MXPA97003690A - Reverse flow air filter arrangement and operating method - Google Patents

Abstract

The present invention relates to an air filter element characterized in that it comprises (a) a cylindrical extension of filter means defining an interior of the open filter, the filter means are embedded within the first and second end caps; ) an internal support lining; (c) an external support lining; (d) the first end cap has a hole for air entry therein; (e) the second end cap has: (i) an orifice central drainage, the orifice is substantially smaller than the inner diameter of the filter means, and (ii) an inner surface with an end region, the inner surface is angular from the outer region towards the central drainage hole and is constructed and arrange to transport moisture collected on the inner surface of the second end cap to the drain hole centr

Description

REVERSE FLOW AIR FILTER ARRANGEMENT AND OPERATING METHOD FIELD OF THE INVENTION The present invention relates to arrangements of reverse flow air cleaners. That is, the invention is concerned with air cleaner arrangements where the filtration flow is in one direction with the "clean" side of the air filter around it and a "dirty" side of the air filter only at the long of an interior thereof. The invention is concerned in particular with such air cleaning arrangements having drainage systems for the accumulation of water in an interior of the associated air filter elements. The invention is also concerned with the provision of preferred components, such as air filter elements, for use with such arrangements and with methods involving the use of such arrangements.

BACKGROUND OF THE INVENTION In general, air cleaning arrangements include a housing and an air filter element. The housing is configured in such a way that the air is directed through the air filter element, for filtering. Various geometrical configurations of the air cleaner housing, the air filter element and related seal arrangements are used to effect this. Many air cleaner arrangements include general cylindrical air filter elements. Such elements commonly include REF: 24717 filter media arranged in a cylindrical configuration, with end caps. Seal arrangements are used either on or in conjunction with the end caps to provide proper sealing with the housing or other portions of the air cleaner and to control the direction of air flow. Reverse air flow air cleaner arrangements are generally those in which air is directed to an interior of an air filter element before it is filtered and the air is filtered as it passes through the air element. Air filter from the inside to the outside. If the air filter element is cylindrical, this means that the unfiltered air is directed to the inside of the cylinder and then through the filter media, to an outside, during filtration. The material entrained in the air directed to the air filter is then left along an interior of the cylindrical filter means. Consider for example an arrangement of reverse flow air cleaner, which has a cylindrical air filter element, used in a truck for long distances. The air directed into the interior of the cylindrical element may include dust, leaves, large particles and even moisture entrained therein. This material will tend to accumulate inside the air filter element with the passage of time. If the depth of water inside the air filter element becomes significant, water alone or with fine particles or salt in suspension, can penetrate the filter medium. This has the potential to damage the engine components. It would be preferred that arrangements be provided to drain the water from the interior of the filter element.

In those arrangements where the filter element is operationally oriented in such a way that the longitudinal axis of the cylindrical air filter is substantially vertical, drainage arrangements involving drainage holes in one of the end caps have been used. In general, these have involved displaced holes (from a central location) in an end cap and unless the air filter element is vertically oriented almost perfectly, the drainage is inefficient. Also, in such arrangements sometimes, debris may be collected along the interior surfaces of the housing when the arrangement is opened and the element is separated unless the housing is completely cleaned before the element is reinserted into the housing. Waste can interfere with obtaining a good seal at critical sites.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, an air filter arrangement is provided. The air filter arrangement includes a housing and an air filter element having first and second opposed end caps, filtering means and an open filter interior. The first end cap has a hole for air to enter it, so that the air passes to the arrangement to be filtered. The second end cap has a central drain hole and an interior surface constructed and arranged to transport the moisture that is collected on the inner surface of the second end cap to the central drain hole and outwardly from the filter element. The central drain hole is preferably positioned at a center of the second end cap with a longitudinal axis of the air filter element passing through it. The air filter arrangement also includes an arrangement for the flow direction of the air filter. air, constructed and arranged to direct the flow of air to the housing into the open filter, through the filter media for filtration and then out of the housing as filtered air The arrangement for the direction of the air flow comprises in general various characteristics of the housing, seals and filter element Preferably, the inner surface of the second end cap is circular. In certain embodiments, it includes a plurality of radially directed conduits or channels, which terminate in a central drain hole. The conduits or channels They can be used to help transport and direct the collected moisture on an interior surface of the elemen of air filter in use (ie "when mounted operaonally or operatively") In certain preferred arrangements, the second end cap includes an rnal annular compressible portion and the housing includes an annular sealing surface against which the second compressible portion The outer annular of the second end cap is sealed, when the air filter arrangement is operatively mounted for use. Such a seal is referred to herein as an annular or radial annular seal, around the second end cap. That is, in this cont, the term "annular" refers to a sealing portion around the outside of the end layer which seals under radial compression. In a preferred embodiment, the housing includes a base having a central tray, preferably recessed and a sealing cord. positioned circumferentially around the central recessed tray. A drain hole is provided in the central tray, such that the water collected in the tray can be removed from the housing. With such an arrangement, preferably the second end cap is constructed and arranged to form a secondary seal with the sealing bead at the base, when the air filter element is operatively positioned within the housing. Preferably, the manner of coupling with the seal cord is by providing a coupling "conduit" on the rnal surface of the second end cap. Preferably the outer surface of the second end cap has an outer lip or lip and the outer surface of the second end cap is recessed (or depressed) in nsion between the outer edge and the conduit which is brought into contact with the cord. sealed and the base. Thus, in a preferred manner a space or spacing is provided between the second end cap of the filter element and the base of the housing, in the region between the sealing bead of the base and an outer peripheral area of the base. A space on this site collects waste that can be collected in the housing, without interference with the seal between the second end cap and the housing. This is facilitated by those arrangements that involve the provision of the seal along an annular portion of the end cap, such as a radial seal, rather than as an eme or axial seal.

Preferably the outer surface of the second end cap is configured to provide a transport surface having an angle of inclination of at least about 1 ° and preferably 1 ° to 3 ° in the extension region between the outer edge of the second end cap and the portion of the end cap which is brought into contact with the sealing cord in the base. In preferred arrangements, an evacuation valve is mounted in the drainage hole of the tray recessed in the base. This provides a preferred, controlled drainage of system moisture. In preferred embodiments, a soft polymeric material is used for the first and second end caps. Preferably each of the polymer end caps consists of polyurethane. For the end caps, a polyurethane foam material having a "as molded" (or untreated) density of about 0.22-0.35 grams per cubic centimeter (14-22 pounds per cubic foot) will be preferred (more preferably about 18.4 grams per cubic centimeter (18.4)). In some embodiments, the same material can be used for both end caps. In preferred constructions, a tube for air entry into the housing is provided, which is configured to generate a radial seal with the first end cap of the filter element. In an alternative embodiment, an arrangement having an end cap of sheet metal is provided as the second end cap. This arrangement is preferably sealed axially, by the provision of a main seal, compressed axially between the second end cap and the base, when the air filter array is operationally mounted. A secondary seal can also be provided in such arrangements between a selected portion of the second end cap and the base of the housing. In accordance with the present invention, a preferred filter element is provided. The preferred filter element comprises a generally cylindrical extension of the filter means. The filter means may consist, for example, of folded paper filtration means. Preferably, an internal support liner and an external support liner are provided for the cylindrical extension of the filter means. Preferably the arrangement has first and second end caps, the first end cap includes a hole for the air inlet therein. The second end cap preferably has a central drainage hole and an interior surface constructed and arranged to convey the moisture collected on the interior surface of the second end cap to the central drainage hole. The central drainage hole is preferably located in a center near the end cap, on a longitudinal axis of the cylindrical extension of the filtration means. A preferred configuration for the inner surface of the second end cap is like the inside of a funnel. In some embodiments, the interior surface of the second end cap includes a plurality of conduits or channels directed radially therein, which terminate in the central drain orifice.

Other preferred features for the preferred air filter element include: a circular sealing duct on an outer surface of the second end cap and a gap between an outer edge of the outer surface of the end layer and the circular duct or channel. Also, a compressible region is preferred, which provides a radial seal along an annular portion of the second end cap. According to the present invention, a method for the operation of a reverse flow air filter arrangement is provided. In general, the method comprises collecting moisture within the filter element and draining moisture from the filter element through a central hole in the end cap, by transporting the moisture to the central orifice.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view of an air cleaner arrangement according to the present invention. Fig. 2 is a top plan view of the arrangement shown in Fig. 1. Fig. 3 is an exploded plan view of the arrangement shown in Fig. 1. Fig. 4 is an enlarged fragmentary side cross-sectional view of a portion. of the arrangement shown in figure 1; Figure 4 is a view taken generally along line 4-4 of Figure 1.

Figure 5 is a fragmentary cross-sectional view of a portion of the arrangement shown in Figure 1; Figure 5 is a view taken generally along line 5-5 of Figure 1. Figure 6 is a fragmentary exploded view of a portion of the arrangement shown in Figure 5. Figure 7 is a view in fragmentary top plan of a portion of the arrangement shown in Figure 6. Figure 8 is a fragmentary cross-sectional view of an alternative embodiment to that shown in Figures 1-7.

DETAILED DESCRIPTION OF THE INVENTION Reference numeral 1 of Figure 1 generally designates an air cleaner assembly according to the present invention. Figure 1 is a side elevation view of the air cleaner assembly 1. In the figure, the housing 2 is generally shown. The housing includes an inlet construction 3 and a receiver of the filter element or can 4. The can 4 includes the outlet 7. In use, the air to be filtered passes to through the inlet construction 3 and is directed to an interior of the can 4. Inside the can 4, the air is directed through a filter element that is not seen in figure 1. After being filtered by the filter element, the air passes out through the outlet 7 and is directed to the air intake of the engine, not shown. Here, the term "airflow direction arrangement" is used to refer generally to those characteristics of an air filter arrangement which directs the air flow in a preferred manner or along a preferred path . The term can refer to a variety of characteristics and usually refers to the internal configurations of the housing and the filter, as well as to the various seals. Still with reference to Figure 1, the inlet construction 3 is mounted on the can 4 and secured thereto by bolts 8 and nuts 9. Access to the interior of the can 4 and a filter element positioned therein, it is obtained by loosening the bolts 8 and separating the entrance construction 3 from the can 4. For the particular construction shown, the entrance construction 3 includes an upper dome 12, a perforated screen 13 for air intake and an inlet pipe 14 (the inlet tube is not shown in figure 1, but is shown in figure 4 in cross section). Referring still to Figure 1, the can 4 includes a drain hole therein, the drain hole is not shown in Figure 1, but is shown with the number 18 in Figure 5. The drain hole is covered. by means of an evacuation valve 19. The evacuation valve 19 may be for example, as described in U.S. Patent 3,429,108, the disclosure of which is incorporated herein by reference. In general, the drain hole 18 is positioned in a portion of the can 4 which will be, when the assembly 1 is installed operatively, positioned at the bottom of the assembly 1. Thus, the water will tend to accumulate near the hole 18 and to be drained of it during use. This will be made more readily apparent from the additional descriptions where the internal details of the air cleaner assembly 1 are presented. With reference to Figure 2, the air cleaner assembly 1 includes four bolts and nuts 9 to secure the inlet construction 3 to the filter can 4. While the number of bolts used may vary, depending on the particular application, it is an advantage of the constructions according to the present invention that filter assemblies as large as approximately 38 cm (15 inches) in outer diameter can be closed safely and reliably, with so few as approximately three or five bolts. The features which facilitate this will be evident from the additional descriptions. An exploded view of the air cleaner assembly 1 is shown in Figure 3. In Figure 3, the air cleaner assembly 1 is shown with the inlet construction 3 separated from the filter can 4 and with the cleaning element 21 of air separated from the can 4. For the particular arrangement shown, the air cleaner element 21 is generally cylindrical. The element 21 includes first and second end caps 23 and 24; filter means 25; internal support 26 (figure 4) and external support 27. For the particular embodiment shown, the filter means 25 comprises a folded paper construction 30. In general, the folded paper construction 30 comprises a corrugated paper cylinder 31, the corrugations run in a longitudinal direction along and generally parallel to a central axis 33 of the element 21. It will be understood that media constructions could be used. of alternative filters. In general, the filter means 25 extend between the end caps 23 and 24. For the assembly 1 shown, the end caps 23 and 24 comprise polymeric material as described below, on which the opposite ends of the filter are mounted or planted. the filter means 25. In Figure 4 a fragmentary cross-sectional view of the air cleaner assembly 1 is shown. In Figure 4, the inlet construction 3 and the portions of the air cleaner assembly 1 are shown in association therewith. In general, the filter means 25 are positioned between the internal support 26 and the external support 27. Each support generally comprises a tubular or cylindrical extension of perforated metal or expanded metal, the opposite ends of which are also fitted or planted at the ends. end caps 23 and 24. In general, the end cap 23 is opened and the end cap 24 is closed. That is, the end cap 23 includes a large inlet hole 28 (FIG. 24) therein, for introducing air to be filtered into the interior 35 of the filter element. The end cap 24, on the other hand, is generally closed, except for a drainage hole extending therethrough as described below. Still referring to Figure 4, it can be seen that the inlet construction 3 includes the inlet pipe 14. When mounted, the inlet pipe 14 extends to the hole 28 in the end cover 23. At least in this location , the end cap 23 is preferably formed of a soft compressible material. When the inlet pipe 14 is not inserted into the hole 28, at least a portion of the hole 28 in its unpressed state will generally have an internal diameter slightly larger than an outer diameter of the section 39 of the inlet pipe 14; that is, the portion of the tube 14 which is brought into contact with the end cap 23 when the arrangement 1 is mounted operatively. Thus, when the inlet tube 14 is inserted through the hole 28, the material of the end cap in the region 40 will be pressed. In this manner a seal is formed in region 41. Such seals are described, for example, in conjunction with the air cleaner assemblies in U.S. Patent B2 4,720,292, the disclosure of which is incorporated herein by reference. It will be noted that the arrangement of U.S. Patent 4,720,282 is not necessarily a reverse flow arrangement; however, the principles that relate to stamp formation are basically the same. Such seals are sometimes referred to as "radial" or "radial" seals, since the forces maintaining the seal are directed radially about a central longitudinal axis 33 (FIG. 3) of the tube and element, instead of coextensive or coaxially with it. For the particular arrangement shown in Figures 1-7, the material in the region 40 is pressed between and against the inlet tube 14 and the internal support 26; this is the internal support 26 adjusts to a sufficient depth to the end cap 23, that a portion thereof is positioned behind the compressible region 40 to provide support. This is how a good seal is made. The shape of the hole 28 in the region 41 will preferably be a funnel with ribs or graduations (or tapered) to facilitate the coupling. Such arranged ribs are shown in U.S. Patent No. 5,238,474, incorporated herein by reference. In the North American patent 4No. 720,292 shows a similarly tapered surface without ribs. Preferably three tiers of equal size are used from a region of diameter approximately the same as the outside diameter of the inlet tube, the amount of the total compression of the smaller diameter rib (this is the region of most compression) is of approximately 21.4% (20% ± 3%). The size of each tier will depend in part on the diameter of the inlet tube. In general, for an element used with an inlet tube having an external diameter of 175-200 mm, a total compression therethrough of 2.7 mm (or 1.35 mm for any site since any site is compressed by approximately one half of total compression) would be used for the smaller rib. It will then be understood that for the arrangement shown in the figures 1-7, the seal 47 prevents air directed into the filter 35 through the inlet pipe 14 from being diverted from the filter means 25 and into the plenum chamber 44 for clean air. In general, the various portions of the arrangement 4 cooperate as an array of air flow direction to direct the air flow to the housing, to the interior of the filter, through the filter means and out of the housing. Another point of potential leakage of unfiltered air to the plenum chamber 44 of clean air occurs at the site where the inlet construction 3 comes into contact with the can 4 of the filter. This region is generally located at 50; this is where the bolts 8 ensure the construction of the inlet 3 to the can 4 of the filter. In region 50, the inlet construction 3 is provided with a flange 52 extending outwardly and the can 4 is provided with a flange 53 extending outwardly. The seal ring 54 is provided in the extension around the can 4, between the flanges 52 and 53. The seal ring 54 is positioned at a location between the bolts 8 and the filter element 21. When the bolts 8 are tightened , the seal ring 54 will be compressed between the flanges 52 and 53, that is at a location between the inlet construction 3 and the filter can 4, to provide a seal. Thus, air leaks to the plenum chamber 44 through the passage between the portions of the can 4 and the inlet construction 3 are inhibited. The filter ring 54 can be a conventional O-ring seal. Now the attention is drawn to Figure 5, which is an opposite cross-sectional view showing the "lower half" or "opposite end" of assembly 1 from the end where the input construction 3 is located. With reference to 5, the reference number 60 designates in general one end of the wall 61 of the can. A cover or base 63 of the can 4 is positioned within the end 60. The base 63 is advantageously configured in a preferred manner. For the particular embodiment shown, the base 63 is circular, to conform to the cross-sectional configuration of the wall 61 of the can at the end 60. For the particular construction shown, the base 63 is also radially symmetrical. That is, the characteristics of the base 63 are configured in a radially symmetrical manner about the central axis 33. The base 63 includes an end flange 65 for engagement with the end 60, for example by means of welds. Progressively inward from the flange 65 towards its center 66, the characteristics of the preferred base 63 shown are as follows: an annular circumferential sealing surface 67 is provided; a curvature or corner 68; and an end surface 69; a secondary seal cord or shoulder 70 and a central tray 71. In the center 66 of the tray 71, a drain hole 18 is provided. The arrangement shown in Figures 1-7 is preferably configured in such a way that when it is oriented for use, the tray 71 is in its lower or recessed location, in such a way that the water will drain to the tray 71 under the influence of gravity. As the water drains into the tray 71, it will drain outward from the air cleaner assembly 1 through the drain hole 18. Particular features described herein are provided, for a form of waste collection within the assembly 1 and the drainage of accumulated moisture to the orifice 18. Still with reference to Figure 5, the filter element 21 includes the end cap 24 thereon. The end cap 24 is of an appropriate material and of appropriate size, such that when pushed against and against the base 63, an outer circumferential surface 75 of the end cap 24 engages with the surface 67 of the base 63 in a manner sealant That is, an annular seal 76 is formed in the region 77, circumferentially around the end cap 24. This is facilitated by preferably providing the surface 67 in a cylindrical configuration that extends generally parallel to the axis 33. The seal prevents the unfiltered air reaches the chamber 44 impeller of clean air. As a result of the circumferential seal 76, the sealing against the air flow is not required between any of the other portions of the filter element 21 and the base 63. A secondary seal 80, described hereinafter, is nevertheless provided between the end cap 24 and the base 63. A secondary seal 80 is generally provided to inhibit the movement of debris or water to region 81, between element 21 and base 63, instead of necessarily preventing the flow of air therebetween. Thus, while the seal 76 must be in a form sufficient to withstand a differential pressure therethrough of up to approximately 0.1 Kg / cm2 (40 inches of water), the secondary seal 80 will generally be sufficient if it can maintain a pressure differential therethrough of up to about 0.0051 Kg / cm2 (2 inches of water) (and usually only up to about 0.0051-0.0101 Kg / cm2 (2 - 4 inches of water)). Still referring to Figure 5, the end cap 24 includes a circular recess or duct 85 therein. The conduit 85 is dimensioned and configured to receive and engage sealingly with the cord 70. The conduit 85 must be dimensioned, relative to the cord 70, in such a way that when the element 21 is pressed against the base 63, the cord 70 it is pushed into conduit 85 to form a seal therewith, capable of maintaining a pressure differential of up to about 0.0051-0.0101 Kg / cm2 (2-4 inches of water). This could be easily accomplished by forming the related region 86 of the end cap 24 of an appropriately soft, pressible polymer material to which the rigid cord 70 can be pressed for coupling. With reference to Figures 5 and 6, it will be noted that for the shown surface 90 of the preferred embodiment of the end cap 24 is recessed from the outer edge 91 to the region 92, in such a way that a space is provided between the surface 90 and the end surface 69, when the filter element 21 is operatively positioned within the can 4. The amount of gap may vary, depending on the size of the arrangement. In general, an angle of inclination of the edge 91 to the region 92 of the order of approximately 1 to 3 | It will be enough. The advantages resulting from this inclination will be apparent from the additional descriptions given hereunder. In general, the space between the surface 90 and the end surface 69 ensures that there will be no interference with easy formation of the radial annular seal. Still referring to Figures 5 and 6, the inner surface 94 of the end cap 24 is configured to tilt downwards, when the assembly 1 is oriented as shown in Figures 5 and 6 in extension from the outer region 95 towards the center hole 96. Preferably the inner surface 95 is conical or funnel-shaped in this region. Thus all the water that is collected on the internal surface 94 will tend to flow towards the central hole 96 and through it to the recessed tray 71. In some embodiments, recessed radial channels or channels extending outward and upward may be used. to facilitate this flow. Such an arrangement is shown for example in Figure 7 (a top plan view of the element 21) showing four recessed channels or channels 99, spaced evenly (radially). It will be understood that each of the channels 99 slopes generally downward as it extends from the region 95 to the central orifice 96, to facilitate the collection of water in the interior 35 and the direction of the collected water to the central orifice 96. An advantage for the conduits 99 is that if a large sheet or particulate material is positioned in the central hole 96, water can still flow to and through the orifice 96 via the conduits 99, since the conduits 99 can direct in In general, the flow of water below the waste collected on the inner surface 94. Numerous advantages result from the preferred characteristics described. Since assembly 1 is used for a filtration operation, the air will flow in general through the inlet pipe 14 to the interior 35, to transport with the same humidity and / or debris. Moisture and debris tend to be collected in the interior 35, on the inner surface 94 of the end cap 24, since the arrangement 1 will be generally configured with the end cap 24 positioned below the inlet pipe 14. The water that is collected on the inner surface 95 will generally be directed towards the central hole 96, for drainage to the recessed tray 71 and inevitably draining outwardly of the assembly 1 through the drain hole 18. The evacuation valve 19, if use, will facilitate this. Because the seal between the end cap 24 and the housing 2 is positioned along annular circular sealing surface 67, that is in region 77, the critical seal is not located on a surface where the waste is dispersed or collected, since element 21 is separated from and housing 2 is replaced, during normal maintenance operations. Because the surface 90 is recessed from the end surface 69, in extension between the edge 91 and the region 92, any debris may be dispersed along the external surface 69 during operations involving the separation and insertion of the elements. of filter to housing 2, will probably not interfere with the sufficient insertion of element 21 into can 4 for the development of a good seal in region 77. That is, some of the accumulated waste along the bottom of base 63 is well tolerated Also, secondary seal 80 will inhibit the likelihood of debris or moisture moving from tray 71 to surface 69 or rec. 7. This will also facilitate the separation of moisture from assembly 1, since moisture will tend to to concentrate near the drain hole 18. In figure 6 the arrangement of figure 5 is shown in exploded view. From this, a preferred configuration for the surface 75 will be understood, in relation to the circular sealing surface 67 (annular). In particular, the surface 75 includes tiers 101, 102 and 103 with extensions 105 and 106 therebetween.

The tier 103 is approximately the same diameter as the circular sealing surface 67 and facilitates the guidance of the air cleaner element 21 to engagement with the base 63 during assembly. The tier 102 is preferably slightly larger in diameter than the circular sealing surface 67 and the tier 101 is preferably slightly larger in diameter than the tier 102, to improve compression of the end cap material in the region 77, as the element 21 is inserted into the base 63 during assembly. In this way a good seal is formed. In general, for the preferred embodiments, the actual amount of compression of the end cap in the region or tier 102 is 3 mm ± 1 mm in diameter (or 1.5 mm at any location). The diameter of the tier 102 is preferably approximately 1.5 mm greater than the tier 101 and approximately 3 mm greater than the tier 103. The amount of compression in the tier 102 would be approximately 21.4% (20% ± 3%). As indicated, the arrangement described with respect to Figures 1-7 generally uses a radial seal coupling in region 77. Alternate sealing arrangements can be used. An example of such an arrangement is illustrated in the alternative mode of Figure 8.

Alternative modality of axial sealing system Figure 8 provides an alternative application of the principles according to the present invention. Figure 8 illustrates a coupling between the base of the air cleaner assembly and a filter element, to provide the advantages according to the present invention, in an arrangement which uses an "axial seal" between the filter element and the coupling, at least on this site. In general, the axial seal is a seal which is held by the forces directed along an axis of the filter element, as opposed to the radial seal arrangements described with respect to FIGS. 1-7 which use the forces directed radially around an axis. Axial seal arrangements have been widely used in filter elements in a variety of ways. Frequently a central axle or fork is provided, along which the forces between the housing and the element are directed. In other systems an array of bolts between the portions of the housing is used to press the element against one end or both ends of the housing. The O-ring 54 in the embodiment of Figures 1-7, for example, provides the seal by axial compression. Figure 8 is a fragmentary cross-sectional view of an alternative air cleaner assembly 115 according to the present invention. The air cleaner assembly 115 is also a reverse flow arrangement. The assembly 115 includes the housing 166 and the air filter element 117. An input array, not shown, would be used to direct the air flow to the interior 118. The air flow would then be directed through the filter element 117 to the plenum chamber 120 of clean air and out through an outlet conventional, not shown, to an air inlet for a motor. In Figure 8 the outer wall of the housing 116 or can is generally shown at 121. The end of the housing or base 123 is configured to perform functions generally analogous to those for the base 63 of Figures 1-7. with reference to figure 8, the filter element 118 has an end cover of sheet metal, such as the end cap 125. The filter element 117 includes filter means 126 embedded in the end cap 125 (the opposite end cap is not shown in figure 8). Element 117 includes internal and external liners 127 and 128 respectively. The seal between the element 117 and the base, against the air flow between them, is provided by the joint 130. That is, an appropriate mechanism for applying axial forces in the direction of the arrow 131 against the element 117 must be provided to compress the joint 130 between the end cap 125 and the base and form a seal. This can be carried out with bolts used to drive an end cover or entrance construction against an opposite end of the element 117. Preferably appropriate sizes and configurations of the element 117 are selected., the base 123 and the joint 130, such that the seal of the joint 130 will be sufficient to maintain a pressure differential of at least about 0.10 Kg / cm2 (40 inches of H2O) therethrough. In this way, the unfiltered air in the region 132 is prevented from reaching the plenum chamber 120 of clean air during use. In general, the characteristics of the preferred base 132 shown are as follows. The base 123 is radially symmetrical and includes the outer flange 135, for securing to the wall 121 of the can, such as by welding. The base or hollow area 136 is provided to receive a seal 130 therein during sealing. This is accomplished by the recessed area 126 that forms a conduit 137. The region 138, of the base 123, rises above the conduit 137 and provides a raised surface 139 for the provision of a secondary seal, as described below . Then the base 123 defines a tray 145 by the sloping wall or that extends downwards 146 towards a recessed central hole. With respect to the filter element, the end cap 125 includes a downward inclined surface 149 towards the central tray 150 having a drain hole 151 therein. A secondary seal is provided between the end cap 125 and the surface 139 by the secondary seal seal 155. This seal 155 is intended to inhibit migration of moisture and debris from recessed tray 145 to region 137, where it could interfere with seal 130. Secondary seal 155 needs only to provide a sufficient seal to inhibit migration of moisture and debris and does not need to be a fundamental air seal. Thus, the board 155 needs only to be compressed enough to withstand a pressure differential of up to about 0.0051-0.0101 Kg / cm2 (2-4 inches of H2O) therethrough. The operation of assembly 115 will now be evident. When mounted, sufficient axial pressure is applied along the direction of the arrow 131 to provide an air seal end in the seal 130 and a secondary seal in the seal 155. Wastes and moisture directed into the interior 118 they will generally be collected in the tray 150. In general, the moisture that is collected along the recessed surfaces 149 will be directed downward toward and through the hole 151, to the tray 145 of the base 123 and inevitably through the orifice drain 147 and outward of assembly 115. It will be understood that a channel system (analogous to that described in Figures 1-7) can be used in tray 150 if desired, to inhibit the likelihood of the drain hole 151 is plugged or plugged by debris.

Materials While a wide variety of materials may be used in constructions in accordance with the present invention, the principles described herein may advantageously be developed in particular for use with systems constructed from certain preferred materials. In general, the constructions were designed for use with laminar metal housing systems or stainless steel housing systems; this is arrangements where the housing, in particular the input assembly, the can and the base are formed from sheet metal or stainless steel parts which are secured together by welding. Useful materials for such fabrication include stainless steel or lamellar metal of 1.9 - 0.63 cm (0.75 - 0.25 inches) thick, although other thicknesses are usable. You can also use plastics.

For the arrangement of Figures 1-7, the preferred end cap material for forming the regions in the end cap that need to be compressed to form a seal consists of a soft polymeric material, such as foamed polyurethane. Such materials include the following polyurethane, processed to a final product having a density as molded of 14 -0.22-0.35 g / cm3 (22 pounds per cubic foot (lbs / ft3)). The preferred polyurethane comprises a material made with resin I35453R and isocyanate I3050U. The materials should be mixed in a mixing ratio of 100 parts of I35453 resin to 36.2 parts of isocyanate I3050U (by weight). The specific gravity of the resin is 1.04 (8.7 pounds / gallon) and for the isocyanate it is 1.20 (10 pounds / gallon). The materials are usually mixed with a high dynamic shear blender. The temperatures of the components should be 21-35 ° C (70-95 ° F). Mold temperatures should be 46-57 ° C (115-135 ° F). The resin material has the following description: (a) Average molecular weight (1) Polyether polyol base = 500-15,000 (2) Diols = 60-10,000 (3) Trioles = 500-15,000 (b) Average functionality (1) System total = 1.5 - 3.2 (c) Hydroxyl number (1) Total systems = 1.5 - 3.2 (d) Catalysts (1) amine = Air products 0.1 - 3.0 PPH (2) tin = Witco 0.01 - 0.5 PPH (e) Surfactants (1) Total system = 0.1 - 2.0 PPH (f) Water (1) Total system = 0.1 - 2.0 PPH (g) Pigments / dyes (1) Total system = 1.5% carbon black (h) Blowing agent (1) 0.1 - 6.0% of HFC 134A.

The description of isocyanate I3050U is as follows: (a) NCO content - 22.4 - 23.4% by weight (b) Viscosity, cps at 25 ° C = 600 - 800 (c) Density = 1.21 g / cm3 at 25 ° C. (d) Initial boiling point 190 ° C to 5 mm Hg (e) Vapor pressure = 0.0002 mm Hg at 25 ° C (f) Appearance - colorless liquid (g) Flash point (Densky-Martins closed cup) ) = 200 ° C Materials I35453R and I3050U are available from BASF Corporation, Wyandotte, Michigan 48192.

For the arrangement shown in Figure 8, the filter element includes end caps of sheet metal with a corrugated filter paper media element embedded therein. Conventional arrangements such as plastisol embedded can be used.

Dimensions of a classic mode Consider an air cleaner arrangement as shown in figure 1, used on a truck for long distances (heavy duty truck). The housing would be approximately 33-38 cm (13-15 inches) in diameter and approximately 81 cm (32 inches) long. The element would be approximately 28-33 cm (11-13 inches) in diameter and approximately 58-66 cm (23-26 inches) long. The inner diameter of the smallest rib on the sealing portion of the end cap with the inlet tube (before compression) would be approximately 17.22-18.9 cm (6.78-7.44 inches). The inner diameter of the annular surface at the base of the housing where it is presented The radial seal with the second end cap would be approximately 28.65 cm - 50.6 cm (11.28 -19.94 inches). The outer diameter of the largest tier in the second end cap for sealing with the base would be approximately 29.0-33.17 cm (11.4-13.06 inches). The cord on the base for coupling with the second end cap would be large enough to extend the conduit on the end cap to approximately 0.89 cm (0.35 inches). The angle of inclination in the second end cap from its outer rim to the recess that comes into contact with the cord would be about 1 J5 °. The angle of inclination on the inner side of the second end cap would be approximately 4o ± 2 °.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention Having described the invention as above, property is claimed as contained in the following

Claims (19)

1. Claims 1. An air filter element characterized in that it comprises (a) a cylindrical extension of filter means defining an interior of the open filter, the filter means are embedded within the first and second end caps; (b) an internal support lining; (c) an external support liner; (d) the first end cap has a hole for air entry therein; (e) the second end cap has: (i) a central drain hole; the hole is substantially smaller than the inside diameter of the filter means; and (ii) an inner surface with an outer region; The inner surface is angular from the outer region to the central drainage hole and is constructed and arranged to convey the collected moisture on the inner surface of the second end cap to the central drainage hole.
2. 2. An air filter element according to claim 1, characterized in that: (a) the inner surface of the second end cap includes therein a plurality of radially directed conduits, which terminate in the central drain hole.
3. 3. An air filter element according to claim 2, characterized in that: (a) the second end cap has an outer surface that includes a circular sealing duct therein.
4. 4. An air filter element according to claim 3, characterized in that: (a) the external surface of the second end cap includes an outer edge; and (b) the outer surface of the second end cap is recessed in extension between the outer edge and the circular conduit.
5. 5. An air filter element according to claim 4, characterized in that: (a) the recess or recess of the outer surface of the end cap is a funnel-shaped region on the external surface, which has an inclination angle of at least about 1o in extension from the outer edge to the circular conduit. J
6. 6. An air filter arrangement according to claim 1, characterized in that it further includes: (a) a housing; and (b) an arrangement for the direction of the air flow constructed and arranged to direct the air flow: to the housing; inside the open filter; through the filter media and outwards from the housing.
7. 7. An air filter arrangement according to claim 6, characterized in that: (a) the second end cap includes an external, annular, pre-passable portion and (b) the housing includes an annular sealing surface against which the outer portion, The annular, preloading of the second outer cap is sealed when the air filter array is operatively mounted for use.
8. 8. An air filter arrangement according to claim 7, characterized in that: (a) the housing includes a base; the base includes: a central tray and a sealing cord arranged circumferentially around the central recessed tray; (i) the central tray includes a central drain hole; (b) the second end cap is constructed and arranged to form a secondary seal with the weld bead at the base, when the air filter element is operatively positioned within the housing.
9. 9. An air filter arrangement according to claim 8, characterized in that: (a) the second end cap has an external surface that includes a circular duct therein, sized and positioned for the sealing engagement with the sealing bead in base.
10. 10. An air filter arrangement according to claim 8, characterized in that: (a) the inner surface of the second end cap includes therein a plurality of radially directed conduits, which terminate in the central drain orifice.
11. 11. An air filter arrangement according to claim 10, characterized in that it includes (a) an evacuation valve mounted in the drainage hole of the central recessed tray in the base.
12. 12. An air filter element according to claim 10, characterized in that: (a) the second end cap comprises a soft honeycomb polymeric material having a "as molded" density of 7.32 - 10.7 g / cm2 (15-22 lbs. per square foot).
13. 13. An air filter arrangement according to claim 7, characterized in that: (a) the first and second end caps each comprise a soft polymeric material.
14. 14. An air filter arrangement according to claim 13, characterized in that it includes: (a) a tube for the air inlet, constructed and arranged to form a radially directed seal with the hole for the air inlet in the first end cap , when the filter element is operationally positioned within the housing.
15. 15. An air filter arrangement according to claim 6 characterized in that: (a) the second end cap of the filter element consists of an end cover of sheet metal; (b) the housing includes a base having a central tray with a central drain hole, and (c) a primary seal is axially pressed between the second end cap and the base when the air filter arrangement is operationally mounted .
16. 16. An air filter arrangement according to claim 15, characterized in that: (a) the base includes a secondary sealing surface oriented at a higher level than the central recessed tray and between the central tray and the primary seal when The air filter arrangement is assembled operationally; and (b) a secondary seal gasket is compressed between the second end cap of the filter element and the secondary sealing surface of the base when the air filter array is assembled operationally.
17. 17. A method for operating a reverse flow air filter array that includes a cylindrical air filter element therein; the filter element has an upper end cap with a hole for air intake and a lower end cap with a funnel surface and a central hole; the method is characterized in that it includes the steps of: (a) collecting moisture within the cylindrical filter element; and (b) draining moisture from the filter element through the center hole of the lower end cap by channeling moisture along the surface of the funnel to the center hole.
18. 18. A method according to claim 17, characterized in that: (a) the step of draining the moisture from the filter element through the central orifice of the lower end cap includes channeling the moisture along a plurality of radially directed conduits in the lower end cap to the central hole.
19. 19. A method according to claim 17, characterized further includes: (a) after the step of draining the moisture from the filter element through the central hole of the lower end cap, drain the moisture to the tray under the end cap bottom and through a drain hole in the tray.