SU982718A1 - Device for suppressing foam - Google Patents

Description

one

The invention relates to devices for the destruction of technological and other types of foam before feeding it into special apparatus, for example thickeners, and can be used in mineral processing.

A defoaming apparatus is known, comprising a cylindrical-conical mesh insert fixed to housing 1.

The disadvantage of this device is the high energy consumption and the required constancy of the height of the foam layer introduced into the cylinder-conical insert, as well as the intensive influx of foam onto the surface intended for its destruction, i.e. secondary-foaming.

The closest in technical essence and the achieved result to the invention is a device for defoaming, including a cylindrical antifoaming chamber, discharge and discharge pipes 2.

A disadvantage of the known device is its low efficiency, intensive secondary foaming, high intensity of deposition of mineral components in a cylindrical

casing, which leads to frequent blockage of the openings of the septum.

The aim of the invention is to intensify the defoaming of the flotation slurry of sulfur ores.

5Goal is achieved by the fact that in the defoaming device, which includes an antifoaming chamber and pipelines, the antifoaming chamber is provided with a mentor threshold and a drop-like projection placed opposite each other.

It is advisable to perform the threshold with a bevel of 45 ° to the axis of the chamber and with longitudinal slits.

FIG. 1 shows a defoaming device, general view; in fig. 2 - view

15 slotted thresholds; in fig. 3 shows section A-A in FIG. one.

The defoaming device consists of a cylindrical defoaming chamber 1 with a discharge pipe 2 and a diverter pipe 3, a branch pipe 4 and a suction box 5.

Claims (2)

Inside Chamber 1, threshold 6 is located opposite to each other with longitudinal slits 7 on the surface and a drop-shaped projection 8. In the box 5 is made holes 9. The device operates as follows. The discharge pipe 2 from the clarified part of the thickener is supplied with water, which enters the cylindrical defoaming chamber 1. Located inside the chamber, threshold 6 with a 45 ° bevel with slots 7 on the surface and a drop-shaped projection 8 behind the threshold increase the turbulence and speed water, which allows to create a vacuum below the threshold, where an antifoaming solution is supplied through pipe 4. The solution of the defoaming agent, for example polyacrylamide, being in a vacuum zone and partially mixing with water, divided into streams, forms a foam. At this time, the water flow moving through chamber 1, the passage through the protrusion 8, in turn, creates a vacuum behind it and in the intake box 5, where the foam of the sulfur ores or other types of minerals is sucked through the holes 9. The entrance to the chamber 1 of the flotation pulp foam is captured by a moving stream of water and mixed with the foam formed from the antifoaming solution, thereby forming a large contact surface between the foam and the antifoaming agent, which leads to intensive quenching of the foam. As the mixing products move along chamber 1, they are effectively and repeatedly contacted, thereby enhancing the defoaming effect and, eliminating secondary foaming, the destroyed foam enters the discharge pipe, which is withdrawn into the thickener to settle or thicken. Theoretical and experimental studies have established that in order for capillary pressure P to destroy a film of an air bubble in a state, its value should be inversely proportional to the radius of curvature of the surface, since P is C – C. The magnitude of the surface tension 6g-g is for technological conditions a constant value. Therefore, as stated, the introduction of the foaming solution into the chamber 1, followed by the contacting of the foam and suction formed in the chamber through the intake box 5, makes it possible to vary the thickness of the films that separate the individual bubbles; reduce the area, which at constant volume causes an increase in the rate of destruction of the foam. For example, if the value of .. 35.0 - 40.0 dyn / cm 2 and the size of air bubbles of the frothy product entering through box 5 in chamber 1, diameters of 0.15 - 0.20 cm, the capillary pressure is 40- 46 dyn / cm2. This pressure is not enough to destroy foam bubbles. Contacting them with the foam formed as a result of the injection of the foaming solution drastically changes the structural parameters of the foam (thickness of the films separating individual bubbles, their size), which allows capillary pressure forces to freely break the film and thus destroy the foam. The effect of defoaming is 50-100 times greater than defoaming, which occurs in a known apparatus, eliminates the possibility of precipitating mineral components. The proposed design of a defoaming device is simple in design and maintenance, has no rotating components and parts, can be easily manufactured and introduced into production at the beneficiation plants of the sulfuric, coal and other industries. Claim 1. A defoaming device including a cylindrical antifoaming chamber, an injection and an outlet piping, characterized in that, in order to intensify the movement, the antifoaming chamber is provided with a segment-shaped threshold and a drop-shaped projection against each other. 2. The device according to claim 1, characterized in that the threshold is made with a bevel of 45 ° to the axis of the chamber and with longitudinal slits. Sources of information taken into account during the examination 1. USSR author's certificate No. 208594, cl. On 01 D 19/02, 1966. 2. USSR author's certificate number 226521, cl. On 01 D 19/02, 1967. 7 6 Fig.Z