Problems with the methanol wash startup pipeline
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We use the Linde five-tower process with liquid nitrogen washing. What should be done in the event of an emergency shutdown when the feed lines cannot be opened, that is, when valve A or valve B will not open? Please give me some advice!
We haven’t encountered this situation yet, but it is dangerous if it does occur; the pressure in the system can be stabilized by releasing air after making a change.
So where is the pressure from the methanol wash high-pressure system released? If it is vented after the transformation, it will cause too much damage to Tower T01!
Let me ask a basic question: what is the purpose of driving pipelines?
It’s fine as long as it’s detected in time; close the valve that leads to the methanol wash unit, and vent from after the converter. Maintain pressure in one tower, contact the instrumentation team, and vent through the safety valve bypass while paying attention to controlling the rate of venting；
1. Pressure can be released from the upstream process. 2. It can also be released via the redundant safety valve of the low-washing main scrubber tower
I’ve never encountered this issue before, but in our plant there was a situation where the large valve used for feeding low-methanol wash suddenly closed, causing the pressure in the upstream system to rise rapidly. The vent valves couldn’t relieve this pressure either, so the only option was to initiate an emergency shutdown.
It is possible to request the gas generation or shift system to be vented.
1. In an emergency, find a way to force the valve open. 2. Generally, the feed gas is vented in the shift unit. 3. Either those two valves are interlocked. In fact, the valves for controlling the flow of fluid should be designed in the DCS to allow for manual \"intervention,\" so that the valves can still be opened even if interlocks are activated.