SU1632459A1 - Thickener - Google Patents

Abstract

The invention relates to the separation of solids from liquid, more precisely to the clarification of circulating and washing waters, and can be used in the mining and processing, chemical, construction and other industries. The aim of the invention is to increase the purity of the drain. The thickener contains a housing, the nozzles of the input of the initial suspension, the output of the condensed product and the clarified solution. The hull is divided into a soothing chamber, a sedimentation unit and a sludge tank. The precipitation and separation plates are located in the deposition unit. The separator plates are made with openings in the form of transverse slits having equal length and width, decreasing in the course of the movement of the pulp. The holes are arranged in a checkerboard pattern. 2 Il.

Description

The invention relates to the separation of a solid phase from a liquid one, more precisely to the clarification of industrial circulating water, and can be used in mining, chemical, construction and other industries.

The purpose of the invention is to improve the quality of the clarified water.

FIG. 1 shows the thickener, a general view; in fig. 2 shows section A-A in FIG. one.

The thickener includes a housing 1, nozzles of the input of the initial suspension 2, the output of the condensed product 3 and the clarified solution 4. The housing 1 is divided into a soothing chamber 5, a precipitation unit 6 and a sludge collector 7. In the precipitation unit 6 there are deposition plates 8 and separation plates 9. Dividing plates made with holes 10 in the form of transverse slots, for example, rectangular

forms (Fig. 2). The holes are staggered, their length is constant, the width varies. For a thickener with an upward flow of pulp (Fig. 1) in the sedimentation channels, the width of the holes decreases from bottom to top (Fig. 2). Each separator plate 8 is connected to the underlying precipitation plate 9 by a bridge 11. Jumper 11 is installed with an inclination from the center to the edges of the plates.

The thickener works as follows.

The initial slurry enters through pipe 2 into the stilling chamber 5, where the turbulence is quenched and the foam is destroyed. Next, the pulp enters the precipitation unit 6. Since the bridges 11 overlap the lower part of each precipitation channel (Fig. 1), the pulp falls into its upper zone - between the settling channel and the lower section.

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dividing plates. Already at the entrance to this zone, the largest particles begin to evaporate. These particles either enter the lowermost opening 10 of the separation plate 9, or remain in the sludge collector 7. As the pulp moves, less and less large particles remain in it. Small and colloidal particles in the presence of floccules form floccules that settle onto the separation plate 9. Under the action of gravity, they slide to the nearest slit and, falling onto the settling plate 8, are isolated from the main pulp flow. Gradually, mounds of floccules and individual particles accumulate under the gaps. Due to the inevitable penetration of a portion of the upward flow into the lower zone of the channel, these mounds are leveled to form a layer without sudden changes in thickness. In this lower zone, there are no jumps in pressure and velocity, the sedimentation of the sediment decreases.

When the critical thickness is reached, the layer on the settling plate collapses downwards, falling onto the lintel 11. Along the lintel, due to its inclination, the sediment evacuates to the walls of the sludge accumulator without mixing with the incoming pulp. From the sludge collector 7, the clot is removed through nozzle 3. The clarified solution is withdrawn through nozzle 4.

In order to effectively distinguish between the moving pulp and the settled material, the separation plate must have a certain living section, i.e. the ratio of the area of the holes to the total area of the plate. Replacing solid slit-like slots with their chess arrangement allows placing these slots more often with the same living section. In other words, it is possible to reduce the distance between the rows of slits by placing additional holes between the former gaps. If old

If the distance between the former slots is represented by a dashed arrow (Fig. 2), then taking into account the solid arrows, it becomes clear that the average distance traveled by the particle along the separation plate is reduced.

It is known that the flow of fluid through the hole is proportional to the square of its size. The gradual reduction of the width of the slots, thus, leads to a fairly rapid decrease in water flow through these slots. Consequently, in the upper part of the sedimentation channels, the penetration of water from the lower to the upper zone is reduced. Such conditions are very favorable for the deposition of small particles, and the smaller the particles, the better the conditions for it (the reduction of particles and the width of the slits goes in the same direction).

The slits may also have an oval, rhomboid or other shape, optimal from the point of view of the minimum vortex formation. Separating plates are preferably made of a material with minimal friction.

The proposed lamellar thickener will significantly increase the purity of circulating water, which will affect the lengthening of the service life of pumps, pipelines, gate valves, the cleanliness of factory premises, a reduction in sludge losses in waste, etc.

Claims (1)

Invention Formula A thickener, comprising a body with a slave collector, pipes for introducing the original pulp, for withdrawing thickened sludge and clarified water, a package of inclined precipitation plates and spaced in between separating plates with holes, which, in order to improve the quality water holes are made in the form of staggered transverse slots of equal length and width, decreasing in the direction of flow of the pulp. 1 9 F i