Precautions for using box type high-temperature heat treatment furnace

When using a box type high-temperature heat treatment furnace, it is necessary to strictly control multiple aspects such as pre operation preparation, standardized operation process, safety protection, maintenance, and special working condition treatment to ensure the safe operation of the equipment and extend its service life. The following are specific precautions:

1. Preparation before operation
Equipment inspection
Appearance inspection: Confirm that there are no cracks or deformations in the furnace body, furnace door, and observation window, and that the sealing strip is intact and undamaged.
Electrical system inspection: Check if the power cord, plug, and control panel connections are secure, without aging or exposed wires; Use a multimeter to check the grounding resistance and ensure good grounding.
Heating element inspection: Check whether the heating element (such as resistance wire, silicon carbide rod) is broken, short circuited or severely oxidized by visual inspection or instrument, and replace it if necessary.
Temperature control system calibration: Use a standard temperature source (such as a thermocouple calibrator) to verify the accuracy of the temperature sensor, ensuring that the displayed value of the temperature control instrument is consistent with the actual temperature.
Ventilation system inspection: Confirm that the fan is operating normally, the ventilation ducts are unobstructed, and the air flow meets the process requirements.
Environmental confirmation
Ensure that there are no flammable or explosive materials around the furnace, good ventilation, and avoid damage to personnel or equipment caused by high temperature radiation.
Check if the workbench is flat to prevent component damage caused by tilting of the furnace body.
Process parameter setting
Set a reasonable heating rate, holding time, and cooling method based on material characteristics such as melting point and thermal expansion coefficient.
Avoid sudden temperature changes (such as rapid cooling), prevent material cracking or furnace damage.

2. Operation process specification
Loading and fixing
The sample should be evenly placed in the center of the furnace to avoid local overheating; Large or heavy samples need to be fixed with high-temperature resistant brackets to prevent tipping.
Ensure that the sample is kept at a safe distance (usually ≥ 50mm) from the heating element and furnace wall to prevent short circuits or local overheating.
atmosphere control
Introduce inert gases (such as nitrogen and argon) or active gases (such as oxygen and hydrogen) according to process requirements, and adjust the flow rate to a stable value.
When operating flammable gases such as hydrogen, it is necessary to first empty the furnace with nitrogen gas, then gradually introduce hydrogen gas, and install explosion-proof devices.
Heating and insulation
Strictly follow the process curve to raise the temperature and avoid overheating; During the heating process, closely observe temperature changes and immediately shut down for inspection if any abnormalities are found.
During the insulation stage, it is necessary to maintain temperature stability and avoid frequent opening and closing of the furnace door, which may cause heat loss.
Cooling treatment
Natural cooling: Suitable for materials with no special requirements for cooling rate. The heating power must be completely turned off before waiting for the furnace temperature to drop to a safe range (usually ≤ 200 ℃) before opening the furnace door.
Forced cooling: If rapid cooling is required, compressed air or circulating water can be introduced, but it is necessary to ensure that the cooling system is compatible with the furnace body to avoid thermal stress causing cracking of the furnace body.

3. Security protection
Personal Protection
Operators are required to wear heat-resistant gloves, protective face shields, and thermal insulation clothing to prevent burns or radiation injuries.
Avoid direct contact with the surface of the furnace body, especially high-temperature parts such as furnace doors and observation windows.
Fire and explosion prevention
Fire extinguishers, sandboxes, and other firefighting equipment should be equipped near the furnace body, and their effectiveness should be regularly checked.
When handling flammable and explosive materials, it is necessary to do so in a fume hood and install a combustible gas alarm device.
Electrical safety
Do not operate equipment with wet hands to avoid the risk of electric shock.
Regularly check the leakage protection device to ensure its sensitivity and reliability.
Emergency treatment
Develop emergency plans and clarify procedures for shutdown, power outage, evacuation, etc.
The operator needs to be familiar with the location of the emergency stop button and immediately press it in case of any abnormality.

4. Maintenance and upkeep
Daily cleaning
Clean the residue in the furnace after each use to prevent oxidation scale or impurities from affecting the next experiment.
Regularly clean the sealing strip of the furnace door to ensure good air tightness.
Regular maintenance
Check the resistance value of heating elements every quarter and replace aging or damaged elements.
Conduct comprehensive calibration of the temperature control system every year to ensure temperature control accuracy.
Check the lubrication condition of the ventilation system fan bearings and add lubricating oil if necessary.
Lubrication and fastening
Regularly lubricate mechanical components such as furnace hinges and slides to reduce wear and tear.
Check if the fixing bolts of the furnace body are loose and tighten them in a timely manner to prevent vibration or deformation.

5. Special working condition handling
Over temperature alarm
Immediately stop the machine and check if the temperature control system is faulty, such as damaged sensors or incorrect temperature control instrument parameters.
Confirm if the heating element is short circuited or if the sample accumulation in the furnace is causing local overheating.
Abnormal atmosphere
If pressure fluctuations or abnormal odors are found in the furnace atmosphere, immediately stop ventilation and check for leaks in the gas source, pipelines, and valves.
When operating hydrogen and other gases, it is necessary to equip a hydrogen detector and regularly test its sensitivity.
mechanical failure
If the furnace door cannot be closed or has difficulty opening, check whether the sealing strip is stuck or the hinge is deformed, and replace the components if necessary.
To avoid further damage to the equipment caused by forced operation.