What must be known when using corundum tube in tubular electric furnace and the key skills and methods of its maintenance and use

Tube furnace is generally used in the process of its use temperature is different, the tube used is not the same, the general furnace tube quartz tube, corundum tube, we will explain and analyze the tube furnace corundum tube maintenance and its common use and operation methods, common sense precautions, etc. The newly bought corundum tube or the furnace tube which has been idle for a long time needs to be roasted at 300-400 ℃ for about 5-6 hours. The moisture in the corundum tube must be roasted off, which will prolong the basic service life of the corundum tube.

An important factor for the fracture of corundum tube caused by moisture can not be ignored, Corundum tube is made of corundum material. It has poor tolerance to temperature difference during rapid cooling and heating. We usually recommend that the temperature rise and fall rate should be kept at 5 ℃ / min It must be slow, but in the cooling process, the cooling curve must be set to operate. Remember that it can not be cooled naturally at high temperature. If this operation greatly increases the possibility of furnace tube cracking, the temperature of furnace tube cracking is usually between 810 ℃ and 1010 ℃, in addition, its service life and durability are not very long.

The cleanliness of the furnace tube must be maintained. There must be no residue of basic substances that react with Al2O3 in the tube. When burning materials, do not put the materials directly on the furnace tube, and hold them in a boat shaped crucible, which will prolong the life of the furnace tube. During heating, alumina furnace plug must be placed in furnace tube, two on one side and four in total. The end distance between furnace plugs on both sides can be controlled at 360mm. IF furnace plug is not placed, the temperature at both ends of furnace tube will be higher. When O-ring cannot bear high temperature, its air tightness will be affected. Putting furnace plug on both ends of furnace tube is more conducive to balanced temperature field space.

Do not put materials directly in the furnace tube, which will pollute the furnace tube. If the burning material is volatile material, the matching of different materials can be used. The tube of tubular furnace is easy to disassemble. Continuous use of tubular electric furnace can make the temperature drop to about 200 ℃ and keep continuous, without reducing to normal temperature, which will increase the service life of furnace tube. The temperature resistance of corundum tube is closely related to its purity. Generally speaking, the higher the purity is, the higher the temperature resistance will be. The disadvantage is that the ability to withstand rapid cooling and heating is relatively poor. This needs attention. The flange at both ends of the corundum tube needs to be supported by a support frame. The reason is that the corundum pipe is subjected to vertical stress, and the corundum tube will not bend or break due to stress at high temperature.