A Centrifugal Air Classifier for Ultrafine Powder

Abstract

The invention discloses a centrifugal air classifier for ultra-fine powder. The centrifugal air classifier comprises an air inlet pipe, a classification chamber, a top cover, an air guide blade grid,a classification impeller, a fine powder transferring chamber, a conical shell, a coarse powder discharge port and an air outlet pipe, wherein the air guide blade grid and the classification impellerare each provided with an air flow channel composed of bending-torsional blades annularly distributed around the corresponding axis, the bending-torsional blades are in a shape combining radial bending with axial torsioning, the bending angle ranges from 5 degrees to 90 degrees, and the torsioning angle ranges from 5 degrees to 60 degrees. By means of the design of the blades adopting the bending-torsional combined shape, the size and strength of the vortex movement between the blades of the air guide blade grid and the blades of the classification impeller are reduced, the disturbance effectof channel vortexes on separation and movement behaviors of powder particles is weakened, the ultra-fine powder classification precision is improved, the classification lower limit is reduced, and aneffective device is provided for dry efficient classification of the ultra-fine powder.

Description

technical field [0001] The invention relates to a powder classification device, in particular to a centrifugal air classifier for superfine powder, suitable for dry classification of mineral powder and other powder materials, and belongs to the field of powder preparation. Background technique [0002] Ultrafine powders are widely used in many fields such as fine chemicals, materials, building materials, mineral processing, medicine, and food. With the development of the national economy and science and technology, various industries have put forward higher and higher requirements for ultra-fine powders, not only requiring extremely fine powders, but also narrow particle size distribution, which puts forward higher requirements for powder classification technology. Require. Centrifugal air classifiers have high-speed rotating classifying impellers to form a forced vortex centrifugal force flow field. The centrifugal acceleration of particles in this flow field is hundreds o...

AI Technical Summary

Problems solved by technology

For classifiers with straight blades or equal-curvature arc-shaped blades, the turbulent intensity of the flow field in the classification space is relatively large, the vortex motion in the flow channel between the blades is strong, the energy loss of the secondary flow is large, and the velocity gradient in the flow channel is excessive. Large, strong disturbance to the particle separation movement behavior, which limits the improvement of ultrafine powder classification accuracy and the reduction of the lower limit of classification

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