Conveyors: power-driven – Conveyor section – Screw
Patent
1996-09-11
1998-01-20
Bidwell, James R.
Conveyors: power-driven
Conveyor section
Screw
198671, B65G 3312
Patent
active
057092966
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The invention concerns a device relating to a feeder tube, i.e. a conveyor intended for bulk product, in particular a feed-out device, which comprises a cylindrical drum or tube in which there are accommodated inlet openings distributed along the length of the tube, a screw conveyor disposed coaxially within the tube, means for rotating the tube about its axis, means for rotating the screw conveyor relative to the tube, means for displacing the feeder tube in the lateral direction, and activators for the bulk product, which activators are disposed on the tube in association with the inlet openings and form projections on the outer side of the tube.
PRIOR ART
Feeder tubes of the above-stated type are previously known and commonly used. Examples of such feeder tubes are described in Swedish Patent Applications 7611862-9 and 8004449-8. Feeder tubes can be used as conveyors for a host of different bulk products (bulk material) such as wood chips, coal, paper pulp, peat, sand, cement, ashes, grain, pellets, etc. In order to facilitate the movements of the goods in the silo or equivalent in which the bulk product is stored and stimulate its feed-in through feed-in openings, activators, i.e. projections on the tube, are located at the back edge of the inlet openings. By back edge is herein meant the rear edge of the inlet opening viewed in the direction of rotation.
If the tube is considered in cross-section and it is assumed that the tube is rotated in the clockwise direction, then there is a risk of bulk product becoming wedged between the tube and the bottom of the silo or equivalent if the feeder tube is displaced to the right in the considered section, especially if the distance between the feeder tube and floor is relatively small, which it should be in order to achieve optimal working conditions for the feeder tube. This jamming can be eliminated if the rotation of the tube is reversed. In this case, however, no effective feed-in and/or activation of the bulk product is obtained, since in this case the activators come to be situated at the leading (front) edge of the feed-in openings and are essentially inactive. A particularly serious drawback with the said original feeder tube is that it is not suitable for use for material which is difficult to feed, such as damp forest waste, bark and similar materials which may contain fragments of longer branches, large chips, long bark flakes and similar fragments. Product of this kind is able to be forcibly fed using a conventional screw conveyor, provided that there are very large drive forces available and the screw, the force transmission and the bearings are given correspondingly large dimensions, but the wear becomes very great and the working life of the screw, above all, is disagreeably short. As far as the feeder tube in its original construction is concerned, this can by no means be used for handling this difficult-to-feed material and, however much the drive power is increased, this is no help. It does not help for the tube to be provided with activators on the one side of the inlet openings, as shown in Swedish Patent Specification 7611862-9. Nor does it help if such activators as are shown in the patent specification, i.e. activators which extend along the entire length of the openings, are disposed on both sides of the feed openings. In this case, the activating effect is completely eliminated. If one either has a tube which is without activators, a tube with activators according to SE 7611862-9, or activators on both sides of the feed-in openings and constructed according to the patent specification, then the result, when it is a case of the said difficult-to-feed material, is simply that the material packs harder and harder or merely swirls around, or that the tube becomes jammed.
BRIEF DISCLOSURE OF THE INVENTION
The object of the invention is to eliminate the above-mentioned problems. Other objects which can also be achieved by virtue of the invention, at least in certain embodiments thereof, are that symmetrical working rela
REFERENCES:
patent: 3788446 (1974-01-01), Postel-Vinay
patent: 4266902 (1981-05-01), Forsberg
patent: 4351627 (1982-09-01), Forsberg
patent: 4393609 (1983-07-01), Persson
patent: 4511066 (1985-04-01), Forsberg
LandOfFree
Feeder tube does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Feeder tube, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Feeder tube will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-719738