US2783888A - Apparatus for separating stem portions from disintegrated tobacco mass - Google Patents

Description

March 5, 1957 E. R. DAHLSTRC'DM ET AL 2,783,888 APPARATUS FOR SEPARATING STEM PORTIONS FROM DISINTEGRATED TOBACCO MASS Filed April 6, 1954 INVEN TORS E.R. DAHLSTROM .C. 6; 3-. ROTHELIUS APPARATUS FOR SEPARATING STEM PORTIONS FROM DISINTEGRATED TOBACCO MASS Ernst Ruben Dahlstriim, Alsten, and Carl Georg Bertil Rothelius, Stockholm, Sweden, assignors to Arenco Aktiebolag, Stockholm, Sweden, a Swedish joint-stock company Application April 6, 1954, Serial No. 421,345 Claims priority, application Sweden April 29, 1953 4 Claims. (Cl. 209-295) This invention relates to apparatus for separating stem portions from disintegrated tobacco mass and more particularly to an apparatus of that kind provided with an endless sieve, e. g. a drum or band, and stripper means for removing impurities and waste from the surface of said sieve. It is an object of the invention to prevent tobacco leaf fragments, adhering by suction to the sieve, from following the impurities and waste all the way to the stripper means which would cause losses of tobacco if said leaf fragments are to be removed together with the waste. Another object of the invention is to prevent contamination of the cleaned tobacco which would be the result if leaf fragments removed by the stripper means would be returned to the tobacco mass together with the waste.

These and other objects and advantages of the invention will in part be described and in part be understood from the following detailed description of a preferred embodiment, which is illustrated in the accompanying drawing.

Referring to the drawing, disintegrated tobacco mass is supplied to a jigger 2 which delivers the tobacco through an opening 3 into a vertical separating channel 4, in which an ascending air current elevates the relatively light tobacco leaf fragments while the relatively heavy stem portions are allowed to sink down in the channel and further through a bottom opening 5 into a receptacle 6. The leaf fragments follow the air current out of the outlet opening 7 of the horizontal portion 4a of the separating channel 4 and enter a relatively large chamber 8 in which the leaf fragments sink down, whereafter they are removed through a rotary sluice 9 in the bottom of the chamber.

A continuously revolving sieve drum 10 is positioned in the upper portion of the chamber 8 opposite to the opening 7. The drum 10 may be perforated or it may consist of wire network. Close by the inner surface of the drum 10 and concentrically thereto is positioned a stationary tubular shield 11 which has perforations in its front portion only, i. e. in the portion turned towards the outlet opening 7 of the separating channel 4. Right behind or at least approximately right behind the rear side of the shield 11 is a stripper roll 13 mounted rotatably. The roll 13 has longitudinal fillets or lamellae 25 of a soft material, e. g. leather, which beat upon the sieve drum 18 when the roll 13 rotates.

A plate 14 extends obliquely from the sieve drum 10 down to the rear wall 15 of the chamber 8. The upper edge 22 of the plate 14 is positioned close by the sieve drum 1G in the proximity of the rear vertical plane of tangency of the drum. The plate 14 forms one of the walls of a pocket 16 closed at its bottom and having a collecting box or drawer 17 inserted therein. The drawer 17 can be pulled out of the pocket 16 through a normally closed opening 18 in one of the side walls of the chamber 8. The ends of the sieve drum 10 are located close by the side walls of the chamber 8 and it is at one of 2 said walls or at both the walls connected to a conduit 23 which over a dust separator (not shown) is connected to the suctionsid'e of afan 20. The pressure side of the fan 201s through; a conduit 24'tightly connected to the receptacle 6.--

Intheopera'tion ofthe apparatus the sieve. drum 10 and the stripperrol-l 13*are-rotated in the directions as shown in the drawing. Air flowing out of the outlet opening 7 of the channel 4 will mainly find its way substantially directly to the portion of the sieve drum 10 covering the perforations 12 of the shield 11 where dust is sucked in through said perforations and coarser impurities such as fibrous particles will adhere by suction to the drum and follow same in its rotary direction until they reach the roll 13 which is beating against the sieve drum so that the impurities are removed therefrom and drop into the box 17 in the pocket 14. The suction effect on the leaf fragments thatadhere to the drum 10 opposite to the perforations 12 of the shield 11 and follow the drum against the stripper roll 13 is cording as they approach said roll. The air gap 21 between the shield 11 and the drum 10 is so thin that the peripheral air currents in same are choked. The suction effect on the rear side of the sieve drum 10, turned towards the rear wall 15 of the chamber 8, is so feeble that no leaf fragments or a few fragments only will be sucked through the passage between the top portion of the drum 10 and the top wall of the chamber 8. Leaf fragments that do not leave the drum 10 until they reach the plate 14 may be stripped off the drum by means of the upper edge 22 of said plate. Fibrous and matted impurities will stick more firmly to the drum 10 than the leaf fragments but when they have reached the roll 13 they are in a zone in which the suction effect is a minimum wherefore the roll 13 will be capable of loosening them from the drum.

We claim:

1. In an apparatus for separating stem portions from a disintegrated tobacco mass, an endless sieve, a stem separating channel heaving an outlet for cleaned tobacco leaf portions located opposite to said sieve, a stationary shield located closely inside said sieve and conforming to Said sieve and having an air inlet only in a-front side opposite to said channel outlet, said sieve being mounted for rotation over said air inlet, a suction conduit connected to the interior of said shield, and stripper means located at the rear side of said sieve and operatively associated with said sieve to remove waste therefrom.

2. In an apparatus for separating stem portions from a disintegrated tobacco mass, an endless sieve, a stem separating channel having an outlet for cleaned tobacco leaf portions located opposite to said sieve, a stationary shield located closely inside said sieve and conforming to said sieve and having an air inlet only in a front side opposite to said channel outlet, said sieve being mounted for rotation over said air inlet, a suction conduit connected to the interior of said shield, a roll having leather lamellae and being located at the rear side of said sieve, and said roll being mounted for rotation to cause its lamellae to beat on said sieve and remove waste therefrom.

3. In an apparatus for separating stem portions from a disintegrated tobacco mass, an endless sieve, a stem separating channel having an outlet for cleaned tobacco leaf portions located opposite to said sieve, a stationary shield located closely inside said sieve and conforming to said sieve and having an air inlet only in a front side opposite to said channel outlet, said sieve being mounted for rotation over said air inlet, a suction conduit connected to the interior of said shield, stripper means located at the rear side of said sieve and operatively associated with said sieve to remove waste therefrom, and a waste collecting pocket below said stripper means, said pocket decreased successively achaving a downwardly extending wall having an upper' nected to the interior of said shield, a roll having longiedgelocated close by the rear portion of said sieve below said stripper n1eans. V

4. In an apparatus for separating stem portions from a disintegrated tobacco mass, an endlesssievega stern separating channel having an outlet for cleaned tobacco leaf portions located opposite to said sieve, a stationary shield located closely inside said sieve and conforming to said sieve and having an air inlet only in'a 'front side opposite to said channel outlet, said sieve being mounted for rotation over said air inlet, a suction conduit contudinal filletsflof a soft material and being located at the rear side of said sieve, and said roll being mounted for rotation to cause said fillets to beat on said sieve and remove waste therefrom.

References Cited in the file of this patent FOREIGN PATENTS

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