US2131451A - Device for separating a mixture of fine and coarse material particles - Google Patents

Description

Sept.'27, 1938. A. MULLER I 2,131,451 DEVICE FOR SEPARATING A MIXTURE OF FINE AND GOA ESE MATERIAL PARTICLES Filed April 16, 1936 I ##arneys Patented Sept. 27, 1938 PATENT- OFFICE DEVICE FOR SEPARATING A MIXTURE OF FINE AND COARSE MATERIAL PARTICLES Adolf Miiller, Niedersediltz, near Dresden,

Germany Application April 16, 1936, Serial No. 74,674

In Germany April 26, 1935 2 Claims.

This invention relates to a device for separating a mixture of fine and coarse particles of material by means of an air current, by which the particles are entrained, and a separating wheel 3 rotating transversely of said current within a separating chamber having inlet and outlet openings but otherwise closed.

Devices of this kind are already known. In the known constructions the separating wheel which is to remove the coarse material as completely as possible from the mixture entrained by the air current is equipped with paddle-like blades; or, in lieu of paddles, it ha been proposed to provide the separating wheel with impact bodies consisting of bars, chains, ropes or the like. In no case has the precise separation or the coarse material from the fine material been obtained. In the first place, trouble is caused by an additional air current like that produced by a fan which is set up by the wheel blades, whether of fiat form or of bar form, rotating at high speed, as compared to the speed of the main air current. This interferes with the separating action or the separating wheel, and prevents the exact adJustment of the grade of separating by altering the speed of the air current or the number of rotations of the wheel. A second objection is that the blades are relied on to eiiect separating over their entire radial dimensions, and, consequently, difierent parts of the blades rotating at difiel'ent peripheral speeds, depending on the radial distance from the axis of rotation, come into play in the separating operation and confuse the setting of the separating limit.

,According to the invention, these drawbacks are substantially avoided by reason that there is employed for separating only a narrow annular zone of the separating wheel. Accordingly, of the several annular zones of the wheel having substantially difier'ent peripheral speeds there comes into action only a single narrow zone which for practical purposes may be egarded as rotating at one speed. In order to obtain the maximum separating action from a given size of separating wheel the inlet opening in the siftin wheel casing necessary for the air current does not extend over the entire circumference of a circle so as to form a complete annular slot, but the cross section of the inlet opening is formed in the shape of a segment of an annulus registering with the annular zone of the separating wheel, of such width as to avoid restriction oi! the air flow by excessiv contraction oi. the opening.

(c1. 2oa-144) An embodimentof the invention is illustrated diagrammatically in the accompanying drawing in which Fig. 1 is a. vertical longitudinal section on the line A-B of Fig. 2; Fig. 2 is an .end view.

Of the supply conduit i for the current of air 5 by which the material is entrained there is shown only the upper portion with the mouthpiece 2 having an arcuate termination which leads into the correspondingly formed inlet opening in the separating wheel casing 3. The separating wheel 4 allows the fine material to enter between the blades 5.in the direction of the arrow 6 into a chamber 1, part only of which is shown, to dep sit therein, while the coarse material separated from the fine material collects in the lower part of the separating wheel casing 3 and is discharged in known manner by a slowly rotating wheel 8 presenting compartments. The blades 5 do not only extend away from the hub to which they are attached at an angle to an imaginary radius of such hub and in a direction opposite to that of their rotation, but they are slightly curved, being convex on their forwardly-progressing .faces. This construction-increases the force with which the particles are shoved to the 25 perimeter of the wheel as they progress toward such perimeter.

What I claim is: 1. In a device of the character described, a source of supply of mixed air and fine and coarse '3 particles, a rotatable separating wheel with transverse curved blades curving away from the axis of said wheel in a direction opposite to that of their rotation, and means adapted, to direct said supply between said blades in a narrow zone near the perimeter of said wheel, said directing means being substantially a section of an annulus in cross-area, the geometric center of said annulus-substantially coinciding with the axis of said wheel.

2. A device for separating materials comprising a stationary housing, a rotating separating wheel carrying transversely extending blades mounted in said casing, means for supplying a mixture of air and fine and coarse material to said separating wheel and for causing said air to flow through said separating wheel in an axial direction, said supply means including a slot in said housing near the Per phery ot'said wheel and a conduit connecting with said slot, said slot and the' adlacent portion of said conduit being in the form of a segment of a narrow annulus concentric wi h the axis of said wheel.

ADOLF MfiILER.

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