Screw air elutriation fine-coal remover for dry classification before fine coal preparation

Abstract

The invention belongs to the technical field of fines removal classification before coal preparation and particularly relates to a screw air elutriation fine-coal remover for dry classification before fine coal preparation. The fine-coal remover comprises a primary classification region which uses a spiral airflow conveying method and a secondary classification region which uses a tangential airflow jetting rotating classification method. During the declining process, materials are subjected to the comprehensive action of spiral centrifugal force and airflow conveying force, intensifying classification is obtained under the comprehensive action, primary fine materials which are subjected to primary classification enter the secondary classification region, are subjected to secondary classification and are discharged, downward negative pressure is introduced into the secondary classification region, and materials can be discharged smoothly when large classification grain sizes are required. By the aid of the fine-coal remover, the problem of blocking of screening holes is solved, the classification grain sizes can be adjusted and controlled at will in a range from 0 to 13 mm in accordance with requirements, and a new technology is provided for power coal fines removing and washing.

Description

technical field [0001] The invention belongs to the technical field of powder removal and classification before coal washing, and in particular relates to a spiral air screen powder removal machine used for dry classification before fine coal separation. Background technique [0002] my country is rich in steam coal resources, but because my country's steam coal is mainly distributed in the north and west, this geographical distribution determines the coal transportation and sales structure of "north coal transportation" and "west coal transportation" in China, while my country's coal However, there is a shortage of transportation capacity in transportation. With the construction and development of large-scale pithead power stations in my country, it has become an inevitable trend to switch from coal transportation to electricity transmission. [0003] With the improvement of coal mining mechanization, the content of pulverized coal in raw coal has greatly increased, and the ...

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Problems solved by technology

[0004] At the same time, in coal washing and selection, if the fine-grained coal is selected by wet method, not only the coal slime recovery system is complicated, the recovery rate is low, but also the investment is large, the production cost is high, and it also causes damage to the environment while wasting resources.

[0005] For dry coal preparation, although certain results have been achieved, such as the application of air-heavy medium fluidized bed and FX-type, FGX-type dry separators, etc., it is also in line with the coal washing environment in the western and northern regions with drought and less water, but the dry method The effective lower limit particle size of coal preparation and separation is 6mm, and the grading sieve used in actual production still often has the problem of sieve clogging in the sieving and grading of 6mm and below particle size, and the coal type has poor adaptability, which cannot guarantee the classification efficiency

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