Answers to the problems encountered in the use of high temperature muffle furnace
Time：2019-09-24 08:56 Click：
The high-temperature muffle furnace is used in industrial and mining enterprises, university laboratories, research institutes, etc., mainly for chemical analysis, physical determination, ceramic sintering, etc. In the process of using, some small problems may often appear. Sometimes a small problem may cause our experiment to fail. How to solve some common problems? Today, our Zhengzhou Kejia electric furnace will give you a detailed answer.
1. What is the error of the muffle furnace at 200 degrees?
Answer: The temperature control error of the muffle furnace is mainly due to the poor airtightness and the large temperature distribution in the furnace. Sometimes the temperature difference between the innermost and near furnace door can be more than 50 degrees. This is also related to the thermocouple model. Some muffle furnaces are accurate at high temperatures, and some are accurate at low temperatures.
2. Why does the temperature controller of the muffle furnace keep heating up?
Answer: It is normal for the muffle furnace to exceed the set temperature by 15-20 degrees. During the heating process, the ammeter will drop to zero for a while and the display will be normal. If the set temperature is too high, it will automatically cut off the current to cool down. If the temperature is lower than the set temperature, the program will automatically replenish the current to increase the temperature. If the temperature exceeds 50 ℃, you need to pay attention. In addition, if it does not drop after one hour, it is possible that the place where the thermocouple is connected is about to burn. It is recommended to check it.
3. How to fill the vacuumized muffle furnace with nitrogen?
Answer: Generally speaking, nitrogen is not too dangerous, but the pressure you charge should not exceed the withstand pressure of the furnace. If you use a general rubber hose instead of a metal tube to connect the nitrogen cylinder to the furnace body, first open the valve between the pressure reducing valve and the furnace, and then open the pressure reducing valve, because the general pressure hose is only 15 If the kilogram of pressure resistance is connected to the cylinder and not passed into the furnace, it is afraid that the pressure tube will burst.
4. How to pass nitrogen protection when using muffle furnace as catalyst carbonization?
Answer: If you simply burn off the organics and retain the active components/carriers, you can use an ordinary Maffei furnace; if your catalyst is not protected by nitrogen, the active components/carriers (such as activated carbon) will be destroyed, so you must Protect the furnace with nitrogen. Or according to your conditions, "nitrogen protection 600 degrees for 8 hours" can be burned in a tube furnace.
5. When calcining copper nitrate in a muffle furnace, do the crucibles used need to be covered?
Answer: For samples that will evaporate during calcination, the lid needs to be covered during calcination, but for samples that do not volatilize during calcination, you can choose not to cover the lid. For the copper nitrate sample, its melting point is 114.5 degrees, and decomposition will occur at 170 degrees, so the calcination temperature should not exceed 170 degrees. It is best to cover the lid when calcining over 114.5 degrees to prevent waste of the sample.