摘要:
A carbon heater to fire a silicon-containing material in a non-oxidizing atmosphere includes a cross-sectional shape of a substantially n-sided polygon, and n represents any one of 3 to 8.
摘要:
A heater unit includes a power source, a plurality of heaters, and a power supply position-switching device. The power source includes a first power source terminal and a second power source terminal. The plurality of heaters are each connected to one another in series and include a first heater and a second heater. The power supply position-switching device is configured to switch between a first state and a second state. In the first state, the first power source terminal is connected with a first heater terminal of the first heater, and the second power source terminal is connected with a third heater terminal of the second heater. In the second state, the first power source terminal is connected with a second heater terminal of the first heater, and the second power source terminal is connected with a fourth heater terminal of the second heater.