Daily maintenance of multi temperature gradient experimental tube furnace

As a precision experimental equipment, the daily maintenance of the multi temperature gradient experimental tube furnace directly affects the service life, experimental accuracy, and safety of the equipment.

1. Cleaning and maintenance
Furnace cleaning
Frequency: Clean after each experiment and conduct regular deep cleaning (such as once a month).
method:
After the furnace has cooled to room temperature, use a vacuum cleaner or soft bristled brush to remove residues (such as oxides and powders).
Stubborn stains can be wiped with non-woven fabric dipped in alcohol or specialized cleaning agents to avoid scratching with metal tools.
Attention: It is strictly prohibited to clean directly at high temperatures to prevent damage or burns to furnace materials.
Seal maintenance
Inspection: Check the furnace door and flange sealing ring for aging, deformation, or damage every week.
Replacement: If there are cracks or decreased elasticity in the sealing ring, it should be replaced immediately to avoid air leakage that may affect the vacuum degree or temperature uniformity.
Lubrication: Apply a small amount of high-temperature resistant silicone grease (such as Dow Corning 732) on the surface of the sealing ring to reduce wear.
Air intake/exhaust system
Filter cleaning: Check the intake filter monthly, clean the accumulated dust or replace the filter element.
Pipeline inspection: Regularly check whether the gas pipeline leaks (can be detected with soap water) to ensure that the valve switches flexibly.

2. Component inspection and replacement
heating element
Inspection: Check the resistance wire quarterly for breakage, oxidation, or deformation.
Replacement: If there is obvious damage or uneven heating of the resistance wire, it should be replaced in a timely manner to avoid accidents caused by local overheating.
Attention: When replacing, ensure that the resistance wire is well insulated from the furnace to prevent short circuits.
Thermocouple
Calibration: Calibrate the thermocouple every six months to ensure accurate temperature measurement.
Replacement: If the thermocouple responds slowly or displays abnormally, a new probe needs to be replaced and the temperature controller needs to be recalibrated.
vacuum system
Vacuum pump maintenance: Replace the vacuum pump oil and clean the oil mist filter every quarter.
Vacuum degree testing: Use a vacuum gauge to test the vacuum degree inside the furnace every month to ensure compliance with experimental requirements (such as ≤ 10 ⁻ ³ Pa).

3. Operating standards
Heating/cooling control
Avoid rapid cooling and heating: After the experiment, slowly cool down according to the set program (such as ≤ 10 ℃/min) to prevent furnace cracking.
Temperature gradient setting: Reasonably set the temperature of each temperature zone according to experimental requirements to avoid local overheating or excessive temperature differences.
Sample placement
Uniform distribution: The sample should be evenly placed in the furnace to avoid blocking the thermocouple or heating element.
Avoid overloading: The weight of a single experimental sample should not exceed the furnace’s load-bearing capacity (such as ≤ 5kg) to prevent furnace deformation.
atmosphere control
Gas purity: When introducing gas (such as argon or nitrogen), ensure that the gas purity is ≥ 99.99% to avoid impurity contamination of the sample.
Flow regulation: Adjust the gas flow rate according to experimental requirements (such as 50-200 sccm) to maintain a stable atmosphere inside the furnace.

4. Environmental control
Placement environment
Temperature: The equipment should be placed in an environment with stable temperature (20-30 ℃) and humidity ≤ 60%, avoiding direct sunlight.
Ventilation: Ensure good ventilation around the equipment to avoid the accumulation of high-temperature or harmful gases.
Dustproof and moisture-proof
Dust cover: When not in use for a long time, cover the equipment with a dust cover to prevent dust from entering.
Moisture proof treatment: In humid environments, desiccants can be placed or dehumidifiers can be used to prevent electrical components from getting damp.

5. Regular calibration and recording
temperature calibration
Frequency: Calibrate every six months and compare measurements using a standard thermometer (such as a platinum resistance thermometer).
Record: Record calibration data, adjust temperature controller parameters, ensure temperature error is ≤ ± 1 ℃.
Maintain records
Content: Record each maintenance time, content, replacement parts, and experimental parameters.
Traceability: Establish equipment records for easy troubleshooting and performance analysis.

6. Safety precautions
Power off operation: Before maintenance, the power must be cut off and a “Do not close” warning sign must be hung.
Anti scald: Wear insulated gloves during high-temperature operations to avoid direct contact with the furnace body.
Gas safety: When introducing flammable and explosive gases (such as hydrogen), ensure that the equipment is well grounded to prevent static sparks.

Through the daily maintenance of the above system, the service life of the multi temperature gradient experimental tube furnace can be significantly extended, the failure rate can be reduced, and the accuracy and repeatability of the experimental results can be ensured. It is recommended that the laboratory develop a detailed maintenance plan and assign a dedicated person to execute it.