What is the reason for the high N2 content in the system during polysilicon production?
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What is the reason for the high N2 content in the system during polysilicon production? How should it be solved?
The production system is complex; may I ask which stage does have a high N2 content as referred to by LZ?
Was it not replaced thoroughly during the replacement?
In the hydrogen system, including the pure hydrogen storage tanks, the nitrogen content was analyzed to be 2000PPM; this level rose suddenly after the system had been operating normally for some time, and there was no shutdown of the furnace during that period
It might be a leak in the nitrogen valve or an inaccurate result from the first test
I have been conducting analyses for several days now; the values were around 800 previously, but they suddenly increased. The nitrogen valves we use are all three-valve assemblies, so even if there is internal leakage it doesn’t matter
That further indicates an internal leak; the N2 in the hydrogen tank either comes directly from the hydrogen station or results from a leak in the N2 pipeline； If safety permits, it is recommended to reduce the nitrogen pressure below that of H2 before conducting the test
Or install a temporary pressure gauge between the nitrogen valves; internal leaks should be detectable this way
Check all the nitrogen double valves connected to the system; there is a high likelihood of internal leakage. Whether there is a separate system that can be turned on or off, or whether it is connected to the main system, as well as the inclusion of a new hydrogen compressor in the system, can all lead to an increase in the nitrogen level in the system. Increase the amount of hydrogen supplied and the amount of hydrogen that is vented to see if this will reduce the nitrogen level
We use a three-valve assembly: one valve for the nitrogen pipeline (normally closed), one valve in the system (normally closed), and an exhaust valve between the two valves (normally open). Currently, there are no new devices that have been shut down, so we are increasing the amount of hydrogen supplied and the amount of hydrogen that is vented to see if this will help reduce the problem. This is indeed the method I am using right now