Purification Technology Edition Daily Question (Short Answer) [2018-2-1]
Thread Content
For low-temperature methanol washing units, what should be done with the raw gas when operation is suspended? 1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate ； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the stripping nitrogen supply to the stripping tower, and stop the compressor (it can remain operational depending on the situation). Depending on the length of time the vehicle has been parked, it is determined whether to proceed with the scheduled parking procedure.
1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the stripping nitrogen supply to the stripping tower, and stop the compressor (it can remain operational depending on the situation). Depending on the length of time the vehicle has been parked, it is determined whether to proceed with the scheduled parking procedure.
Answer: 1) Close the inlet and outlet system shut-off valves, and close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the stripping nitrogen supply to the stripping tower, and stop the compressor (it can remain operational depending on the situation). Depending on the length of time the vehicle has been parked, it is determined whether to proceed with the scheduled parking procedure.
1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the stripping nitrogen supply to the stripping tower, and stop the compressor (it can remain operational depending on the situation). Depending on the length of time the vehicle has been parked, it is determined whether to proceed with the scheduled parking procedure.
1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol valve for spraying paint ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are routed to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the nitrogen supply to the air lift tower and shut down the compressor (it may continue to operate depending on the situation). It is determined whether to continue with the scheduled parking procedure based on the length of time the vehicle has been parked.
1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the stripping nitrogen supply to the stripping tower, and stop the compressor (it can remain operational depending on the situation). Depending on the length of time the vehicle has been parked, it is determined whether to proceed with the scheduled parking procedure.
1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) The system continues to operate at its minimum circulation rate.
1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the stripping nitrogen supply to the stripping tower, and stop the compressor (it can remain operational depending on the situation). Depending on the length of time the vehicle has been parked, it is determined whether to proceed with the scheduled parking procedure.
1) Close the inlet and outlet system isolation valves; close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Continue operating at the minimum system circulation rate
Answer: 1) Close the inlet and outlet system isolation valves, and close one of the stop valves as appropriate； 2) Close the liquid ammonia inlet stop valve of the ammonia cooler, and close the methanol spray valve ； 3) Contact the dispatcher to stop feeding gas to the sulfur recovery unit, and vent the system. The sulfur recovery unit is shut down, and the acidic gases are diverted to the flare ； 4) Keep the system operating at its minimum circulation rate; use nitrogen to pressurize it when the pressure is low ； 5) Stop the stripping nitrogen supply to the stripping tower, and stop the compressor (it can remain operational depending on the situation). Depending on the length of time the vehicle has been parked, it is determined whether to proceed with the scheduled parking procedure.
1. Close the on-site coarse valve and the main clean gas valve. Pressurize with medium-pressure nitrogen. 2. Stop the gas supply and release nitrogen. 3. Pay attention to the operation of each pump and adjust the liquid levels accordingly. 4. Stop spraying methanol. 5. Reduce the methanol circulation rate to 50% and maintain methanol circulation. Decide whether to initiate the methanol shutdown cycle based on the parking time length