Common faults and troubleshooting methods of vacuum tube CVD electric furnace

The common faults and troubleshooting methods of vacuum tube CVD electric furnace in the preparation process of nanomaterials can be summarized as follows:

1. Temperature control malfunction
The temperature cannot reach the set value
Possible reasons: heating element malfunction, control system issues, temperature sensor malfunction.
Exclusion method:
Check if the heating element is damaged or aged, and replace it if necessary.
Check the control system, including controller and PID parameter settings, to ensure normal operation.
Check the temperature sensor, confirm its accuracy and position, and calibrate or replace it if necessary.
High temperature alarm
Possible reasons: high temperature setting, control system malfunction, safety device triggering.
Exclusion method:
Reduce the temperature setting value to ensure it is within a safe range.
Check the control system and troubleshoot.
Check the safety device and confirm its normal operation.
Large temperature fluctuations
Possible reasons: wind circulation system malfunction, poor thermocouple contact, unstable control system.
Exclusion method:
Check the air circulation system to ensure normal air circulation, and adjust the baffle opening appropriately.
Check the connection of the thermocouple to ensure good contact.
Adjust PID parameters to optimize the stability of the control system.

2. Vacuum system malfunction
Insufficient vacuum degree
Possible reasons: Vacuum pump malfunction, aging or damage of vacuum seals, leakage.
Exclusion method:
Check the operation of the vacuum pump, clean or replace damaged seals.
Perform leak detection on the furnace body and pipelines, and repair the leakage points.
Vacuum cannot be drawn up or is too low
Possible reasons: abnormal vacuum source, vacuum gauge malfunction, door not tightly closed or poor sealing.
Exclusion method:
Confirm whether the vacuum gas source is normal and whether the compressed air pressure is within the normal range of use.
Check if the vacuum gauge is in good condition and calibrate it against the vacuum gauge in normal use.
Check if the door is tightly closed, if the sealing film at the entrance is damaged or deformed, and if there are any foreign objects on the door panel.

3. Gas system malfunction
Inaccurate gas flow control
Possible reasons: gas flow controller malfunction, unreasonable design of gas distribution system.
Exclusion method:
Check the gas flow controller to ensure it is working properly.
Optimize the design of gas distribution system to ensure uniform gas flow.
Uneven gas mixing
Possible reasons: design defects in the reaction chamber and poor performance of the mixing device.
Exclusion method:
Optimize the reaction chamber design to improve mixing performance, such as adding mixers or adjusting the inlet position.
Strengthen the monitoring of the reaction process to ensure even gas mixing.

4. Other faults
Incomplete cleaning of equipment
Possible reasons: Improper cleaning methods and inappropriate selection of cleaning agents.
Exclusion method:
Strengthen equipment cleaning work and use appropriate cleaning agents and methods.
Ensure that there are no residues inside the device to avoid contamination during the preparation of nanomaterials.
Improper operation
Possible reasons: Operators are not familiar with equipment operating procedures and lack professional training.
Exclusion method:
Provide professional training to operators to enhance their understanding and operational skills of the equipment.
Develop and adhere to standard operating procedures (SOP), standardize operational steps, and reduce the occurrence of malfunctions caused by human error.