SU42301A1 - Signaling device to prevent the anode effect in electrolytic baths - Google Patents

Description

A known industrial process for the production of aluminum is the electrolysis of alumina dissolved in molten cryolite.

When the alumina content in the bath decreases below certain limits, the stress periodically increases dramatically. At the same time, the bath overheats significantly and its normal course is disturbed. This phenomenon is known as the anode effect or flash, and, being a source of unproductive energy loss, at the same time complicates and increases the cost of plant electrical equipment.

Attempts to conduct the process without flashes, for example, with continuous or preventive loading of alumina, did not lead to the desired results, since this method of work inevitably led to the reduction of electrolyte alumina, which had a very harmful effect on the process and duration of the bath.

The proposed device aims to create the possibility of normal operation of the bath without flashes, by giving a signal at a time when the concentration of alumina in the electrolyte is already small, but e, did not reach the critical value that corresponds to the onset of the anode effect. The effect of this adaptation is based on the automatic registration of the number of ampere hours required for the decomposition of the portion of alumina introduced into the bath. For this purpose, an ampere-hour counter is applied to the dowel in the supply rails of the bath, automatically giving a signal at a time when their number is in accordance with the alumina load produced. After loading, in accordance with its size, the required current in the shunt circuit is set using a rheostat, the scale of which is graded per kilogram of alumina. To provide a timely signal, by taking into account fluctuations in the current output, a second regulating rheostat is set in the bath, graduated by the percentage of current output.

The magnitude of the current efficiency for a given bath is always known with sufficient accuracy, and a possible error in its estimation cannot be too sharply reflected in the timeliness of the signal, since its changes occur slowly.

The drawing shows the scheme of the proposed device, in which the baths B are connected to a mercury wattmeter W, having a shunt 5 in the circuit, a loading regulator rj and a current output regulator Gg. In the signal circuit there is a forward regulator T connected by a fixed contact K with a wattmeter W, a relay /, a lamp L and a bell G.

It is proposed to use a mercury wattmeter W as an ampere-hour meter, although the possibility of using another ampere-hour meter is not ruled out in principle. A mercury wattmeter device consists of two communicating glass vessels for anodic and cathodic mercury, filled with an appropriate electrolyte, for example, a solution of iodine mercury in potassium iodide. A curved tube is attached to the bottom of the cathode vessel to indicate the level of cathode mercury accumulation. Contact K is pushed into the same tube, which, in contact with mercury, closes the electrical circuit to the relay connected in parallel with the bath. The latter includes connected to the lighting network sound (bell G) and light (lamp L} signals indicating the need to load alumina.

To stop the signal and bring the device into operation readiness, it is necessary to open the tap V connecting the anode and cathode wattmeter vessels. After mercury becomes at a common zero level e, valve V is closed and the device is again ready for operation. The signal must be ahead of the anode flash for some time. This advance can be very precisely adjusted by vertical movement of contact K. All components of the device can be incorporated into a common metal protective cover attached to the anode frame of bath B.

The fixture relay R can work on any fixture for automatically loading alumina into the bath.

As the shunt S on which the wattmeter W is connected, it is possible to use the resistance of a portion of one of the feeding baths.

The subject matter of the invention.

Claims (2)

1. A signaling device to prevent the anode effect in electrolytic baths, mainly for producing aluminum, characterized in that it is driven by an ampere-hour meter, equipped with a device for adjusting the current depending on the alumina load produced and the expected current output. 2. In the device according to claim 1, use as a counter of ampere-hours of a mercury meter IV, the cathode compartment of which is equipped with a moving contact L for closing the advance time with a signal of the anode effect, which closes the signal circuit. to the author's testimony G. I. JVb 42501 Hvilivitsky