WO2004045743A1

WO2004045743A1 - Apparatus and method for filtering an aerosol-bearing gas stream

Info

Publication number: WO2004045743A1
Application number: PCT/US2003/036835
Authority: WO
Inventors: Steven Scott Gieseke; Robert A. Dushek; Jan Leo Maria Cappuyns; Peter J. Murray
Original assignee: Donaldson Company, Inc.; MURRAY, Philip, J.
Priority date: 2002-11-18
Filing date: 2003-11-17
Publication date: 2004-06-03
Also published as: WO2004045743A9; AU2003287676A1; AU2003287676A8

Abstract

An arrangement for separating a liquid phase from a gaseous stream includes a filter element having first and second regions of media, operating as a coalescer filter and a particulate filter. There is also a valve construction that helps to regulate gas flow. Preferred orientations include the arrangement being mounted in a top-load configuration. Systems include a combination of the arrangement with an internal combustion engine crankcase. Methods of treating engine blow-by gases include using arrangements of these types. Methods of servicing include servicing arrangements from a position above the portion that would remain in operational connection with the crankcase during servicing.

Description

APPARATUS AND METHOD FOR FILTERING AN AEROSOL-BEARING GAS STREAM

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); Steven Scott Gieseke, a U.S. citizen and resident (Applicant for US only); Robert Allen Dushek, a U.S. citizen and resident (Applicant for US only); Peter J. Murray (deceased) (Applicant for US only); and Jan Leo Maria Cappuyns, a Belgian citizen and resident (Applicant for US only) on 17 November 2003, designating all countries and claiming priority to U.S. serial number 60/427,510 filed 18 November 2002.

Technical Field

This disclosure relates to systems and methods for separating hydrophobic fluids (such as oils) which are entrained as aerosols, from gas streams (for example, air streams). Preferred arrangements also provide for filtration of other fine contaminants, for example carbon material, from the gas streams. Methods for conducting the separations are also provided. This disclosure incorporates by reference herein the following U.S. patents and publications: 5,853,439; 6,171,355; 6,143,049; 6,290,739; and WO 01/47618 (dated July 5, 2001).

Background

Certain gas streams, such as blow-by gases from the crankcase of internal combustion engines, such as diesel engines, carry substantial amounts of entrained oils therein, as aerosol. The majority of the oil droplets within the aerosol are generally within the size of 0.1 -5.0 microns.

In addition, such gas streams also carry substantial amounts of fine contaminant, such as carbon contaminants. Such contaminants generally have an average particle size of about 0.5-3.0 microns.

In some systems, it is desirable to vent such gases to the atmosphere. In general, it is preferred that before the gases are vented to the atmosphere, they be cleaned of a substantial portion of the aerosol and/or organic particulate contaminants therein.

In other instances, it is desirable to direct the air or gas stream into equipment. When such is the case, it may be desirable to separate aerosol and/or particulates from the stream during the circulation, in order to provide such benefits as: reduced negative effects on the downstream equipment; improved efficiency; recapture of otherwise lost oils; and/or to address environmental concerns.

A variety of efforts have been directed to the above types of concerns. The variables toward which improvements are desired generally concern the following:

(a) size/efficiency concerns; that is, a desire for good efficiency of separation while at the same time avoidance of a requirement for a large separator system;

(b) cost/efficiency; that is, a desire for good or high efficiency without the requirement of substantially expensive systems; (c) versatility; that is, development of systems that can be adapted for a wide variety of applications and uses, without significant re-engineering; and, (d) cleanability/regeneratability; that is, development of systems which can be readily cleaned (or regenerated) if such becomes desired, after prolonged use.

Summary of the Disclosure

An arrangement for separating a liquid phase from a gaseous stream includes a filter element having first and second regions of media, operating as a coalescer filter and a particulate filter. There is also a valve construction that helps to regulate gas flow. Preferred orientations include the arrangement being mounted in a top- load configuration.

Systems include a combination of the arrangement with a diesel engine crankcase.

Methods of treating diesel engine blow-by gases include using arrangements of these types. Methods of servicing include servicing arrangements from a position above the engine crankcase.

Brief Description of the Drawings

FIG. 1 is a schematic view of an engine system using a filter arrangement constructed according to principles of this disclosure; FIG. 2 is a perspective view of one embodiment of a filter arrangement, constructed according to principles of this disclosure;

FIG. 3 is an exploded view of the filter arrangement depicted in FIG. 2; FIG. 4 is a top plan view of the filter arrangement depicted in FIG. 2; FIG. 5 is a cross-sectional view of the filter arrangement depicted in FIGS. 2- 4, the cross-section being taken along the line 5-5 of FIG. 4;

FIG. 6 is a schematic, perspective view of a filter element usable in the filter arrangement of FIGS. 2-5; FIG. 7 is a top plan view of the filter element of FIG. 6; and

FIG. 8 is a cross-sectional view of the filter element of FIGS. 6 and 7, the cross-section being taken along the line 8-8 of FIG. 7.

Detailed Description I. A Typical Application — Engine Crankcase Breather Filter

Internal combustion engines, such as pressure-charged diesel engines, often generate "blow-by" gases, i.e., a flow of air-fuel mixture leaking past pistons from the combustion chambers. Such "blow-by gases" generally comprise a gas phase, for example air or combustion off gases, carrying therein: (a) hydrophobic fluid (e.g., oil including fuel aerosol) principally comprising 0.1-5.0 micron droplets (principally, by number); and, (b) carbon contaminant from combustion, typically comprising carbon particles, a majority of which are about 0.1-10 microns in size. Such "blow-by gases" are generally directed outwardly from the engine block, through a blow-by vent. Herein when the term "hydrophobic" fluids is used in reference to the entrained liquid aerosol in gas flow, reference is meant to nonaqueous fluids, especially oils. Generally such materials are immiscible in water. Herein the term "gas" or variants thereof, used in connection with the carrier fluid, refers to air, combustion off gases, and other carrier gases for the aerosol. The gases may carry substantial amounts of other components. Such components may include, for example, copper, lead, silicone, aluminum, iron, chromium, sodium, molybdenum, tin, and other heavy metals.

Engines operating in such systems as trucks, farm machinery, boats, buses, and other systems generally comprising diesel engines, may have significant gas flows contaminated as described above. For example, flow rates and volumes on the order of 2-50 cubic feet per minute (cfin), typically 5 to 10 cfin, are fairly common.

Fig. 1 illustrates a schematic indicating a typical system 28 in which a coalescer/separator arrangement according to the present invention would be utilized. Referring to Fig. 1, block 30 represents an internal combustion engine, for example, a turbocharged diesel engine crankcase. Air is taken to the engine 30 through an air filter 32. Air filter or cleaner 32 cleans the air taken in from the atmosphere. A turbo 34 draws the clean air from the air filter 32 and pushes it through an after-cooler 33 into engine crankcase 30. While in engine 30, the air undergoes compression and combustion by engaging with pistons and fuel. During the combustion process, the engine 30 gives off blow-by gases 38. A filter arrangement 36 is in gas flow communication with engine 30 and cleans the blow-by gases 38.

From filter arrangement 36, the air is directed through a regulator valve 40. From there, the air is again pulled through by the turbo 34 and into the engine 30. Regulator valve 40 regulates the amount of pressure in the engine crankcase 30. Regulator valve 40 opens more and more, as the pressure in the engine crankcase increases, in order to try to decrease the pressure to an optimal level. The regulator valve 40 closes to a smaller amount when it is desirable to increase the pressure within the engine 30. When air intake system vacuum increases, the regulator valve 40 closes to prevent the crankcase 30 from reaching larger negative pressures. The regulator valve 40 automatically adjusts crankcase pressures as the air filter loads and increases the intake system vacuum, and as the oil-coalescing filter arrangement 36 loads with contaminant and increases the crankcase pressure. In some cases, a check valve is provided, such that when the pressure exceeds a certain amount in the engine crankcase 30, the check valve opens to prevent engine damage.

According to this disclosure, the filter arrangement 36 for separating a hydrophobic liquid phase from a gaseous stream (sometimes referred to herein as a coalescer/separator arrangement) is provided. In operation, a contaminated gas flow is directed into the coalescer/separator arrangement 36. Within the arrangement 36, the fine oil phase or aerosol phase (i.e., hydrophobic phase) coalesces. The arrangement 36 is constructed so that as the hydrophobic phase coalesces into droplets, it will drain as a liquid such that it can readily be collected and removed from the system. With preferred arrangements as described herein below, the coalescer or coalescer/ separator, especially with the oil phase in part loaded thereon, operates as a prefilter for carbon contaminant carried in the gas stream. Indeed, in preferred systems, as the oil is drained from the system, it will provide some self-cleaning of the coalescer because the oil will carry therein a portion of the trapped carbon contaminant.

From the arrangement 36, coalesced oil drains by gravity at 35 to, for example, the engine sump. In some applications, it is desirable to use a check valve upstream from the engine sump to allow the coalesced oil to drain while preventing evacuation of oil from the sump. A service cover 42 allows access to the filter arrangement 36 from a position above or over the part that remains fixed on the engine crankcase 30 in operational position during servicing.

II. Multi-Stage Oil Aerosol Separator Embodiment, FIGS. 2-8

Referring to FIG. 2, an embodiment of a crankcase gas filter or filter arrangement 36 is depicted at reference numeral 50. The preferred filter arrangement 50 depicted includes a housing 52 holding a filter element 140 and a regulator valve assembly 51. In the one depicted in the drawings, the housing 52 includes: a body subassembly 57; a valve housing subassembly 100; and a fluid port construction 74.

In the embodiment depicted in FIG. 2, the housing 52 includes a service cover 54 removably attachable to housing body 56. The housing body 56, in the embodiment depicted, includes a generally cylindrical wall 58 defining an interior volume 60 (FIG. 3). The wall 58 includes, on an exterior portion 61, engagement or fastener structure 62 (FIG. 3) for receiving the service cover 54. In particular, the fastener structure 62 includes threads 63 and protrusions 64 that act as stops for the service cover 54 engagement. The service cover 54 defines recesses 65 (recessed slots) that receive the protrusion 64. Ends of the recesses 65 in the service cover 54 will engage the protrusions 64 to prevent rotation of the service cover 54 relative to the body 56.

The service cover 54 has a generally cylindrical outer wall 66, which defines the recesses 65. Joining the outer wall 66 is an end wall 68. When the filter arrangement 50 is operably installed on an engine crankcase, such as the one shown in FIG. 1 at 30, the end wall 68 will form a top cover 69.

In FIG. 5, it can be seen that the service cover 54 also includes an inner wall 70. The inner wall 70 is circumscribed by the outer wall 66. Between the inner wall 70 and the outer wall 66, there is defined a groove 71. The groove 71 holds a gasket member 72 for forming a seal 73 between the service cover 54 and the body 56. Secured to and an integral part of the body 56 is first fluid port construction 74. The first fluid port construction 74 includes a base 76 for engagement with surface 77, forming an end wall 78 for body subassembly 57. The base 76 defines an inner channel or bore 80. The inner bore 80 is in fluid communication with an interior volume 217 of the filter arrangement 50 and with fluid channels outside of the filter arrangement 50, to be explained further below. The inner bore 80 forms a first fluid port 82, which, in certain preferred applications, forms both a fluid inlet and a fluid outlet port, to be explained further below. Extending from the base 76, and in fluid communication with the bore 80, is a fluid tube 84 (FIG. 2) defining a channel or bore 85. Also extending from the base 76 and being coaxial therewith is a fluid tube 86. The tube 86 defines a fluid channel or bore 87. In FIG. 2, it can be seen how the tube 84 and tube 86, in this particular embodiment, have axes that are perpendicular relative to each other. As will be explained further below, in preferred embodiments, the bore 85 receives below-by gases from an engine crankcase, while the bore 87 receives coalesced liquid from the filter arrangement 50 to be returned to, for example, an engine sump. In the particular embodiment illustrated, the tube 84 has a tube 88 extending there from. The tube 88 defines a fluid channel or bore 89 for connection to a restriction indicator (not shown) for detecting restriction (pressure). Extending from the base 76, and forming a part of the bore 80, is a tube section 90. The tube section 90, in the embodiment shown, is a slotted cylindrical wall 92. The wall 92 defines a plurality of slots 93, extending completely from free end 94 to the base 76. The slots 93 allow the tube section 90 to flex radially inwardly to mateably engage with an end portion 95 of a neck 163 of the body subassembly 57. The wall 92 has catches 96 to allow for the engagement with the end portion 95.

In the embodiment illustrated, a gasket member 98 is oriented between the first fluid port construction 74 and the body subassembly 57, between base 76 and surface 77, to form a seal 99 and prevent leakage there between. The neck 163 projects axially inwardly from wall 78 of the body subassembly 57. The neck 163 defines the end portion 95 of the body subassembly 57, which engages the catches 96 of the wall 92. The neck 163 defines an aperture 97, which receives the tube section 90. Secured to the body subassembly 57, and part of the overall body 56, is valve housing subassembly 100. The valve housing subassembly holds the regulator valve assembly 51. The valve housing subassembly 100 includes a valve housing body 102 and a valve housing cover 104. The valve housing body 102 includes an outer wall 106 defining an open interior volume 107 (FIG. 5).

A second fluid port construction 108 (FIGS. 2 - 4) is in fluid communication with the interior volume 107 (FIG. 5). The second fluid port construction 108 includes a tube 109 extending from the outer wall 106 and defines an inner fluid passage or bore 110. The tube 109 passes through the outer wall 106 and terminates at a valve seat 112 (FIGS. 3 and 5). The valve seat 112 is defined by a tubular wall

113, which is circumscribed by the outer wall 106.

In FIG. 5, it can be seen that the valve seat 112 defines an inner shoulder

114. The shoulder 114 supports a portion of the valve assembly 51, a biasing mechanism, such as a spring 116. The spring 116 is biased against another part of the valve assembly 51 , diaphragm 118. The diaphragm 118 is held by a groove 119 defined between the outer wall 106 and an internal ring 120 circumscribed by the outer wall 106. As such, the diaphragm 118 is operably oriented between the valve housing cover 104 and the valve housing body 102.

The diaphragm 118, in the embodiment illustrated, includes an outer lip 122 that is seated within the groove 119. The diaphragm 118 extends from the groove 119 and extends across the valve housing body 102 to cover and close the interior volume 107. The diaphragm 118, in the embodiment illustrated, includes an axial extending ring 124 that engages and is received within the spring 116.

Between the diaphragm 118 and service cover 104 is an open volume 126. In operation, when the filter arrangement 50 has sufficient pressure there within to overcome the compressive force of the spring 116, the diaphragm 118 is elastically deformed to occupy the space in the volume 126.

The valve housing body 102 includes a plurality of threaded bores 128 for accommodating fasteners, such as bolts 129 to allows selective removability and attachment of the valve housing subassembly 100 to the body assembly 57. This permits servicing of the regulator valve construction 51. A plate 130 is provided to ensure a good connection between the body subassembly 57 and the valve housing subassembly 100. In FIG. 3, it can be seen how the body assembly 57 defines surface 133 for interfacing with the valve housing subassembly 100. hi particular, the surface 133 engages the plate 130 and also defines therein fastener receiving bores 134.

The cover 104 is removably attachable to the valve housing body 102. As can be seen in FIGS. 2 and 3, the cover 104 defines fastener flanges 132 for receiving the bolts 129. In the exploded view shown in FIG. 3, it can be seen how the filter arrangement 50 includes within the housing 52 a removable and replaceable filter element 140. The filter element 140 includes within it a first stage coalescer filter 141 and a second stage filter media 142. In use, a liquid entrained gas stream is directed through the first stage coalescer filter 141, in which a portion of the liquid phase is coalesced and removed from the gaseous stream by the first stage coalescer filter 141. The liquid that is coalesced within the first stage coalescer filter 141 drains and exits the housing 52 through the first fluid port construction 74. The gas phase is directed through the second stage filter media 142. The second stage 142 removes at least a portion of particulates from the gas stream, and then the cleaned gas stream is directed into the valve housing subassembly 100 and out through the second fluid port construction 108. hi reference now to FIGS. 6 - 8, the filter element 140 is depicted as a single, unitary construction 144. In preferred embodiments, the filter element 140 is removable and replaceable from the housing 52. As used herein, the term "unitary" means that the first stage filter 141 and the second stage media 142 cannot be separated without destroying a portion of the element 140. In the particular embodiment illustrated, the element 140 includes first and second opposite end caps 146, 147 that are part of the unitary construction 144. When the filter element 140 is handled, for example, during servicing, both the first stage coalescer filter 141 and the second stage media construction 142 are handled together.

The filter element 140, in preferred embodiments, is constructed similarly to filter element embodiments described in publication WO 01/47618, published on July 5, 2001 and incorporated herein by reference.

In general, the second stage media construction 142 includes a tubular construction of media 148 defining an open filter interior volume 149 (FIG. 8). In preferred implementations, the tubular construction of media 148 will be configured to have a generally cylindrical shape, defining a circular cross-section. In preferred embodiments, the first stage media 141 is oriented in extension across the tubular extension of media 148 and in gas flow communication with the open filter interior volume 149.

In certain preferred embodiments, the tubular construction of media 148 includes pleated media 150. The pleated media 150 defines a plurality of pleats 151 from which gas to be treated flows. The pleated media 150 acts as a polishing filter to remove some of the particulates and debris from the gas stream before exiting the filter arrangement 50.

The pleated media 150 has a first end 152 and an opposite, second end 153. The length of the individual pleats 151 of the pleat media 150 extends between the first end 152 and the second end 153. In the particular embodiment illustrated, the first end cap 146 is secured to the first end 152 of the media 142, while the second end cap 147 is secured to the second end 153. In certain preferred implementations, the pleated media 150 is embedded and molded within the end caps 146, 147.

The filter element 140 depicted includes at least one filter support 168. In the embodiment shown, the support 168 is an outer, perforated liner 169, extending between the first and second end caps 146, 147 and circumscribing the media 148. In other embodiments, there may be an inner liner within the media 148.

In preferred embodiments, the end cap 146 includes a ring 154 of a molded, polymeric material. The ring 154 defines a center aperture 155 that, in the preferred embodiment illustrated, is centered in the ring 154. By "centered", it is meant that the aperture 155 has a center of symmetry that is the same as the center of symmetry of the ring 154. In other words, the center 155 is preferably not eccentrically disposed within the ring 154.

The ring 154 also includes an inner, annular surface 156. When filter element 140 is operably assembled within housing 52, the inner annular sealing surface 156 functions as a sealing portion 158. In preferred arrangements, the sealing portion 158 includes a stepped construction 159.

In particular, the stepped construction 159 helps with the insertion and formation of a radial seal 160 (FIG. 5) between the end-cap 146 and the sealing surface 157 of the housing 52. In FIG. 8, the stepped construction 159 includes decreasing diameters and results in a construction that helps with the insertion of the filter element 140 in the body 56. Note that, in the embodiment illustrated, the sealing surface 157 is along an outer wall 161 of a neck 163 of the body subassembly 57. The sealing portion 158 of the end cap 147 is preferably made from a compressible material, such that there is radial compression of the sealing portion 158 against the sealing surface 157, when the element is operably installed in the housing 52. In general, preferred end caps 146 will comprise a soft, polyurethane foam having an as-molded density of typically, less than 22 lbs per cubic foot, for example about 14-22 lbs. per cubic foot.

Still in reference to FIG. 8, there is a frame construction 162 oriented in the center aperture 155 of the ring 154. The frame construction 162 holds, contains, and encapsulates a region of fibrous media 164. hi the construction shown, the fibrous media 164 is used as the first stage coalescer filter 141. i certain preferred arrangements, the fibrous media 164 comprises at least one layer, and typically, a plurality of layers 165 of nonwoven, nonpleated, non open-tubular, coalescing media. In the embodiment shown in FIG. 8, there are two layers 166, 167 of fibrous media 164. Certain usable, example materials for the fibrous media 164 are described further below.

Still in reference to FIG. 8, in the frame construction 162 depicted, the frame construction 162 is a multi-piece, in particular, a two-piece construction including a first frame piece 170 and a second frame piece 172. The first frame piece 170 has a wall or an outer annular rim 174. Axially spanning across one end of the rim 174 and integral with it is a support grid 176, preferably in the form of a porous, mesh screen 178. The screen 178 provides structural support to the media 164 and permits gas flow to reach the media 164.

The wall or rim 174 preferably defines a recess 180 for engaging and receiving a mating detent 182. The detent 182 is part of the second frame piece 172, in the particular preferred embodiment illustrated. The detent 182, recess 180 arrangement provides for convenient, quick assembly and permits the first and second frame pieces 170, 172 to be snapped together. Of course, many other embodiments of mechanical engagement between the first and second frame pieces

170, 172 are contemplated. The second frame piece 172 preferably includes an annular wall 184 surrounding and defining an open volume 186. In the particular embodiment illustrated, the wall 184 has a generally circular cross-section, which may be constant (to form a cylinder) or tapered to form a conical shape. The second frame piece wall 184 includes first and second opposite ends, 187, 188. In the embodiment illustrated, the end 187 generally corresponds to an inlet end. In preferred orientations, the end 187 will also correspond to an outlet end for coalesced liquids. Second frame piece 172 also preferably includes a support grid 190 spanning the open volume 186 and integral with the wall 184. Preferably, the grid 190 comprises a screen 191. The screen 191 provides structural support to the coalescing media 164 and preferably engages and holds the downstream face 192 of the media 164.

The first and second frame pieces 170, 172 form an interior volume or retaining pocket 193 to hold, entrap, and encapsulate the coalescing media 164. Preferably, the media 164 is mechanically compressed within the pocket 193, such that the grid 1 6 engages the upstream face 194 and the grid 190 engages the downstream face 192. As described above, the wall 184 includes projection or detent 182 extending or projecting internally into the volume 186 to engage or snap into the recess 180. The second frame piece 172 also includes mechanical engagement structure to securably attach to a wall 196 of a tube 198. In particular, the second frame piece 172 and the tube 198 also includes mechanical engagement structure, such as a detent/recess engagement 199. In this manner, the second frame piece 172 easily snaps and interlocks with the tube 198. Preferred frame constructions 162 also include support ring or frame 202.

The support frame 202 helps to center the frame construction 162 and hold it evenly within an open filter interior 149. The support frame 202, in the one depicted, in FIG. 5, includes a ring construction 204 having at least an inner ring 206 and an outer ring 208. The inner ring 206 and the outer ring 208 are preferably joined by a plurality of spokes or ribs 209. Between the inner rings 208 and outer ring 209, the ring construction 204 defines a plurality of gas flow passageways 210 (FIG. 7).

The ring construction 204 and the tube 198 are constructed and arranged to permit convenient manufacturing and assembly. In particular, the ring construction 204 and the tube 198 are configured to be secured together, such as by a mechanical engagement such as a detent/recess arrangement 212.

Referring again to FIG. 8, the filter element 140 preferably includes a flow construction arrangement 215 oriented to direct fluid, such as gas, from the first region of media 141 toward the second stage media 142. In general, the flow construction arrangement 215 preferably includes tube 198 formed by impervious, continuous, uninterrupted wall 196 surrounding and defining an open, fluid passage 217. In preferred embodiments, the tube 198 extends from the downstream face 192 of the first stage coalescer filter 141 at least partially in a direction toward the second end cap 147. In preferred embodiments, the tube 198 extends a complete distance between the downstream face 192 and the second end cap 147. In the particular arrangement depicted, the tube 198 forms an aperture 218, preferably a fluid exit aperture 219, at the end 220 of the wall 216 adjacent to the second end cap 147. In this manner, in this particular arrangement, in preferred embodiments, liquid that is coalesced by the first stage coalescer filter 141 is allowed to collect along the interior 221 of the tube 198 and drip by gravity back through the first stage media 141 and through the first flow port 74 (FIG. 5). Alternate drain arrangements are also usable. While in the depicted embodiment, the entire wall 216 includes an imperforate section 222, in other embodiments, only portions of the wall 196 will be imperforate. In the embodiment of FIG. 8, the flow construction arrangement 215 is depicted as a conical section 223 having a sloped or tapered wall 196. hi preferred constructions, the angle of taper on the wall 196 will be adjusted depending upon the overall length of the element 140.

After passing through the first stage coalescer filter 141, the gas flows through the fluid passageway 217, out through exit aperture 218, and then into a gas flow plenum 224. The gas flow plenum 224 is formed between the wall 196 of the tube 198 and the pleated media 150. The taper on the wall 196 causes the gas flow plenum 224 to be angled between a volume 225 adjacent to the second end cap 147 and a volume 226 adjacent to the first end cap 146 and the frame construction 162 that is smaller than volume 225.

The depicted second end cap 147 includes a ring 228 defining a center aperture 230. The end cap 147 supports a sealing arrangement 232 for forming a seal 233 (FIG. 5) with the housing 52. In the embodiment illustrated in FIG. 5, the particular seal 233 depicted is an axial seal 234 formed between the filter element 140 and an inner sealing surface 235 of the cover member 54. In preferred embodiments, the sealing arrangement 232 includes a projection 236 extending or projecting in an axial direction from a generally flat, planar portion 237 of the second end cap 147. In many preferred embodiments, the projection 236 forms a continuous ring 238 (FIG. 7). Preferred constructions include the end cap 147 and the projection 236 being a single, unitary, molded construction. In preferred embodiments, the end cap 147 is made from a polymeric material, preferably, a compressible polymeric material such as polyurethane. In many preferred embodiments, the second end cap 147 is made from the same material as the first end cap 146. The axial seal 234 helps to prevent gas from bypassing the first stage coalescer filter 141 and the second stage construction of filter media 142.

III. Principles Related to Size, Efficiency, and Performance; Materials

An arrangement utilizing principles described herein can be configured in a relatively small package, with efficient operation. For example, the first stage coalescer filter 141 is configured to have an upstream surface area of no more than 25%, usually no more than 10% of the upstream surface area of the second stage filter media 142. I-n many applications, this percentage is much lower, typically 2% or less and often 1% or less. Typical percentages of the upstream surface area of the first stage coalescer filter 141 to the second stage filter media 142 are in the range of at least 0.1 %, typically 0.2% - 1%. For heavy duty engines (engines having a 12-15 liter piston displacement), the percentage is on the order of less than 0.5%, typically 0.25%). For medium duty engines (engines having a 6-9 liter piston displacement), the percentage is often less than 0.8%, for example about 0.4%>. For light duty engines (engines having a piston displacement of less than 6 liters), the percentage is usually less than 1.5%, for example on the order of 0.8%.

It is foreseen that systems such as those depicted in the figures will be configured in relatively small overall packages. For example, overall sizes for the element 140 will have an outside diameter of no greater than 8 inches, and at least 3 inches, with a length of no greater than 15 inches, and at least 4 inches. For heavy duty engines, the size of the element 140 will be about 5.5 inches diameter and 11 inches long. For medium duty engines, the element 140 will be about 5 inches in diameter and 8 inches long. For light duty engines, the size of the element 140 will be about 4 inches in diameter and 6 inches long. When selecting the size for the element 140, the amount of filter media used in the element 140 is adjusted in order to maintain a desirable range of air velocities through the engine. In systems described herein, it is preferred that the face velocity across the first stage filter media 141 be maintained at a constant of 250-400 feet per minute. Similarly, it is preferable in systems described herein to maintain the face velocity across the second stage filter media 141 of no more than 1 foot per minute.

The amount of media for each of the first stage coalescer filter 141 and second stage filter media 142 are selected up to achieve efficient filtering, while limiting the amount of restriction. In systems described herein, the overall efficiency of the filter arrangement 50 is on the order of at least 80%, and typically 90-95%). By "efficiency", it is meant the fraction of mass in the gas stream that is captured or trapped by the first stage coalescer filter 141 and second stage filter media 142. The efficiency of the first stage coalescer filter 141 is usually at least 25%>, in some cases no greater than 70%, typically 30-60%, for example 50%. The second stage filter media 142 preferably has a greater efficiency than the first stage coalescer media 141, on the order of at least 70%, typically 80-90%>.

Restrictions across the first stage coalescer filter 141 are on the order of 0.5 inch of water at the beginning of the filter life, typically 3-4 inches, and on the order of 5.0 inches of water at the end of the filter life. For the second stage filter media 142, the restriction will be at least 0.5 inch of water (typically at the beginning of the filter life), and up to about 15 inches of water at the end of the life. Usable Materials The sealing portions 158, 232, and preferably, the entire end caps 146, 147 preferably comprise foamed polyurethane. One example foamed polyurethane is described above. Another usable foamed polyurethane is as follows: BASF 36361R resin / WUC 3259T isocyanate, with processing conditions of: component temperatures of 75-95° F for the resin and for the isocyanate. The mold temperature should be 120-140°F. The demold time should be 6 minutes. The compression deflection at 70°F, average 10 +4/-3 psi; after heat aging 7 days at 158°F, +/-20% change from original deflection; at -40°F cold temperature, 100 psi maximum average. The compression set, after heat aging 22 hours at 212°F, 15% maximum. The hardness should be 26 Shore A. The tensile strength should be 92 psi target. The elongation should be 120% minimum average. The tear strength should be 10 lb/in minimum average. The as molded density should be less than 30 lbs/ft³, for example, 23-28 lbs/ft³, and can be in the range of 10-24 lbs/ft³. The housing 52 preferably comprises plastic, such as carbon filled nylon. The preformed insert 215 is preferably injection molded from a synthetic resinous plastic material, such as DELRLN®, available from DuPont.

The media for the coalescer filter 141 preferably comprises polyester, depth media. One useable type is generally non-pleated, non-cylindrical, polyester fibrous media having an average fiber diameter of less than about 18 microns, typically about 12.5 microns and a percent solidity, free state, of no greater than about 1.05%. The media 141 has an upstream, and a downstream exposed surface area of at least 1

9 9 9 in. , no greater than about 7 in. , and typically about 3-4 in. The material has an average fiber diameter of 1.5 denier (about 12.5 micron), and a solidity in a free state of at least 0.85%>. It has a weight of, typically, greater than about 3.1 ounces per square yard. Typically, it has a weight less than 3.8 ounces per square yard. Typical weights are within the range of 3.1-3.8 ounces per square yard (105-129 grams per square meter). Typically, the media has a thickness at 0.002 psi compression (free thickness) of greater than about 0.32 inches. Typically, the media has a thickness at 0.002 psi compression (free thickness) of less than about 0.42 inches. Typical free thicknesses for the media are in the range of 0.32-0.42 inches (8.1-10.7 millimeters). The media has a typical permeability of no less than about 370 feet per minute (113 meters per minute). The pleated media tubular filter 150 is preferably constructed of a synthetic glass fiber filter medium, coated and corrugated to enhance performance in ambient air-oil mist conditions. The media 150 has a face velocity of at least 0.1 ft/min., no greater than 5 ft/min., and typically about 0.3-0.6 ft./min. The pleat depth is no less than 0.5 in., no greater than 3 in., and typically about 0.75-2 in. The pleat length is at least 1 in., no greater than 15 in., and typically 3-6 in. The pleated media 150 has an upstream media surface area of at least 2 ft² and preferably about 3-5 ft². There are at least 30 pleats, no greater than about 150 pleats, and typically about 60-100 pleats. The synthetic glass fiber filter media may be coated with a low surface energy material, such as an aliphatic fluorocarbon material, available from 3M of St. Paul, Mimiesota. Prior to coating and corrugating, the media has a weight of at least 80 pounds/ 3000 sq. ft; no greater than about 88 pounds/3000 sq. ft; typically in a range from about 80-88 pounds/3000 square feet (136.8 ± 6.5 grams per square meter). The media 150 has a thickness of 0.027 ± 0.004 inches (0.69 ± 0.10 millimeters); a pore size of about 41-53 microns; a resin content of about 21-27%; a burst strength, wet off the machine of 13-23 psi (124 ± 34 kPa); a burst strength wet after 5 minutes at 300°F of 37 ± 12 psi (255 ± 83 kPa); a burst strength ratio of about 0.30-0.60; and a permeability of 33 ± 6 feet per minute (10.1 ± 1.8 meters per minute). After corrugating and coating, the media has the following properties: corrugation depth of about 0.023-0.027 inches (0.58-0.69 millimeters); a wet tensile strength of about 6-10 pounds per inch (3.6 ± 0.91 kilograms per inch); and a dry burst strength after corrugating of no less than 30 psi (207 kPa).

IN. Example Operation And Service

In preferred applications, the filter arrangement 50 will be mounted for use with engine crankcase 30 in a "top-load" orientation. By the term "top-load", it is meant that the filter arrangement 50 is installed in an orientation that permits servicing or access to the filter arrangement 50 from a position over or above whatever part that remains fixed to the engine in operational position during servicing, when the engine crankcase 30 is in normal, operable orientation. In top- load configurations of the type shown in FIGS. 1 - 8, the person servicing the filter arrangement 50 is not required to be in a position underneath or below the engine crankcase 30. Instead, the person servicing the filter arrangement 50 is able to access it from the top of the engine crankcase 30. For example, in a vehicle having an engine that is selectively accessible by a moveable hood, the filter arrangement 50 would be accessible merely by raising the hood of the vehicle and then removing the service cover 54 of the housing 52. It should be understood that alternate orientations of the filter arrangement 50 could also be used. In operation, one typical filter arrangement 50 would work as follows.

Blow-by gases 38 from engine crankcase 30 are taken in through the fluid channel 85 defined by the tube 84. A gas flow direction arrangement directs the gases into the first fluid port construction 74 and through the fluid channel 80. From there, the gases flow through the first stage coalescer media 141. The coalescer media 141 separates liquids, with any entrained solids, from the rest of the gas stream. A liquid collection arrangement directs the liquid to flow out of the first stage coalescer media 141 and, in the preferred orientation shown, drip back through the coalescer media 141 and drains by gravity back through the first fluid port construction 74.

The liquid, which is often oil, will typically be drained through the channel 87 and directed to an oil sump for reuse by the crankcase 30. The liquid collection arrangement can include the housing construction and suitable ports that allow for the drainage of the liquid. The gas flow direction arrangement can include various combinations of the housing construction and fluid ports. The gas stream that is not coalesced by the first stage coalescer filter 141 flows through the fluid passage 217 of the flow construction 215 and through the exit aperture 218, around the end 220 of the wall 196 (making about 180° turn), through the gas flow passageway 210 and into the gas flow plenum 224. Some liquid that remains in the gas may coalesce by impingement against the wall 196 of the flow construction 215 and drip by gravity back through the first stage coalescer filter and then exit the filter arrangement 50 through the first fluid port construction 74.

From the gas flow plenum 224, the gas flows through the second stage filter media 142, which removes additional particles and solids from the gas stream. The gas flow is prevented from bypassing the second stage media 142 due to the seals 160, 233. The cleaned gas then flows downstream from the second stage filter media 142 and into the valve housing subassembly 100.

The gas flows into the interior volume 107 and into the valve seat 112. The gas exits the filter arrangement 50 through the second fluid port construction 108, in particular through the fluid bore or channel 110. From there, the gas is pulled by the turbo 34 back into the engine 30. The regulator valve construction 51 regulates the amount of pressure in the engine crankcase 30. As pressure in the engine crankcase 30 increases, the gas within the volume 107 has an increased pressure. This pressure results in a force to move the diaphragm 118 in a direction against the spring 116 and into the volume 126 toward the valve housing cover 104. When the diaphragm 118 is moved in this direction, the channel 110 is opened more to allow more volume of gas to flow therethrough. When the pressure within the engine crankcase 30 decreases, the regulator valve construction 51 adjusts, in that the diaphragm 118 moves away from the cover 104 and this decreases the opening allowed to flow into the channel 110. When the air intake system vacuum increases, the regulator valve construction 51 closes to prevent the crankcase 30 from reaching larger negative pressures.

The filter arrangement 50 is serviced as follows. When the filter arrangement 50 is mounted in a top-load configuration and the engine crankcase is in a normal, operable orientation, the cover 54 is removed from the housing body 56 by accessing the filter arrangement 50 from a position above or over the portions of the filter arrangement that remains in operational position during servicing. I-n the configuration shown, this includes the first fluid port construction 74. If the engine is protected by a moveable hood, the hood is first raised to expose the engine 30, and then the service cover 54 is removed from a position over the first fluid port construction 74. In the example shown in FIG. 1, this also happens to be a configuration of over or above the crankcase 30.

The cover 54 is removed from the body 56 by rotating the cover 54 relative to the body 56 and releasing the protrusions 64 from the recesses 65. When the cover 54 is removed from the body 56, the seal 233 between the body 56 and the cover 54 is released. The filter element 140 is exposed. The end of the filter element 140 adjacent to the second end cap 147 is grasped, typically by hand, and the filter element 140 is pulled in an axial direction from the interior 60 of the body 56. As the filter element 140 is pulled from the interior 60, the radial seal 160 between the filter element 140 and body 56 is released. This step removes simultaneously both the first stage coalescer filter 141 and the second stage media construction 142. The filter element 140 is removed from the housing 52 from a position above or over the first fluid port construction 74 and the engine crankcase 30, in preferred orientations. This filter element 140 may then be disposed of, such as by incineration.

A second, new, replacement filter element 140 is then provided. The replacement element 140 also includes the first stage coalescer filter 141 and the second stage media construction 142. The replacement element 140 is inserted through the open end 67 of the body 56. Note that the open end 67 is at an opposite end from the opening of the neck 163. The filter element 140 is oriented such that the sealing portion 158 of the first end cap 146 is compressed between and against the first frame member 172 and the sealing surface 157 of the neck 163 to form radial seal 160 there between. Next, the service cover 54 is placed over the opening 67 of the housing body

56. The cover 54 is rotated by threaded engagement into operable security with the body 56 until the protrusions 64 are located within the recesses 65. This also creates axial seal 233 between the service cover 54 and the element 140 by compression of the seal projection 236 on the second end cap 147 against the service cover 54. V. Example Principles of the Invention

A filter arrangement includes a filter housing construction having a sidewall and defining an interior volume and at least first and second fluid ports; a filter element operably positioned in the interior volume of the housing construction; the filter element including: first media defining an open filter interior; a region of second media oriented in extension across the first media in gas flow communication; the region of second media being constructed and arranged to separate at least a portion of a liquid phase from gases flowing therethrough; a gas flow direction arrangement constructed and arranged to direct gas flow from the first fluid port, through the region of second media, through the first media, and out through the second fluid port; and a liquid collection arrangement constructed and arranged to direct liquid collected by the region of second media to the first fluid port. In example embodiments, the filter element is removable and replaceable in the housing construction.

In example embodiments, the filter element includes first and second opposite end caps; the first end cap forming a first seal with the housing construction; and the second end cap forming a second seal with the housing construction.

In example embodiments, the first end cap has an inner, annular surface comprising a polymeric material; the inner annular surface being positioned to form the first seal with the housing construction; and the second end cap includes an axial projection comprising a polymeric material oriented to form the second seal with the housing construction.

In example embodiments, the housing construction includes a body member and a cover removable there from.

In example embodiments, a regulator valve arrangement is held within the housing construction. A diesel engine blow-by recovery system includes an internal combustion engine having a crankcase; and the filter arrangement in fluid flow communication with the crankcase; the filter arrangement including the filter housing construction; the filter housing construction having a body including the sidewall, and a service cover removable from the body; the filter arrangement being mounted relative to the crankcase to result in the service cover being above the crankcase, when the engine and crankcase are in an operable orientation.

In example embodiments, the filter element is removable and replaceable in the housing construction from a position above the crankcase and engine. In example embodiments, the filter arrangement includes a valve arrangement held within the housing construction; the valve arrangement being downstream of the first media and upstream of the second fluid port.

A method of treating engine blow-by gases includes steps of: directing blow-by gases from an engine through a first fluid port to a coalescer filter; removing at least a portion of a liquid phase from the gases with the coalescer filter as a collected liquid; after the step of removing at least a portion of a liquid phase, directing the gases through a tubular media filter; filtering at least a portion of particulates from the gases with the tubular media filter; and after the step of removing at least a portion of the collected liquid phase, draining by gravity at least a portion of the collected liquid from the coalescer filter through the first fluid port.

In a filter arrangement operably mounted to an engine crankcase, the engine crankcase being in an operable orientation; a method of servicing including from a position above the filter arrangement, removing a cover of the filter arrangement from a body of the filter arrangement; installing a filter element into the body; the step of installing the filter element includes installing a coalescer filter and a downstream particulate filter; and securing the service cover onto the body.

In some examples, the step of installing includes forming a radial seal between the filter element and the body.

This description represents example principles of the inventions. Many embodiments can be made.

Claims

We claim:

1. An aerosol filter arrangement comprising:

(a) a filter housing construction having a sidewall and defining an interior volume and at least first and second fluid ports;

(b) a filter element operably positioned in said interior volume of said housing construction; said filter element including:

(i) a tubular extension of first media defining an open filter interior; (ii) a region of second media oriented in extension across said tubular extension of first media in gas flow communication with said open filter interior; (A) said region of second media being constructed and arranged to separate at least a portion of a liquid phase from gases flowing therethrough;

(c) a gas flow direction arrangement constructed and arranged to direct gas flow from said first fluid port, through said region of second media, into said open filter interior, through said tubular extension of first media, and out through said second fluid port; and

(e) a liquid collection arrangement constructed and arranged to direct liquid collected by said region of second media to said first fluid port.

2. A filter arrangement according to claim 1 wherein:

(a) said filter element is removable and replaceable in said housing construction.

3. A filter arrangement according to any one of claims 1 and 2 wherein: (a) said filter element includes first and second opposite end caps;

(i) said first end cap forming a first seal with said housing construction; and (ii) said second end cap forming a second seal with said housing construction.

4. A filter arrangement according to claim 3 wherem:

(a) said first end cap has an inner, annular surface comprising a polymeric material; said inner annular surface being positioned to form said first seal with said housing construction; and

(b) said second end cap includes an axial projection comprising a polymeric material oriented to form said second seal with said housing construction.

5. A filter arrangement according to any one of claims 1-4 wherein:

(a) said housing construction includes a body member and a cover removable there from.

6. A filter arrangement according to any one of claims 1-5 further comprising: (a) a regulator valve arrangement held within said housing construction.

7. A diesel engine blow-by recovery system comprising:

(a) an internal combustion engine having a crankcase; and

(b) the aerosol filter arrangement according to claim 1 in fluid flow communication with said crankcase;

(i) the filter arrangement including the filter housing construction; the filter housing construction having a body including the sidewall, and a service cover removable from the body;

(ii) the filter arrangement being mounted relative to said crankcase to result in said service cover being above said crankcase, when said engine and crankcase are in an operable orientation.

8. A system according to claim 7 wherein:

(a) said filter element is removable and replaceable in said housing construction from a position above said crankcase and engine.

9. A system according to any one of claims 7 and 8 wherein:

(a) said filter arrangement includes a valve arrangement held within said housing construction; said valve arrangement being downstream of said first media and upstream of said second fluid port.

10. A method of treating engine blow-by gases; the method comprising steps of:

(a) directing blow-by gases from an engine through a first fluid port to a coalescer filter;

(b) removing at least a portion of a liquid phase from the gases with the coalescer filter as a collected liquid;

(c) after said step of removing at least a portion of a liquid phase, ' directing the gases through a media filter;

(d) filtering at least a portion of particulates from the gases with the media filter; and

(e) after said step of removing at least a portion of the collected liquid phase, draining by gravity at least a portion of the collected liquid from the coalescer filter through the first fluid port.

11. A method according to claim 10 wherein:

(a) the media filter is a tubular media filter; and

(b) said step of directing the gases through the media filter includes directing the gases along an interior volume of an inner tube oriented within the interior of the tubular media filter, around an end of the inner tube, and into a gas flow plenum between a volume outside of the inner tube and inside of the tubular media filter.

12. A method according to claim 10 further including:

(a) after said step of filtering at least a portion of particulates from the gases with the media filter, directing the filtered gases through a valve arrangement and out through a second fluid port.

13. A method of servicing an aerosol filter arrangement according to claim 1; the filter arrangement being operably mounted to an engine crankcase, the engine crankcase being in an operable orientation; the method comprising: (a) from a position above the aerosol filter arrangement, installing a filter element into the aerosol filter arrangement body;

(i) said step of installing the filter element includes installing a coalescer filter and a downstream particulate filter; and

(b) securing a service cover onto the body.

14. A method of servicing according to claim 13 wherein:

(a) before said step of installing, removing the cover of the aerosol filter arrangement from the body of the filter arrangement; and

(b) said step of installing includes forming a radial seal between the filter element and the body.

15. A method of servicing according to any one of claims 13 and 14 wherein:

(a) the filter arrangement is operably mounted to an engine crankcase for a vehicle having a movable hood for selective access to the engine crankcase; and

(b) before said step of removing, raising the hood of the vehicle and then removing the service cover from a position over the engine crankcase.

16. A method of servicing according to any one of claims 13-15 wherein:

(a) said step of securing the service cover includes threadably rotating the service cover relative to the body until protrusions on one of the service cover and body engage recessed slots on the other of the service cover and body.

17. A method of servicing according to any one of claims 13-16 wherein: (a) said step of installing a filter element includes simultaneously installing a coalescer filter and a downstream particulate filter; the coalescer filter and downstream particulate filter being part of a single integral filter element.