How is the coil of the induction heating furnace made?
Before winding the coil of the induction heating furnace, the pure copper tube is annealed. Keep the pure copper tube at 650-700℃ for 30-40min, and then quickly cool it in 20-30%: water. The heating equipment is preferably a resistance furnace.
(1) Winding. The pure copper tube is wound into the coil of the induction heating furnace. Use iron or wood molds when winding. Considering the springback of the copper tube after winding, the size of the mold should be slightly smaller than the required size. When the winding radius is small, hot winding should be carried out, that is, the pure copper tube at the bending part should be baked with a flame in the winding.
(2) Correction. Correct the coil of the wound induction heating furnace to the required size and press it with a clamp.
(3) Annealing. The coil annealing temperature, time and method of induction heating furnace are the same as those of pure copper tube annealing.
(4) Hydrostatic test. Pass water or air with a pressure 1.5 times the design pressure of the feedwater into the pure copper pipe of the coil of the induction heating furnace, and check whether there is any water leakage at the joint between the pure copper pipe and the pipe.
(5) Insulating layer. Overlap the alkali-free glass ribbon on the pure copper tube.
(6) Dip insulating varnish. Preheat the coil of the induction heating furnace covered with an insulating layer in a resistance furnace or a hot air drying box, and then immerse it in an organic insulating varnish for 15 minutes. If there are many bubbles in the paint during the dipping process, the dipping time should be extended, generally three times.
(7) Drying. It is carried out in a resistance furnace or a hot air drying box. When the coil of the induction heating furnace is installed, the furnace temperature should not be higher than 50°C, and the temperature should be raised at a rate of 15°C/h, and it should be dried for 20 hours at 100-110°C, but it should be baked until the paint film does not stick to the hands. Finally, the prepared permeable magnet and the coil of the induction heating furnace are assembled into a complete inductor.