DE1117514B - Use of a vibrating drum screen for the screening of moist raw coal - Google Patents

Description

Use of a vibrating drum screen to screen damp Raw coal The subject of the invention is the screening of moist, finely grained coal.

Efforts have been made for many years to put moist coal on wire mesh screen linings to sieve. These coverings, which are placed on conventional vibrating screens, are, however, unsuitable for sieving moist coal, because they are proportionate add a short time. The sieving effect is then completely inadequate, so that one is forced is to shut down the sieve again and again at short intervals and to close the covering clean.

To eliminate these shortcomings the conventional vibrating screens are Special screening machines, e.g. B. the Umbrasieb, the Rhewumsieb and the sieves with electric heated screen linings according to B ü r s t 1 e i n. With these special screening machines or screen linings, the technical effort is great and the acquisition and maintenance expensive, but the success is also insufficient. Despite the complexity of the The aforementioned complicated sieve systems are being tried to further develop them to advance because the pit moisture of the coal as a result of official regulations for underground dust control has increased steadily over the past few years.

Air separators are also used to separate the finest components, However, with the increasing moisture content of the coal, this is no longer the case either work satisfactorily. The forces occurring during air sifting are often sufficient not enough to remove the fine grains of to separate the coarse. In addition, there is the disadvantage that a wind sifting large percentage of coarse components with a diameter greater than 0.5 mm, is excreted, although these components, in contrast to the sludge-forming Fine grains of 0 to 0.5 mm can be easily processed on fine grain setting machines, for coarse belong.

The mentioned sieving or sifting processes have a solution to the Problem of the separation of moist fine components in economic and technical terms has not yet been achieved in a satisfactory manner. Also the expensive and only for coal pulp suitable flakes is not very satisfactory.

The invention, however, enables a solution to the problems discussed, and that with the least technical and economic effort and in a special way simple and elegant way. The invention is characterized by the use a vibrating drum screen for the screening of moist coal during a separating cut of about a minimum of 1 mm, the drum screen is rotated so slowly that it does not acted upon sieve surfaces are completely shaken free of adhering material.

The invention makes it possible that after tests carried out in the sieve residue only 1% of the sludge-forming fine grain components 0 to 0.5 mm is located. This result was obtained with a surface moisture content of the grain 0 to 1 mm achieved by 4.3%. A similar success was also achieved with surface moisture achieved the same grain size range of 7%, a value at which the previously known devices already work very imperfectly or fail completely.

An embodiment of the invention is shown in the accompanying drawing shown in perspective. The sieve box 1 takes instead of a normal sieve bottom the drum-shaped, rotatable sieve tray carrier 2. This is caused by the drive 3 driven by a V-belt 4 on its central shaft 5 and in a slow, the clogging speed adapted rotation offset, in each case the three overhead screen linings 6 are in the cleaning process, if necessary can be supported by air nozzles 7.

Claims (1)

PATENT CLAIM: Use of a vibrating drum screen for the Screening moist raw coal in a range of about 0 to 1 mm, using the drum screen is rotated so slowly that the surface parts of the screen that are not acted upon are shaken free will.