Start the furnace with nitrogen or hydrogen?
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Please discuss whether it is better to start the furnace with nitrogen or hydrogen Are there any key factors?
If both nitrogen and hydrogen are pure, either one will work; but when neither is pure, hydrogen should be given priority. It depends on whether you are using products at the electronic level or at the solar energy level
If hydrogen is chosen to start the furnace, what pressure inside the furnace is appropriate?
Nitrogen can still be used when starting up the furnace; you’re really a genius. Some people are even afraid to use a little nitrogen during furnace startup, so don’t mislead them
Hydrogen is used for starting and operating the furnace to prevent the introduction of impurities
Study the operating procedures carefully; generally speaking, they are relatively accurate.
There shouldn’t be any manufacturers that use nitrogen yet, mainly due to considerations regarding product quality :)
After checking the airtightness with nitrogen purging, hydrogen is introduced for displacement.
If the furnace is started with nitrogen, after the silicon core becomes red-hot, vacuum pumping and gas replacement are still required.
Generally, after purging with nitrogen during pressure testing, hydrogen must be used for displacement before the furnace can be started
If the furnace is started with nitrogen, introducing hydrogen at such high temperatures will cause nitrogen to react with hydrogen to form ammonia, thereby introducing new impurities. Therefore, the furnace cannot be started with nitrogen.
Starting a furnace with hydrogen is a very common practice, and whenever it’s possible to use hydrogen for this purpose, nitrogen is avoided; however, this doesn’t mean there are no cases where nitrogen is used for starting the furnace. As far as I know, there is one such example. Also, at the beginning of operation the temperature inside the furnace is not high, so the senior colleague upstairs said that ammonia formation is basically impossible.
What do you mean by starting the furnace? If it refers to plasma initiation, there are more than one manufacturer in China that uses plasma to break down silicon cores in a nitrogen atmosphere
It seems that nitrogen and hydrogen cannot produce ammonia in this state