The characteristics of the quartz tube should be paid attention to during the use of the tube furnac
Because of its unique structure, the tube furnace is an important and key component, and it is also the reaction place and working area during the production test. And the furnace tube is directly related to gas, pressure and operation method. Therefore, during the use of the tube furnace, you must pay attention to the use and maintenance of the quartz tube. The following is a brief introduction to the matters needing attention in the maintenance of quartz tubes:
1. The softening point of the quartz tube is 1270 degrees, and it should not be used for more than 3 hours at 1200 degrees.
2. Under normal circumstances, it is not recommended for customers to pass hydrogen through the tube furnace. Except for the non-hydrogen content that is at the limit explosion concentration, if the customer needs to use the tube furnace to pass hydrogen with a concentration other than the explosion concentration, safety measures must be taken to vent the gas. Do not stand at both ends of the furnace tube. If you pass hydrogen, please use stainless steel tube. Since the thermal conductivity of stainless steel is larger than that of quartz, both ends of stainless steel need to be cooled by water, otherwise the temperature of the O-ring is too high and cannot be sealed.
3. Keep the inside of the furnace tube clean and hygienic, and no substances that react with SiO2 can remain in the furnace tube. When burning materials, in order to make the furnace tube have a longer service life, do not put the materials directly on the furnace tube, and use a boat-shaped crucible to hold it (as follows shown in the figure).
4. Be sure to put a ceramic furnace plug in the furnace tube when heating, otherwise the temperature at both ends of the furnace tube will be high, and the O-ring in the flange cannot withstand the high temperature, which will make the air tightness not good. The end is conducive to the formation of a balanced temperature field.
5. When heating, be sure to put alumina plugs in the furnace tube, 2 on one side, 4 in total, and the distance between the inner ends of the furnace plugs on both sides can be about 450mm (because the length of the heating section of the HTL1200 split tube furnace is 400mm), If the furnace plug is not placed, the temperature at both ends of the furnace tube is high, and the O-ring in the flange cannot withstand the high temperature, which makes the air tightness poor. Putting the furnace plug at both ends of the furnace tube is conducive to forming a balanced temperature field .
6. The temperature resistance of the quartz tube is related to its purity. The higher the purity, the higher the temperature resistance.