Daily maintenance of box type resistor muffle furnace

The daily maintenance of the box type resistor muffle furnace is the key to ensuring stable operation of the equipment, extending its service life, and ensuring experimental safety. The following provides a detailed explanation of maintenance points from four aspects: cleaning and maintenance, component inspection, operating procedures, and environmental management:

1. Cleaning and maintenance
Furnace cleaning
Regular cleaning: After each experiment, when the furnace temperature drops below 50 ℃, use a soft bristled brush or vacuum cleaner to remove residual sample debris, oxides, and other impurities in the furnace.
Deep cleaning: Use a neutral cleaning agent (such as alcohol) to wipe the inner wall of the furnace every month, avoiding the use of strong acid or alkali solutions to prevent corrosion of refractory materials.
Attention: Wear heat-resistant gloves when cleaning to avoid burns; If there are stubborn stains on the furnace, they can be gently scraped off with a wooden or silicone spatula, and the use of metal tools is strictly prohibited.
Cleaning of furnace door sealing strip
Cleaning frequency: Check and clean the dust or stains on the surface of the sealing strip every week to ensure sealing.
Method: Wipe the sealing strip with a damp cloth, dry it, and apply a small amount of silicone grease for lubrication to prevent aging and cracking.
Replacement standard: If the sealing strip hardens, deforms or is damaged, it should be replaced immediately to avoid temperature fluctuations caused by heat dissipation.
Cleaning of exhaust outlets and ventilation ducts
Cleaning cycle: Check if the exhaust port is blocked every month, and clean up accumulated dust or foreign objects.
Ventilation duct maintenance: Check the ventilation duct connections for looseness every quarter to ensure smooth exhaust and prevent the accumulation of harmful gases.

2. Component inspection and maintenance
Heating element inspection
Appearance inspection: Visually inspect the resistance wire, silicon carbon rod, or silicon molybdenum rod every month to see if they are broken, oxidized, or deformed.
Resistance test: Measure the resistance value of the heating element with a multimeter every six months. If the deviation exceeds 10% of the rated value, it needs to be replaced.
Replacement precautions: When replacing the heating element, ensure that the model matches, the installation is firm, and avoid contact with the inner wall of the furnace.
Thermocouple calibration and replacement
Calibration cycle: Send it to a professional organization for calibration once a year to ensure temperature measurement accuracy.
Daily inspection: Check the thermocouple connection for looseness every month, test the open circuit condition with a multimeter, and replace it immediately if it is damaged.
Installation requirements: The thermocouple end should be located at the center of the furnace, avoiding contact with heating elements or samples to prevent temperature measurement distortion.
Controller and Instrument Maintenance
Clean the surface: Wipe the controller housing with a dry cloth every week to prevent dust from entering the internal circuit.
Functional testing: Check the temperature display, program control, and alarm functions for normal operation every month. If there are any abnormalities, contact the manufacturer for repair.
Parameter backup: Regularly backup controller program parameters to prevent data loss caused by misoperation.
Fan and circuit inspection
Fan maintenance: Check the fan impeller for imbalance and bearings for oil shortage every quarter, and add lubricating oil or replace the fan if necessary.
Circuit inspection: Check the power cord and plug for damage every six months, and ensure that the grounding resistance is ≤ 4 Ω to ensure electrical safety.

3. Operating standards and habits
Heating and cooling control
Avoid rapid cooling and heating: The heating rate should not exceed the rated value of the equipment (such as ceramic fiber furnace ≤ 20 ℃/min), and cooling should be done naturally or controlled according to the program to prevent furnace cracking.
Empty furnace heating: When new equipment is used or not used for a long time, the furnace needs to be heated to the highest temperature and kept at that temperature for 2 hours to remove moisture and impurities from the furnace.
Sample placement requirements
Uniform distribution: The sample should be placed in the center of the furnace to avoid blocking the hot air circulation path and ensure temperature uniformity.
Container selection: Use high temperature resistant and low heat capacity containers (such as alumina crucibles) to reduce thermal shock to the furnace.
Operation record
Record content: Record the temperature curve, running time, abnormal phenomena (such as temperature fluctuations, noise), etc. for each experiment.
Data analysis: Regularly analyze and record data to detect potential faults in advance (such as slow heating due to aging heating elements).

4. Environmental management
Requirements for placement environment
Good ventilation: The equipment should be placed in a dry and ventilated laboratory or workshop to avoid electrical short circuits caused by humid environments.
Stay away from corrosive substances: Avoid contact with corrosive gases or liquids such as acids and alkalis to prevent corrosion of the casing and components.
Horizontal placement: The equipment should be placed on a level ground to prevent vibration from causing parts to loosen.
Dust and moisture prevention
Cover with dust cover: When not in use for a long time, cover the equipment with a dust cover to reduce the entry of dust.
Desiccant usage: During humid seasons, desiccants (such as silica gel) can be placed inside the equipment and replaced regularly to maintain dryness.

5. Long term shutdown and restart maintenance
Long term disuse maintenance
Clean and dry: Thoroughly clean the furnace before stopping use, and close the furnace door after natural drying.
Power outage handling: Disconnect the power supply, unplug the plug, and prevent electrical leakage or lightning damage to the equipment.
Regular power on: Power on and run once every 3 months (raise the temperature of the empty furnace to 200 ℃ and keep it warm for 1 hour) to remove moisture and prevent circuit aging.
Check before restart
Comprehensive inspection: Before restarting, check whether the heating elements, thermocouples, sealing strips, and other components are intact. After confirming that there are no abnormalities, turn on the power.
Empty furnace operation: The first restart requires 1-2 empty furnace operations to observe whether the temperature control and fan operation are normal.