Daily maintenance of vacuum tube CVD electric furnace

As a key equipment for the preparation of nanomaterials, the daily maintenance of the vacuum tube CVD electric furnace directly affects the performance, service life, and reliability of experimental results. The following elaborates on the daily maintenance points of vacuum tube CVD electric furnaces from five aspects: cleaning and maintenance, vacuum system maintenance, electrical system inspection, safety protection, operation records, and spare parts management:

1. Cleaning and maintenance
External cleaning of furnace body
Regular wiping: Use a soft dry cloth or slightly damp cloth (avoid using corrosive cleaning agents) to wipe the surface of the furnace body every week to remove impurities such as dust and oil, and prevent accumulation that affects heat dissipation or causes short circuits.
Key areas: Clean dust prone areas such as control panels, buttons, and indicator lights to ensure that the operating interface is clear and visible.
Internal cleaning of furnace
High temperature burning: When there is no sample, burn the furnace at a lower temperature (such as 200-300 ℃) for 1-2 hours to decompose residual organic compounds or volatile impurities.
Mechanical cleaning: After the furnace cools down, use a soft bristled brush or vacuum cleaner to remove particles and avoid scratching the inner wall (such as quartz tubes).
Chemical cleaning: If there are stubborn stains (such as metal oxides) in the furnace, they can be wiped with dilute hydrochloric acid or alcohol, but they must be thoroughly dried before use.
Quartz tube/reaction chamber cleaning
Regular inspection: Check the inner wall of the quartz tube monthly for sediment or discoloration. If it affects transparency or reaction uniformity, it should be replaced in a timely manner.
Wipe with anhydrous ethanol: Wet a cotton cloth with anhydrous ethanol and gently wipe the inner and outer surfaces of the quartz tube to avoid scratching with hard objects.

2. Vacuum system maintenance
Vacuum pump maintenance
Regular oil change: According to the pump type (such as mechanical pump, molecular pump) and instructions, replace the vacuum pump oil every 3-6 months to prevent oil quality deterioration from affecting pumping efficiency.
Oil level inspection: Observe the pump oil level daily to ensure it is within the range of the dipstick and avoid overheating or damage to the pump body due to lack of oil.
Inlet filtration: Install a filter at the inlet of the vacuum pump, regularly clean or replace the filter screen to prevent particulate matter from entering the pump body.
Vacuum valve inspection
Sealing test: Use a helium mass spectrometer leak detector or soapy water to check the sealing of the valve every month. If a leak is found, tighten the bolts or replace the sealing ring.
Flexibility of action: Manually operate the valve several times to confirm that the switch is smooth and there is no jamming or abnormal noise.
Vacuum gauge calibration
Regular calibration: Use a standard vacuum gauge to calibrate the vacuum gauge inside the furnace every six months to ensure accurate readings and avoid experimental failure due to errors.
Avoid contamination: Ensure that the regulation is clean before calibration to prevent oil vapor or particulate matter from adhering.

3. Electrical system inspection
Power and Circuit Inspection
Grounding test: Use a grounding resistance tester to check the grounding resistance of the equipment every month to ensure it is ≤ 4 Ω and prevent the risk of leakage.
Line aging: Regularly check whether the power cord and heating element connection wire are damaged or aging, and replace cables with cracked insulation layers in a timely manner.
Temperature controller calibration
Thermocouple calibration: Use a standard thermometer to calibrate the thermocouple readings every quarter, and adjust or replace them if the error exceeds ± 1 ℃.
PID parameter optimization: Based on experimental requirements, regularly optimize the PID parameters of the temperature controller to reduce temperature fluctuations (usually ≤± 0.5 ℃).
Maintenance of gas flow controller
Flow calibration: Calibrate the gas flow controller with a soap film flowmeter every six months to ensure flow control accuracy (usually ≤± 1% FS).
Filter cleaning: Regularly clean the gas inlet filter to prevent impurities from blocking the flow meter or reaction chamber.

4. Security protection
Safety device inspection
Overtemperature protection: Test the overtemperature alarm function every month to confirm that the heating power can be automatically cut off when the temperature exceeds the set value.
Overpressure protection: Check if the pressure relief valve is working properly to prevent the risk of explosion caused by excessive pressure inside the furnace.
Personal protective equipment
Operating standards: Operators are required to wear heat-resistant gloves, goggles, and gas masks to avoid contact with high-temperature components or inhalation of harmful gases.
Emergency response: Equip fire extinguishers and first aid kits near the furnace, and regularly organize safety training to improve emergency response capabilities.

5. Operation records and spare parts management
Operation records
Maintenance log: Detailed records of the time, content, replacement parts, and abnormal situations of each maintenance, providing a basis for equipment failure analysis.
Experimental parameters: Record key parameters such as temperature, vacuum degree, and gas flow rate for each experiment, in order to trace the relationship between experimental conditions and results.
Spare parts inventory management
Key spare parts reserve: Reserve commonly used spare parts (such as quartz tubes, sealing rings, thermocouples, vacuum pump oil) to ensure timely replacement in case of failure.
Supplier contact: Establish a list of spare parts suppliers, regularly check inventory, and avoid prolonged equipment downtime due to missing parts.