Vertical spiral vibrating screen

Abstract

The invention discloses a vertical spiral vibrating screen capable of greatly increasing the area of a screen and lengthening the movement stroke of powder. The vertical spiral vibrating screen comprises a base, a screen arranged on the base through a plurality of supporting springs, a vibrating device connected with the lower end of the screen and positioned in the base, a bin arranged at the upper end of the screen and a feeding valve arranged in the bin. The screen comprises a shell, a middle upright post and a screen net. The shell is a cylinder provided with a cover plate and a bottom plate, and the lower part of the shell is provided with a fine powder feeding hole and a coarse powder feeding hole; the middle upright post is vertical to the center of the shell; and the screen net comprises a bottom screen net, a lateral screen net and a top plate, wherein the inner edge of the bottom screen net is fixed on the middle upright post and is downwards spiral around the middle upright post, the lateral screen net is arranged coaxial with the middle upright post and is downwards spiral around the middle upright post, the lower end of the lateral screen net is connected with the outer edge of the bottom screen net, and the inner edge of the top plate is fixed on the middle upright post and is downwards spiral around the middle upright post.

Description

technical field [0001] The invention relates to a high-precision fine powder screening machine, in particular to a vertical spiral vibrating screen. technical background [0002] When the particle size of the powder is below 1mm, the mesh of the sieve in the screening equipment is no longer at the millimeter level, but "mesh" is used as the unit of measurement. Due to the small particle size, the difficulty of screening increases, making the same equipment The processing capacity of the application in powder sieving is greatly reduced. In addition, the powder industry also has high requirements for screening accuracy. In some fields, the screening accuracy must be higher than 97% (screening accuracy refers to the fine powder mixed in the finished product after screening, that is, the powder whose particle size is smaller than the pore size of the sieve. Body, the proportion of the screened finished product). [0003] The screening equipment currently used in the powder fie...

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Problems solved by technology

[0004] 1) When the screening accuracy is increased to 97% or even higher, the processing capacity will drop significantly, which is 1 / 3 or even lower than its nominal output, especially the finer the powder, the more serious the drop;

[0005] 2) Due to the structural limitations of the rotary vibrating screen, the thin-walled sheet metal structure is difficult to withstand long-term fatigue vibration, so the maximum diameter of the rotary vibrating screen is only 2 meters, which makes it difficult to increase the processing capacity and cannot adapt to The growing demand for capacity in the powder industry

The structure of the "avalanche sieve" actually doubles the area of ​​the fine powder sieve to achieve the purpose of increasing the processing capacity, but there is still a big gap between this and the user's requirements.

[0007] Judging from the current situation, there is a big contradiction between increasing the processing capacity and improving the screening accuracy, that is, under the condition of a certain screen area, if the feeding amount is too large, some powders will be discharged before they touch the screen. In addition, for powders with difficult-to-sieve particle sizes (the particle size is relatively close to the sieve aperture), in order to increase the probability of passing through the sieve, it is necessary to increase the number of contact times with the sieve. The movement stroke on the screen, which also prolongs the screening time, thus reducing the throughput

Therefore, due to their structural limitations, the existing "rotary vibrating screen" and "avalanche screen" cannot solve the contradiction

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