There is a Propane Import - Export terminal which comprise:
- Jetty facilities; Tank Cargo.
- A main transport line 20” from the dock to refrigerated tanks at -42 °C, 2 km long.
- Pumps facilities to transport trailers, suction line 20” (300 m long) and discharge line 8”.
- Pumps facilities to tanker, suction line 36” (300 m long) and discharge line 20”.
Since tank cargo comes to the dock once a month, it is not recommended hold refrigerated propane in the 36” suction line, we are not sure altogether about the best solution for draining these lines, we have been thinking about the following solutions:
- Flushing the line with N2 and recycling refrigerated Propane to the storage tank, we find that pumps are not required because N2 could be injected with enough pressure to displace the liquid.
- Flushing the line with N2 and send Propane to another refrigerated tank where the liquid would be pumped to the storage tank.
We are not sure that these solutions could be the best, and low risk.
Could anybody tell us, if there is or are another or better solution? or if These solutions could work?
It is not necessary to drain another pipes since the plant has another facilities to do so.
For the best understanding, I attached some process sketches for solutions 1 and 2.