Let’s discuss how to address the high temperature of exhaust gases in the reduction furnace
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The exhaust gas temperature in the reduction furnace is high; how can this be resolved? Do any experts have any good methods?
It should be the same as the case with boilers and heating furnaces. Reduce the air intake volume and close the exhaust valve.
High exhaust gas temperatures in the reduction furnace generally occur in the middle to later stages; during this period, the silicon rods grow larger and the feed rate increases, resulting in higher exhaust gas temperatures. You can try to reduce the feed rate and current at later stages, control the feed temperature, and at the same time check whether the flow rate in your jacket water (bell jar water, base plate water, exhaust pipe cooling water) system is sufficient. Excessively high exhaust gas temperatures may cause silicon powder to be generated in the exhaust gases and carried into the recycling process. Polysilicon reduction deposition is relatively well-developed in China; you’ll understand it after observing it a few times.
Is there a better way for cooling the exhaust gas jacket? Currently, we use chassis water cooling for our exhaust pipes. . .
Check the exhaust pipe for blockages; for reference only
At present, there is no better way to ensure sufficient feed and current flow rates in order to maintain production efficiency; this is what leads to high temperatures at the gas outlet. A jacket is used for cooling in order to ensure the safety of the materials. You should understand that this cooling is not intended to reduce the temperature of the process gas to a certain level – its main purpose is to protect the materials in the outlet pipes from such high temperatures. It is not about achieving optimal heat exchange effects, so having a properly designed jacket is more important than using cooling water.
It’s quite good; I’ve benefited a lot from it. :)
How is the process controlled? Inlet temperature and outlet temperature are two very important parameters; if even the outlet temperature cannot be controlled, then the working conditions are extremely dangerous. There have been cases of explosions in CVD furnaces in China
Yes, it’s important to control the exhaust temperature properly :)
Silicon accumulation in the exhaust pipe affects heat exchange; as the furnace temperature rises over time, so does the exhaust gas temperature. However, there should be a balance point, and the specific situation needs to be analyzed on a case-by-case basis.
Only Dunan Company uses upper and lower furnaces, and it even rewarded the inventor with 5 million yuan – such a foolish company that insists on proceeding with projects even when there are difficulties, or creates difficulties just to keep going