Powder granule circulation whirlwind multi-level grading device and its grading method and use

Abstract

A circumfluent cyclone multi-grade classification device and a classification method and use of powder particles are provided. The device includes a particle classifier and a cyclone dust remover, which respectively comprises a direct cylinder, an inner part, a gas import, a cone, two ball valves, an ash storehouse, a nitrogen import, etc. the inner lateral of the inner part of the classifier and the inner lateral of the cone are respectively equipped with two to four flat slab-shaped or arc slab-shaped guide slide ways. The method includes that air containing dusts is extracted and is introduced into the particle classifier. The particles lager than 15-20 Mu m are separated and are returned. The extracted air is introduced into the cyclone dust remover. The dust remover is used to remove the fine particles smaller than 15 Mu m. And the air of which the fine particles are returned to a reactor. The catalyst particles which are larger than 20 Mu m are recovered through the classification of the catalyst particles which can be used in an acrylonitrile fluidized bed reactor. Fine catalyst powders can be ensured to be not carried out by airflow, classified and discharged. The equipment can be prevented from being blocked. The efficiency is improved and the cost is lowered. The device can be widely applied to the multi-grade classifications of various powder particles.

Description

technical field [0001] The invention belongs to the technical field of multi-stage classification of powder particles, and more specifically relates to the design of a circular-flow cyclone multi-stage classification device for powder particles and its classification method and application. Background technique [0002] At present, the production of ultrafine powder generally adopts mechanical processing method, and the particle size distribution range of the obtained powder is very wide. However, sometimes there are only a few percent of unsatisfactory coarse or fine particles in the product, which will greatly reduce the overall particle size index. Therefore, according to the requirements of the production process, the powder should be sorted or classified according to a narrow range of one or several particle sizes. [0003] However, due to the lack of high-fineness multi-stage grading equipment at present, the production or grading of ultra-fine powder is difficult to ...

AI Technical Summary

Problems solved by technology

The traditional acrylonitrile reactor cannot recycle these expensive large catalyst particles, thus increasing the production cost of acrylonitrile; and it cannot exclude some unnecessary fine particle powder, which leads to the disadvantages of clogging equipment and reducing production efficiency.

[0005] If the dust removal efficiency is too high, the fine dust in the fluidized bed cannot be discharged in time, which will lead to a decrease in the activity of the catalyst bed, and it is necessary to continuously add new catalyst to the bed

However, after adding the catalyst, the bed layer will be too high, resulting in a large pressure drop and side reactions.

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