Common faults and solutions of ceramic hot pressing sintering furnace

Common faults and solutions of ceramic hot pressing sintering furnace

1. Abnormal temperature control
Fault phenomenon: The furnace temperature cannot reach the set value, the temperature is out of control due to overheating, or the temperature is uneven.
Possible reasons:
Heating element problem: Resistance wire melting, oxidation of silicon molybdenum rod or local short circuit, resulting in decreased heating capacity or local overheating.
Temperature control system malfunction: PID parameter drift, sensor failure, or relay adhesion, affecting temperature regulation accuracy.
Sealing and airflow issues: Poor sealing of the furnace door can cause heat leakage, or malfunction of the atmosphere stirring fan can hinder airflow circulation.
resolvent:
Heating element inspection:
After power off, check if the resistance wire is blown and if there is a severe oxide layer on the surface of the silicon molybdenum rod. Replace it if necessary.
Measure the resistance value of the heating element with a multimeter to confirm if there is an open circuit or short circuit.
Temperature control system calibration:
Re calibrate the PID parameters or reset to factory settings before re debugging.
Check the output terminal of the thermostat. If the relay is stuck, replace the thermostat or relay module.
Sealing and airflow optimization:
Replace the damaged furnace door sealing ring (such as ceramic fiber, asbestos pad) to ensure that the furnace door is tightly closed.
Check if the atmosphere stirring fan is rotating, and replace it if the motor is faulty.

2. Atmosphere system malfunction
Fault symptoms: inability to introduce atmosphere, insufficient purity, or abnormal pressure.
Possible reasons:
Air source and pipeline issues: Insufficient pressure in the gas cylinder, pipeline blockage, or malfunction of the solenoid valve.
Furnace leakage: Poor sealing of welds and flanges leads to a decrease in atmosphere purity.
Exhaust and pressure control failure: Exhaust valve blockage or pressure sensor malfunction.
resolvent:
Air source and pipeline inspection:
Confirm whether the pressure of the gas cylinder is sufficient (if nitrogen needs to be ≥ 0.1MPa), and replace the full cylinder with gas.
Dismantle the pipeline, blow and remove impurities with compressed air, or flush the condensation and icing areas with corresponding inert gas.
Check the power wiring of the solenoid valve. If the valve core is stuck, disassemble, clean or replace it.
Sealing test of furnace body:
Conduct airtightness test: Fill the furnace with a pressure of 0.05MPa, and if the pressure drops by ≤ 5% within 30 minutes after turning off the gas source, it is considered qualified; If there is a leak, repair the weld seam or replace the flange gasket.
Exhaust and pressure control adjustment:
Calibrate the pressure controller and replace it if the sensor fails.
Check if the exhaust valve is stuck, disassemble and clean it, and ensure that it is in a “slightly open” state when heating up.

3. Pressure system malfunction
Fault phenomenon: The pressure cannot rise to the set value, the pressure is uneven, or the hydraulic system leaks.
Possible reasons:
Hydraulic system issues: oil pump failure, poor cylinder sealing, or hydraulic oil leakage.
Pressure system issues: insufficient gas source pressure, gas pipeline leakage, or worn pneumatic cylinder.
Pressure head and mold issues: Non parallel contact surfaces or mold installation deviations result in uneven pressure distribution.
resolvent:
Hydraulic system inspection:
Check the hydraulic oil level, if there is a leak, locate the leak point and repair it.
Check the working condition of the oil pump, and repair or replace it if there are any problems; At the same time, check the oil cylinder seals to ensure they are intact and undamaged.
Pressure system adjustment:
Supplement the gas source pressure to the specified value and repair the gas pipeline leakage point.
Replace worn components such as pneumatic cylinder piston rings.
Pressure head and mold calibration:
Check the flatness and parallelism of the indenter, and grind and repair any uneven areas.
Ensure that the mold is installed correctly and the center lines of the upper and lower molds are consistent.

4. The device cannot start or is interrupted during operation
Fault phenomenon: The equipment has no power display, frequent trips, or sudden stops during operation.
Possible reasons:
Power issue: The main power supply is not connected, the circuit breaker trips, or the power switch is damaged.
Safety protection trigger: equipment shutdown caused by overheating alarm, gas leakage alarm or grounding fault.
Line fault: Internal power line is open or short circuited.
resolvent:
Power check:
Check if the circuit breaker of the distribution box trips. If it trips, check for overload (such as a short circuit in the heating element) and reset the circuit breaker.
Replace the damaged power switch.
Security protection reset:
Check if the sensor wiring is loose (such as thermocouples), re fix and calibrate the sensor accuracy.
Confirm whether it really exceeds the standard (if it exceeds the temperature limit, it will be treated as “temperature out of control”, and if it leaks, it will be treated as “furnace leakage”).
Line investigation and repair:
Use a multimeter to check the internal power cord and repair any open or short circuits.

5. Sealing and furnace body failure
Fault phenomenon: The furnace door cannot be opened/closed, the vacuum degree decreases, or the furnace body leaks water.
Possible reasons:
Furnace door mechanism issues: hinge jamming, locking mechanism failure, or furnace pressure not being relieved.
Seal aging: The sealing ring at the furnace door, observation window, or pipeline connection is aging or damaged.
Furnace damage: Welding seam cracking or blockage of cooling water pipeline leading to water leakage.
resolvent:
Furnace door mechanism maintenance:
Clean the hinge and apply high-temperature grease (such as molybdenum disulfide grease) after power failure.
Check whether the locking mechanism screw is corroded, polish it with sandpaper and apply lubricating grease; If the motor is not working, check the power supply or replace it.
First, open the exhaust valve to relieve the pressure inside the furnace, and then open the furnace door after the pressure drops to atmospheric pressure.
Seal replacement:
Replace aging furnace doors, observation windows, or sealing rings at pipeline connections to ensure proper installation.
Furnace body repair:
Repair the cracked area of the weld seam and conduct a new air tightness test.
Turn off the water source, dismantle the cooling water pipeline and clean the scale with a descaling agent (such as citric acid solution), then rinse with clean water until dry