The heating chamber of a high-temperature vacuum sintering furnace is composed of refractory materials such as silicon carbide, magnesium oxide, and aluminum oxide. The electric heating wires are made of nickel-chromium alloy. The muffle furnace body is made of iron plates, coated with wrinkle paint. The furnace door has a small viewing hole with a transparent mica sheet for observation. The door is easy to open and close.
The muffle furnace is equipped with an automatic temperature controller and thermocouple.
Automatic Temperature Control:
The controller uses a high-frequency oscillation circuit with vacuum tubes. The energy storage coil is properly coupled to maintain a fixed oscillation frequency. The storage coil provides a constant temperature reference, and the thermocouple accurately measures the furnace temperature. A small metal flag on the indicator shows when the desired temperature is reached.
- When the furnace reaches the set temperature: The temperature index is minimal. The flag couples with the energy storage coil, stopping the oscillation current. This change triggers a strong relay to cut off power to the heating wire, preventing further temperature rise.
- When the furnace cools: The pointer flag decouples from the coil, restoring oscillation and reactivating the relay, allowing current to flow again. This on-off cycling of current automatically maintains a stable temperature.
Operating Adjustments:
- If the temperature drops below the desired setpoint, cut off power, rotate the control knob left to adjust the temperature index to the new setpoint, then reconnect power.
- If the temperature rises above the setpoint, rotate the knob right to adjust. The furnace will continue to maintain the set temperature through this controlled cycling.
This system allows precise automatic control of furnace temperature, ensuring stable heating for high-temperature sintering processes.