SU893268A2 - Hydraulic cyclone for concentrating and classifying minerals - Google Patents

Description

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This invention relates to the enrichment of minerals and can be used in the ore-processing, chemical and other industries.

Spin pulp flows are widely used in the classification and enrichment of small mineral size classes as an effective means of intensifying these operations in hydrocyclones. It has been observed that with an increase in the intensity of the feed of the source material into the hydrocyclone, the hydraulic resistance at the inlet increases and the energy consumption for the advancement of the pulp flow increases. This increase is generally attributed to the effect of mass forces that generate secondary currents and an increased level of turbulence. Another property of a swirling flow is its ability to spontaneously excite intense regulatory pulsations of velocity and pressure, which is especially characteristic in the zone where the starting material is introduced into the hydrocyclone.

In order to skip the necessary amount of pulp through a hydrocyclone and obtain certain technological parameters, it is necessary to create in the feed

the pipeline directly in front of the inlet nozzle is such a pressure that would overcome the hydraulic resistance in the latter, as well as in the drain pipe, and the centrifugal pressure arising during the rotation of the fluid. The largest share among total head losses is occupied by losses associated with centrifugal pressure. The inlet loss is about 20% 1 for a normal ratio of the diameters of the drain and supply holes (1-1.2).

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According to the main author. St. No. 789160 is known for a hydrocyclone comprising a cylindrical body, an elastic funnel-shaped element with a lower base facing down, a spherical cap, a supply nozzle and a discharge device in the bottom. In the lower part of the elastic funnel-shaped element a fin balance type stabilizer is fixed, and in the upper part a ball, the unloading device is made in the form of concentrically mounted on the bottom of the shells 2.

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A disadvantage of the known device is a high hydraulic resistance at the entrance of the pulp into the hydrocyclone. The purpose of the invention is to increase the specific productivity due to a decrease in the | - i-resistance. The goal is achieved by the fact that the hydro cyclone is provided with an annular chute and a damping device made in the form of a separating elastic insert, one end of which is fixed on the lower edge of the generator of the supply nozzle and the other on the cylindrical surface of the annular chute located in the upper part of the body. FIG. 1 shows a hydrocyclone, a general view; in fig. 2 shows section A-A in FIG. 1. A hydrocyclone consists of a cylindrical body 1, which transforms into an annular groove 2, a tangentially installed feed elbow 3. The annular groove 2 decreases in height by the size of the energetic nozzle and is provided with a damping device 4, made in the form of a separable elastic insert, which is a flexible elastic the base of the annular gutter. The separating elastic insert 4, for example, of rubber, is fixed along the lower edge of the generatrix 5 of the supply nozzle 3 and the cylindrical surface of the annular groove 2. The hydrocyclone is bounded in the upper part by a hemispherical cap 6, facing the convexity of the housing, in the lower - bottom and discharge device 7. Coaxially inside The case 1 has a hollow cone element 8 made of an elastic material, for example, rubber, equipped with a ball 9 and a nipple - a branch pipe 10. On a smaller base of the cone element 8, a balance bar is installed - stabilized p, having profiled fin type blades on the outer spherical surface (not shown). Hydrocyclone works as follows. The pulp flow arriving at a certain speed through the feed nozzle 3 into the annular chute 2 forms a rotationally accessible movement from top to bottom towards the discharge device 7 of the hydrocyclone. A continuous energy exchange takes place between the main pulp flow in the working volume and the incoming flow in the ring chute 2, the development of which in some cases acquires a pronounced self-oscillatory character. In connection with the absorption of friction energy by a viscous medium under any static pressure, the proposed elastic insert located between these two streams may have any desired characteristic of damping ability and elasticity. The resulting deformations are evenly distributed over the entire surface of the separating elastic insert and are smoothed. There is an increase in the range of the initial pulp flow and a smooth connection (infusion) of it with the main flow of pulp in the hydrocyclone. In the rotating volume of the pulp, the elastic element 8 rises and is oriented along the hydrocyclone axis. It, in contact with ball 9 with profiled hemispherical lid 6, forms a sliding support at its top under the action of weight, lifting force due to the gradient of hydrostatic pressure in the rotating flow and the reaction of the stabilizer fin type with the pulp flow. The element 8, filled with air through the nipple 10, takes the form of the free surface of the rotating pulp and has a circumferential speed, approximately equal to the tangential component of the speed of movement of the pulp layers in contact with its surface. The self-centering of the elastic element 8 is carried out by a high stability created by the center of gravity being displaced downward by a balance bar filled with an adapter, a ball-support and a central ring discharge of separation products. The stabilizers enhance the hydrodynamic effect of the rotating pulp flow on the elastic element for its more stable coaxial rotation. In the centrifugal field of forces, the solid phase is distributed by size and density in the radial and axial directions. The pulp with the classified material in the discharge zone is divided by shells into three products. Their qualitative and quantitative characteristics are established by adjusting the discharge device 7. Separation products are removed from the hydrocyclone by chambers II and 12 and the central nozzle 13. The elastic insert prevents direct contact with the main rotating pulp flow in the working volume of the apparatus and the similar flow through the feed nozzle , and thereby excludes the possibility of non-stationary interaction between them. It was established experimentally that stabilization of the pulp flow in the zone of its entry into the working volume of a hydrocyclone, achieved by applying the proposed technical solution, is always accompanied by a decrease in m of hydraulic resistance. The pressure loss at the inlet at an inlet pressure of from 20 to 150 kPa is 7-10%, which is about half as compared with the known design solution for supplying the starting material to the hydrocyclone. At the same time, the productivity of a hydrocyclone with a diameter of 140 mm with an elastic damping insert in the input area of the initial product increased by 23-28%.

Claims (2)

1.Povarov A.I. Hydrocyclones at concentrators. M., "Nedra, 1978, p. 28 2. USSR author's certificate number 789160, cl. On 04 3/06, 1979.