JLSeagull
Electrical
- Feb 19, 2006
- 2,070
One topic posted pertains to flow measurement in a cold flare line. Many new measurement technologies exist that eliminate problems within industry. However, plants have implemented many installations in cold service where the instrumentation is not rated for the temperature.
Most engineers and designers have used siphons on steam installations that permit condensation to separate the steam from the instrument. Similar concepts apply to cold service too. Simply using long impulse lines can permit the ambient to warm the tubing. Typically a differential pressure transmitter is limited on the cold side to about -40 degrees. One differential pressure level measurement example includes the transmitter mounted a few feet above both taps. The liquid line works as a bubbler to sense the pressure while the vapor above the liquid is warmed by the ambient. Some may coil the tubing on such installations. I have seen this sort of installation in Demethanizer level for gas plants and ethylene units. Such design temperatures are about -150 degree C, too cold for standard practices. Air separation installations are actually cryogenic.
What are examples of installation methods for cryogenic service that accommodate old technologies and examples of new technologies that eliminate problems associated with cold/cryogenic applications?
Most engineers and designers have used siphons on steam installations that permit condensation to separate the steam from the instrument. Similar concepts apply to cold service too. Simply using long impulse lines can permit the ambient to warm the tubing. Typically a differential pressure transmitter is limited on the cold side to about -40 degrees. One differential pressure level measurement example includes the transmitter mounted a few feet above both taps. The liquid line works as a bubbler to sense the pressure while the vapor above the liquid is warmed by the ambient. Some may coil the tubing on such installations. I have seen this sort of installation in Demethanizer level for gas plants and ethylene units. Such design temperatures are about -150 degree C, too cold for standard practices. Air separation installations are actually cryogenic.
What are examples of installation methods for cryogenic service that accommodate old technologies and examples of new technologies that eliminate problems associated with cold/cryogenic applications?
