SU1437073A1 - Thickener - Google Patents

Abstract

The invention relates to a device for the separation and thickening of slurries and can be used in the mining, chemical, chemical, pulp and paper, metallurgical, food and other industries. The purpose of the invention is to increase the efficiency of the thickening process by stabilizing the flow of pulp at the entrance to the settling tank. The thickener contains a collecting tank 1, a device 2 for the condensed product, and a device 3 for the clarified product. In the upper part of the sedimentation tank 1, there is an external cone 4 of the pulp injection device and an internal cone 5 coaxially arranged with it, the opening angle of which is 10-25 °. less The pulp divider 6 is made in the form of a reverse cone with an opening angle of 40-80 °. The original pulp enters the pulp feed unit 7 and, using the pulp splitter 6, is distributed into 2 streams, one of which enters the inner cone 5 and the other into the annular gap formed by the surfaces of the outer cone 4 and the inner cone 5. From there the pulp enters the condensation in the collecting tank 1 and is removed through the device 2 of the condensed product. 1 il. (ABOUT

Description

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The invention relates to devices for the separation and thickening of slurries and can be used in mining and chemical, chemical, pulp and paper, metallurgical, food, medical and other industries.

The purpose of the invention is to increase the efficiency of the condensation process by stabilizing the pulp flow at the inlet to the precipitator.

The drawing shows a thickener, a longitudinal section.

The thickener includes a sedimentation tank 1, a condensed product outlet device 2 and a clarified product outlet device 3. In the upper part of the desiccant tank 1, the external cone 4 of the pulp injection device is placed in the internal cone 5 coaxially located with it, the opening angle of which is 10-25. A pulp divider 6 is rigidly fastened to the upper end of the inner cone; you are: filled with an inverse cone with an opening angle of 40-80 °. The upper end of the outer cone 4 is connected to the slurry pipe 7, through which the slurry is fed to the thickener.

The device works as follows.

The original pulp enters the pulp feed unit 4 and, using the pulp splitter 6, is divided into two streams, one of which enters the inner cone o and the other an annular gap formed by the surfaces of the outer cone 4 and the inner cone 5. The distribution and regulation of the flow ratio between the two channels is performed by selecting the opening angle of the pulp divider 6 and is determined by the condition for maximum dynamic gain of the two streams in the pulp input device as a whole. From the inner channel formed by the inner surface of the cone 5 and the channel formed by the outer cone 4 and the inner cone 5, the pulp enters the condensation tank 1, from where the condensed part is removed through the device 2 of the condensed product, and the clarified liquid through the device 3 output clarified product.

The intensification of the separation process using the proposed device is achieved by reducing the dynamic pressure of the pulp, reducing its velocity at the entrance to the precipitation capacity, which determines the lamination of the flow and the improvement of the hydrodynamic conditions of sedimentation of dispersed particles. This is due to the fact that

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when increasing the opening angle of the cone above 25-30 °, flow separation from the housing walls and flow turbulization are observed. Therefore, the opening angle of the inner body, as well as in the known device, does not exceed 30 °. However, it is possible to increase the opening angle of the outer cone and to ensure the conditions of continuous flow in the ring. Preferably, the opening angle of the outer cone exceeds the opening angle of the inner cone by 10-25 °. In this case, maximum loss is achieved in the boot device. In addition, an increase in the opening angle of the outer cone makes it possible to increase the floor area of the outlet section by a factor of 2.2–9.0. This is equivalent to a decrease in the pulp velocity at the entrance to the sedimentation tank by the same amount, which also improves the hydrodynamic conditions for the deposition of solid particles.

A pulp divider made in the form of an inverse cone, rigidly connected to the upper end of the inner cone, allows adjusting the distribution of the pulp between both channels, which is important when the previous technological conversions are unstable. An increase in the load above the nominal value leads to an increase in the coaxial ratio of the divider and the redistribution of the flow in the direction of increasing the load on the spring annular channel. At low loads, the main part of the pulp is fed into the collecting vessel through an internal channel of circular cross section. The opening angle of the pulp divider, lying in the range of 40-80 °, provides the best conditions for the distribution of flows between the channels, which reduce the dynamic head.

Claims (1)

Invention Formula A thickener containing a settling tank, a conical pulp injection device, a device for withdrawing thickened and clarified products, characterized in that, in order to increase the efficiency of the thickening process by stabilizing the pulp flow at the outlet into the collecting capacity, the pulp input device is coaxially inside a truncated cone, the opening angle of which is 10-25 ° less than the opening angle of the external cone, and a pulp divider made in the form of a reverse cone with a opening angle of 40-80 ° rigidly connected to the top he end of the inner cone. 0 five 0 0