SU687143A1 - Electrolyzer for obtaining aluminium - Google Patents

Description

I

The invention relates to the production of aluminum by an electrolytic method and is intended for use in aluminum plants equipped with electrolyzers for a current above 100 kA.

A known electrolyzer for producing aluminum with a cathode lining, containing side coal plates, bottom blocks, heat insulation in the form of refractory brickwork and provided with a contour assembled from heat exchange elements 1.

Such a device significantly complicates the design of the electrolyzer. In addition, the regulation of heat removal around the entire perimeter of the cathode is difficult, since a significant amount of valves is required, and the labor costs for servicing the electrolyzer increase.

The purpose of the invention is to provide the possibility of thermal regulation and to simplify the design of the electrolyzer.

This is achieved by the fact that heat-conducting blocks are installed in the central part of the end sides of the cathode lining, in which heat exchange elements are mounted.

FIG. 1, 2 shows the proposed device placed on the electrolyzer, the general view and section; in fig. 3, 4 — its connection with the coolant flow rate controller and the external heat exchange circuit.

The device has a heat exchange element 1 consisting of two pipes for inlet and outlet of the heat transfer medium with vertical tubular bridges. The heat exchange element is built using fill 2

in the heat-conducting unit 3. The latter forms the central part of the brick edge of the 4 end sides. The cathode lining of the electrolyzer has side coal plates 5, bottom blocks 6 with current-carrying

rods 7, heat insulation in the form of refractory brickwork 8 and backfill 9. The entire lining is placed in the cathode casing 10. The anode 11 is placed on top of the cathode. an external heat exchange circuit consisting of the internal pipe 14 and the external condenser tank; i 15. The latter is connected by pipes 16 to the heat exchange element I. A heat regulator 17 of the heat-transfer fluid is mounted on the lower pipe. On the electrolyzer installed on these two devices, according to the number of front sides.

The device works as follows.

During the operation of the cell, alumina is periodically loaded into the electrolyte, and the electrolyte crust with alumina poured on its surface collapses. On modern electrolyzers with a current of 150-160 kA, the treatment is carried out along the longitudinal sides, on the sides of which a skull is formed. On the front sides of the skullcaps are practically absent, so it is much easier to regulate the thermal mode of the electrolyzer through the ends. The heat transfer element 1 is admitted to the coolant through the flow regulator 17 from the condenser 15, cooled through the block 3, the end side plates 5, the removal of heat from the electrolyte and molten aluminum. The coolant heated to 200-300 ° C, is released into the condenser 15, insulated from the outside. The coolant is cooled by passing condensate through line 14 to heat it.

The cooled coolant is accumulated in the condenser 15 and then the cycle is repeated.

Using the flow controller 17, varying the volume of the coolant in the heat exchange element 1, regulate the removal of heat from the side walls, and hence from the molten medium, respectively, affect the thermal mode of the electrolyzer. The control of the controller can be remote.

When the electrolyzer is disconnected for overhaul, the external circuit is depleted. The dismantled unit 3 with heat exchange element 1 is used on a new electrolyzer.

Technological disruptions due to the hot stroke of the electrolyzer amount to about the total number of disruptions in the process mode.

Claims (1)

1. USSR author's certificate No. 404894, cl. C 25 C 3/08, 1972. Heatworms