Common faults and troubleshooting methods of vertical vacuum furnace

The common faults of vertical vacuum furnaces can be divided into vacuum system faults, heating system faults, sealing faults, mechanical structure faults, and other faults. The following are specific fault phenomena and troubleshooting methods:

Vacuum system malfunction
Fault symptoms: insufficient vacuum degree, prolonged pumping time, loud noise from the vacuum pump, oil injection from the vacuum pump, etc.
Exclusion method:
Insufficient vacuum degree: Check whether the vacuum pump oil is contaminated, too little or too thin, and if necessary, clean the vacuum pump and replace it with new oil; Check if the exhaust filter is clogged, clean or replace the filter; Check if there are any leaks in the furnace body, use a helium mass spectrometer leak detector or soapy water to detect and repair the leaks; Extend the pumping time.
High noise of vacuum pump: Check whether the vacuum pump coupling is worn or broken, and replace the coupling if necessary.
Vacuum pump fuel injection: Check if the O-ring of the suction valve has come off, reinstall or replace the O-ring.
Vacuum pump oil leakage: Check if the return valve is blocked and clean the return valve.

Heating system malfunction
Fault symptoms: no heating, insufficient heating temperature, heating not stopping, etc.
Exclusion method:
Not heating: Check if the heating rod is burnt out and replace it if necessary; Check if the heating time relay is burnt out and replace it if necessary; Check if the AC contactor controlling heating has been reset, repair or replace the contactor.
Insufficient heating temperature: Check if the temperature controller parameters are normal, calibrate or replace the temperature controller if necessary; Check whether the thermocouple is open, short circuited or damaged, and replace it if necessary; Check if the heating element is aging or damaged, and replace it if necessary.
Heating does not stop: Check if the heating time relay is in good contact and adjust or replace the time relay if necessary.

Seal failure
Fault symptoms: Poor sealing of furnace door, leakage of sealing components, etc.
Exclusion method:
Poor sealing of furnace door: Check whether the sealing ring of the furnace door is aging or deformed, and replace the sealing ring if necessary; Check if the furnace door hinge is loose or deformed, and adjust or replace the hinge if necessary; Check if the furnace door latch is malfunctioning and replace it if necessary.
Seal leakage: Check if the seal is installed correctly and reinstall if necessary; Check if the seals are damaged and replace them if necessary.

Mechanical structural failure
Fault symptoms: stuck transmission components, poor closure of furnace doors, abnormal fan noise, etc.
Exclusion method:
Transmission components stuck: Check if the fan bearings are lacking oil and replenish lubricating oil if necessary; Check if the motor screws are loose and tighten them if necessary; Check for foreign objects entering and clean them if necessary.
Poor closure of furnace door: Check if the hinge is deformed and correct it if necessary; Check if the lock buckle is malfunctioning and replace it if necessary; Check if the furnace body is deformed and repair it if necessary.
Fan abnormal noise: Check for foreign objects inside the fan impeller and clean them if necessary; Check if the motor fixing bolts are loose and tighten them if necessary.

Other faults
Fault symptoms: blocked cooling system, uneven quenching surface, carbonization of parts, etc.
Exclusion method:
Cooling system blockage: Check whether the water cooling pipeline is scaled, and if necessary, acid wash the scale; Check if the water pump is faulty and replace it if necessary; Add filtering devices to prevent impurities from entering the cooling system.
The quenched surface is not shiny: increase the vacuum degree, extend the pumping time, and check for leaks; Ensure thorough degassing of quenching oil.
Carbonization of parts: Clean the furnace by using acetone or trichloroethylene for cleaning; Regularly clean the residue to prevent it from evaporating and adhering to the workpiece.