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Publication numberUS1548839 A
Publication typeGrant
Publication dateAug 11, 1925
Filing dateNov 22, 1924
Priority dateNov 22, 1924
Publication numberUS 1548839 A, US 1548839A, US-A-1548839, US1548839 A, US1548839A
InventorsPercival P Henshall
Original AssigneeJohn J Nesbitt Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1548839 A
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Description  (OCR text may contain errors)

Patented Aug. 11, 1925.




Application filed November 22, 1924. Serial No. 751,597.

To allwhom it may concern:

Be it known that PERCIVAL P. HnNsHALL, a citizen of the United States, residing at Atlantic City, in the county of Atlantic 6 and State of New Jersey, has invented certain new and useful. Improvements in Ventilators, of which the following is a specification. I

This invention relates to air filters for l heating and ventilating units.

The primary object of my invention is to produce an air-filter which may be installed in the fresh air intake of a ventilating unit to exclude the dust, dirt and foreign matter being drawn into the ventilating unit by fans; to overcome the resistance to the flow of air against; an ordinary bafile; plate; to permit the delivery of the maximum quantity of air Without retarding the operation of the motor and fans; to separate and retain the heavier dust and dirt particles in advance of the dust and soot, and to finally remove and cleanse the air of the fine par v ticles before it enters the interior of the ventilating and heating unit, and thence to the room.

In order to more fully understand and appreciate my invention,- reference is had to the accompanying drawing, showing a preferred embodiment of my construction, wherein:

' Fig. 1 is a fragmentary view, in section,

showing the bottom of a heating and ventilating unit and the position of the filter in the freshair intake.

the filter.

Fig. 3 is a view of the bafie plates within the casing of the filter.

Fig. '4 is an enlarged fragmentary view of the bafiile plates, showing the relative size of the openings.

Referring now to the drawing, wherein like reference characters designate corresponding parts of the several views of the drawing, 5. designates the bottom of the ventilator casing 6. A. fan housing 7, damper 8 and inspection door 9 are in a direct pathfwith a series of louvers 10 and wire mesh screen 11, positioned in the wall box 12 which constitutes the fresh air inlet of the casing.

Between the louvers and the fan housingis positioned my novel and improved air filter for cleansing the air as it is drawn through the ventilator casing into the room from the outside of the building.

Referring particularly to Figs. 2, 3 and 4, it will be observed that the filter comprises a frame having a top and bottom 13, 14, sides 15 being open at its front and rear for the passage of the air as it is drawn into the casing by the fans. A series of superimposed, baflle plates 16, 17, 18 and 19 preferably formed from a single pieceof material, are soldered or welded to the sides of with the minimunt amount of air friction.

When the air passes through the filter'it must continually change direction due tothree forces:

Force 1The course which the air would take if the bafile plates were made of a solid material which would be in a sinuous path Fig. 2 is a side View, partly in section of between the respective plates.

Force 2The course which the air would take if it were compelled to travel in the direct path through the holes stampedin the plates.

Force 3--The course. which the air takes as a result of a combination of these forces, that is, being drawn in contact with the The plates are ar plates continually, as they change direction.

What actually takes place in the filter can best be determined by a study of the deposits on the respective bafile plates. A certain part of the air travels through the holes in the plates, the said holes being of me same size throughout the surfaces of the plates or graduated in size, smaller toward the back, as indicated by Fig. 4. The holes are in staggered relation relative to each other so that of necessity, any air carrying particles of dust passing through the larger holes 25 of baffle would strike baflle plate 21. Any air carrying particles of dust passand the next plate 23. Upon examination of the filtering plates, it is found that the heavier and lar er particles of dust are deposited on the gaflle at the inlet, while the very fine particles of dust are deposited on the bafiies 21 and 22: On baffle 23, the size of the particles are so small and so few that this filter plate is never dirty except when the filter is overloaded. The purpose therefor of bafile plate 23 is to take care of the over-load.

The first section 20 of the bafile plate is provided with apertures 24 throughout its surface; it catches the heavier and larger particles of dust and dirt entering the filter through the plates.

and at the same time creates the least amount of air friction, being nearest the inlet, the apertures being one-sixteenth in diameter. The adjacent sections 21, 22 of the baffle plate are provided with apertures" 25 which are smaller, being three sixty-fourths in diameter. They catch the smaller particles of dustor soot, passing the first section. The relation of the size of dust particles filtered to the size of holes stamped in the various plates approaches a constant ,free air capacity The back section 23 of the baffle plate is provided withathe smallest apertures 26, which second of an inch in diameter.

a The filters are dipped in a special viscous oil and the plates at-the points where each hole is stamped, act as a separate oiLreservoir. When the air is drawn into the filter and impinges itself on the plates, the dust particles adhere to the oil. At this point there is a definite and immediate action.

The oil penetrates the dust and has a similar effect to that of placing a lamp-wick on the face of the filter plate, that is, the oil is caused to advance in a position upward from one reservoir to the next aperture or reser- 1r immediately above it, and so on. This action causes the face of the plate to present 55 a sticky surface to the dust particles rendering the baflles more eflicient. Both sides of the plates are of course covered with the 011. As the air strikes the top surface of one plate it is deflected to the bottom surface of the next and adjacent plate. In other words when the air strikes the top surface of plate 17 upon entering the filter, a certain volume will be deflected toward the bottom surface of plate 16. On the ing through baffle 21 would strike plate 22v are only one thirty-' with dirt particles and dust thus obtaining" the maximum efliciency within the filter.

The bafie plates are preferably,.con-' structed of tin, Monel metal or the like, whilethe frame for the battle plates are of galvanized iron or steel.

Having shown and described my invention, what I now claim as new and desire to secure by Letters Patent of the United States is 1. An air filter of the iclass described comprising a frame open at its front and back, a plurality of superimposed, apertured bafiie plates arranged within the said frame adjacent and in direct communication witheach other to exclude the larger dirt particles in advance of the smaller dirt particles.

2. An air filter of the class fdescribed comprising a frame open at its'front and back, a plurality of superimposed, bent baffle plates secured within the frame and having apertures diminishing in size from front to back and arranged to exclude the larger dirt particles in advance of the smaller dirt particles.

3. An air filter of the class described comprising a frame open at its front and back, a plurality of superimposed bafile plates divided into sections and secured to the sides of the frame, said sections having apertures diminishing in size from front to back and arranged in different planes to exclude the lar er dirt particles in advance of the smaller irt particles.

(1. An air filter of the class described comprising a frame open at its front and back, a lurality of superimposed bafle plates divided into a plurality of equalsections secured to the sides ofthe frame, said sections being disposed at an angle to each other and having apertures diminishing in sizefrom front to rear whereby the larger dirt particles are excluded in advance of the. smaller dirt particles.

5. An air filter of the class described comprising a frame open at its front and back, a plurality of superimposed baflle plates secured to the sides of said frame, each plate being bent into four sections, each section being disposed at an angle to each other, the front section of each plate having large apertures and the rear section of said plate having small apertures therethrough, said intermediate and connecting sections having apertures of a size intermediate the size of the apertures in the front-and rear sectionswhereloy the larger dirt particles are maaeaa excluded in advance of the smaller dirt particles.

6. An air filter comprising a frame open at its front and back, a plurality of superimposed zig zag baffle plates arranged within said frame in close proximity to each other, said plates having apertures throughout their surfaces and a viscous coating on the top and bottom surfaces thereof for exclud-- ing dirt particles from the air passing 1 through said apertures and over the coated surfaces.

In testimony whereof I afiix my signature.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2635278 *Aug 18, 1951Apr 21, 1953William J BelknapFloor drying apparatus containing baffle structure for separation of entrained liquid
US2703151 *Jan 24, 1951Mar 1, 1955Carl GlinkaSeparation of finely divided solid material from gases
US2837835 *Mar 4, 1954Jun 10, 1958Electric Aire Engineering CorpDryer
US3026967 *Mar 6, 1959Mar 27, 1962Georgia Tool & Engineering CoAir filter
US7740530 *May 11, 2006Jun 22, 2010Ruskin CompanyAir handling system
US8097059 *Sep 15, 2008Jan 17, 2012Alstom Technology LtdExhauster bypass system
U.S. Classification55/440, 55/445, 55/DIG.370, 236/38, 15/347, 55/524
International ClassificationB01D45/08
Cooperative ClassificationB01D45/08, Y10S55/37
European ClassificationB01D45/08