This picture is a simple flow chart of dry gas sealing. What is the significance of the measured pressure difference drawn in the picture?
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The compressor adopts a series labyrinth dry gas seal. The secondary sealing gas and isolation gas are sealed with nitrogen. The primary sealing gas is medium gas or nitrogen. The pressure difference circled in the figure shows the isolation gas injection, and the pressure difference on the gas side of the isolation gas is measured! Does this detection of pressure difference have any practical significance? Thank you sea friends!
It is considered to be the pressure difference of the filter. An increase in pressure difference indicates that it is time to replace the filter element.
1. The purpose of the isolation gas is to isolate the gas leaked from the secondary seal from the bearing box to prevent the leaked gas from the secondary seal from entering the bearing box and destroying the quality of the lubricating oil. 2. This design is more sophisticated. The calibration of the pressure gauge is measured at standard atmospheric pressure to ensure the isolation air pressure at different altitudes and atmospheric pressures. If the compressor is operating below sea level, the atmospheric pressure at this time is relatively high (if the atmospheric pressure at this time is 150kPa), then the pressure of the isolation air also needs to be increased to 200KPa to ensure that the leaked gas is discharged from the compressor body. ； If the compressor is running several kilometers above sea level (assuming the atmospheric pressure is 50kPa at this time), only a very low gas pressure of 100kPa is needed to discharge the leaked gas from the compressor body.
What was said upstairs is very specific, that is, to ensure that the isolation air pressure is 58KPA higher than the secondary exhaust pressure. I would like to ask which manufacturer your unit is from.
Dresser-Rand Dresser-Rand Machinery Equipment Co., Ltd. USA
The filter has a separate pressure line to display the pressure difference!
The purpose of the isolation gas is to prevent lubricating oil from entering the dry gas seal, right? Can nitrogen go into the bearing box? What I have seen before is that the remote pressure on the isolation gas is higher than the pressure in the lubricating oil main pipe! Now I am measuring the pressure difference, which is a bit unclear!
Another question is that according to the second explanation, the nitrogen pressure is about 0.6Mpa (gauge pressure), the isolation gas injection pressure is about 58kpa higher than the atmospheric pressure, plus the atmospheric pressure is about 0.158Mpa, the current operating lubricating oil pressure is about 0.25Mpa! Is it possible for lubricating oil to get into the dry gas seal? The previous unit control was to control the pressure behind the isolation valve at about 0.3Mpa, but there was no such pressure difference control!
This is to control the amount of leakage. The greater the differential pressure, the greater the leakage. Interlocking regulating valve control.
The ultimate purpose of the isolation gas is to discharge the mixed gas to the atmosphere.