METHOD AND DEVICE FOR ELECTRIC FURNACE HEATER CONTROL Russian patent published in 2015 - IPC G01N11/00 

FIELD: heating.

SUBSTANCE: invention refers to engineering physics, particularly to control methods and devices for physical parameters, such as viscosity, electric conductivity, density, surface tension, in melted metal samples. It can be used at metallurgical facilities, in research centres, laboratory works at institutes. The method is based on parameter measurement in one coil of power transformer and involves comparison of parameters measured with a preset threshold value, and of an electric parameter exceeds the threshold a decision is made as to halt and replace the heater. Device includes heater, power transformer, thermal controller, parameter monitoring unit connected to one coil of the power transformer, temperature sensor, thermocouple, computer connected to the thermal controller, temperature sensor and control units for physical parameters, and additionally features comparator consisting of two units with programmable thresholds, multiplexer, differentiating unit, AND logical device, where signal inputs of multiplexer are connected to parameter control unit, control input of parameter control unit is connected to the computer, and output bus is connected to one of AND inputs while the other AND input is connected to temperature sensor connected in parallel to one of inputs of the differentiating unit and to the computer while the other input of differentiating unit is connected to AND output, comparator unit outputs are connected to the computer, input of one comparator unit is connected to differentiating unit output, and input of the other comparator unit is connected to output of AND logical device.

EFFECT: elimination of unpredictable interruption of experiments, faster operation, more simple and cost-effective elements.

4 cl, 6 dwg