Low-temperature methanol pump seal gas
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Hello everyone. The main methanol pump used for methanol washing in our company is from Fox Fluids, and its sealing gas is low-pressure nitrogen. However, since this pump is located in the pump room, the doors and windows must be closed due to the low temperatures in winter; as a result, the sealed nitrogen poses a risk inside the room. Is it possible to replace it with instrument air?
I don’t think it’s possible; there is always some water vapor in the air, and inert gases are generally used as sealing gases.
This post was last edited by genren on 2012-9-4 14:53. Ah, nitrogen is mainly used to prevent the sealing compartment from freezing; compressed air contains some water anyway, so it wouldn’t be effective. The nitrogen pipes I’ve used were all DN15 in size, and there shouldn’t be any problems with releasing the gas directly~
Since temperatures are low in winter and the pumps are located indoors, the doors and windows must be closed during that season; this sealing of nitrogen leads to a lack of oxygen inside, which may cause inspection personnel to suffocate. The dew point of our instrument air is always below -60 degrees, so there should be no problem as far as freezing is concerned.
Is the main methanol washing pump the pump that discharges material from the methanol regeneration tower? If so, the methanol flowing inside the pump already contains 0.005% water. However, this pump feeds into the initial raw gas heat exchanger; if instrument air is used for sealing and water vapor is introduced, it will increase the moisture content in methanol, which may reduce the effectiveness of the methanol washing process or require an increased amount of methanol to be used. (Linde process)
Is the main methanol washing pump the pump that discharges material from the methanol regeneration tower? If so, the methanol flowing inside the pump already contains 0.005% water. However, this pump feeds into the initial raw gas heat exchanger; if instrument air is used for sealing and water vapor is introduced, it will increase the moisture content in methanol, which may reduce the effectiveness of the methanol washing process or require an increased amount of methanol to be used. (Linde process)
Instrument air contains a small amount of saturated water vapor as well as oxygen, and is not suitable as a sealing gas! A small exhaust fan can be installed!