US 2560874 A
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July 17,. 1951 F. KELSO CENTRIFUGAL AIR CLEANER 2 Sheets-Sheet 2 Filed April 6. 1950 Patented July 17, 1951 UNITED STATES PATENT OFFICE CENT'R'IFUGAL AIR CLEANER Frank Kelso, ;Fort William, Ontario, Canada Application April 6, 1950, Serial N 0. 154,211
My invention relates to air cleaners and, more particularly, to air cleaners of the centrifugal type.
More specifically, my invention relates to improvements in mechanically-driven air cleaners as distinguished from the well-known cyclone type in which a swirling motion is imparted to the air in a shell by means of introducing the same into the shell tangentially and under pressure.
The primary object of my invention is to provide a structure which is of the class above-described, and which is more efficient than structures .of this type heretofore produced.
A further object of my invention is the pro- Fig. 2 is an enlarged view, partly in plan and a partly in horizontal section, taken on the line 22'of Fig. 1, some parts being broken awayj Fig. 3 is a vertically axial section, taken on the line 3-3 of Fig. 2; and
Fig. 4 is a view in perspective of my novel air cleaner, some parts being broken away and some parts being shown in section.
My novel air cleaner comprises spaced upper and lower wall-forming elements I and 2 respectively which define an expansion chamber 3. The upper wall-forming element I is for the most part fiat and, at its peripheral portion, is downwardly dished as indicated at 4, converging with the lower wall-forming element 2, which is preferably conical in shape. The peripheral edges of the wall-forming elements I and 2 are spaced apart to provide a restricted peripheral dust passage 5. A central outlet 6 in the wall-forming element I is axially-aligned with an inlet I in the wall-forming element '2. An imperforate circular baflie plate 8 divides the chamber 3 into inlet .and outlet compartments 9 and I respectively, the former communicating with the inlet 1 and the latter communicating with the outlet 6. The baflle plate 8 lies substantially in the plane of the peripheral dust passage .5 and is of smaller diameter than the wall-forming plates 1 and 2, the space between the peripheral edges of the baille plate and the peripheral edges of the wall-forming elements I and 2 providing an annular gas passage II.
A plurality of circumferentially-spaced radially-projecting imperforate vanes I2 are radially disposed Within the inlet compartment 9 and extend from the inlet 1 thereof to the .peripheral edge of the baffle plate 8. A plurality of sirnilarl spaced imperforate vanes I3 are radially-disposed within the outlet compartment I0 and extend outwardly from the outlet 6 to the periphery edge of the wall-forming element I, The vanes I2 and I3 are rigidly secured at their opposite side edges to the bafile plate 8 and their respective wall-forming elements I and 2. With reference to Figs. 2,, 3, and 4, it will be seen that the vanes I3 are equal in number to the vanes I 2, .one each of the vanes I3 overlying one of the vanes I2.
An annular generally conical baffle plate III is located within the outlet compartment .II'I concentric with the outlet 6, and has its inner portion rigidly secured'by welding or the like to the baffle plate 8, its outer peripheral edge being in relatively closely spaced relationship to the wallforming element I, whereby to provide a restricted gas or air passage I5 therebetween. It will be noted that the baffle plate I4 is of less diameter than the baflie plate 8. The vanes I3 may be slotted to receive the conical baffle plate I4, or said baffle plate I4 may be made in sections, each extending between adjacent vanes I3. In any event, the conical baflle plate It is rigidly secured to each of the vanes I3 by welding or the like.
My improved air cleaner is adapted to be mounted for rotation within a downwardly-tapered conical housing or the like I6, the axis of which is concentric to the axis of the cleaners. The housing I6 is provided with a relatively flat top wall I-I and a downwardly-opening dust-discharge outlet I8 at its apex portion. A conduit I6 extends through and is supported by the tapered side wall of the housing I6 and terminates within the inlet 1 of the air cleaner. The conduit I 9 extends to and is adapted to conduct dustladen air from a desired room or area, not shown. A second conduit 20 extends axially through the top wall H of the housing I6 and is supported thereby as indicated at 2 I. The conduit 20 is bent to form an elbow portion 22 and is adapted to extend to and be coupled with the intake of a blower not shown, whereby dust-laden air may be drawn through the conduit I9, the expansion chamber 3, and the conduit 20. The intake end of the conduit 20 is enlarged, as indicated at 20', and encompasses the outlet 6 of the wall-forming element I sufiiciently loosely to permit free rotation of the wall-forming element I with respect to the conduit 20.
A rotary shaft 23 is axially aligned with the wall-forming elements I and 2 and has its lower end rigidly secured by Welding or the like to'the center of the baflle plate 8, as indicated at 24. The shaft extends axially upwardly through the outlet 6 and the lower portion of the conduit 29, and through the wall of the elbow portion 22, where it is journalled in a bearing 25. It will be noted that the air cleaner structure, including the wall-forming elements I and 2, depend from the shaft 23 and are supported against downward movement with respect to the conduits I9 and 20 and the housing I6 by a collar 26 pinned or otherwise rigidly secured to the upper end portion of the shaft 23 and engaging the outer end of the bearing 25. The shaft 23 is further journalled in a bearing 2'1 rigidly mounted in the lower end portion of the conduit 20 by means of a conventional spider mounting or the like 23. Rotary movement is applied to the shaft 23 and the air cleaner supported thereby from a motor or other rotary 'element not shown but adapted to be connected to the shaft 23 by a V-belt or the like 29 running over a pulley 3i! rigidly secured to the 'upper end of the shaft 23.
When it is desired to utilize my novel air cleaner to remove dust from a particular area, the air is caused to be drawn through the conduits I9 and 2B and the expansion chamber 3 of the air cleaner by the blower, not shown. Simultaneously, the cleaner is caused to rotate on the axis ofthe shaft 23. As the dust-laden air enters the expansion chamber, its velocity is appreciably decreased. However, rotation of the cleaner causes the dust in the air to impinge upon the vanes I2 of the inlet compartment and be discharged radially outwardly through the restricted peripheral passage 5 by the action of centrifugal force, together with a relatively small amount of air. The bulk of the air drawn into the inlet compartment 9 is drawn upwardly through the annular gas passage II into the outlet compartment H] and radially inwardly through the restricted passage I5 to the outlet 6 and upwardly through the conduit 20. The conical bafiie plate I4, due to its inclination toward the wall-forming element I, tends to set up eddy currents in the air travelling radially inwardly from the annular passages II. Any
'residual dust failing to escape through the peripheral dust passage 5 and being carried upwardly through the annular passage H is caught in the eddy currents below the peripheral edge portion of the baffle plate I4, as shown by broken arrows in Fig. 3, and impinges against the rotating vanes I3 and is thrown radially outwardly.
by centrifugal force through the air stream flowing upwardly through the annular passage II and through the peripheral dust passage 5 into the housing I6. The eddy currents extract substantially all the remaining dust in the air fiow-' ing through the compartment In, so that relatively dust-free air is drawn inwardly through the restricted passage I5, the outlet 6, and the conduit 20. Obviously, the suction of the blower is sufiicient to maintain a continual flow,
of air upwardly through the air cleaner to overcome the tendency of the air to be blown outwardly through the peripheral dust passage 5. However, the speed of rotation of the shaft 23 and the baffles, vanes, and wall-forming elements carried thereby, is such that the dust particles are discharged radially through the peripheral dust passage 5 and the air is permitted to be drawn radially inwardly through the compartment I0 and restricted passage I5 against the action of centrifugal force.
My improved cleaner has been thoroughly tested and found to be completely satisfactory for the accomplishment of the objectives set forth; and, while I have shown and described a commercial embodiment of my rotary air cleaner, it will be understood that the same is capable of modification without departure from the spirit and scope of the invention as defined in the claims.
What I claim is:
1. In a device of the class described, upper and lower wall-forming elements defining an expansion chamber, said elements having aligned central inlet and outlet openings one in each thereof, said wall-forming elements converging toward their peripheral edges, said peripheral edges being spaced apart to provide a restricted peripheral dust passage, an imperforate baflle plate within said chamber, said bafiie plate be ing in substantially the same plane as the restricted dust passage and dividing said chamber into inlet and outlet compartments, said baffle plate terminating radially inwardly of said restricted dust passage whereby to provide an annular gas passage between said inlet and outlet compartments, a plurality of circumferentially-spaced radially-projecting imperforate vanes in each of said compartments, an annular generally conical baflie plate in the outlet compartment, said last-mentioned baffle plate being 'secured at its inner portion to said first-mentioned baiile plate and terminating at its peripheral edge intermediate said first-mentioned bafile plate and the adjacent wall-forming element, the outer diameter of said last-mentioned bafile plate being less than the diameter of said first-mentioned bafiie plate, and means for simultaneously rotating said wall-forming elements said baiile plates and said vanes as a unit about the axis of said inlet and outlet openings.
2. The structure defined in claim 1 in which said outlet compartment overlies said inlet compartment and in which said last-mentioned baffie plate is concentric with said inlet and outlet openings.
3. The structure defined in claim 1 in which the vanes in the inlet compartment extend. from the inlet opening to the peripheral edge of the first-mentioned baflle plate and in which the vanes in the outlet compartment extend from the outlet opening to the peripheral edge of the adjacent upper wall-forming element.
4. The structure defined in claim 1 in further combination with a non-rotary housing encompassing said wall-forming elements, said housing terminating at its lower endin a dust discharge opening concentric with the inlet and outlet openings of the expansion chamber, a non-rotary elbow-shaped conduit projecting through the wall and a bearing centrally mounted in said lastmentioned elbow adjacent said outlet, said means for simultaneously rotating said wall-forming elements including a drive shaft journalled in said bearing, said drive shaft having its inner end rigidly secured to the central portion of said first-mentioned bafiie plate and its outer end projecting through its cooperating elbow, and driving connections on said. shaft outwardly of said elbow.
REFERENCES CITED The following references are of record in the file of this patent:
Number 39 Number 6 '1 UNITED STATES PATENTS Name Date Kelley et a1. May 6, 1919 Thompson Feb. 27, 1923 Jett Aug. 19, 1924 Aalborg Feb. 19, 1929 Dodge Dec. 5, 1944 FOREIGN PATENTS Country Date Great Britain Nov. 5, 1940