one can be used with the various techniques described herein. A radial inlet is depicted in U.S. Provisional Patent Application Serial No. 60/431,432 (filed December 6, 2002) at reference numeral 12; the complete disclosure of U.S. Provisional Patent Application Serial No. 60/431,432 being incorporated herein by reference. Referring now to media pack 50, typical media packs include a coalescing stage 83 and a drain stage 84. For the particular serviceable separator element 35 depicted, the coalescing stage 83 and drain stage 84 are both permanently secured within the serviceable separator element 35.
III. The Embodiments of Figs. 4-9. A. The Embodiment of Figs. 4-7.
In Fig. 4, the gas/liquid separation assembly 99 is depicted. Assembly 99, Fig. 4, is the same as assembly 1, Fig. 1, however with an improved serviceable separator element 100 mounted therein. Except for the improved serviceable separator element 100, the assembly 99 of Fig. 4, can be the same as the assembly 1, Fig. 1. That is, the assembly 99 includes a top cover and pressure vessel arrangement, indeed the identical vessel 4 and top cover 6 arrangement as in Fig. 1
are shown. In Fig. 4, identical reference numerals are thus used, where appropriate, to reference identical or analogous parts. Referring to Fig. 4, serviceable separator 100 includes media pack 102, with ends 102a, 102b, and mounting plate assembly 103. In addition, it includes end piece or cap 104, at an opposite end 102b of the media pack 102 from mounting plate assembly 103. The end cap 104 defines internal sump 105. End cap 104 may comprise a metal or molded plastic member. For the particular gas/liquid separator 100 depicted, it comprises a metal piece secured to the media pack 102, for example by potting with an adhesive. The mounting plate 103 includes mounting flange section 108, media pack mounting section 109 and central gas flow aperture 107. Attention is now directed to Fig. 6, in which gas/liquid separator element 100 is depicted in cross-sectional view. In general, gas/liquid separator assembly 100, again, includes mounting plate assembly 103 and media pack arrangement 102. Mounting plate assembly 103 includes mounting flange section 110 and media pack mounting section 111. Media pack mounting section 111 includes base Ilia, inner lip 11 lb and outer lip 111c. The mounting flange section 110 is attached to base 11 la by wall 112. For the particular mounting plate assembly 103 depicted, mounting flange section 110, wall 112, base I lia and lip 11 lb are integral with one another, each being a section of a single, integral metal, piece. Flange 11 lc, on the other hand, is a part of a separate metal piece secured to base I l ia, for example by welding to flange 111; flange 111c being integral with a base piece l id, Fig. 7. The mounting plate 103 is shown in Fig. 7, without the media pack thereon. Referring again to Fig. 6, for the arrangement shown, base 11 la is generally planar, and is in a plane separate from the plane in which mounting flange 110 is positioned; the separation being by section 112, and bends 112a, 112b. Alternate arrangements in which base Ilia and mounting flange 110 are in the same plane are possible, as discussed below in connection with Figs. 8 and 9. The mounting flange section 110 includes section 114 and section
115. Section 114, for the specific example shown, is planar, although alternatives are possible, and has first and second opposite sides 114a, 114b. Section 115, for the embodiment shown, is configured to have at least a portion 115a projecting axially away from side 114a; and, a portion 115b projecting axially away from side
114b. Portions 115a and 115b together, comprise an integral, axially directed, conductive portion, as discussed below. Herein when it is said that portion 115a projects axially away from side 114a, it is meant that it projects in a direction generally parallel to central axis 120, in a direction outwardly from a plane defined by side 114a, since side 114a is planar. If side 114a were not planar, in general the same definition would apply with the plane defined simply being one that approximates the side 114a. An analogous definition applies to the portion 115b projecting axially away from a plane defined by side 114b. The extent of extension axially in each direction, is in part an issue of choice, but in general relates to compression of gasket material as described below. For the particular arrangement shown, the non-planar section 115 comprises a formation which, in cross-section, includes a rib or bump 117, in section
115b spaced from edge 118, with bump 117 projecting outwardly from side 114b. Outer peripheral edge 118 forms section 115a and projects axially outwardly away from side 114a. Groove 121 is an artifact from the formation of bump 117 and edge
118. Preferably portions 115a and 115b each project axially at least 0.05 inch (about
1.2 mm), typically 0.05 - 0.07 inch; i.e., about 1.2 - 1.8 mm. As will be apparent from following descriptions, an inverse formation from that shown in Fig. 6, could be used, in which the bump (corresponding to bump
117) projects outwardly from surface 114a, and the edge (corresponding to edge
118) projects in a opposite direction; i.e., outwardly from surface 114b. Indeed, many alternate configurations for the integral, axially directed, conductive arrangement can be used, to achieve the affects desired. This will be more apparent, after the following discussion of the desirable affects. Attention is still directed to Fig. 6. In Fig. 6 a gasket ring 122 is shown positioned on surface 114a, and an opposite gasket ring 123 is shown positioned on surface 114b. For the particular arrangement shown, the gasket rings
122, 123 are identical to one another, and are positioned as mirror images, although alternates are possible. In general, gasket rings 122, 123 together form a gasket arrangement, 124. In an initially applied, non-compressed, configuration as shown in
Fig. 6, each gasket ring 122, 123 extends further, axially, from its associated surface portion (114a, 114b respectively), than the associated portion (115a, 115b
respectively) of the non-planar section 115. Thus gasket 122 projects axially outwardly from surface 114a further than does edge 118; and, gasket 123 projects axially outwardly further from surface 114b than does bump 117. Operation will be understood by reference to Figs. 4 and 5. In Fig. 4, it can be seen that mounting flange section 110 is positioned between top cover 6 and plate 12. Referring to Fig. 5, an enlarged fragmentary view of a portion of Fig. 4, tightening of the bolts (Fig. 4), results in compression (axially) of the gasket rings 122 and 123. The compression should be made to occur until metal to metal contact is made between: top cover 6 and edge 118; and, plate 12 and bump 117. Thus, non- planar section 115 provides (when the mounting plate assembly 103 is installed and the gasket material is compressed), for electrically conductive contact between and among top plate 6, mounting plate 103 and the pressure vessel bottom section 4a. The non-planar section 115 also provides for a compression stop. hi more general teπns, non-planar section 115 provides for electrically conductive contact between and among top plate 6, mounting plate 103 and pressure vessel bottom section 4a, when the gas/liquid separator element is mounted with mounting plate section 110 trapped between cover 6 and pressure vessel bottom section 4a, and the gasket arrangement 124 is sufficiently compressed to the compression stop. Further, for the particular preferred arrangement shown, the non-planar section 115 is integral with a remainder of the moimting plate assembly 103. In general, what is needed to provide for an appropriate electrical contact, in operation, are the following: (a) an appropriate amount of extension axially (in opposite directions of parts of non-planar portion 115) of the mounting flange section 110, to reach metal-to-metal contact during an appropriate amount of compression of the gasket material; and, (b) gasket material which compresses • appropriately to allow the metal-to-metal contact while maintaining an appropriate sealing contact. It can be seen that a variety of configurations to the mounting flange section can be used, to provide for the metal to metal contact, upon installation. The particular arrangement shown, which uses the annular bump and projecting edge, are merely examples. In general, the construction avoids use of the staples, and a stapling step during assembly.
The techniques described are preferably applied in a manner which also avoids use of pre-cut or pre-made gaskets, although they could be used with such mounting flanges if they possess appropriate compressibility. Preferably, gaskets 122, 123 are formed from a flowable, thixotropic, material applied as a continuous bead, to the surfaces 114a, 114b respectively. In general, what is required is a material that has appropriate flow properties to be applied in this manner, and also which after application, will form an appropriate gasket with adherence to the mounting flange section. One such material would be a two component polyurethane such as: Part A K31-9308-1-NP3; Part B K31-B81, available from Automated Dispensing Solutions, Inc., Circle Pines, MΝ 55014, a distributor for Sonderhoff GMBH, Koln, Germany. It is generally expected that what will be preferred will be a gasket which compresses at least 25%, preferably at least 35% and most preferably to an extent within the range of 40-60% inclusive (in thickness) in use during sealing; usually about 50%. It is anticipated that a typical non-compressed thickness for each gasket 122, 123 would be at least 0.1 inch (2.5 mm) and typically within the range of 0.1 - 0.13 inch (2.5 - 3.3 mm). Typically, then the bump 117 projects outwardly axially from surface 114b by a distance of half the thickness of a gasket; and the edge 118 projects axially outwardly from plane defined by surface 114a, by a distance of half the thickness of the gasket. Herein, gaskets which are applied to mounting plate flanges in the form of a flowable bead will be referred to as "mold-in-place gaskets." The term "mold-in-place gasket" is meant to exclude, from its definition, pre-formed gaskets that are cut from material and which are then applied to a mounting plate arrangement. The term "mold-in-place gasket" is not meant to refer to any particular shape of gasket or any particular material used for the gasket, unless otherwise defined. However it is meant to reference a gasket that results from flowing a flowable material, applied the appropriate location, with or without use of a form or mold. Herein, when reference is made to a "non-compressed" thickness of the gasket material, reference is meant to the gasket material thickness prior to it having been compressed, even for the first time, in mounting, after it has been molded in place. It is not a requirement that the gasket material be of a type which will fully rebound to its initial non-compressed state, after the gas/liquid separator
element has been mounted once, and then the top cover is removed to allow the element to be serviced. However, in general, preferred materials will rebound to at least 85%o of their thickness prior to compression. Although alternate configurations are possible, it is noted that for the particular arrangement shown, each portion of the mounting flange section which projects outwardly, axially, circumscribes a gasket member positioned on that side. For example projection 118 circumscribes seal 122; and, projection 117 circumscribes seal 123, Fig. 5. Although alternates are possible, the particular projection member 117 depicted comprises a radially continuous convex bead opposite a radially continuous concave groove; and, projection 118 comprises a radially continuous edge. Attention is directed to Fig. 7, in which the mounting flange arrangement 103 is depicted without the media pack mounted thereon. It is noted that a variety of cross-sectional shapes can be used, when a bead 117 is used for one of the projections in portion 115. Although a semi-circular shape of the bead can be used, it is anticipated that in typical instances the seal bead (non-compressed) will be a little wider than it is high. The size of the bead preferred, may depend upon the particular size of the unit. An example of a useable size is a radius approximately within the range of about 0.2 - 0.3 inches (5-7.5 mm). The specific construction in the media pack is not critical to the general principles of the assembly configuration described herein, and is a matter of choice. In general, the size and construction of the media pack will be selected based upon such issues as air flow, the level of efficiency of separation desired, the amount of restriction acceptable, the lifetime of use preferred and the size and space available. A characterization of some possibilities is provided in Section IN below.
B. The Alternate Embodiment of Figs. 8 and 9.
In Fig. 8, an alternate mounting plate assembly, minus gaskets, to the mounting plate assembly utilized in the embodiment of Figs. 4-7 as shown.
Referring to Fig. 8, mounting plate assembly 150 is depicted. The mounting plate assembly includes gas outlet flow flange 151 and region 152. Region 152 provides for: portion 153 as media pack mounting portion; and, portion 154 as an integral,
' axially directed, electrically conductive arrangement. Portion 154 comprises a bead 155 and edge 156, analogous to the arrangement of Fig. 6. Attention is now directed to Fig. 9, which shows mounting plate assembly 150 with gasket arrangement 160 thereon, comprising bead 161 and bead 162, on opposite sides of section 152. The portion of the mounting plate at 165, whereat the beads 161, 162 are located, would be the mounting flange. In general, the mounting plate arrangement of Fig. 9 can be utilized analogously to that of Fig. 4, simply with the media pack secured to a portion of the mounting plate (at 153) coplanar with a portion (at 165) to which the gasket material 160 is applied. The same advantages relating to electrical conductivity would result, during use. From a comparison of Figures 8 and 9 with the embodiment of Fig. 6, it will be apparent that a variety of arrangements can be utilized. In addition, alternates to the edge, bead arrangement can be used, to accomplish the integral axially projection to accomplish the electrical conductivity or grounding contact, during compression of the gasket arrangement. Further, there is no specific requirement that the region to which the media pack is secured be planar, although this would be preferred in many systems and arrangements. Mounting plate assemblies of the type shown in Figs. 6, 7, 8 and 9, can be made by metal forming techniques such as stamping and spinning, with separate parts (if used) attached for example by welds. Thus, the shapes can be relatively inexpensively obtained.
IV. Some Media Pack Materials and Alternatives. Components of media packs of air/oil separators are described, for example, in U.S. 6,093,231; U.S. 6,136,016; WO 99/47211; WO 99/43412; UK 1,603,519; U.S. 6, 419,721; and U.S. 4,836,931, the complete disclosures of the seven identified references being incorporated herein by reference. The principles of these types of arrangements can, for example, be applied for separator units having herein. hi general, the coalescing stage comprises appropriate material to cause coalescing of an entrained liquid particles within an air stream passing into the coalescing stage. The drain stage operates to collect coalesced particles, to facilitate drainage from the media pack.
In typical constructions, the coalescing stage will be positioned in the element, to be upstream from the drain stage. For out-to-in flow elements such as those depicted in the figures, the coalescing stage is positioned around drain stage. For the particular element depicted in Fig. 6, a drain stage 140 is positioned surrounded by a coalescing stage 141, and spaced therefrom by central liner 142. The central liner may comprise a variety of materials, for example a porous metal or plastic screen. An expanded metal screen can be used, for example. Also, the media pack can be provided with upstream and/or downstream liners, if desired. It is anticipated that the coalescing stage may comprise a formed media. It is anticipated that the drain stage, at least in some instances, would comprise a wrapped felt or other air laid material. For example a polyester felt or similar material. The thickness of the coalescing stage and drain stage may be varied, depending on the particular system. A typical example would be: a coalescing medium having a thickness of about 0.4 - 0.6 inches (about 10-15 mm), for example about 0.5 inches (12.5 mm); and, a drain stage medium having an overall thickness of about 0.2 - 0.3 inches (5-7.6 mm), for example 0.25 inches (6.4 mm). For the drain stage, this can be accomplished by using several wraps of media, for example. Above it was stated that the coalescing stage may comprise formed media. In general foreign media comprises media construction by deposition of media fibers on to a form or mandrel, from suspension. Adhesives may be applied and/or binder fibers may be used, to help retain the form shape on the mandrel. It is noted that for the embodiments depicted the entire media pack is secured to the mounting plate assembly. This is not a specific requirement of application of principles according to the present invention. For example the mounting flange arrangement may have secured thereto only a selected portion of the media pack arrangement, with the remainder of the media pack arrangement either being removeably mounted, or mounted on a separate component. An example of such a possibility, that can be adapted to apply the principles of the present disclosure, is shown in U.S. 6,585,790 at Fig. 7, the complete disclosure of
U.S. 6,585,790 being incorporated herein by reference. It will be apparent that a mounting plate useable with partial media packs can be provided with the same desirable features as the arrangements characterized above. In general when it is said that a media pack or media pack component is attached to a mounting plate
assembly, it is not meant to be specified as to whether some or all of the components are attached, unless otherwise indicated.
V. Some Concluding Observations In general, according to the present disclosure a gas/liquid separator element is provided which, in assembly and use, provides advantage. A principal advantage is provided by manufacturing a mounting plate assembly at the separator element from an electrically conductive material with an integral, axially projecting, portion thereon, which will come into contact with the top plate and housing arrangement, when installed and when an appropriately positioned gasket arrangement is compressed during sealing. A particularly advantageous arrangement, which involves an axially projecting bead and an axially projecting edge, is provided. The techniques can be advantageously applied with a variety of types of gaskets. However a particularly advantageous gasket arrangement, which involves compressible flowable material applied to the mounting plate assembly as a mold-in-place gasket, is described and shown. Such an arrangement is particularly advantageous, since it avoids the use of pre-made or pre-cut materials. When such a material is chosen, it is preferably one which will compress in thickness at least 25%, preferably at least 35%, and most preferably within the range of 40%-60% inclusive, in use. Such arrangements are generally referred to herein as "mold-in- place" gaskets. The gaskets are typically from an electrically insulating material, such as a compressible polyurethane. In general, the gasket arrangement of the preferred gas/liquid separator elements can be characterized as having a first, compressible, electrically insulating gasket member positioned on a first side of an annular mounting flange; and, a second, compressible, electrically insulating gasket member positioned on a second side of the annular mounting flange. In general each can be characterized as having a first, non-compressed, configuration in which it projects outwardly in greater relief, relative to a portion of the mounting flange section on which it is mounted, than does an axially directed conducted portion of that mounting flange; and, a second, compressed, configuration in which the gasket member does not project outwardly in greater relief, from a portion of the mounting flange section in which it is mounted, then does an axially directed conductive portion.
The principles described can be characterized as involving the provision of a gas/liquid separator arrangement as characterized, with a preferred mounting plate assembly as described, operably mounted in a pressure vessel of a gas/liquid separation assembly. Further principles apply to methods of installation of gas/liquid separator assemblies, and their use. Also methods of assembling preferred gas/liquid separator elements through formation of preferred mounting plate assemblies, are provided.