US2173088A - Separating device - Google Patents

Description

Sept. 19, 1939. o. E. ElssMANN SEPARATING DEVI CE Filed sept. f1, 193s r izve oswam amm Hagnau Patented Sept. 19, 1939 UNITED STATES 2,173,088 SEPARATING DEVICE Oswald Erich Eissmann, Richmond, Va., assigner Universelle Cigarettenmaschinenfabrik J. C. Mller & Co., Dresden, Germany Application September 1, 1936, Serial No. 98,917 In Germany September 19, 1935 1 Claim.

, The present invention relates to improvements in separating devices, and relates more particularly to a device designed for segregating the heavy rib portions from the leaf portions of l 5 tobacco plants.

It is an, object of the invention to provide a pneumatic arrangement for achieving a rapid and effective separation of the ribs from the `leaf portions in which the separation will be clean-cut l and unaccompanied by any admixture of these two elements. Such admixture would impair the value of the commercial product.

A further object of the invention is to achieve this separation by -a simple mechanism, simply and economically operated.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claim appended hereto. l

In the drawing, the figure is a vertical longitudinal section taken substantially centrally through a separating device embodying the features of the present invention.

Referring more particularly to the drawing the leaf portions of the tobacco are fed by the obliquely ascending endless conveyor belt 3. This conveyor belt 3 runs over a` lower roller not shown in the figure, as it is well known, and over an upper roller illustrated in the iigure.

This upper conveyor belt roller 5 is situated in approximately the horizontal central portion of the base of an uptake air channel 6. Such channel is preferably rectangular in horizontal cross-section. In vertical cross-section, the air uptake channel 6 is frusto-conical with smooth walls.' This air channel-6 progresses from a relatively Wide base, at or about which the conveyor enters, upwardly in constantly diminishing crosssection to an upper truncated portion of minimum lcross-section, which connectskwith an elbow or curved section 1 turning substantially horizontally and entering the separating chamber 8.

Above the guide roller 5 of the conveyor there is disposed in the air channel 6 a partition 9,

the lower end of which is spaced a distance above the upper run of the conveyor. The walls of this partition are smooth and preferably straight. Between the lower end. of the partition and the upper run of the conveyor belt is a slot III of desiredcross-section through which the material carried upwardly by the conveyor moves, as indicated by the arrow. f

'I'he partition 9 is placed obliquely, that is at anv angleto the vertical, and inclining upwardly 55 toward the right or toward the input side of the arriving material'. By this arrangement there results a narrow passage II at the right side of the upper end of partition 9, and a wider passageor mouth I2 at the left side of the par- 50 tition 9.

(ol. zoe-139) Adjoining the guide roller 5 is an air aperture I 3, which aperture is at the base of the left channel or the channel to the left of the partition 9, which channel has the wide mouth I2 at the top thereof. Below, and communicating with the air aperture I3 is an air cannel I4 rising from a chamber\or space I5.

The separation chamber 8 has therein a sieve or screen I5 forming the rear wall of such chamber 8. This sieve or screen is placed obliquely and it is disposed opposite an inclined chamber wall I1. The two walls I6 and I1 form substantially a funnel.

At the lower constricted end of the funnel is a discharge opening I8 leading to a sluice I9. The sluice discharges into a pipe 20, a funnel 2l and into a receiving box 22. Behind the sieve or screen wall I6 there is a suction chamber in ywhich suction is produced by means of a suction pipe 23 connected with the chamber as indicated at 24. Preferably this suction chamber 30 is separated from the screen chamberl 3| by a partition wall 32, which wall has an opening 25 placing the chambers 30 and 3l in communication. The opening 25 is in the upper part of the wall 32. The suction pipe line 23 leads to the suction blower 26. The suction blower discharges through a pipe line 21 `to a dust lter not shown.

In the operation of the invention, the material on the belt 3 is elevated by such belt into the separating device. This material is caused to pass through the slot I0 between the conveyor belt and the partition 9 and it thereby comes under the influence of the current of suction air which is being drawn by the blower 26 upwardly from the space I5 through the channel I4, inlet port I3 and into the uptake air channel 6. 'I'his suction of air, as represented by the arrows in the figure, rises through the channel 6, passes about the elbow 1 and enters the separation chamber 8; whereupon it passes through the screen I6, aperture 25, port 24 and into .the trunk 23 by which it passes to the suction blower 26.

The'channel I4 guides and conflnes the upwardly entering air and, by reason of itsscrosssection, determines the speed of ow. Such air current sweeps the material upwardly, except the heaviest rib portions which are suiciently heavy to drop down through the channel I4 and into the space I5. The lighter portions of the material will become entrained with the ascending air currents. Due to the progressively enlarging left channel such air currents will be influenced to undergo a swirling action, as indicated by the arrows, just above the widened mouth I2. This swirling action takes place in a circulating or eddying manner and has the effect to move the heavier rib portions of the entrained material over toward the right or against the right wall of the conical passage 6. In other words the heavier rib portions are shifted over by this eddying action to a position directly above the smaller mouth II of the right section of the air channel.

At this point the upward air pressure is at a minimum, or itis much less than above the mouth I2, and consequently such heavier rib portions in the eddying current are permitted to drop down through the aperture II and upon the conveyor belt 3, whereby they are introduced anew through the slot I0 into the current of suction air. The light ribfree leaf portions, on the other hand, are carried along upwardly in the air channel 6, through the elbow'I and into the receiving chamber 8. Such parts of this material as reach the sieve or screen I6 will slide down the inclined wall of this screen and be deflected to the exit opening I8. Such of this leaf material as encounters the other opposite wall I1 will also be guided downwardly thereby to, and out through, the exit opening I8. 'I'he dust which is picked up and entrained with the. current of air in the intermingling swirling motion given the tobacco leaves is drawn oir but the suction through the sieve or screen I6, carried down the trunk 23 to the blower 26, driven out the trunk 21 and required to pass through the dust-separating filter.

The novel points of the invention might be summarized as follows:

(a) The arrangement of a suction blower connected to the separation chamber 8 for the purpose of creating a current of suction air, which draws the air through a channel ll'having its air inlet aperture I3 adjacent the material inlet I0.

(b) 'Ihe shaping of the perpendicular crosssection of the channel 6 as a smooth-walled cone having agentle tapering toward the leaf outlet end, and. in connection with this channel, the arrangement of the material introducing device (in this instance the conveyor) with its discharging end disposed in a central portion of the base part of the channel, and cooperating with the partition 9 spaced above this discharge end of the conveyor and inclining upwardly and toward the Y side on which the material is introduced.

(c) The arrangement of the air inlet I3 and the air supply channel I4 which is directed downwardly adjacent the point where the material is introduced, and below this air channel I4 a space I5 for the reception of the rib portions which have dropped down by gravity even against the influence of this rising air current.

(d) Isofar as the receiving or separation chamber 8 is concerned, the arrangement of the obliquely placed sieve or screen I6 with the suction pipe line connected behind the same in combination with the oppositely situated 0bliquely placed wall I1, both walls forming a funnel at whose outlet aperture there is located a sluice for the sluicing out of the tobacco leaves which trickle down'the funnel. A

It is not to be understood that the invention is J, limited to a combinationvof al1 four of the"above items but each item is believed to be novel in l current of air while at the same time such partition creates a sub-division of spaces or compartments in the cone 6 such as to promote the segregation of the rib portions. The chamber 8, which receives the rib-free leaf portions which issue from the upper end of the channel B is itself fashioned as a funnel in which the arriving leaves are conducted downwardly, one of the funnel walls serving as a dust-separating sieve or screen, and with such compartment there is connected the well known sluice for the discharge of the tobacco which descends by gravity therein.

In certain cases, a door 35, may be provided and when this is open the air ilow at the part where the arrows 36 are shown in the gure, may be regulated, and then certain of the leaves or stems may drop here to be carried along by some later air current, and thereby separation is aided.

Reference is made to my co-pending application, Serial Number 88,712, filed July 3, 1936, for a Tobacco sorting and separating machine.

It is obvious that various changes and modications may be made in the vdetails of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claim.

What is claimed is:

In a separating device for shredded tobacco, a housing having an inlet portion with upwardly converging walls substantially equidistantl,Y spaced from a vertical axis, a conveyor for t0- bacco leading through one side,'of the housing and extending into substantially the central portion of the lower end of the said inlet portion and cooperating with the adjacent housing wall to'effect a substantial closing of the conveyor in the side of the inlet portion during normal operation, a vertical partition disposed intermediately in the lower end of the upwardly converging inlet portion and extending upwardly from the inner end of the conveyor at an inclination toward the housing side wall rising from the conveyor, the partition terminating at its upper end in spaced relation to said wall and providing at one side a downwardly flaring lateral passage above the conveyor and at its other side providing an upwardly aring main branch passage leading into the upper end of the inlet portionV above the partition and having its lower smaller end adjacent the inner end of the conveyor, said housing having a vertical passage of a cross-sectional area not greater than and opening upwardly into the lower end of said main branch passage of the inlet portion, vand air stream inducing means connected to the upper end of the inlet portion for creating an air stream upwardly through the main branch passage past the conveyor for drawing the tobacco upwardly therefrom into said A oswALD ERICH ErssMANN.

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