Temperature controller of electromagnetic induction heater and its start system

摘要

The present invention of a temperature controller is used for an electromagnetic induction heating apparatus provided with a heating element 12 made of magnetic material and prepared in a fluid passage, a coil 13 prepared in perimeter of the heating element 12 and a high frequency electric current generator 5 for the coil 13. The electromagnetic induction heating apparatus has a magnetic transformation temperature where a degree of magnetism suddenly decreases when magnetic material of the heating element becomes high-temperature. The temperature controller comprises an electric current detection means 31 for measuring the electric current flowing from the high frequency electric current generator 5 to the coil 13 and detecting that the temperature of magnetic material forming the heating element 12 reaches in the vicinity of the magnetic transformation temperature, and an electric current restrictive means 32 for limiting the electric current flowing to the coil 13 based on the electric current detection means 31. When the temperature of the heating element 12 reaches in the vicinity of the magnetic transformation temperature, the electric current detection means 31 detects the rising electric current and the electric current restrictive means 32 limits the further rising electric current. An starting method of the invention uses the above temperature controller and comprises the following process 1 &cir& - 4 &cir& . 1 &cir& filling the fluid passage with the fluid so as to keep the heating element in the static fluid 2 &cir& flowing the electric current from the high frequency electric current generator to the coil to set a required temperature in the temperature regulator. 3 &cir& preheating the heating element and the fluid with limiting the electric current and taking precedence of an instruction of the temperature regulator when a temperature of the magnetic material forming the heating element reaches in the vicinity of a magnetic transformation and the electric current flowing through the coil increases, 4 &cir& starting the electromagnetic induction heating apparatus to flow out the fluid from the fluid passage.