US978397A - Fan. - Google Patents

Description

G. S. RICE.

FA'N.

APPLIoA rmN I'ILED' nno.12.19oa.

978,397. Patented Dec. 13, 1910.

2 SHEETS-SHEET 1.

G. S. RICE.

FAN.

APPLIOATION IILBD DBO.12.1008.

Patented Dec. 13, 1910.

2 SHEETSSHEET 2.

q/v'vtmeooco UNITED STATES PATENT OFFICE.

GEORGE S. RICE, 0F EVANSTON, ILLINOIS.

FAN.

Specification of Letters Patent.

Patented Dec. 13, 1910.

Application filed December 12, 1908. Serial No. 467,241.

To all whom it may concern:

Be it known that I, GEORGE S. Bron, a citizen of the United States, and resldent of 'Evanston, Cook county, Illinois, have in- -illustrates the cross sectional form of one of the spokes at difierent parts of its length, as

"-The shaft 1 ofthe fan is eccentrically disposed within the casing A, of general spiral v outline -sfuch as is usual in this class of ap- "'paratu's, and carries the fan D, the casing having side openings for the entrance of the air, and a discharge neck2.

To facilitate the inflow of the air the walls 3 of the side openings constituting the inlets expand outward in a gradual curve, preferably constituting the flange 4 of a metal plate 5 which constitutes the side of the casing, or when the casing is of masonry the said walls maybe formed in the masonry itself of brick, stone or concrete. The curve thus given to these walls is of a character known in hydraulics as a 'vena contracta curve, inasmuchas' this proportion of curvature 'isfone which will best insure the inflow of the air without anyl eddies or counteracting'currents.

The peripheryof the fan, whatever may beitscharacter, is supported by arms 6 which meet the hub 7 of the wheel 1 radially,

" gradually increases, as shown by the cross and extend on said radial lines outward to the periphery or rim, and, instead of being 1n the form of bars ,of'substantially uniform cross-section as usual, they consist each of a late which is bent'or'twisted to an increas- Jngangle toward-the'rim of the wheel; thus,

the inner end of each plate in its crosssection correspondin to an angle which is acute to the axis of t e shaft, and this angle sections Fig. 3, toward an angle approximating at the outer end about 45 to the axis. This gives to each plate a propellerlike form so that as the fan rotates the blades, "instead of constituting an obstructionand producing eddies which interfere with the inflow of the air current, actually serve as propellers to insure a steady and continuous and unbroken inflow. The plates are twisted inwardly so that the outside edges are straight and radial and, therefore, present an even surface.

The periphery or rim of the fan consists of a series of curved blades 8, the curvature of each blade being forward and the blades being pitched in a forward direction with a sufficient space between the blades to permit the ready passage of the air drawn in as aforesaid by the action of the propeller arms and carried outward by the centrifugal action resulting from the further driving of the air by the blades 8 themselves, the curvature and inclination of the said blades insur' ing a hold upon the air so that there is no possible back current or eddies. These blades are preferably short and arranged between a series of circular plates 9 concentric 'with the shaft, each blade having at each end a side flange 10 which is bolted or otherwise secured to the adjacent plate or ring 9, and when the whole are thus secured together the rim of the wheel possesses great stiffness and rigidity so that the fan may be rotated at'a high speed without undue strain or breakage. In some cases the fan may be double and in this case there is a central partition 12 to the fan and a corresponding partition 13 in the casing, the air admitted to the opposite sides being thrown outward by the different sections of the fan.

(loacting with the blades of the fan are other blades 14 arranged in a circle about the fun and supported by the casing and slightly curved inward, eachblade extending forward approximately at right angles to v the radius of the fan and overlapping the heel of the next forward blade, as shown in Fig. 2. These blades are properly supported in the casing,andas the fan rotates, the air which is thrown from the fan is projected approximately tangentially to the periphcry of the fan and, meeting the inner curved surfaces of theblades 14 is directed in lines substantially parallel to the outline of the casing A so as to flow, Without counter currents or eddies, freely toward the outlet of the casing. The overlapping arrangement of these blades 14, while it insures the ready outflow of the currents and without any obstructionto the lineof flow in which the air is projected by the fan, effectually serves to prevent any counter-flow or back flow toward the wheel.

The division of the blades of the wheel into small sections by means of the rings 9 also compels the air to take a course at right angles to the shaft, preventing side deflections, and also aids in preventing any counter currents as each portion of the aircarried outward bycentrifugal force under the action of these blades or vanes is itself so small in volume that counter currents cannot be generated as in fans of ordinary construction where the blades .which act upon the air are segments with its blades may be so arranged as when removed to permit the fan to be carried to an opening in the casing closed by a section X. This section may have edge angle bars 22 coinciding with similar bars 21 on the casing, securing bolts 23 passing through the two meeting bars. To facilitate such removal of the fan the hubs of the wheel and the shaft are keyed together by keys 20, on the removal of which the shaft can be withdrawn, and it will be seen that the sides of the hubs do not project beyond the planeof the sides of the fan, so the latter may be almost equal to the full width of the casing without its withdrawal being interfered with.

The internal diameter of the rings is substantially the same as the diameter of the side opening or the mouth. It is, therefore, insured that the lines of flow will be uniform throughout the fan and,therefore, the forma- I tion of eddies will be prevented. The rings are alsoflat and of uniform depth. Therefore, it is insured that each unit shall receive the same impetus. Where the rings are not of uniform depth .one set of vanes or blades is liable to receive more than its share of the Work, and, therefore, eddies are liable to be .-formed, causing loss inefliciency'. By constructing the rings "and the vanes in this manner, and giving'the mouthpiece an out- I out shock, and thus all eddies will be prewardly flaring form, the gjair will enter the fan at a-uniform rate, will be given a uniformrotative motion as it enters the 'fan, and will be received by the fan blades withvented.

i I Without limiting myself to the precisecondrivin twisted radially, the angle of the twist,

measured with respect to a plane-at right angles to the fan shaft, decreasing toward the rim of the Wheel.

2. The combination with a shaft and casing of a centrifugal fan, of a wheel having peripheral blades, and supporting spokes at each side consisting of blades bent or twisted radially to secure a progressive decrease of the angle of twist, measured with respect to a planeatright angles to the fan shaft, toward the rim of the wheel. I v

3. The combination with a fan shaft, of a series of flat rings concentric with said shaft,

a series of sets of radial blades provided with side flanges, fastening means passing through the flanges and rings so as to secure said parts into a rigid structure, and

side spokes for connecting saidend .rings to said shaft.

4. The combination with the casing and shaft of a centrifugal blower, of a fan the .peripheryof which consists of a series of parallel rings and intermediate flanged curved blades, the flanges secured to said rings and with spokes at each side, each spoke twisted radially with a decreasing angle, measured with respect to a plane at right angles to the fan shaft, toward the rim as set forth. p

' 5. The combination of the shaft, a fan having forwardly curved radial blades at the periphery, and casing having a series of overlapping curved blades arranged in a circle about the fan ,-and propeller arms for the air into the fan, each arm being twlsted radially to a gradually decreasing angle of twist, measured with respect to aplane at right angles to the fan shaft, toward the rim of the fan.

61 The combination of a casing having side and peripheral walls, said walls having side openings and said peripheral wall having a .removable'peripheral section, a shaft, and a .fan greater in diameter than the side openings, thesaid fan detachably secured to said shaft, wwhereby said fan may be moved through the opening formed in the 'periph-' .eral wall by the removal of the section.

"I. Thecombination of a centrifugal blower, of a caslng having side openings, a removable peripheral section and circular series ofblades, of segments supporting sections/of the blades and connected detachably to the casing, a fan, and a shaft connected detachably to the fan. 8. The combination of a shaft and a fan detachably secured thereto, a casing having a removable peripheral section, a series of blades arranged in a circle around the fan, and supports for those blades between the fan and said section, detachably connected to the casing.

9. The combination with a shaft and casing of a centrifugal fan, of a wheel having peripheral blades, and side spokes consisting of'blades to act as propellers to carry the air into the fan, the blades bein twisted radially and inwardly so that t e outside edges ofthe blades are straight and radial.

10. The combination of a fan shaft, a series of parallel fiat rings concentric with said shaft, an intermediate series of sets forwardly curved radial blades securing said rings together, and side spokes securing the end rings to the shaft.

11. The combination with a casing having side inlets of a fan shaft in said casing, a series of parallel flat rings concentric with said shaft and mounted in said casing, intermediate series of sets of forwardly curved radial blades securing said rings together, side spokes securing the'end rings to the shaft, and a partition plate securing an intermediate ring to said shaft.

12. In a centrifugal fan, the combination with a casing having a side inlet opening of curved cross section and flarin of a fan wheel rotatable in sai casing and comprisingla series of concentric and parallel rings, t e internal diameter of said rings being substantially equal to the inner diameter of said inlet, and blades between said rings and secured thereto, said rings dividing the part of the wheel open to said inlet into a plurality of annular sections extending longitudinally of the wheel, for the purpose set forth.

In testimony whereof I afiix my signature in presence of two witnesses.

GEORGE S. RICE.

Witnesses:

W. R. JOHNSTON, J. C. ROBERT.

outwardly,

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