PLC controlled intelligence well-type electric furnace

Abstract

This invention discloses a PLC-controlled intelligentized well-type electric furnace, which is composed of a furnace body, a furnace cover and a resistance heater. Besides, the electric furnace is also composed of a system for PLC-controlling of the load main circuit. The system performs zoning temperature control on the main circuit, and is composed of three programmable PID controllers, three integrated threephase electric power controllers and one temperature-controlling meter connecter. In each temperature control zone, a thermal couple is equipped to connect the programmable PID controller. The input side of the thermal couple is connected with the temperature-controlling meter connector, and the output side is connected with the integrated threephase electric power controller, and is connected with the main circuit in a serial-parallel mode through a temperature-controlling switch and a solid-state relay. The threephase electric power controller can collect the input signals from the programmable PID controller, and perform closed-loop control on the heating system. The well-type furnace has such advantages as rapid heating, uniform temperature distribution, low error and rapid cooling.

Description

technical field [0001] The present invention relates to an annealing furnace using direct resistance heating, and in particular to the control or adjustment of the heat treatment process of a well-type furnace. Background technique [0002] In the prior art, direct resistance heating is used for well-type electric furnaces. Its control method is still the traditional relay control. In this way, it is difficult to adjust the power output of the load main circuit, and it is impossible to perform closed-loop control according to the furnace temperature, resulting in uneven furnace temperature, low thermal efficiency, and overheating or undertemperature can easily lead to waste products or major quality accidents. Therefore, PLC programmable controllers and related technologies are used to improve the existing well-type resistance heating furnace, and the main load circuit provides PWM cycle power output regulated by programmable PID to realize closed-loop control of furnace te...

AI Technical Summary

Problems solved by technology

In this way, it is difficult to adjust the power output of the load main circuit, and it is impossible to perform closed-loop control according to the furnace temperature, resulting in uneven furnace temperature, low thermal efficiency, and overheating or undertemperature can easily lead to waste products or major quality accidents.

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