Dry gas seal air supply system equipment setting issues
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Masters, give me some guidance: The centrifugal compressor is equipped with a dry gas sealing system: the primary and secondary sealing gas generally passes through the regulating valve first, and then passes through the filter to each sealing point. There will be a pressure drop after passing through the filter. Is it more reasonable to install a regulating valve after passing through the filter? Please give your opinion?
It doesn't matter whether the pressure regulating valve is placed before or after the filter. It mainly depends on the location of the pressure measuring point. If the air supply pressure required by the dry gas seal system is very strict, the pressure measuring point should be placed immediately before the inlet seal.
In principle, it is possible. If the gas is relatively clean, you can filter first and then adjust the pressure, or adjust the pressure first and then filter. The problem is not big. It is just that the pressure level of the instrument selection may be different. However, for circulating hydrogen units (especially units with many heavy components) and typical units such as carbon dioxide, it is recommended to adjust the pressure first and then filter, because the Joule Thomson effect of the regulating valve must be considered. In this way, even if the temperature drops after decompression and the condensation is caused, it is relatively safer after filtering.
Nowadays, the dry gas seal of the pump is brought together with the pressure gauge itself, so there is no need to consider these issues. However, during use, it is found that the effect of placing the regulating valve at the back is better.
Yes, there will be liquid entrainment after the pressure is reduced, so the filter needs to be placed at the back