Intermediate-frequency furnace combined type square heater for polycrystalline silicon ingot casting or purification

The invention relates to a low-cost combined type square heater for polycrystalline silicon ingot casting or purification, which belongs to the technical field of manufacture of polycrystalline silicon ingots or purifying furnaces. The heater receives the induction heating of a square copper coil by using a square heat insulation layer. The conventional heater processed by the integral graphite is replaced, the cost of the heater is greatly reduced due to the composition of the graphite sheets, and the design method prevents the destruction caused by poor contact of the combined heater. The square combined heater is characterized in that the graphite sheets are combined into an upper square graphite coil and a lower square graphite coil; the edge connecting part of the graphite sheets is processed into a sawtooth shape and fixed by carbon fiber screws after combination; graphite slurry is coated on all connecting surfaces and the connecting surfaces of the carbon fiber screws; the graphite coils are sintered