CA1069001A - Air cleaner with integral louvered precleaner - Google Patents
Air cleaner with integral louvered precleanerInfo
- Publication number
- CA1069001A CA1069001A CA284,507A CA284507A CA1069001A CA 1069001 A CA1069001 A CA 1069001A CA 284507 A CA284507 A CA 284507A CA 1069001 A CA1069001 A CA 1069001A
- Authority
- CA
- Canada
- Prior art keywords
- outlet
- air
- separator
- frustoconical
- casing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/52—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material
- B01D46/521—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D45/00—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces
- B01D45/12—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by centrifugal forces
- B01D45/16—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by centrifugal forces generated by the winding course of the gas stream, the centrifugal forces being generated solely or partly by mechanical means, e.g. fixed swirl vanes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
- B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
- B01D46/2411—Filter cartridges
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D50/00—Combinations of methods or devices for separating particles from gases or vapours
- B01D50/20—Combinations of devices covered by groups B01D45/00 and B01D46/00
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
- F02M35/02—Air cleaners
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2275/00—Filter media structures for filters specially adapted for separating dispersed particles from gases or vapours
- B01D2275/20—Shape of filtering material
- B01D2275/201—Conical shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2279/00—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses
- B01D2279/60—Filters adapted for separating dispersed particles from gases or vapours specially modified for specific uses for the intake of internal combustion engines or turbines
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
- Y02A50/2351—Atmospheric particulate matter [PM], e.g. carbon smoke microparticles, smog, aerosol particles, dust
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
- Separating Particles In Gases By Inertia (AREA)
Abstract
ABSTRACT
This disclosure is directed to an air cleaner for use with internal combustion engines that cleans the air by separating particulate matter prior to filtration. The air cleaner consists of a cylindrical casing having an axial inlet for uncleaned air, a first outlet for the separated particulate matter and a second outlet for the cleaned air. A separator taking the form of a truncated cone converges from the inlet to the first outlet, and includes a plurality of louvers that define a flow path to the filter and clean air outlet. By reason of its inertia, particulate matter in the incoming uncleaned air is incapable of changing its direction to flow through the louvers, and it continues toward the first outlet for discharge. The filter is also conically shaped and con-centric with the separator, formed from inner and outer perforate shells with a pleated filter sandwiched therebetween. The separator and filter are preferably formed as a single unit that is replaceable through removal of an end cap of a casing.
The apparatus may also include a high pressure nozzle to assist in removal of the separated particulate matter from the unit.
This disclosure is directed to an air cleaner for use with internal combustion engines that cleans the air by separating particulate matter prior to filtration. The air cleaner consists of a cylindrical casing having an axial inlet for uncleaned air, a first outlet for the separated particulate matter and a second outlet for the cleaned air. A separator taking the form of a truncated cone converges from the inlet to the first outlet, and includes a plurality of louvers that define a flow path to the filter and clean air outlet. By reason of its inertia, particulate matter in the incoming uncleaned air is incapable of changing its direction to flow through the louvers, and it continues toward the first outlet for discharge. The filter is also conically shaped and con-centric with the separator, formed from inner and outer perforate shells with a pleated filter sandwiched therebetween. The separator and filter are preferably formed as a single unit that is replaceable through removal of an end cap of a casing.
The apparatus may also include a high pressure nozzle to assist in removal of the separated particulate matter from the unit.
Description
The invention is generally related to apparatus for cleaning air, and is specifically directed to an air cleaner for use with internal combustion engines which are operated under extremely dusty conditions or in an environment contain-ing substantial particulate matter of varying size.
The conventional approach to the cleaning of intake air for internal combustion engines is filtration; e.g., causing the air to flow through a pGrOuS medium to remove particles by interception, impaction and diffusion. Although filtration can be a highly efficient process in the cleaning of fluids, a problem does arise in extremely dirty environments because the filtered particulate matter tends to clog the filter element very quickly. This results in the frequent replacement or cleaning of the filter element, or an inadequate supply of fluid due to the increased pressure drop across the clogged element.
Because of this problem, it has long been the practice to preclean the air by separation, in which a force field is applied to a fluid containing particulate matter in such a way that the applied force can be overcome by the fluid, but not by some of the particulate matter. In this way, the efficiency of the filter element is prolonged, and the requirement for replacement or maintenance is less frequent.
More recently, air cleaners which utilize both separa-tion and filtration in a single unit have been developed and advanta~eously used, and this invention is directed to an improve-ment in such devices. More specifically, we have been concerned with the development of an air cleaner in which air taken in from a dusty environment is more efficiently precleaned by separation, and then thoroughly filtered by passing it through a porous medium for delivery to an internal combustion engine.
An additional and necessary objective, which arises from space limitations encountered in the area of use, is that the unit be of compact size without compromising its overall effectiveness.
It has been ascertained that maintaining the uncleaned air at a uniform or, preferably, increasing velocity as it passes through the separation stage enahles separation to uni-formly and effectively occur over the entire length of the separation stage. Although this has been recoynized in prior art apparatus, the means for accomplishing a uniform or in-creasing velocity require an additional structural element which occupies a significant amount of space within the unit.
In addition, the resulting unit is more difficult to assemble and more costly to manufacture~
Other prior art structuxes have recognized the need for both separation and filtration in a single unit, but this has been accomplished at the expense of separation or filtration efficiency, or without serious regard to economy or space limi-tations.
The improved and inventive air cleaner combines the advantages of separation and filtration in a single unit which is extremely compact in size. As pointed out ahove, maintaining uniform or increasing velocity throughout the separation stage gives rise to extremely efficient separation; and this is accomplished with structure which also uniquely enables the unit to be of lesser size than prior art devices. ~ore speci-fically, in the preferred embodiment we provide a cylindrical casing having an inlet for uncleaned air at one axial end and a first outlet for scavenged particulate matter at the opposite axial end. A ~enerally fxustoconical wall member is disposed within the casing, defining a flow path for the inlet air which converges toward the outlet. A plurality of louvers are formed through the frustoconical wall member and ~paced over its length.
Each of the louvers extends radially inward and at the same ~V~9~
time in the downstream direction, so that it is necessaxy for air to partially reverse its downstream direction in order to pass through the conical wall member. However, the particulate matter, which is of greater density than the air, builds up an inertial force which is of such magnitude as to preclude the particles from reversing direction as they pass through the converging flow path, and separation of the particulate matter from a substantial portion of the air is thus effected. The converging flow path maintains the air at a uniform or increas-in~ flow velocity by compensating for the loss of air through upstream louvers, and this enables the spaced louvers to have equal effectiveness at any point on the conical separation surface. As such, highly efficient separation occurs within a very small area, with the scavenged particulate matter passing out of the device through the axial outlet.
A filter element, preferably of the pleated, dry por-ous paper type is disposed radially outward of the frustoconical wall member. In order to take full advantage of the uniform flow velocity, the pleated filter element also takes a generally frustoconical form which receives the precleaned air from the spaced louvers and filters the air as it passes through the por-ous medium. As is well known in the art, the pleated medium sub-stantially increases the filtration surface of the element as well as provides it with increased structural strength.
In the preferred embodiment, the pleated filter ele-ment includes an annular inner and outer perforate lining for additional support, and is integrally formed with the louvered frustoconical wall member into a separation, filtration element which is easily replaceable within the cylindrical casing.
The space defined between the outer surface of the pleated filter element and the inner surface of the cylindrical casing diverges or increases in flow area from the inlet end to the outlet end. The structural configuration is a space saving feature since the resulting chamber has its smallest dimension closestto the inlet end, where a lesser volume of filtered air enters. By the same token, as this outlet chamber increases in size, it is capable of accommodating a greater volume of air as it leaves the pleated filter element. A second outlet is formed in the wall of the cylindrical casing in direct communi-cation with this outlet chamber.
The unit may also advantageously include a safety filter element which is also frustoconical in shape and disposed within the outlet chamber immediately outward of the pleated filter element. The safety element consists of inner and outer perforate frustoconical liners and a single layer of dry paper therebetween which is of greater porosity than that of the pleated element. As such, the safety filter element is capable of performing minimal filtration to protect the internal com-bustion engine should a breakage occur in the pleated element.
According to the invention there is to be provided an apparatus for cleaning air comprises a general]y cylindrical casing having first and second axial ends and defining an internal chamber, the cylindrical casing further comprising an inlet in the first axial end, a first outlet in the second axial end for discharging particulate matter, and a second outlet. The apparatus further comprises a separator comprising a hollow, frustoconical member disposed within the said chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for inlet air which decreases in flow area from the inlet to the first outlet, and louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being constructed to cause air to partially change direction in order to flow therethrough, ~ _ 4 _ O~
thereby enabling the separation of partlculate matter from the air. The apparatus further comprises a hollow, frustoconical filter element disposed in the said chamber in concentric, encircling relation to the separator with its larger end sealably engaging the first axial end of the casing and its smaller end sealably engaging the second axial end of the casing, the frustoconical filter element diverging relative to the separator to define a first annular space therebetween which increases in flow area from the Eirst axial end of the casing to its second axial end. The frustoconical filter element further defines a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end. The second outlet of the cylindrical casing is in fluid communi-cation with the second annular space to receive filtered air from the filter element, and to discharge filtered air from the apparatus.
The inventive apparatus for cleaning air may also comprise a generally cylindrical casing having first and second axial ends and defining an internal chamberr the cylin-drical casing further comprising an inlet in the first axial énd, a first outlet in the second axial end for discharging particulate matter and a second outlet. The apparatus further comprises a separator comprising a hollow frustoconical member having open axial ends and formed from a plurality of tapered frustoconical segments, the frustoconical member disposed within the chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for inlet air which decreases in flow area from the inlet to the first outlet, with louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being constructed to ~ - 4a -~ \
-cause air to partially chan~e direction in order to flow there-through, thereby enabling the separation o~ particulate matter from the air. The apparatus further comprises a hollow, frusto-conical filter element disposed in the chamber in concentric, encircling relation to the separator, with its large end sealably engaging the first axial end and its smaller end sealably engaging the second axial end. Means are also included for spacing the frustoconical separator fro~ the frustoconical filter element to define an annular space therebetween. The frustoconical element further defines a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end. The second outlet of the casing is disposed in fluid communication with the second annular space to receive filtered air from the filter element and to discharge filtered air from the apparatus.
According to another aspect of the invention, the frustoconical separator is separate from the pleated filter element and formed from a stack of annular members of progress-ively decreasing diameter which are held in relative positionby a plurality of longitudinal stringers. The relationship of the annular members one to another defines the desired louvered configuration.
The frustoconical separator can be constructed by other manufacturing methods, such as spiral winding, which simultaneously forms the louvers, or by molding the entire unit.
According to yet another aspect of the invention, a reversed outlet tube is provided for the scavenged particulate matter, and means including a high pressure nozzle are included in cooperation with the outlet tube to assist in the removal of scavenged matter.
- 4b -Brie~ Description of the Drawings Figure l is a view in side elevation of air cleaning apparatus embodying the subject invention, portions thereof broken away and shown in section;
Figure 2 is an exploded perspective view of the re-placeable separator/filter assembly for the air cleaning apparatus;
Fi~ure 3 is an enlarged end view of the frustoconical separator of the separator/filter assembly;
Figure ~ is a fragmentary view in side elevation of an alternative embodiment of the invention with portions there-of broken away and shown in section;
Figure 5 is a side elevational view which is dimin-ish~ed in size of the frustoconical separator of the alternative embodiment;
Figure 6 is an end view of the alternative frusto-conical separator; and Figures 7-9 are views taken in longitudinal section of alternative embodiments of the invention, each of which specifically discloses the variation in the outlet treatment of scavenged particulate matter.
Description of the Preferred Embodiment With initial reference to Figure 1, an air cleaner embodying the inventive concept is represented generally by the numeral ll. Cleaner ll comprises a cylindrical casing 12 having a longitudinal axis, and which, in unassembled form, is open at both axial ends. The inlet end (the right end of Figure l) of casing 12 has an annular flange 13 secured thereto which receives an end cap 14 in a manner described in greater detail herein-below. Cap 14 defines a central axial opening 15 which servesas the inlet for uncleaned air to the cleaner ll.
At the opposite or outlet end, a cap 16 is secured to , ~ ~
the casing 12 as by welding, the cap 16 defining a central axial opening 17 of smaller diameter than opening 15, and which serves as an initial outlet for the device. The opening 17 empties into a cylindrical collector 18 of short axial dimension and which includes an outlet tube 19 which extends radially outward for venting scavenged pa~ticulate matter.
Casing 12 also has a large, generally circular opening formed through its side adjacent the outlet end to which an out-let 20 for clean air is rigidly and sealably secured.
With additional reference to Figures 2 and 3, a sepa-rator/filter assembly for the device 11 is represented generally by the numeral 21. Assembly 21 comprises a separator 22 which is the innermost component~ Generally speaking, separator 22 defines a wall or partition which converges from the inlet 15 to the outlet opening 17, thus presenting a flow path of pro-gressively decreasing area to the uncleaned air entering the device. Specifically, separator 22 is a truncated cone formed from a plurality of frustoconical segments 23. To this end, each of the segments 23 is arcuate in section and tapered as a function of the progressively decreasing cone diameter. As best shown in Figure 3, each of the segments 23 is formed with an upturned side 23a which in assembled form extends radially outward to form a longitudinal spacer rib. The opposite side of each segment is formed to define a step 23b which extends radially inward an amount approximating the thickness of the segment so that it receives the opposite side of the adjacent segment while at the same time continuing the circular configu-ration as viewed in transverse cross section~ As constructed, the overlapping, fitted sides of ad~acent segments 23 are welded or epoxied together to define the frustoconical shape.
With reference to Figures 1 and 2, each of the segments 23 is formed with a plurality of louvers 24 which . ~ .
~3t~9(~
are disposed in two longitudinal rows. In assembled form, the louvers of each segment 23 are aligned with the louvers of other segments to define circumferential rows. In the preferred embodiment, the louvers 24 are punched from the body of the se~ment 23, thus creating edges which project radially inward.
The resulting louver surfaces are inclined toward the outlet;
or, stated otherwise, they converge in the general direction of uncleaned air flow. As shown in Figure 1, the flow of air through the louvers 24 is permitted only upon a partial reversal of flow direction. For a substantial amount of particulate matter, which is of greater density than the air, the buildup of inertia is too large to permit such partial reversal, and the particulate matter is thus swept through the entire length of the separator 22 for discharge through the outlet.
Separa~or/filter assembly 21 further comprises a pleated filter element 25 sandwiched between inner and outer liners 26, 27, respectively. Filter element 25 is made from porous paper, and, as is well known in the art, pleated to increase the filtration surface as well as to strengthen the element itself. Inner and outer liners 26, 27 are made from thin metal or plastic to provide additional strength to the filter element 25, and include large perforations to permit the unobstructed flow of air.
As shown in ~igure l, the sandwich of filter element 25 and liners 26, 27 also takes the form of a truncated cone, although it diverges slightly with respect to the separator 22.
This divergence may be observed with the increasing radial dimension of the single spacer side 23a shown in Figure 1. The divergence is included to increase the size of the inner diameter of the filter element 25, while at the same time permitting the outlet opening 17 to be small. The opening 17 must be sufficient- -ly small relative to the inlet 15 to permit sufficient convergence an~ thereby control the flow veLocity, and the separator 22 must converge smoothly to the opening 17 without abrupt changes to insure maximum effectiveness. However, were the inner dia-meter of the smaller end of filter element 25 to correspond more closely to the outlet opening 17, the pleats would be too close together to permit full and efficient filtration, and the con-centration of pleats could also create the possibility of struc-tural defects. The spacing effect of the sides 23a thus enables the filter element 25 to assume more desirable dimensions.
It is intended that the separator/filter assembly 21 be easily removed and replaced as a unit, and the several elements are therefore held in relative position by end caps 28, 29.
~ach of the end caps 28, 29 is annular in shape and cupped to receive the component ends. The caps are secured to the elements by an adhesive material.
It is also preferable that the device 11 include a safety filter element, which is represented by the numeral 31 in Figure 1. Safety element 31 consists of inner and outer linings 32, 33 which are similar to the linings 26, 27 but for the difference in diameter. A single layer of paper 34 is sand-wiched between the linings 32, 33, the porosity of which is , greater than that of the filter element 25, but which is suffi-cient to perform minimal filtration should a break occur in the element 25. Safety element 31 further includes an annular cap 35 at its smaller end which is adhered to the elements 32-34.
An end cap 36 having a radial flange is adhered to the larger end, the flange serving to mount the safety element 31 in proper position.
The separator/filter assembly 21 and safety element 31 are sealably mounted within the device 11 through the use of gaskets 37, which are adhesively secured to the respective end caps 14, 16 of the device for engagement with the end caps 28, 29 and 35, 36. For assembling purposes, the inlet cap 14 is removed, and the safety element 31 is initially inserted with its tapered sides in engagement with the cylindrical casing 12 at the inlet end (see Figure 1). This has the effect of center-ing the element 31, and the subsequent insertion of the separa-tor/filter assembly 21 is thus centered by the engagement of its end caps with those of the element 31. The cap 14 is then placed over the inlet end of the unit and secured in place with a nut and bolt assembly.
~ bracket 39 is mounted to the casing 12 for mounting the device.
In operation, uncleaned air is admitted through the inlet 15, passing through the longitudinal flow path defined within the separator 22. Depending on the selected degree of convergence of the frustoconical separator, the flow of the air is maintained at a uniform or increasing velocity; and separa-tion of a substantial amount of the particulate matter therefore occurs uniformly over its length. In this regard, we have found that optimum separation efficiency occurs when the flow velocity at the scavenge outlet is more than two times greater than the flow velocity at the dirty air inlet. As pointed out above, separation occurs because the particles are of greater density than the air, and are unable to reverse the essentially straight flow path due to the buildup of inertia. The scavenged parti-culate matter thus passes entirely through the separator 22, entering the collector 18 from the opening 17 and passing to atmosphere from the outlet tube 19.
That portion of the air flow which separates from the main stream by passing through the louvers 24 then moves essen-tially radially outward through the filter element 25. The pre-cleaned and filtered air then passes through the safety element 31 and into an outlet chamber 40 r from which it leaves through ~/
the ou-tlet 20 ~or use in the internal combustion engine. The chamber 40 increases in size toward the outlet end of the device, commensurate with the volume of flow delivered from the assembly 21 over its length.
A vacuum assist may be used in conjunction with the outlet l9 to enhance the removal of particulate matter, and/or with the outlet 20 to assist in the separation and filtration processes.
With reference to Figures 4-6, an alternative air cleanin~ device is represented generally by tne numeral 41.
In these figures, like numerals represent structure identical to that of the device ll, and additional numerals represent new or modified structure.
The principal difference between devices 41 and ll resides in the separation and filtration stages. Rather than an integral assembly, the device includes a separate separator 42 and a separate filter element 43, along with the identical safety element 31.
With specific reference to Figures 5 and 6, separator 42 comprises a plurality of annular rigid bands 44, each of which takes the form of a truncated cone having a large diameter i as compared with its axial dimension. The rigid bands 44 are of progressively decreasing diameter in the direction of air flow; and, in order to define the necessary louvered passages, the smallest diameter of each band is smaller than the largest diameter of the adjacent band, thus creating a flow passage therebetween. The plurality of bands 44 are arranged in a stacked relationship and commonly secured by four longitudinal stringers 45O
At the inlet end of the separator 42, a larger rigid band 46 of greater axial dimension and converging in the opposite direction is secured to the first band 44 and defines an inlet ~or the separator 42. A cruci~orm 47, consistin~ of a pair of orthogonal blades 48, extends into the inlet of the separator 42 and is secured to the inner surface of the larger band 46.
The cruciform 47 assists in maintainin~ straight, axial flow through the separator 42, which results in better separation of the particulate matter.
At the outlet end of separator 42, a cylindrical outlet sleeve 49 is secured to the smallest rigid band 44.
An annular flange 50 extends radially outward from ~he outlet sleeve 49. The outer diameter of sleeve 4g corresponds to the inner diameter of outlet opening 17, permitting a sliding rela-tion. ~n additional gasket 37 is positioned on outlet cap 16 for sealing engagement with the flange 50, as shown in Figure 4.
With continued reference to Figure 4, the filter ele-ment 43 consists of the same pleated element 25 and liners 26, 27, but includes modified end caps 52, 53 which do not accommo-date the separator 42.
The construction of device 41 is otherwise essentially the same as device 11. The stacked construction of separator 42 creates an increased louvered passage flow area. It will also be appreciated that the separate construction of the separator 42 and filter element 43 enables them to be individually removed and replaced from the device 41.
Figures 7-9 disclose three further embodiments which include means for assisting in the removal of scavenged parti-culate matter, and which are particularly useful in extremely dusty and dirty conditions. In Figure 7, an air cleaning device represented generally by the numeral 61 comprises a cylindrical casing 62 which is open at both ends and formed with a peripheral flange 63 at the inlet end. Casing 62 also includes an outlet 64 for cleaned air which opens from its side approximately the outlet end. A removeable cap 65 is sealably secured to the ~3ti9U~l casing 62 by nut and bolt assemblies 66 and an 0-ring 67.
Inlet cap 65 is formed with a large inlet 68 which admits uncleaned air to the device 61.
An end cap 69 is permanently and sealably secured to the outlet end of casing 62. As shown, end cap 69 is formed with a cylindrical recess which receives the smaller end of a frustoconical separator/filter assembly 71. The assembly 71 comprises a frustoconical separator 72 having louvers 73 and a pleated dry paper filter element 74 which is also frustoconical in shape. The separator 7~ and filter element 74 are integrally held by end caps 75, 76, the former of which includes a peri-pheral flange which is clamped between the end cap 65 and flange~
63 of casing 62. A flat annular seal 77 is disposed between end caps 76 and 69 for air tight operation. An outlet stack 78 is secured to and supported by the inlet cap 65, projecting vir-tually to the outlet end of the separator 72 to define a separa-tion flow passage 79 and an outlet flow passage 80 which are concentric. It will be observed that the end cap 76 for the separator/filter assembly 71 is a solid circular cap, as dis-tinguished from the annular configuration of end cap 75, so thatthe scavenged particulate matter and carrier air flow do not leave from the bottom o~ the device 61 as shown in Figure 7.
The end cap 76 is formed with an annular, concave recess 76a which conforms generally to the annular, rounded lower end of the outlet stack 78, so that the scavenging air flow from sepa-ration passage 79 to outlet passage 80 is smoothly reversed.
It will be further observed that the outlet passage 80 `
initially assumes a constant diameter and then expands to a larger flow area before curving outwardly for issuance through the side of inlet cap 65. To this end, outlet stack 78 is formed from an outer lining 81 which is generally c~lindrical and an inner lining 82 which defines the expanding flow passage.
,, .`j ,~.',~
. ,,j . , .
The connection between the linings 81, 82, designated by refer-ence numeral 83, initially conforms to the shape of the lower-most louver 73 and is then rounded to effect the smooth reversal of flow as noted above.
To assist in the rapid and efficient removal o~
scavenged particulate matter, an air nozzle 8~ is introduced through the end cap 76, projecting axially into the inlet of outlet passage 80. Air nozzle 84 is sealably clamped against the end cap 76 through the use of an O-ring 85, and is adapted for connection to a high pressure air source through the use of an enlarged fitting 86.
Separation and fil~ration of the air cleaner 61 is much the same as air cleaner 11, although it will be noted that incoming air must pass around the outlet stack 78 into the -annular separation flow passage 79. This passage is convergent to maintain a uniform flow velocity to achieve efficient separa-tion.
As the particulate matter and its carrier flow leave the separation passage 79, a smooth flow reversal takes place which is significantly assisted by the high velocity flow issuing from air nozzle 84. Nozzle 84 creates a flow pressure within outlet passage 80 which is lower than that within separation passage 79, and which draws the scavenged particulate matter into the outlet passage and out of the outlet stack 78. This in-creased flow significantly improves the separation capability of the device 61 and is th~s well adapted to extremely dusty environments.
Figure 8 discloses an air cleaner which is essentially the same as device 61, with the exception of a modified outlet stack 91. Stack 91 comprises an outer lining 92 which has a progressively increasing diameter as it approaches the lower end of the separator 72, thus increasing the degree of conver-gence of a separator flow passa~e 93. An inner lining 94 is cylindrical in shape, thus defining an outlet passage 95 of constant cross sectional area. The outlet end of stack 91 bends radially outward through the side of the inlet cap as shown.
In figure 9, an outlet stack 101 is defined by a cylindrical outer lining 102 and a cylindrical inner lining 103 to define a separator ~low passage 104 having a lesser degree of convergence and an outlet passage 105 o~ constant cross sectional area. The upper end of outer lining 102 terminates in a dome 106 which is disposed in the inlet of the device to assist in smoothly dividing the flow into the annular separation passage 104. The inner lining 103 bends radially outward through the outer lining 102 and the side o~ the inlet cap to discharge the scavenged particulate matter.
The space defined between inner and outer linings 81~
82, 92-94, and 102-103 is dead space and is not exposed to flow.
The embodiments of Figure 7-9 are somewhat schematic for purposes of clarity, and do not disclose any support for the outlet stacks 78, 91 and 10~ other than the support provided by the associated inlet cap. It is possible to include radial struts between the stack and the inlet cap or associated separator if necessary for additional support.
The conventional approach to the cleaning of intake air for internal combustion engines is filtration; e.g., causing the air to flow through a pGrOuS medium to remove particles by interception, impaction and diffusion. Although filtration can be a highly efficient process in the cleaning of fluids, a problem does arise in extremely dirty environments because the filtered particulate matter tends to clog the filter element very quickly. This results in the frequent replacement or cleaning of the filter element, or an inadequate supply of fluid due to the increased pressure drop across the clogged element.
Because of this problem, it has long been the practice to preclean the air by separation, in which a force field is applied to a fluid containing particulate matter in such a way that the applied force can be overcome by the fluid, but not by some of the particulate matter. In this way, the efficiency of the filter element is prolonged, and the requirement for replacement or maintenance is less frequent.
More recently, air cleaners which utilize both separa-tion and filtration in a single unit have been developed and advanta~eously used, and this invention is directed to an improve-ment in such devices. More specifically, we have been concerned with the development of an air cleaner in which air taken in from a dusty environment is more efficiently precleaned by separation, and then thoroughly filtered by passing it through a porous medium for delivery to an internal combustion engine.
An additional and necessary objective, which arises from space limitations encountered in the area of use, is that the unit be of compact size without compromising its overall effectiveness.
It has been ascertained that maintaining the uncleaned air at a uniform or, preferably, increasing velocity as it passes through the separation stage enahles separation to uni-formly and effectively occur over the entire length of the separation stage. Although this has been recoynized in prior art apparatus, the means for accomplishing a uniform or in-creasing velocity require an additional structural element which occupies a significant amount of space within the unit.
In addition, the resulting unit is more difficult to assemble and more costly to manufacture~
Other prior art structuxes have recognized the need for both separation and filtration in a single unit, but this has been accomplished at the expense of separation or filtration efficiency, or without serious regard to economy or space limi-tations.
The improved and inventive air cleaner combines the advantages of separation and filtration in a single unit which is extremely compact in size. As pointed out ahove, maintaining uniform or increasing velocity throughout the separation stage gives rise to extremely efficient separation; and this is accomplished with structure which also uniquely enables the unit to be of lesser size than prior art devices. ~ore speci-fically, in the preferred embodiment we provide a cylindrical casing having an inlet for uncleaned air at one axial end and a first outlet for scavenged particulate matter at the opposite axial end. A ~enerally fxustoconical wall member is disposed within the casing, defining a flow path for the inlet air which converges toward the outlet. A plurality of louvers are formed through the frustoconical wall member and ~paced over its length.
Each of the louvers extends radially inward and at the same ~V~9~
time in the downstream direction, so that it is necessaxy for air to partially reverse its downstream direction in order to pass through the conical wall member. However, the particulate matter, which is of greater density than the air, builds up an inertial force which is of such magnitude as to preclude the particles from reversing direction as they pass through the converging flow path, and separation of the particulate matter from a substantial portion of the air is thus effected. The converging flow path maintains the air at a uniform or increas-in~ flow velocity by compensating for the loss of air through upstream louvers, and this enables the spaced louvers to have equal effectiveness at any point on the conical separation surface. As such, highly efficient separation occurs within a very small area, with the scavenged particulate matter passing out of the device through the axial outlet.
A filter element, preferably of the pleated, dry por-ous paper type is disposed radially outward of the frustoconical wall member. In order to take full advantage of the uniform flow velocity, the pleated filter element also takes a generally frustoconical form which receives the precleaned air from the spaced louvers and filters the air as it passes through the por-ous medium. As is well known in the art, the pleated medium sub-stantially increases the filtration surface of the element as well as provides it with increased structural strength.
In the preferred embodiment, the pleated filter ele-ment includes an annular inner and outer perforate lining for additional support, and is integrally formed with the louvered frustoconical wall member into a separation, filtration element which is easily replaceable within the cylindrical casing.
The space defined between the outer surface of the pleated filter element and the inner surface of the cylindrical casing diverges or increases in flow area from the inlet end to the outlet end. The structural configuration is a space saving feature since the resulting chamber has its smallest dimension closestto the inlet end, where a lesser volume of filtered air enters. By the same token, as this outlet chamber increases in size, it is capable of accommodating a greater volume of air as it leaves the pleated filter element. A second outlet is formed in the wall of the cylindrical casing in direct communi-cation with this outlet chamber.
The unit may also advantageously include a safety filter element which is also frustoconical in shape and disposed within the outlet chamber immediately outward of the pleated filter element. The safety element consists of inner and outer perforate frustoconical liners and a single layer of dry paper therebetween which is of greater porosity than that of the pleated element. As such, the safety filter element is capable of performing minimal filtration to protect the internal com-bustion engine should a breakage occur in the pleated element.
According to the invention there is to be provided an apparatus for cleaning air comprises a general]y cylindrical casing having first and second axial ends and defining an internal chamber, the cylindrical casing further comprising an inlet in the first axial end, a first outlet in the second axial end for discharging particulate matter, and a second outlet. The apparatus further comprises a separator comprising a hollow, frustoconical member disposed within the said chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for inlet air which decreases in flow area from the inlet to the first outlet, and louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being constructed to cause air to partially change direction in order to flow therethrough, ~ _ 4 _ O~
thereby enabling the separation of partlculate matter from the air. The apparatus further comprises a hollow, frustoconical filter element disposed in the said chamber in concentric, encircling relation to the separator with its larger end sealably engaging the first axial end of the casing and its smaller end sealably engaging the second axial end of the casing, the frustoconical filter element diverging relative to the separator to define a first annular space therebetween which increases in flow area from the Eirst axial end of the casing to its second axial end. The frustoconical filter element further defines a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end. The second outlet of the cylindrical casing is in fluid communi-cation with the second annular space to receive filtered air from the filter element, and to discharge filtered air from the apparatus.
The inventive apparatus for cleaning air may also comprise a generally cylindrical casing having first and second axial ends and defining an internal chamberr the cylin-drical casing further comprising an inlet in the first axial énd, a first outlet in the second axial end for discharging particulate matter and a second outlet. The apparatus further comprises a separator comprising a hollow frustoconical member having open axial ends and formed from a plurality of tapered frustoconical segments, the frustoconical member disposed within the chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for inlet air which decreases in flow area from the inlet to the first outlet, with louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being constructed to ~ - 4a -~ \
-cause air to partially chan~e direction in order to flow there-through, thereby enabling the separation o~ particulate matter from the air. The apparatus further comprises a hollow, frusto-conical filter element disposed in the chamber in concentric, encircling relation to the separator, with its large end sealably engaging the first axial end and its smaller end sealably engaging the second axial end. Means are also included for spacing the frustoconical separator fro~ the frustoconical filter element to define an annular space therebetween. The frustoconical element further defines a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end. The second outlet of the casing is disposed in fluid communication with the second annular space to receive filtered air from the filter element and to discharge filtered air from the apparatus.
According to another aspect of the invention, the frustoconical separator is separate from the pleated filter element and formed from a stack of annular members of progress-ively decreasing diameter which are held in relative positionby a plurality of longitudinal stringers. The relationship of the annular members one to another defines the desired louvered configuration.
The frustoconical separator can be constructed by other manufacturing methods, such as spiral winding, which simultaneously forms the louvers, or by molding the entire unit.
According to yet another aspect of the invention, a reversed outlet tube is provided for the scavenged particulate matter, and means including a high pressure nozzle are included in cooperation with the outlet tube to assist in the removal of scavenged matter.
- 4b -Brie~ Description of the Drawings Figure l is a view in side elevation of air cleaning apparatus embodying the subject invention, portions thereof broken away and shown in section;
Figure 2 is an exploded perspective view of the re-placeable separator/filter assembly for the air cleaning apparatus;
Fi~ure 3 is an enlarged end view of the frustoconical separator of the separator/filter assembly;
Figure ~ is a fragmentary view in side elevation of an alternative embodiment of the invention with portions there-of broken away and shown in section;
Figure 5 is a side elevational view which is dimin-ish~ed in size of the frustoconical separator of the alternative embodiment;
Figure 6 is an end view of the alternative frusto-conical separator; and Figures 7-9 are views taken in longitudinal section of alternative embodiments of the invention, each of which specifically discloses the variation in the outlet treatment of scavenged particulate matter.
Description of the Preferred Embodiment With initial reference to Figure 1, an air cleaner embodying the inventive concept is represented generally by the numeral ll. Cleaner ll comprises a cylindrical casing 12 having a longitudinal axis, and which, in unassembled form, is open at both axial ends. The inlet end (the right end of Figure l) of casing 12 has an annular flange 13 secured thereto which receives an end cap 14 in a manner described in greater detail herein-below. Cap 14 defines a central axial opening 15 which servesas the inlet for uncleaned air to the cleaner ll.
At the opposite or outlet end, a cap 16 is secured to , ~ ~
the casing 12 as by welding, the cap 16 defining a central axial opening 17 of smaller diameter than opening 15, and which serves as an initial outlet for the device. The opening 17 empties into a cylindrical collector 18 of short axial dimension and which includes an outlet tube 19 which extends radially outward for venting scavenged pa~ticulate matter.
Casing 12 also has a large, generally circular opening formed through its side adjacent the outlet end to which an out-let 20 for clean air is rigidly and sealably secured.
With additional reference to Figures 2 and 3, a sepa-rator/filter assembly for the device 11 is represented generally by the numeral 21. Assembly 21 comprises a separator 22 which is the innermost component~ Generally speaking, separator 22 defines a wall or partition which converges from the inlet 15 to the outlet opening 17, thus presenting a flow path of pro-gressively decreasing area to the uncleaned air entering the device. Specifically, separator 22 is a truncated cone formed from a plurality of frustoconical segments 23. To this end, each of the segments 23 is arcuate in section and tapered as a function of the progressively decreasing cone diameter. As best shown in Figure 3, each of the segments 23 is formed with an upturned side 23a which in assembled form extends radially outward to form a longitudinal spacer rib. The opposite side of each segment is formed to define a step 23b which extends radially inward an amount approximating the thickness of the segment so that it receives the opposite side of the adjacent segment while at the same time continuing the circular configu-ration as viewed in transverse cross section~ As constructed, the overlapping, fitted sides of ad~acent segments 23 are welded or epoxied together to define the frustoconical shape.
With reference to Figures 1 and 2, each of the segments 23 is formed with a plurality of louvers 24 which . ~ .
~3t~9(~
are disposed in two longitudinal rows. In assembled form, the louvers of each segment 23 are aligned with the louvers of other segments to define circumferential rows. In the preferred embodiment, the louvers 24 are punched from the body of the se~ment 23, thus creating edges which project radially inward.
The resulting louver surfaces are inclined toward the outlet;
or, stated otherwise, they converge in the general direction of uncleaned air flow. As shown in Figure 1, the flow of air through the louvers 24 is permitted only upon a partial reversal of flow direction. For a substantial amount of particulate matter, which is of greater density than the air, the buildup of inertia is too large to permit such partial reversal, and the particulate matter is thus swept through the entire length of the separator 22 for discharge through the outlet.
Separa~or/filter assembly 21 further comprises a pleated filter element 25 sandwiched between inner and outer liners 26, 27, respectively. Filter element 25 is made from porous paper, and, as is well known in the art, pleated to increase the filtration surface as well as to strengthen the element itself. Inner and outer liners 26, 27 are made from thin metal or plastic to provide additional strength to the filter element 25, and include large perforations to permit the unobstructed flow of air.
As shown in ~igure l, the sandwich of filter element 25 and liners 26, 27 also takes the form of a truncated cone, although it diverges slightly with respect to the separator 22.
This divergence may be observed with the increasing radial dimension of the single spacer side 23a shown in Figure 1. The divergence is included to increase the size of the inner diameter of the filter element 25, while at the same time permitting the outlet opening 17 to be small. The opening 17 must be sufficient- -ly small relative to the inlet 15 to permit sufficient convergence an~ thereby control the flow veLocity, and the separator 22 must converge smoothly to the opening 17 without abrupt changes to insure maximum effectiveness. However, were the inner dia-meter of the smaller end of filter element 25 to correspond more closely to the outlet opening 17, the pleats would be too close together to permit full and efficient filtration, and the con-centration of pleats could also create the possibility of struc-tural defects. The spacing effect of the sides 23a thus enables the filter element 25 to assume more desirable dimensions.
It is intended that the separator/filter assembly 21 be easily removed and replaced as a unit, and the several elements are therefore held in relative position by end caps 28, 29.
~ach of the end caps 28, 29 is annular in shape and cupped to receive the component ends. The caps are secured to the elements by an adhesive material.
It is also preferable that the device 11 include a safety filter element, which is represented by the numeral 31 in Figure 1. Safety element 31 consists of inner and outer linings 32, 33 which are similar to the linings 26, 27 but for the difference in diameter. A single layer of paper 34 is sand-wiched between the linings 32, 33, the porosity of which is , greater than that of the filter element 25, but which is suffi-cient to perform minimal filtration should a break occur in the element 25. Safety element 31 further includes an annular cap 35 at its smaller end which is adhered to the elements 32-34.
An end cap 36 having a radial flange is adhered to the larger end, the flange serving to mount the safety element 31 in proper position.
The separator/filter assembly 21 and safety element 31 are sealably mounted within the device 11 through the use of gaskets 37, which are adhesively secured to the respective end caps 14, 16 of the device for engagement with the end caps 28, 29 and 35, 36. For assembling purposes, the inlet cap 14 is removed, and the safety element 31 is initially inserted with its tapered sides in engagement with the cylindrical casing 12 at the inlet end (see Figure 1). This has the effect of center-ing the element 31, and the subsequent insertion of the separa-tor/filter assembly 21 is thus centered by the engagement of its end caps with those of the element 31. The cap 14 is then placed over the inlet end of the unit and secured in place with a nut and bolt assembly.
~ bracket 39 is mounted to the casing 12 for mounting the device.
In operation, uncleaned air is admitted through the inlet 15, passing through the longitudinal flow path defined within the separator 22. Depending on the selected degree of convergence of the frustoconical separator, the flow of the air is maintained at a uniform or increasing velocity; and separa-tion of a substantial amount of the particulate matter therefore occurs uniformly over its length. In this regard, we have found that optimum separation efficiency occurs when the flow velocity at the scavenge outlet is more than two times greater than the flow velocity at the dirty air inlet. As pointed out above, separation occurs because the particles are of greater density than the air, and are unable to reverse the essentially straight flow path due to the buildup of inertia. The scavenged parti-culate matter thus passes entirely through the separator 22, entering the collector 18 from the opening 17 and passing to atmosphere from the outlet tube 19.
That portion of the air flow which separates from the main stream by passing through the louvers 24 then moves essen-tially radially outward through the filter element 25. The pre-cleaned and filtered air then passes through the safety element 31 and into an outlet chamber 40 r from which it leaves through ~/
the ou-tlet 20 ~or use in the internal combustion engine. The chamber 40 increases in size toward the outlet end of the device, commensurate with the volume of flow delivered from the assembly 21 over its length.
A vacuum assist may be used in conjunction with the outlet l9 to enhance the removal of particulate matter, and/or with the outlet 20 to assist in the separation and filtration processes.
With reference to Figures 4-6, an alternative air cleanin~ device is represented generally by tne numeral 41.
In these figures, like numerals represent structure identical to that of the device ll, and additional numerals represent new or modified structure.
The principal difference between devices 41 and ll resides in the separation and filtration stages. Rather than an integral assembly, the device includes a separate separator 42 and a separate filter element 43, along with the identical safety element 31.
With specific reference to Figures 5 and 6, separator 42 comprises a plurality of annular rigid bands 44, each of which takes the form of a truncated cone having a large diameter i as compared with its axial dimension. The rigid bands 44 are of progressively decreasing diameter in the direction of air flow; and, in order to define the necessary louvered passages, the smallest diameter of each band is smaller than the largest diameter of the adjacent band, thus creating a flow passage therebetween. The plurality of bands 44 are arranged in a stacked relationship and commonly secured by four longitudinal stringers 45O
At the inlet end of the separator 42, a larger rigid band 46 of greater axial dimension and converging in the opposite direction is secured to the first band 44 and defines an inlet ~or the separator 42. A cruci~orm 47, consistin~ of a pair of orthogonal blades 48, extends into the inlet of the separator 42 and is secured to the inner surface of the larger band 46.
The cruciform 47 assists in maintainin~ straight, axial flow through the separator 42, which results in better separation of the particulate matter.
At the outlet end of separator 42, a cylindrical outlet sleeve 49 is secured to the smallest rigid band 44.
An annular flange 50 extends radially outward from ~he outlet sleeve 49. The outer diameter of sleeve 4g corresponds to the inner diameter of outlet opening 17, permitting a sliding rela-tion. ~n additional gasket 37 is positioned on outlet cap 16 for sealing engagement with the flange 50, as shown in Figure 4.
With continued reference to Figure 4, the filter ele-ment 43 consists of the same pleated element 25 and liners 26, 27, but includes modified end caps 52, 53 which do not accommo-date the separator 42.
The construction of device 41 is otherwise essentially the same as device 11. The stacked construction of separator 42 creates an increased louvered passage flow area. It will also be appreciated that the separate construction of the separator 42 and filter element 43 enables them to be individually removed and replaced from the device 41.
Figures 7-9 disclose three further embodiments which include means for assisting in the removal of scavenged parti-culate matter, and which are particularly useful in extremely dusty and dirty conditions. In Figure 7, an air cleaning device represented generally by the numeral 61 comprises a cylindrical casing 62 which is open at both ends and formed with a peripheral flange 63 at the inlet end. Casing 62 also includes an outlet 64 for cleaned air which opens from its side approximately the outlet end. A removeable cap 65 is sealably secured to the ~3ti9U~l casing 62 by nut and bolt assemblies 66 and an 0-ring 67.
Inlet cap 65 is formed with a large inlet 68 which admits uncleaned air to the device 61.
An end cap 69 is permanently and sealably secured to the outlet end of casing 62. As shown, end cap 69 is formed with a cylindrical recess which receives the smaller end of a frustoconical separator/filter assembly 71. The assembly 71 comprises a frustoconical separator 72 having louvers 73 and a pleated dry paper filter element 74 which is also frustoconical in shape. The separator 7~ and filter element 74 are integrally held by end caps 75, 76, the former of which includes a peri-pheral flange which is clamped between the end cap 65 and flange~
63 of casing 62. A flat annular seal 77 is disposed between end caps 76 and 69 for air tight operation. An outlet stack 78 is secured to and supported by the inlet cap 65, projecting vir-tually to the outlet end of the separator 72 to define a separa-tion flow passage 79 and an outlet flow passage 80 which are concentric. It will be observed that the end cap 76 for the separator/filter assembly 71 is a solid circular cap, as dis-tinguished from the annular configuration of end cap 75, so thatthe scavenged particulate matter and carrier air flow do not leave from the bottom o~ the device 61 as shown in Figure 7.
The end cap 76 is formed with an annular, concave recess 76a which conforms generally to the annular, rounded lower end of the outlet stack 78, so that the scavenging air flow from sepa-ration passage 79 to outlet passage 80 is smoothly reversed.
It will be further observed that the outlet passage 80 `
initially assumes a constant diameter and then expands to a larger flow area before curving outwardly for issuance through the side of inlet cap 65. To this end, outlet stack 78 is formed from an outer lining 81 which is generally c~lindrical and an inner lining 82 which defines the expanding flow passage.
,, .`j ,~.',~
. ,,j . , .
The connection between the linings 81, 82, designated by refer-ence numeral 83, initially conforms to the shape of the lower-most louver 73 and is then rounded to effect the smooth reversal of flow as noted above.
To assist in the rapid and efficient removal o~
scavenged particulate matter, an air nozzle 8~ is introduced through the end cap 76, projecting axially into the inlet of outlet passage 80. Air nozzle 84 is sealably clamped against the end cap 76 through the use of an O-ring 85, and is adapted for connection to a high pressure air source through the use of an enlarged fitting 86.
Separation and fil~ration of the air cleaner 61 is much the same as air cleaner 11, although it will be noted that incoming air must pass around the outlet stack 78 into the -annular separation flow passage 79. This passage is convergent to maintain a uniform flow velocity to achieve efficient separa-tion.
As the particulate matter and its carrier flow leave the separation passage 79, a smooth flow reversal takes place which is significantly assisted by the high velocity flow issuing from air nozzle 84. Nozzle 84 creates a flow pressure within outlet passage 80 which is lower than that within separation passage 79, and which draws the scavenged particulate matter into the outlet passage and out of the outlet stack 78. This in-creased flow significantly improves the separation capability of the device 61 and is th~s well adapted to extremely dusty environments.
Figure 8 discloses an air cleaner which is essentially the same as device 61, with the exception of a modified outlet stack 91. Stack 91 comprises an outer lining 92 which has a progressively increasing diameter as it approaches the lower end of the separator 72, thus increasing the degree of conver-gence of a separator flow passa~e 93. An inner lining 94 is cylindrical in shape, thus defining an outlet passage 95 of constant cross sectional area. The outlet end of stack 91 bends radially outward through the side of the inlet cap as shown.
In figure 9, an outlet stack 101 is defined by a cylindrical outer lining 102 and a cylindrical inner lining 103 to define a separator ~low passage 104 having a lesser degree of convergence and an outlet passage 105 o~ constant cross sectional area. The upper end of outer lining 102 terminates in a dome 106 which is disposed in the inlet of the device to assist in smoothly dividing the flow into the annular separation passage 104. The inner lining 103 bends radially outward through the outer lining 102 and the side o~ the inlet cap to discharge the scavenged particulate matter.
The space defined between inner and outer linings 81~
82, 92-94, and 102-103 is dead space and is not exposed to flow.
The embodiments of Figure 7-9 are somewhat schematic for purposes of clarity, and do not disclose any support for the outlet stacks 78, 91 and 10~ other than the support provided by the associated inlet cap. It is possible to include radial struts between the stack and the inlet cap or associated separator if necessary for additional support.
Claims (22)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for cleaning air, comprising:
(a) a generally cylindrical casing having first and second axial ends and defining an internal cham-ber, the cylindrical casing further comprising an inlet in the first axial end, a first outlet in the second axial end for discharging particu-late matter, and a second outlet;
(b) a separator comprising (i) a hollow, frustoconical member disposed within the chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for in-let air which decreases in flow area from the inlet to the first outlet;
(ii) louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being con-structed to cause air to partially change direction in order to flow therethrough, thereby enabling the separation of parti-culate matter from the air;
(c) a hollow, frustoconical filter element disposed in the chamber in concentric, encircling relation to the separator with its larger end sealably engaging the first axial end of the casing and its smaller end sealably engaging the second axial end of the casing, the frustoconical filter element diverging relative to the separator to define a first annular space therebetween which increases in flow area from the first axial end of the casing to its second axial end;
(d) the frustoconical filter element further defin-ing a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end;
(e) the second outlet being in fluid communication with the second annular space to receive filter-ed air from the filter element, and to discharge filtered air from the apparatus.
(a) a generally cylindrical casing having first and second axial ends and defining an internal cham-ber, the cylindrical casing further comprising an inlet in the first axial end, a first outlet in the second axial end for discharging particu-late matter, and a second outlet;
(b) a separator comprising (i) a hollow, frustoconical member disposed within the chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for in-let air which decreases in flow area from the inlet to the first outlet;
(ii) louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being con-structed to cause air to partially change direction in order to flow therethrough, thereby enabling the separation of parti-culate matter from the air;
(c) a hollow, frustoconical filter element disposed in the chamber in concentric, encircling relation to the separator with its larger end sealably engaging the first axial end of the casing and its smaller end sealably engaging the second axial end of the casing, the frustoconical filter element diverging relative to the separator to define a first annular space therebetween which increases in flow area from the first axial end of the casing to its second axial end;
(d) the frustoconical filter element further defin-ing a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end;
(e) the second outlet being in fluid communication with the second annular space to receive filter-ed air from the filter element, and to discharge filtered air from the apparatus.
2. The apparatus defined by claim 1, wherein the frusto-conical member of said separator comprises a plurality of tapered, frustoconical segments connected edge to edge.
3. The apparatus defined by claim 1, wherein the separa-tor and filter element are constructed as a unit separator/
filter assembly, the assembly being removeably disposed in the cylindrical casing.
filter assembly, the assembly being removeably disposed in the cylindrical casing.
4. The apparatus defined by claim 3, wherein the cylin-drical casing comprises at least one removeable end cap to permit removal of said separator/filter assembly.
5. The apparatus defined by claim 4, wherein the remove-able end cap is disposed at the inlet end of the casing, said inlet being centrally disposed therein.
6. The apparatus defined by claim 1, wherein the filter element comprises inner and outer perforated frustoconical shells with a body of pleated filter material sandwiched therebetween.
7. The apparatus defined by claim 1, which further com-prises an imperforate annular end cap secured to each axial end of the separator and and filter element to hold them in assembled relation.
8. The apparatus defined by claim 7, and further com-prising gasket means disposed in sealing relation between each of the annular end caps and the casing.
9. The apparatus defined by claim 8, and further com-prising a safety filter element of frustoconical shape dis-posed in said second annular space, the safety filter element being concentric with the separator/filter assembly and in sealable engagement with the ends of the casing.
10. The apparatus defined by claim 8, wherein the second outlet is disposed in the side of the casing.
11. The apparatus defined by claim 1, and further com-prising a collector cap connected to the outlet end of the casing in communication with the first outlet, the collector cap including an outlet tube which extends radially outward for venting particulate matter.
12. The apparatus defined by claim 1, wherein the louver means comprises a plurality of louvers that project radially inward of the frustoconical member and converge in the direc-tion of downstream air flow.
13. The apparatus defined by claim 12, wherein the louvers are disposed in circumferential and longitudinal rows.
14. The apparatus defined by claim 1, wherein the frusto-conical member of said separator comprises a stacked plurality of frustoconically shaped, annular bands, the bands being of progressively decreasing diameter in the direction of air flow, and the smallest diameter of each being smaller than the largest diameter of the adjacent band to define a louvered pass-age therebetween.
15. The apparatus defined by claim 14, wherein the annular bands are interconnected by a plurality of longitudinal stringers.
16. The apparatus defined by claim 15, wherein the sepa-rator further comprises a pair of orthogonal blades extending axially into its inlet for maintaining straight, axial flow therethrough.
17. The apparatus defined by claim 1, wherein the con-verging wall means is constructed to effect a velocity of flow at the first outlet that is approximately the same as the velocity of flow at the inlet.
18. The apparatus defined by claim 1, wherein the con-verging wall means is constructed to effect a velocity of flow at the first outlet that is at least twice the velocity of flow at the inlet.
19. Apparatus for cleaning air, comprising:
(a) a generally cylindrical casing having first and second axial ends and defining an internal chamber, the cylindrical casing further com-prising an inlet in the first axial end, a first outlet in the second axial end for dis-charging particulate matter and a second outlet;
(b) a separator comprising (i) a hollow frustoconical member having open axial ends and formed from a plurality of tapered frustoconical segments, the frustoconical member disposed within the chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for inlet air which decreases in flow area from the inlet to the first outlet;
(ii) louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being con structed to cause air to partially change direction in order to flow therethrough, thereby enabling the separation of parti-culate matter from the air;
(c) a hollow, frustoconical filter element disposed in the chamber in concentric, encircling rela-tion to the separator with its large end seal-ably engaging the first axial end and its smaller end sealably engaging the second axial end;
(d) means for spacing the frustoconical separator from the frustoconical filter element to define an annular space therebetween;
(e) the frustoconical filter element further define ing a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end;
(f) the second outlet being in fluid communication with the second annular space to receive filtered air from the filter element and to discharge filtered air from the apparatus.
(a) a generally cylindrical casing having first and second axial ends and defining an internal chamber, the cylindrical casing further com-prising an inlet in the first axial end, a first outlet in the second axial end for dis-charging particulate matter and a second outlet;
(b) a separator comprising (i) a hollow frustoconical member having open axial ends and formed from a plurality of tapered frustoconical segments, the frustoconical member disposed within the chamber with its larger end sealably encircling the inlet and the smaller end sealably encircling the first outlet to define a first flow path for inlet air which decreases in flow area from the inlet to the first outlet;
(ii) louver means formed in the frustoconical member and defining a second flow path therethrough, the louver means being con structed to cause air to partially change direction in order to flow therethrough, thereby enabling the separation of parti-culate matter from the air;
(c) a hollow, frustoconical filter element disposed in the chamber in concentric, encircling rela-tion to the separator with its large end seal-ably engaging the first axial end and its smaller end sealably engaging the second axial end;
(d) means for spacing the frustoconical separator from the frustoconical filter element to define an annular space therebetween;
(e) the frustoconical filter element further define ing a second annular space with the inner surface of the cylindrical casing that increases in flow area from the first axial end of the casing to its second axial end;
(f) the second outlet being in fluid communication with the second annular space to receive filtered air from the filter element and to discharge filtered air from the apparatus.
20. The apparatus defined by claim 19, wherein each of said tapered frustoconical segments defines first and second longitudinal edges, the first edge being turned radially out-ward to form an elongated spacer rib, each rib being secured to an adjacent second longitudinal edge, the elongated spacer ribs together defining said spacer means.
21. The apparatus defined by claim 20, wherein each of said second longitudinal edges is formed to define a longitu-dinal step which is recessed radially inward an amount approxi-mating the thickness of the tapered segment, said step receiving the first longitudinal edge in overlapping engagement.
22. The apparatus defined by claim 19, wherein the frustoconical filter element diverges relative to the frusto-conical separator so that said first annular space increases in flow area from the first axial end of the casing to the second axial end.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US72012176A | 1976-09-03 | 1976-09-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1069001A true CA1069001A (en) | 1980-01-01 |
Family
ID=24892737
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA284,507A Expired CA1069001A (en) | 1976-09-03 | 1977-08-11 | Air cleaner with integral louvered precleaner |
Country Status (9)
| Country | Link |
|---|---|
| JP (2) | JPS5651949Y2 (en) |
| AU (1) | AU507283B2 (en) |
| BR (1) | BR7705797A (en) |
| CA (1) | CA1069001A (en) |
| DE (1) | DE2738521C2 (en) |
| FR (1) | FR2363360A1 (en) |
| GB (1) | GB1582968A (en) |
| IT (1) | IT1087357B (en) |
| ZA (1) | ZA775329B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4211543A (en) * | 1978-04-24 | 1980-07-08 | Donaldson Company, Inc. | Air cleaner with replaceable filter element |
| GB1604979A (en) * | 1978-05-31 | 1981-12-16 | Engineering Components Ltd | Air filters |
| FR2453667A1 (en) * | 1979-04-10 | 1980-11-07 | Bourguignonne Mec Smb | FILTER FOR DEDUSTING A GASEOUS FLUID |
| US4640201A (en) * | 1986-04-30 | 1987-02-03 | Combustion Engineering, Inc. | Fluidized bed combustor having integral solids separator |
| DE4211752C2 (en) * | 1992-04-08 | 2001-02-22 | Mahle Filtersysteme Gmbh | Dust filter for continuous vertical operation |
| DE10327441A1 (en) * | 2003-06-18 | 2005-01-05 | Daimlerchrysler Ag | Filters air |
| JP2006088104A (en) * | 2004-09-27 | 2006-04-06 | Nippon Rokaki Kk | Air filter apparatus |
| WO2007047433A2 (en) | 2005-10-12 | 2007-04-26 | Kohler Co. | Air cleaner assembly |
| BE1016987A3 (en) * | 2006-02-10 | 2007-11-06 | Atlas Copco Airpower Nv | IMPROVED FLOW DEVICE FOR HANDLING A FLUID AND FLOW ELEMENT THEREFORE APPLIED. |
| USD632770S1 (en) | 2008-06-13 | 2011-02-15 | Kohler Co. | Cyclonic air cleaner housing |
| US8808432B2 (en) | 2008-06-13 | 2014-08-19 | Kohler Co. | Cyclonic air cleaner |
| US8523974B2 (en) * | 2011-08-18 | 2013-09-03 | General Electric Company | Filter core for use with pleated filter cartridges |
| DE102013106334A1 (en) * | 2013-06-18 | 2014-12-18 | Thyssenkrupp Presta Teccenter Ag | Oil separation device, in particular for a crankcase ventilation of an internal combustion engine |
| US11697089B2 (en) * | 2021-04-28 | 2023-07-11 | Eto Magnetic Gmbh | Particulate filtration device, fuel vapor recovery system, vehicle and method for a particulate filtration |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE916617C (en) * | 1946-12-12 | 1954-08-12 | Linderoths Patenter Ab | Device for separating solid components contained in a gas stream |
| US3190058A (en) * | 1961-10-03 | 1965-06-22 | Farr Co | Cylindrical dust-separating device |
| FR1563990A (en) * | 1968-03-05 | 1969-04-18 | ||
| JPS5123775B2 (en) * | 1972-11-27 | 1976-07-19 |
-
1977
- 1977-08-11 CA CA284,507A patent/CA1069001A/en not_active Expired
- 1977-08-16 AU AU27934/77A patent/AU507283B2/en not_active Expired
- 1977-08-26 DE DE2738521A patent/DE2738521C2/en not_active Expired
- 1977-08-29 FR FR7726181A patent/FR2363360A1/en active Granted
- 1977-08-31 IT IT27133/77A patent/IT1087357B/en active
- 1977-08-31 BR BR7705797A patent/BR7705797A/en unknown
- 1977-09-01 GB GB36489/77A patent/GB1582968A/en not_active Expired
- 1977-09-02 ZA ZA00775329A patent/ZA775329B/en unknown
- 1977-09-03 JP JP1977118004U patent/JPS5651949Y2/ja not_active Expired
- 1977-09-03 JP JP10540777A patent/JPS5332477A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5336578U (en) | 1978-03-31 |
| FR2363360B1 (en) | 1981-04-10 |
| DE2738521A1 (en) | 1978-03-09 |
| FR2363360A1 (en) | 1978-03-31 |
| JPS5651949Y2 (en) | 1981-12-04 |
| BR7705797A (en) | 1978-05-30 |
| ZA775329B (en) | 1978-07-26 |
| AU507283B2 (en) | 1980-02-07 |
| GB1582968A (en) | 1981-01-21 |
| JPS5332477A (en) | 1978-03-27 |
| DE2738521C2 (en) | 1984-08-23 |
| IT1087357B (en) | 1985-06-04 |
| AU2793477A (en) | 1979-02-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1069001A (en) | Air cleaner with integral louvered precleaner | |
| US3423909A (en) | Air cleaner with improved filter element assembly | |
| US4350509A (en) | Disposable air cleaner | |
| US4261710A (en) | Two-stage air cleaner and method of preventing contamination of a safety filter | |
| US7740678B2 (en) | High capacity filter | |
| US4304580A (en) | Air cleaner with suspended cartridge | |
| US3884658A (en) | Air cleaner for supercharged engines | |
| US4388091A (en) | Air cleaner having a dust dumping valve | |
| EP1214962B1 (en) | Multi-element cylindrical filter with equalized flow | |
| US6409805B1 (en) | Fluid filter system | |
| CA2730549C (en) | Filter elements; air cleaner; assembly; and, methods | |
| CA1191753A (en) | Vortex air cleaner and self-cleaning barrier filter assembly for supercharged engines | |
| US4647373A (en) | Multi-layered filter apparatus | |
| US4235611A (en) | Air filter | |
| US6923911B1 (en) | Method of filtering air through an air passageway | |
| EP1215371A3 (en) | Method and device for separation of aerosol | |
| US4265647A (en) | Air prefilter | |
| JPH1089186A (en) | Fuel filter for diesel fuel | |
| US5871567A (en) | Dual Media air filter with electrostatic charge | |
| JPS5910358A (en) | Cyclon type air cleaner | |
| JPS592531B2 (en) | Two-stage air purifier safety filter contamination prevention method and main filter | |
| US3993564A (en) | Filtration apparatus | |
| US4606743A (en) | Two stage engine air breather filter | |
| JPS5912327B2 (en) | fluid filter | |
| GB2197802A (en) | Filter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |