Gas leakage in the tube furnace with gas supply

Leakage of gas in a tubular furnace can seriously affect the safety and process effectiveness of experiments or production, and may lead to gas waste, experimental failure, and even safety accidents. The following is a detailed treatment plan for gas leakage in tubular furnaces:

1. Analysis of the causes of gas leakage
Seal aging or damage
Rubber O-rings, silicone pads, and other sealing components are prone to hardening and cracking after long-term high-temperature use, leading to seal failure.
Frequent disassembly and assembly can cause wear or deformation of seals.
Loose flange connection
The bolts are not tightened or the threads are damaged, resulting in gaps between the flanges.
High temperature thermal expansion and contraction cause flange deformation and uneven sealing surface.
Cracks or damages in the furnace tube
The material of the furnace tube is not resistant to high temperature or thermal stress, resulting in cracking.
Mechanical collision or improper installation can cause damage to the furnace tube.
Gas pipeline leakage
Loose pipeline joints, cracked welds, or inadequate valve sealing.
Corrosion of pipeline materials (such as failure to use corrosion-resistant materials when passing corrosive gases).
Air inlet/outlet sealing issues
The quick connector and sleeve connection are not tightened or the sealing ring is damaged.
Improper installation of accessories such as gas filters and flow meters.

2. Leakage detection method
Soap water detection method
Apply soapy water to areas where there may be air leakage, such as flanges, joints, and furnace tube interfaces, and observe for the formation of bubbles.
Advantages: Simple and easy to implement, suitable for low-pressure gas systems.
Disadvantages: Low sensitivity to minor leaks and possible residual moisture affecting the process.
Pressure drop detection method
Close all gas valves, fill the furnace with a certain pressure of gas (such as nitrogen), and record the initial pressure value.
After standing for a period of time, observe whether the pressure decreases. If the pressure significantly decreases, it indicates the presence of a leak.
Applicable scenarios: Medium and high-pressure gas systems, capable of quantitatively evaluating leakage volume.
gas detector
Use portable gas detectors (such as hydrogen detectors, combustible gas detectors) to scan for possible gas leaks.
Advantages: High sensitivity, capable of detecting trace leaks, especially suitable for toxic or flammable gases.
Attention: The appropriate detector should be selected according to the type of gas being introduced.
Ultrasonic leak detector
Locate the leak point by detecting the ultrasonic signal generated by the leak.
Advantages: Non contact detection, suitable for high voltage or difficult to access areas.
Disadvantages: The equipment cost is relatively high and requires professional personnel to operate.

3. Leakage treatment measures
Emergency handling
Immediate shutdown: Close all gas valves, cut off power, and prevent further gas leakage.
Ventilation and air exchange: Open the furnace door and exhaust fan to release the leaked gas outside, avoiding accumulation and causing explosions or poisoning.
Personnel evacuation: If the leaked gas is toxic or flammable, quickly evacuate the scene and set up a warning area.
Locate the leakage point
Determine the location of the leak based on the test results, mark and take photos for recording.
Focus on inspecting flange connections, furnace tube interfaces, gas pipeline joints, and other areas that are prone to leakage.
Fix the leakage point
Replace seals: Use high-temperature and corrosion-resistant sealing materials (such as fluororubber O-rings and graphite gaskets), install and tighten bolts according to specifications.
Tighten the flange: Use a torque wrench to evenly tighten the bolts in diagonal order to avoid excessive local stress.
Repair furnace tube: If the cracks in the furnace tube are small, high-temperature adhesive bonding or welding can be used for repair; If the crack is severe, a new furnace tube needs to be replaced.
Pipeline replacement: Replace corroded or damaged gas pipelines with materials compatible with the gas (such as stainless steel, polytetrafluoroethylene).
Check attachments: Ensure that the inlet/outlet quick couplings, valves, and other accessories are installed correctly, and that the sealing rings are not damaged.
Re leak detection
After repair, perform a leak test again to confirm that there are no leaks before reusing.
The pressure drop detection method or gas detector can be used for retesting.

4. Preventive measures
regular maintenance
Develop a maintenance plan for the tube furnace and regularly inspect the condition of components such as seals, flange connections, and furnace tubes.
Replace aging or damaged seals and clean up carbon deposits or impurities inside the furnace.
Standard operation
Avoid violent operation when installing or disassembling furnace tubes to prevent damage to seals.
Before heating up, ensure that all gas valves are closed, gradually introduce gas and observe pressure changes.
Select high-quality materials
Choose corrosion-resistant and high-temperature resistant furnace tubes and pipeline materials based on the type of gas being introduced.
Choose high-precision and durable seals and flange connectors.
Training and safety education
Train operators on the safe use of tube furnaces and master emergency response methods for gas leaks.
Regularly organize safety drills to improve accident response capabilities.

5. Safety precautions
personal protection
Wear protective gloves, goggles, and gas masks during operation (especially when toxic gases are introduced).
Avoid direct skin contact with high-temperature components or corrosive gases.
Ventilation requirements
Tube furnaces should be installed in well ventilated laboratories or workshops, equipped with forced exhaust systems.
It is strictly prohibited to start electrical equipment during leakage to prevent sparks from igniting flammable gases.
Gas storage
Flammable and toxic gases should be stored in dedicated gas cylinder cabinets, away from sources of fire and heat.
Gas cylinders should be securely fixed to prevent tipping or collision.