SU115358A1 - Automatic regulator for electric arc furnaces - Google Patents

Description

For automatic control of electric arc furnaces, regulators are used that move the electrodes depending on the current deviation or arc voltage (or their ratio) from the set value.

The proposed controller is more perfect than the known ones, since it ensures that the required power is emitted in the furnace for a certain period of time.

This is achieved by the fact that the regulator is supplied with an additional integrating device, to the input of which the value of the deviation of the power allocated to is given relative to a given constant or time variable value.

A correction device is connected to the output of the integrating device, which changes the task to the controller so that the power deviation in the arc, which is equal to the integral of the power deviation from the start of melting to the moment in question, is reduced to zero.

The drawing shows a pripipial diagram of the proposed controller.

The power released by the electric arc in the furnace 1 is measured by any known device 2 and is converted into a voltage proportional to it.

This voltage is continuously compared with a predetermined voltage supplied from potentiometer 3, which determines the magnitude of a given optimum arc power and the required law of variation of it from the network voltage during the melting period of the metal (the lower the arc voltage ).

The difference of these voltages is amplified by amplifier 4 and fed to the input of an integrating device, which can be used, for example, electric motor 5. The magnitude of the speed of the motor 5 will in this case be proportional to the deviation of arc power from the specified value, and the angle of rotation of its shaft is proportional 115358

It is national to search or shortage the arc energy for the time from the beginning of melting to the moment in question.

The motor shaft 5 is connected to the autotransformer shaft 6, the rotation of which changes the task to the controller of the electric arc furnace. In the event of an energy shortage, the autotransformer 6 will automatically change the reference to the controller until it compensates for the energy shortage and maintains the required arc power.

Subject invention

An automatic controller for electric arc furnaces that moves the electrodes depending on the current deviation or arc voltage (or their ratio) from a given value, characterized in that an additional integrating device, at the input of which the deviation of the power allocated in the arc relative to a given constant or time variable value is measured, and a corrective correction is connected to the output its device that changes the setting of the controller in such a way that the specified deviation, equal in magnitude to the integral of the deviation of power from the beginning of melting to the moment in question, is reduced to zero.