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Publication numberUS3791112 A
Publication typeGrant
Publication dateFeb 12, 1974
Filing dateSep 23, 1971
Priority dateSep 23, 1971
Also published asCA965660A1
Publication numberUS 3791112 A, US 3791112A, US-A-3791112, US3791112 A, US3791112A
InventorsJ Lidstone
Original AssigneeDonaldson Co Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Moisture removing stack cap for engine air intakes
US 3791112 A
Abstract
A centrifugal separator is shown, including a collector tube that is large enough to fit over the top end of a vertically extending engine air intake stack to provide a moisture collecting chamber between the walls of the stack and tube; a stack cap base member with a central opening connected to the tube and walls with air intake openings therein flaring outwardly from the central opening; a cover member mounted over the base member to form a chamber therebetween; and a plurality of spaced, tangentially directed vanes mounted in the chamber between the intake openings and central opening.
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Description  (OCR text may contain errors)

Waited States Lidstone [451 Feb. 112, 1974 MOISTURE REMOVING STACK CAP FOR ENGHNE AIR INTAKIES [75] Inventor: James E. Lidstone, St. Louis Park,

Minn.

[73] Assignee: Donaldson Company line,

Minneapolis, Minn.

[22] Filed: Sept. 23, 1971 [21] App]. No.: 182,962

[52] US. Cl 55/385, 55/337, 55/396, 55/419, 55/450, 55/456, 55/459, 55/DlG. 28 [51] Int. Cl. 1304c 3/06 [58] Fieldol'Search ..55/337,D1G. 27,DIG. 28, 55/447-457, 385, 498, 396, 419, 459

[56] References Cited UNITED STATES PATENTS 1,664,683 4/1928 Hawley 55/455 X 2,804,169 8/1957 Olah 55/450 FOREIGN PATENTS OR APPLICATIONS 542,186 4/1956 Italy 55/337 896,609 5/1944 France 55/323 Primary Examiner-Dennis E. Talbert, Jr. Attorney, Agent, or FirmMerehant, Gould, Smith & Edell ABSTRACT A centrifugal separator is shown, including a collector tube that is large enough to fit over the top end of a vertically extending engine air intake stack to provide a moisture collecting chamber between the walls of the stack and tube; a stack cap base member with a central opening connected to the tube and walls with air intake openings therein flaring outwardly from the central opening; a cover member mounted over the base member to form a chamber therebetween; and a plurality of spaced, tangentially directed vanes mounted in the chamber between the intake openings and central opening.

7 Claims, 3 Drawing Figures PATENTEDFEB i 2 1924 I 3791; 112

7&1

J5 INVENTOR /%cm;m 7 e' Jana J3 z/- arm/mam MOISTURE REMOVING STACK CAP FOR ENGINE AIR INTAKES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to devices for removing moisture from the air, and more particularly relates to a stack cap having vanes positioned to rotate the air passing downwardly through a collector tube, to thereby centrifugally force the moisture outwardly against the walls of the tube for collection and disposal.

2. Description of the Prior Art Many vehicles employing internal combustion engines, such as farm tractors, highway trucks and earth moving equipment, employ heavy-duty air cleaners to separate and filter dirt from the air being drawn into the engine. In many applications, the air is drawn into the air cleaner through a vertically extending stack having an open top end. It has been common practice to provide a cap for mounting on the stack to prevent rain or snow from entering the stack, while permitting a free flow of air to the stack opening. In some instances, the stack cap has been provided with screens or separating devices designed to remove some dirt from the air before it reaches the primary filter. An example ofa stack cap performing a centrifugal pre-cleaning function is shown in the Takashi Araki U.S. Pat. No. 3,552,102 that issued Jan. 5, 1971. In the Araki patent, the air enters the stack cap chamber through fins, causing it to swirl within the chamber. Centrifugal force causes the heavier dirt particles to be thrown upwardly and outwardly into a collecting chamber, while the main, now cleaner air stream passes downwardly into the air intake stack. Other patents showing similar structures are Donaldson U.S. Pat Nos. 1,641,746, Cresswell 2,304,778, Kegerreis et a]. 1,934,311, and Russell 2,417,130. In all of these prior art patents, the air enters the bottom of a dome-like structure through a plurality of fins that cause the air to swirl around the interior of the dome. The heavy dirt particles are thus thrown outwardly so that they can be collected. The clean air is drawn to the center and from there flows downwardly through a vertical tube.

The structures of these prior art patents do not completely remove water particles from the air stream during heavy rainfall conditions. Although the dome will prevent most of the rain water from entering the stack, some water will always be carried into the stack. This moisture-laden air may interfere with combustion or may degrade the performance of the air filter. Although the structures shown in the above-identified patents will remove dirt particles from the air, they will not remove any significant amounts of moisture.

Some of the prior art systems as described above, have been modified to separate moisture from the air by placing a set of spirally arranged fins within the stack or an extension thereof. The spiral fins within the tube cause the air to swirl so that the moisture impinges and collects on the interior of the tube. The problem with the vaned tubes has been the excessive cost of production and some undesirable increase in restriction to air flow through the tubes.

SUMMARY OF THE INVENTION The present invention provides a new and unique form of stack cap having simple, effective and inexpen sive means of removing moisture from the air, without significantly reducing air flow. The stack cap includes a dome-like cover and a base member forming a chamber therebetween. The base member has a central opening to which is connected a collector tube. The collector tube is designed to fit over the top of a stack and is sufficiently large to provide a collecting chamber between the stack and the collector tube. The base member is provided with air intake openings, and a plurality of spaced, air directing vanes are mounted in the chamber in a generally tangential relationship with respect to the central opening. Air is drawn by the engine through the intake openings, past the vanes and downwardly through the collector tube and stack. The vanes direct the air so that it enters the collector tube tangentially and thus rotates downwardly through the tube. Centrifugal force causes moisture particles in the air stream to impinge on the walls of the collector tube, from where it drains downwardly into the collecting chamber. The collecting chamber is provided with a drain opening. The central column of air from which moisture has been removed passes downwardly through the stack into the air cleaner and engine. Tests have shown that this system is very efficient in removing excess moisture from the air stream and that the vanes offer very little restriction to air flow. Further, when compared with the vaned tubes, the cost of manufacturing the present system is reduced by about 50 percent. Therefore, in summary, the present invention provides equal or improved performance as compared to the vaned tubes, is considerably lower in cost than the prior art system and causes considerably less restriction to air flow.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation ofa moisture removing cap mounted on a typical air cleaner air intake stack, portions thereof being broken away and shown in section;

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, portions thereof being broken away; and

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1, portions of the background structure having been removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein like reference numerals are used throughout the several views to indicate like elements of the invention, there is disclosed in FIG. 1 an air cleaner 10 having a cylindrical body with an air intake tube 11 at the upper end and an air outlet tube 12 in a side wall thereof. Mounted within the air cleaner 10 is a cylindrical filter element 13. Air outlet tube 12 would be connected to the air intake of an internal combustion engine. The air would be drawn by the engine through tube 1 l, filter element 13 and tube 12.

Connected to air intake tube 11 is a vertically oriented, cylindrical intake stack 14. In the preferred embodiment, air intake stack 14 is in the form of a cylinder. Mounted over the top end of stack 14 is a collector tube 15, also in the form of a cylinder. Tube 15 has a larger cross-sectional dimension or diameter than the corresponding dimension of stack 14 thereby providing an annular moisture collecting chamber 16 between a bottom portion of tube and stack 14. Chamber 16 is an annular chamber having an inwardly sloping bottom wall 17 with a drain opening 18 therein. The inner edge of bottom wall 17 is clamped or otherwise secured to the outer wall of stack 14. A plurality of spacer members 19 are mounted between tube 15 and stack 14 to maintain the coaxial alignment.

Mounted on the top end of collector tube 15 is a stack cap 20 having a base member 21 and a cover member 22. In the preferred embodiment, base member 21 and cover member 22 are molded from a suitable thermoplastic material. Base member 21 includes a tubular mounting flange 23 defining a central opening 24. Mounting flange 23 extends over the top of collector tube 15 and is secured thereto by means of a band 25. Central opening 24 has approximately the same diameter as the interior diameter of tube 15 so that smooth air flow into the tube is insured.

Base member 21 also includes a funnel-shaped wall 21a, flaring upwardly and outwardly from central opening 24, and terminating in a peripheral, horizontally extending portion 21b. Portion 21b is circular in shape. Wall 21a and portion 21b are formed to have a large plurality of openings 26 therein, the openings 26 forming a screen-like air intake portion around the entire base member. Extending downwardly from the outer edge of portion 21b is cylindrical wall 27 having a bottom edge extending below the level of openings 26. Wall 27 acts as a shield to prevent rain and snow from directly entering openings 26.

Cover member 22 is a dome-like structure having a horizontally extending peripheral flange 30, circular in shape, positioned over portion 21!). As best shown in FIG. 1, base member 21 and cover member 22 thus define an air flow chamber 31 within the stack cap 20.

A plurality of air directing vanes 32 are mounted within chamber 31. Each of the vanes 32 has a flat, horizontally extending connector portion 32a and a vertically extending, planar blade portion 32b. In the preferred embodiment, eight vanes 32 are evenly spaced around the periphery of chamber 31 with the connector portion 32a of each positioned between portion 21b and flange 30. The connector portions 32a are frictionally retained in a predetermined position therebetween by rivets 33 extending therethrough. When portion 21b and flange are riveted together with the connector portions therebetween, some slight deformation of the parts occurs to retain the vanes in predetermined positions.

The blade portions 32b each lie in a separate vertical plane that extends generally tangentially with respect to the central opening 24. Each blade portion 32b has an upper edge positioned closely adjacent the cover member 22 and a lower edge psoitioned closely adjacent base member 21 and openings 26. In this embodiment, each blade portion 32b has a vertical innermost edge positioned between the intake openings 26 and the central opening 24. Vanes 32 are preferably constructed from plastic, but could be constructed from metal as well. Further, vanes 32 could be molded to the inner surface of either cover member 22 or base member 21 without departing from the invention.

It is noted that cover member 22 has an outwardly and downwardly extending lip 34 depending from flange 30. Water running from off the top of cover member 22 thus normally drains off the bottom edge of lip 34 without coming in contact with wall 27, and a sufficient distance away from air intake openings 26 so as not to be entrained in the incoming air stream. It is further noted that portion 21b and flange 30 are spaced apart between the connector portions 32a a distance corresponding to the thickness of the connector portions. Therefore, some air can enter chamber 31 between them as well as through openings 26.

During engine operation, air is drawn inwardly through openings 26 at a relatively high velocity. The air is directed by the vanes so that the air stream leaving each vane enters opening 24 and tube 15 generally tangentially with respect thereto. Because the air is traveling at a high velocity, the vanes cause it to swirl or rotate as it passes downwardly through tube 15. This rotation of the air stream causes a centrifugal force to be applied to any water droplets or other moisture particles being carried by the air stream. The moisture particles are thrown outwardly and impinge on the inner wall of collector tube 15, where they collect and drain downwardly into collecting chamber 16. The collected moisture drains to atmosphere through opening 18. The air stream from which the moisture has been removed thus enters stack 14 leading to air cleaner 10. Some varients in the positioning and form of the vanes 32 can be permited without departing from the invention. The function of the vanes is to direct the air stream tangentially into the central opening so that the air stream and moisture carried thereby immediately impinge upon the inner wall of collector tube 15. Because of the high velocity swirling action and because the air immediately impinges upon the top end of the tube 15, only a relatively short section of collector tube 15 is required to effectively separate moisture from the air stream. My invention is defined in the following claims.

What is claimed is:

1. In a moisture removing stack cap having a collector tube adapted to be mounted over a vertically oriented engine air intake stack, said stack cap including a base member having a central opening connected to one end of said tube and a wall flaring outwardly from said central opening with air intake openings therein and terminating in a peripheral edge, and further including a cover member having a peripheral edge connected to the edge of said base member, forming a chamber between said base member and cover member permitting air to flow from said air intake openings through said chamber to said tube, the improvement comprising; a plurality of spaced, air directing vanes secured to said stack cap in said chamber and positioned between said air intake openings and said central opening to rotate the air as it passes into and downwardly through said collector tube thereby causing moisture in the air to impinge on and flow down the walls of said tube to separate the moisture from the air stream, said peripheral edges having mating flanges, and said vanes each having a connector oortion secured between said flanges and a blade portion extending therefrom toward said central opening.

2. The apparatus of claim 1 wherein each of said blade portions lie in a plane extending generally tangentially with respect to said central opening.

3. The apparatus of claim 2 wherein said blade portions each have an upper edge positioned closely adjacent said cover member and a lower edge positioned closely adjacent said base member.

4. A moisture removing stack cap adapted to be mounted over a vertically oriented engine air intake stack, comprising:

a. a collector tube adapted to fit over the top end of a stack to provide an annular chamber between the walls of the tube and stack;

b. a stack cap base member having a central opening connected to the top end of said tube, and a wall flaring outwardly from said central opening, said wall having air intake openings, therein and terminating in a peripheral flange;

c. a dome-like stack cap cover member having a peripheral flange positioned over the flange of said base member, forming an air flow chamber be tween said base member and cover member;

(1. a plurality of spaced, air directing vanes each having a connector portion positioned between said flanges and a blade portion extending therefrom toward said central opening; and

e. means for tightly securing said flanges together to retain said connector portions of said vanes therebetween, said vanes being positioned to cause said air to rotate as it passes into and downwardly through said collector tube thereby causing moisture in the air to impinge on and flow down the walls of said tube to separate the moisture from the air stream. n

5. The apparatus of claim 4 wherein said blade portions are generally tangentially positioned with respect to the central opening.

6. A moisture removing stack cap for a vertically oriented, cylindrical engine air intake stack, comprising:

a. a cylindrical collector tube having a larger cross sectional dimension than the stack;

b. means mounting said collector tube with a bottom portion thereof extending over a top end of said stack, providing an annular moisture collecting and discharging chamber between said tube and said stack, a top portion of said tube extending above said stack;

0. a stack cap base member, mounted on a top end of said tube, having a central opening over said tube and wall flaring upwardly and outwardly from said central opening, said wall having air intake openings therein and terminating in a peripheral flange;

d. dome-like stack cap cover member having a peripheral flange positioned over the flange of said base member, thereby forming an air flow chamber between said base member and cover member;

e. a plurality of air directing vanes each having a flat horizontally extending connector portion positioned between said flanges, and a vertically positioned blade portion extending therefrom toward said central opening in a plane generally tangential with respect to said central opening, said vanes being evenly spaced around the periphery of said stack cap; and

f. means for tightly clamping said flanges together to frictionally retain said connector portions of said vanes therebetween, said vanes causing said air to rotate as it passes into and downwardly through said collector tube thereby causing water into the air to impinge on the walls of said tube and flow downwardly into said annular chamber.

7. A moisture removing stack cap having a genrally cylindrically shaped collector tube with first and second end portions, said first end portion being adapted to be mounted over a vertically oriented engine air intake stack, said second end portion extending vertically upwardly when mounted and having a smooth interior cylindrically shaped wall surface extending to an upper end of said tube, said stack cap including a base member having a central opening of approximately the same diameter as the interior diameter of said tube, means connecting said upper end of said tube directly to an edge of said central opening to provide a smooth air flow path into said tube, said base member further including a wall flaring outwardly from said central opening with air intake openings therein and terminating a peripheral edge, and said stack cap including a cover member having a peripheral edge connected to the peripheral edge of said base member, forming a chamber between said base member and cover member permitting air to flow from said air intake openings throug said chamber to said tube, a plurality of spaced air directing vanes secured to said stack cap and positioned in said chamber between said air intake openings and said central opening to rotate the air as it passes into and downwardly through said collector tube thereby causing moisture in the air to impinge on and flow down the smooth interior wall surface of said tube to separate the moisture from the air stream.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1664683 *May 4, 1925Apr 3, 1928Centrifix CorpSuction air intake
US2804169 *Oct 11, 1954Aug 27, 1957Cleaver Brooks CoCentrifugal separator
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4131441 *Nov 17, 1976Dec 26, 1978Fram CorporationMulti-size rain hood
US4157902 *Dec 7, 1977Jun 12, 1979Donaldson Company, Inc.Tapered air-permeable membrane
US4168694 *Feb 6, 1978Sep 25, 1979Nett James ACarburetor cover kit
US4198217 *Aug 28, 1978Apr 15, 1980Filterwerk Mann & Hummel GmbhProtective air filter intake hood with air deflecting intake screen
US4212659 *Dec 7, 1978Jul 15, 1980Fiat Veicoli Industriali S.P.A.Air-intake devices for internal combustion engines
US4215665 *Mar 15, 1978Aug 5, 1980Caterpillar Tractor Co.Adjustable air intake assembly and method
US4327680 *May 12, 1980May 4, 1982Caterpillar Tractor Co.Air intake assembly
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US4366878 *Dec 17, 1980Jan 4, 1983Paccar Inc.Moisture-removing low-restriction air intake system
US5022903 *Oct 23, 1989Jun 11, 1991American Farm Implement & Specialty, Inc.Air-precleaner
US5449391 *Mar 21, 1994Sep 12, 1995American Farm Implement & Specialty, Inc.Air precleaner
US5505756 *Mar 17, 1995Apr 9, 1996American Farm Implement & Specialty, Inc.Ramp discharge outlet air precleaner
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US6361574Mar 17, 2000Mar 26, 2002American Farm Implement & Specialty, Inc.Intake air cleaning apparatus
US6630007 *Aug 9, 2001Oct 7, 2003Kawasaki Jukogyo Kabushiki KaishaAir cleaner for internal combustion engine
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US8177872Feb 13, 2009May 15, 2012Donaldson Company, Inc.Raincap precleaner, motor vehicle having a raincap precleaner, and method for precleaning air
USRE33085 *May 11, 1988Oct 10, 1989 Precleaner
CN101910601BFeb 13, 2009Nov 6, 2013唐纳森公司Raincap precleaner, motor vechile having a raincap precleaner, and method for precleaning air
EP0541857A1 *Nov 11, 1991May 19, 1993New Holland Belgium N.V.Pre-cleaner for use on an internal-combustion engine
WO1979000761A1 *Feb 12, 1979Oct 4, 1979Caterpillar Tractor CoAdjustable air intake assembly and method
WO2009102988A1 *Feb 13, 2009Aug 20, 2009Donaldson Co IncRaincap precleaner, motor vechile having a raincap precleaner, and method for precleaning air
Classifications
U.S. Classification55/385.3, 55/450, 55/337, 55/DIG.280, 55/459.4, 55/456, 55/396, 55/419
International ClassificationF02M35/10
Cooperative ClassificationF02M35/10013, Y02T10/146, F02M35/02, F02M35/10144, F05C2225/08, F02M35/10262, Y10S55/28
European ClassificationF02M35/10A2, F02M35/10D16, F02M35/10K6