SU1236003A1 - Method of checking temperature of electrolyte in aluminium electrolyzer - Google Patents

Description

The invention relates to non-ferrous metallurgy, namely to the field of aluminum production by an electrolytic method.

The aim of the invention is to improve the accuracy of the temperature control of the electrolyte of the aluminum electrolysis cell by taking into account the fluctuations of the current series.

FIG. 1 shows a diagram of an apparatus for implementing the method in the discrete measurement of voltage and current; in fig. 2 - the same5 with continuous measurement of voltage and current.

A device for monitoring the temperature of the electrolyte (Fig. 1) contains a voltage sensor 2 and a current sensor 3 connected to the tires of the electrolyzer 1. The outputs of sensors 2 and 3 are connected to a dividing device 4. The output of a dividing device is through a switch 5 and the analog-to-digital converter 6 is connected to the digital-to-frequency input of a machine 7.

A device for monitoring electrolyte temperature during continuous measurement of voltage and current (Fig. 2) contains a voltage sensor 2 and a current sensor 3 connected to the electrolysis cell buses 1, the output of which is connected to a separating device 4. as in the case of discrete voltage measurement current. The output of the dividing device 4 through a band-pass filter 8 and a rectifier 9 is connected to the integrato-10, the output of which is connected via the smoothing filter 11 and the analog-to-digital converter 12 to the input of the computer 13.

The method is carried out with discrete measurement of voltage and current as follows.

Using sensors 2 and 3, the voltage and current on the electrolyzer are measured respectively, the signal proportional to the voltage is fed to the input of the divider of the dividing device 4, and proportional to the current to the input of the divider. The output voltage of the dividing device is proportional to the resistance plot anode-cathode.

From the measured values of ngtr and NIN and the current, the temperature value is calculated as follows: 1.

52

(R

R g

(one)

12360032

t de p - the number of measurements; R is the ratio of voltage to current in the i-OM measurement; R V. / I., R - arithmetic average

1 n t

R

R,

(2)

In this case, the rms OTKjiOHeHHe, HcnojTb3yeMoe in the model is determined by the expression

G T

S j --- P

P

t - a + b S,

email

(R - R)

WITH; 3)

(four)

where S is the standard deviation of voltage to current; -j and b - experimentally determined regression coefficients.

For high-power aluminum electrolyzers with an upper current lead of 945 deg, L 98.4 deg / μOhm.

With continuous measurement of voltage and voltage, the method is carried out as follows. With the help of sensors 2 and 3, the voltage and current are measured, with the order of supplying the measured values to the input; the body is similar to the order in the first considered variant. The output of the band-pass filter 8, which transmits a signal in the range of 0, 01–2.0 Hz, is connected via rectifier 9 to integrator 10, the output of which is held at constant intervals of 10–20 s. The input voltage of the smoothing filter 11 is proportional to the integral integral estimate (6). By its value and expression (4), the computer calculates the temperature of the electrolyte.

Prr continuous measuring voltage And

 Y-jr (t) dt

 or by p) is an approximate expression

with; I

  T j

(llldt

(6)

where T is the measurement period j t is time; g is the deviation of the ratio of voltage to current from its value.

The present invention will improve the accuracy of temperature control on average.

Editor L. Rratillo

Order 3067/28 Circulation 615 Subscription

VNIIL of the USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Compiled by A. Ashikhin

Tehred L. Serdyukova Proofreader L. Patay

Claims (1)

METHOD FOR CONTROL OF ELECTROLYTE TEMPERATURE OF ALUMINUM ELECTROLYZER, including measuring the voltage across the electrolyzer in the frequency range 0.01-2.0 Hz, characterized in that, in order to increase the control accuracy, additionally simultaneously with the voltage measure the series current in the same frequency range and calculate the electrolyte temperature from. expression Oh where S is the standard deviation of the ratio of voltage to current; a, b are the regression coefficients. with "5 1236003 A 1 12