Precautions for using alumina tubes and crucibles

Corundum tube Suitable for various laboratory metal and non-metal sample analysis and melting materials. Corundum tube Mainly used for high-temperature vacuum furnaces, vacuum atmosphere furnaces, tin bath tubes for float glass industry, protective tubes for solar glass, electric furnace wire support tubes, aluminum trichloride muffle furnace tubes, etc. The products have the characteristics of operating temperature of 1200-1800 degrees, high density, good thermal shock resistance, acid and alkali resistance, corrosion resistance, and long service life, and are highly praised by colleges and universities, the electric furnace industry, and users. According to customer feedback, the service life of vacuum tubes can reach 60 times within 1800℃, and the service life of tin bath tubes can reach 6 years.

Corundum furnace tube and Corundum crucible Summary of usage experience

Based on our experience:

1. Too large a temperature difference. When using, place the heat insulation plugs (two on each side) Corundum tube in Corundum tube between the hot zone and the cold zone.

2. At such a high temperature, the middle of the tube is soft, so the tube is easily deformed and broken. It is recommended to add supports on both sides of the pipe.

Also, newly purchased tubes should be baked several times at different temperatures before use. Here, newly purchased Corundum tube materials are generally baked several times. At 200℃ and 1000℃, generally keep warm for 1 hour.

4. It is recommended that the heating rate should not be too fast, do not exceed the faster heating rate of 140℃/h, and pay special attention to the limit speed of 10℃/min when cooling! The preferred heating rate should not be higher than 10℃/min, and the cooling rate should be lower than 10℃/min.

This support can reduce deformation and breakage. The red arrow indicates gravity, and the blue arrow indicates support.

5. In addition to the above support issues; also, for samples fired in a tube furnace, especially those to be fired to around 1300℃, it is best to have a low water content (water content refers to adsorbed water, crystal water, etc., which may be generated during the heating process); it is recommended that your samples be pre-fired before being placed in the tube furnace. It is best not to add or remove samples at high temperatures, as this can easily damage the corundum furnace tube.

6. Do not forcefully touch the corundum furnace tube, do not keep the temperature at 300℃-900℃, and do not touch the high-temperature furnace tube with low-temperature objects.

7. ≤5℃/minute below 500℃; 500-800℃ ≤10 ℃/min; 800-1000℃ ≤5 ℃/min; 1000-1400℃ ≤3 ℃/min; 1400-1600℃ ≤2℃/min

Corundum furnace tube and Corundum crucible Summary of usage experience

Based on our experience:

1. Too large a temperature difference. When using, place the heat insulation plugs (two on each side) in the corundum tube, and the corundum tube is located between the hot zone and the cold zone.

2. At such a high temperature, the middle of the tube is soft, so the tube is easily deformed and broken. It is recommended to add supports on both sides of the pipe.

Also, newly purchased tubes should be baked several times at different temperatures before use. Here, newly purchased corundum tubes are generally baked several times. At 200℃ and 1000℃, generally keep warm for 1 hour.

4. It is recommended that the heating rate should not be too fast, do not exceed the faster heating rate of 140℃/h, and pay special attention to the limit speed of 10℃/min when cooling! The preferred heating rate should not be higher than 10℃/min, and the cooling rate should be lower than 10℃/min.

This support can reduce deformation and breakage. The red arrow indicates gravity, and the blue arrow indicates support.

5. In addition to the above support issues; also, for samples fired in a tube furnace, especially those to be fired to around 1300℃, it is best to have a low water content (water content refers to adsorbed water, crystal water, etc., which may be generated during the heating process); it is recommended that your samples be pre-fired before being placed in the tube furnace. It is best not to add or remove samples at high temperatures, as this can easily damage the corundum furnace tube.

6. Do not forcefully touch the corundum furnace tube, do not keep the temperature at 300℃-900℃, and do not touch the high-temperature furnace tube with low-temperature objects.

7. ≤5℃/minute below 500℃; 500-800℃ ≤10 ℃/min; 800-1000℃ ≤5 ℃/min; 1000-1400℃ ≤3 ℃/min; 1400-1600℃ ≤2℃/min