Three-product cyclone classifying screen

Abstract

The invention relates to a three-product cyclone classifying screen. The three-product cyclone classifying screen comprises a cylindrical draft tube, a cyclone cylinder and a cyclone cone, wherein a central tube which passes through the cylindrical draft tube is arranged in the cyclone cylinder; a lower port of the cylindrical draft tube is connected with a cylinder screen; the bottom of the cylinder screen is connected with a cone screen; the cyclone cylinder is sleeved outside the cylinder screen; the lower part of the cyclone cylinder is connected with a cyclone upper cone which is sleevedoutside the cone screen; the lower port of the cone screen is connected with a cyclone lower cone; a hole for discharging sieved products is formed on the cyclone upper cone; a water supply nozzle isarranged on a cyclone lower cone; the lower port of the central tube is provided with a central cone screen; and a guide flow disc is arranged between the central tube and the cone screen. The three-product cyclone classifying screen screens fine particles through the screen by using the pressure difference of outer rotational flows of a side wall under a powerful centrifuge field, eliminates coarse circulatory flows around the side wall of the cyclone and a top cover, effectively controls oversize fractions in overflows and undersize fractions in underflows are, and improves the classification efficiency and the treating capacity of the cyclone.

Description

technical field [0001] The invention relates to a grading sieve, in particular to a three-product cyclone grading sieve suitable for solid-liquid separation, classification and heterogeneous phase separation. Background technique [0002] The current hydrocyclone is composed of a cylinder section, a conical section, an overflow port, an underflow port and a feed port. direction into the cylinder cavity. The high-pressure slurry enters the hydrocyclone along the tangential direction, and the fluid forms a high-speed rotating flow field in the cylinder cavity, and the components with high density and large particles in the slurry move radially outward under the centrifugal force generated by the rotating flow field. At the same time, it moves downward along the axial direction, and then reaches the cone section and continues to move downward along the wall, and is discharged from the bottom flow port, thus forming an external swirl flow; the components with low density and sm...

AI Technical Summary

Problems solved by technology

In order to reduce the impact of back-mixing and short-circuit flow on the separation efficiency of the cyclone, the invention patent with the notification number CN 2684934Y discloses a hydrocyclone with a filter screen. There is a filter screen in between, the diameter and shape of the filter screen are consistent with the axial zero-speed envelope surface of the cyclone, the upper part of the screen is connected with the top wall of the feeding chamber, and the lower part is open, which solves the problem of partial overflow The problem of thick running, but the problem of underflow and fineness has not been solved

Due to the addition of a screen at the zero-velocity envelope of the cyclone, although the influence of short-circuit flow, circulating flow and particle diffusion on the separation efficiency of the cyclone can be resolved, due to the complex and variable flow field inside the cyclone , its zero-speed envelope surface cannot be fixed, especially when the operating parameters or structural parameters of the cyclone change, if the diameter and shape of the filter screen do not change accordingly, the actual zero-speed envelope surface and The phenomenon that the predetermined filter screen cannot overlap. In this case, the preset filter screen will definitely destroy the internal flow field of the cyclone and reduce the classification efficiency of the cyclone; in addition, the overflow of the cyclone is based on the spiral vortex The form (viewed from a two-dimensional plane) is formed by passing through the zero-velocity envelope surface and entering the internal swirl flow. Since the pressure difference on both sides of the screen at the zero-velocity envelope surface is small, and the screen increases the resistance of the particles through the screen, the particles The radial exchange speed is slow, and the classification efficiency is not high. Part of the fine particles will remain in the external swirling flow, and then enter the cyclone bottom flow and be discharged, resulting in fine particles being trapped in the bottom flow.

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