Common faults and solutions of multi temperature zone rotary furnaces used in experiments

The common faults and solutions of the multi temperature zone rotary furnace used in experiments in complex environments with high temperature, rotation, and multi temperature zone collaborative work can be summarized as the following core points:

1. Temperature control malfunction
Fault phenomenon: Slow heating or temperature fluctuation exceeding the standard (＞ ± 1 ℃).
reason:
Thermocouples are stuck or burned by materials, causing temperature measurement distortion.
Heating elements (resistance wires, silicon carbide rods) are aging or have poor contact.
resolvent:
Clean the surface material of the thermocouple or replace the broken thermocouple.
Check if the wiring of the heating element is loose, use a multimeter to measure the resistance value, and replace damaged components.
Regularly calibrate the temperature sensor to ensure that the deviation between the displayed value and the actual value is ≤ ± 0.5 ℃.
Fault phenomenon: Over temperature alarm or uncontrolled heating.
Reason: Improper PID parameter setting or malfunction of temperature controller.
resolvent:
Re debug PID parameters (such as P=20, I=5, D=1) to reduce overshoot.
Replace the temperature controller and set the over temperature protection threshold (such as target temperature+10 ℃).

2. Rotation and transmission faults
Fault phenomenon: Stuck or abnormal noise in the rotation of the furnace body.
reason:
Loose transmission chain or insufficient lubrication of bearings.
Uneven accumulation of materials inside the furnace tube leads to eccentric rotation.
resolvent:
Adjust the tension of the chain and add high-temperature lubricating grease (such as molybdenum disulfide).
After shutdown, clean the materials inside the furnace tube to ensure that the filling amount is ≤ 60% of the volume.
Check the position of the supporting wheel and correct the deviation of the kiln centerline to ≤ 2mm.
Fault phenomenon: Unstable speed or inability to start.
reason:
Inverter parameter setting error, or motor overload.
Power supply voltage fluctuation (>± 5%).
resolvent:
Reset the acceleration time of the frequency converter (e.g. 100s) to avoid short-term overload.
Install a voltage regulator to ensure a stable voltage within the range of 380V ± 5%.

3. Atmosphere control malfunction
Fault phenomenon: The atmosphere purity does not meet the standard (such as oxygen content>1 ppm).
reason:
Gas pipeline leakage or mass flow meter malfunction.
The aging of the furnace sealing ring leads to the leakage of atmosphere.
resolvent:
Use soapy water to check the pipeline connection and repair the leakage point.
Replace the fluororubber or silicone rubber sealing ring and check it every 50 uses.
Regularly calibrate the quality flow meter to ensure flow fluctuations of ≤ ± 5 sccm.
Fault phenomenon: Abnormal gas pressure (>0.5 MPa or<0.1 MPa). reason: Gas pressure reducing valve malfunction or pipeline blockage. resolvent: Replace the pressure reducing valve and adjust the outlet pressure to the required range of the process. Blow the pressure measuring tube and cyclone cone with compressed air to remove dust blockage. 4. Electrical and control system malfunction Fault phenomenon: The equipment suddenly stops or cannot be started. reason: Power supply phase loss or poor grounding. The emergency stop button has not been reset. resolvent: Use a multimeter to check the three-phase voltage, ensuring balance and no missing phases. Check that the grounding resistance is ≤ 4 Ω and reset the emergency stop button. Fault phenomenon: Abnormal data recording or parameter loss. reason: PLC storage module failure, or touch screen communication interruption. resolvent: Backup PLC program and replace storage card. Check the communication cable between the touch screen and PLC, and reconnect it. 5. Mechanical structural faults Fault phenomenon: Deformation or cracking of furnace tube. reason: Long term over temperature operation (>design temperature 50 ℃).
Uneven thermal stress of materials inside the furnace tube.
resolvent:
Strictly control the heating rate (≤ 10 ℃/min) to avoid sudden temperature changes.
When replacing furnace tubes, choose materials that match the process (such as quartz, ceramic, stainless steel).
Fault phenomenon: Vibration of the supporting wheel or rolling ring.
reason:
The position of the supporting wheel is offset, or there is poor contact between the rolling ring and the supporting wheel.
resolvent:
Adjust the supporting wheel bearing seat to ensure even contact between the rolling ring and the supporting wheel.
Regularly check the wear of the supporting wheels and replace damaged parts.

6. Safety and emergency related faults
Fault phenomenon: risk of fire or explosion.
reason:
Combustible gas leakage of materials inside the furnace.
The accumulation of static electricity triggers sparks.
resolvent:
Install a combustible gas detector that automatically alarms and cuts off the gas source when the concentration is ≥ 4%.
The grounding resistance of the furnace body should be ≤ 4 Ω to avoid static electricity accumulation.
Fault phenomenon: The vacuum pump is damaged.
reason:
Before heating up, the vacuum pump was not turned on and high-temperature gas was poured back.
resolvent:
Strictly follow the sequence of “vacuuming first and then heating up” to avoid high-temperature gases entering the vacuum pump.
Regularly replace the vacuum pump oil to prevent emulsification.