Air flow screening device for micron-sized powder materials

Abstract

The invention relates to an air flow screening device for micron-sized powder materials, belonging to the screening technical field of powder engineering. The device is formed by improving the existing boiling dryer as follows: a front exhaust main pipe of the existing dryer is divided into a front exhaust main pipe and a back exhaust main pipe, a sieve plate mesh box with a sieve inside is added between the front exhaust main pipe and the back exhaust main pipe to increase the space dimensions of a fluid bed so as to increase the area of the sieve, so that the effective drift diameter of the sieve is increased, and the pore diameter of the sieve can be changed; a blowback device is added to prevent the sieve from being clogged; a circulating device is added to circulate the powder back to the main cavity of the fluid bed; and a pneumatic transmitting and discharging device is added on the basis of the original exhaust system. The device overcomes the defects that the existing boiling dryer can be only used for millimeter-sized particle materials due to the small sieve area and large meshes of the existing boiling dryer and powder materials are piled on the sieve and clog the sieve to block or even disable the air exhaust so as to affect the normal operation of the air jet screening when a small-pore sieve is used in the existing boiling drier. And the invention is applicable to the screening of powder materials.

Description

technical field [0001] The invention relates to equipment for airflow screening of micron powder materials, and belongs to the technical fields of fluidized bed, pneumatic conveying, screening and powder engineering. Background technique [0002] For sieving granular materials, vibrating sieving is often used, but for micron-sized powder materials with low density, due to the low sieving efficiency, good results cannot be achieved, so a recently developed The method of airflow screening, such as "a full-cycle airflow sieving machine" (patent number: 200610017573.0) authorized by the State Intellectual Property Office is a kind of airflow screening equipment, which uses the kinetic energy of the carrier fluid to do work for screening. , suitable for screening and grading of various difficult-to-sieve fine powders. But in production, this airflow sieving machine also shows the following shortcomings: 1. The airflow sieving machine is not suitable for the screening of all powd...

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Problems solved by technology

[0002] For sieving granular materials, vibrating sieving is often used, but for micron-sized powder materials with low density, due to the low sieving efficiency, good results cannot be achieved, so a recently developed The method of airflow screening, such as "a full-cycle airflow sieving machine" (patent number: 200610017573.0) authorized by the State Intellectual Property Office is a kind of airflow screening equipment, which uses the kinetic energy of the carrier fluid to do work for screening. , suitable for screening and grading of various difficult-to-sieve fine powders

But in production, this airflow sieving machine also shows the following shortcomings: 1. The airflow sieving machine is not suitable for the screening of all powder materials. For some micron-sized materials with light weight and small particle size Such as pine pollen, the screen will be blocked due to the accumulation of pine pollen cells on the screen, so that the screening efficiency is too low and the screening operation cannot be carried out normally; The service life is unfavorable; the replacement and maintenance of the screen is not convenient enough

Even if the pore size of the sieve 20 is replaced with a pore size suitable for powder materials, the area of ​​the sieve 20 of the existing fluidized dryer is too small, and materials with a particle size larger than the pore size of the sieve will accumulate on the sieve 20 and block the sieve. Mesh, more importantly, the existing fluidized dryer does not have a device to prevent the screen from clogging and to dredge it after the screen is blocked, and the material accumulated on the screen 20 and blocking the screen holes will make the exhaust air unsmooth It can't even exhaust the air so that the airflow screening can't be carried out normally, so the existing boiling dryer can't be used for powder materials

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