SU1447911A1 - Method of determining readiness of melt in periodic-action electric furnace - Google Patents

Description

(21) 4224174 / 31-02

(22) 02.23.87

(46) 30–1.2–88. Bksh. 48

(71) Leningrad Lensovet Institute of Technology

(72) A.S. Zubov, A.V., Ostrogorsky, Yu.I.Sidenko V.I., Klepinin,

Yu.MoNazarov, N.M. Burkov, VoAoPisarov. A, JSC Pedro and V.V. Rabotnov

(53) 669.168 (088.8)

(56) Polubelova A.S. and others „Production of abrasive materials, L. j 1968, p.45.

The technological process of the production of normal electrocorundum using aluminum-containing pshakovo 1902010 „01201. 00001, 1980.

(54) METHOD FOR DETERMINING THE READINESS OF THE MELT IN THE EZSCHTROPECHNY OF PERIODIC ACTION

(57) The invention relates to metallurgy and can be used to determine the readiness of a melt in batch-type electric furnaces in the production of, for example, electrocorundum. The purpose of the invention is higher

product quality and reduction of energy consumption. As a parameter characterizing the smelting process, choose the value of the Constant component of the phase voltage of an electric furnace. During smelting, this value is corrected in accordance with the voltage and operating current. The magnitude of the constant component of the phase voltage, which corresponds to the readiness of the melt, is determined by the equation U. c KiK (CC) a, where Uy with the magnitude of the constant component of the phase voltage, Bj K, is the coefficient depending on the value of the secondary phase voltage of the furnace transformer; K2 coefficient taking into account the position of the electrode or the amount of current in it; C is the predetermined concentration of the component, the content of which increases during smelting,%; Cj is the concentration of the same component at which an electric arc occurs,%; a is the coefficient depending on the features of the technological process,%. The method allows to reduce the specific energy consumption by 5%. 1 board, 1 Il.

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The invention relates to metallurgy and can be used to determine the readiness of a melt in electric furnaces of periodic action in the production of an electrocorV.

The purpose of the invention is to improve the quality of the product and reduce energy consumption.

It has been proposed as a parameter characterizing the process of melting and the readiness of the melt to choose the value of a constant component in the phase voltage of an electric furnace.

The constants in the phase voltage are determined by the different electro-emissivity of the electrode and the melt, as well as the extent to which the cathode spot of the electric arc is cooled when it is on the electrode and the melt. Constantly in phase voltage has good informativity, reflecting temperature, chemical and physical composition of the melt, fluidity, etc. The determination of the readiness of the melt and, consequently, the moment of its release in the proposed method is carried out upon reaching the value of a constant in the phase voltage of an electric furnace of a given value determined by the equation

Un.c (C-C,) a,

de Uf, is the constant phase voltage constant, Bj

K - coefficient ;;, hanging

from the stage of the furnace transformer (phase values (..: i.. of the voltage);

K - coefficient, which reflects the position of the electrode or the current in it;

C is the predetermined concentration of the component, the content of which increases during smelting,%;

GO is the concentration of the same ponent at which an electric arc occurs,%; .

a - coefficient depending on the features of the technological process,%:

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five

0 5 0

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The method of determining the readiness of the melt and the moment of its release can be considered by the example of the melting of normal electrocorundum in a 50 m furnace with a capacity of 10.5 MB «.A. Charging load - bauxite (agglomerate), carbonaceous reducing agent. The mass of the charge loaded for one melt is 39 tons. After loading the charge, the electric furnace operates in the resistance mode in the absence of an electric arc. In this case, the constant component of the phase voltage is also absent. After the melting of the top furnace, by this time the content in the melt reaches 92-93%, the further reduction of impurities from the melt and bringing it to a fluid-flowing state occurs in the presence of an electric arc. With the development of an electric arc, i.e., an increase in the concentration of 3 in the melt, the value of the constant component in the phase voltage increases.

Statistical processing of the analysis of rod samples and the values of the constant component corresponding to them at the time of sampling for this furnace can be used to follow the equation of the dependence of the U value of the melt ratio 3

and p; C NW, 3 CAl Oj-303) K K ,.

Usually the melt stage leads are carried out either at the 4th or at the 3rd stage of the furnace transformer. If the refinement is carried out at the 4th stage, then the coefficient of operation at the 3rd stage is K 0.75.

With the normal position of the electrode (the current value has a nominal value)

Thus, if the furnace operates at the 4th stage of a furnace transformer, then upon reaching a melt content of 94.5-95.5%, the value and qc fluctuates within 10-11 V, and during operation at the 3rd stage - within 7 -8 V, which is the signal for the melt to be blown out of the furnace.

The drawing shows a block diagram of the control of the state of the melt in the furnace.

The signal from the phase voltage sensor 1 is fed to a constant filter 2. component "The output of the filter 2 is connected to the input of the summing device Zo. To the input of the device 3 it enters

the signal from the voltage switch of the furnace transformer and the signal proportional to the position of the electrode.

The output of Cy1F1Iruk tsego block 3 serves as the input of block 4 of registration

The table presents data characterizing the average composition of corundum, the production of which is made according to the knowledge of 14 and according to the proposed method. In both cases, the average data for twenty heats are presented. It also shows the deviations from the average values, having a place in individual heats, as well as the average specific energy consumption per ton of corundum.

The duration of smelting according to a known method averages 8.25 hours, according to the proposed 7.75 hours, while the chemical composition of corundum is stabilized and the specific energy consumption is reduced by 5%.

Claims (1)

Invention Formula A method of determining the availability of a melt in a batch furnace, including measuring a parameter characterizing the smelting process, characterized in that, in order to improve product quality and reduce power consumption, a constant value is determined as a parameter characterizing the smelting process. component of phase voltage according to the equation and, K, K2 (C-Co) a, where and n t is the value of the constant component of the phase voltage, V; } С is the coefficient depending on the value of the secondary phase voltage of the furnace transformer; K is the coefficient, the learning position of the electrode or the amount of current in it; C -h given concentration to-that, the content of which increases during smelting,%: GO - the concentration of the same com-. ponenta at which an electric arc occurs,%; a is a coefficient depending on features of the technological process, B /%. specific energy consumption to Etch / t Known 2500 94.8 ± 0.9 0.6 ± 0.2 0.65 + 0.2 0.7 + 0.2} 3.0 ± 0.3 According to the proposed method 2375 95.4 + 0.5 0.6 + 0.15 0.55 + 0.15 0.6 tO, 2 2.6 ± 0.3 Cxio Tioj from switch steps / revffoeo mpoMCQjo / o / amo / ili Ofrwa / n (/ 1 / ka / halo ke / from SJTe / f / nfloffa