The operation of the internal and external heating vacuum oven must strictly follow the following steps to ensure safety and drying effect:
1、 Preparation before operation
Equipment and environmental inspection
Place the oven in a flat, dry, and well ventilated area, and remove any flammable materials from the surrounding area.
Check the grounding of the power supply, the integrity of the sealing strip, and the oil level of the vacuum pump (to be filled to the standard line).
Clean the inner container to avoid residual contamination of the sample.
2、 Operation process
1. Loading and sealing
Place the samples evenly on the material rack and reserve space for heat dissipation.
Close the box door and rotate the vent valve to the 'closed' position (ensuring isolation from the atmosphere).
2. Vacuum processing
Turn on the power of the vacuum pump, and then open the vacuum valve to extract air.
Observe the vacuum gauge, when the pressure drops to -0.1 MPa (or the vacuum degree reaches over 90%), close the vacuum valve → vacuum pump power supply in sequence.
3. Temperature and time setting
Turn on the oven power and press the SET button to enter the temperature setting mode.
Using the secondary heating method: first set the temperature 10-20 ℃ below the target value (if the target is 70 ℃, set 50 ℃ first), and then adjust it to the target value after the temperature stabilizes.
Set the constant temperature time (if no timing is required, set it to 0).
Press the confirm button to start the program, and the heating indicator light flashes to indicate that it is running.
4. Process monitoring
The pressure on the vacuum gauge needs to be evacuated again.
Avoid frequent door opening and wear insulated gloves during high temperature operation.
3、 End operation
1. Shutdown and pressure relief
Turn off the heating power first and wait for the temperature to drop below 60 ℃.
Slowly rotate the vent valve to zero the air pressure (about 5-10 minutes).
Open the door and take out the sample, clean the inner container.
2. Equipment maintenance
Turn off the main power, regularly calibrate the temperature control instrument and check the circuit.
4、 Key safety issues
1. Prohibited materials: organic solvents, flammable and explosive materials.
2. Pressure relief taboo: It is strictly prohibited to relieve pressure (prevent explosion) before the material has cooled to its ignition point.
3. Exception handling: Automatic power-off alarm for over temperature of 20 ℃, immediate maintenance is required.
Tip: The internal and external heating design should ensure that the material rack and the box are heated synchronously to avoid local overheating. Please refer to the equipment manual for operational differences.
Operation basis: The process integrates multiple equipment operation guidelines and safety regulations, and key steps need to be strictly matched with vacuum degree and temperature parameters.