Linde cryogenic methanol washing
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In the Linde process, why are the inlet and outlet of P3008A/B (exhaust gas washing water pumps) designed as semi-hot pipelines? I look forward to your guidance, senior
This is mainly due to the conditions in the north, so it needs to be semi-hot. Prevent freezing!
The main thing in winter is to prevent the crystallization of ammonium carbonate! Provides heat tracing functionality
Where do the ammonium carbonate crystals you mentioned come from? Where do the ammonium carbonate crystals come from at the inlet and outlet pipelines of the bottom pump in the exhaust gas scrubber tower?
Reply to the original poster: Since the medium in the inlet and outlet pipelines of the P8 pump is water, and the water remaining in the pipelines cannot be completely drained when the pump is shut down, this prevents the pipelines from freezing; therefore, heating is used to prevent freezing! Under normal circumstances, heat tracing should be considered for water pipelines!
If the water in the pipe can’t be drained completely, just add a drain line to the pipe, right? Also, why isn’t the desalinated water entering Tower T3006 semi-heated? Is it available right after leaving the tower?
It is mainly for freeze protection reasons. Generally, low flow rates and low temperatures can lead to freezing ； There are also design-related dead zones; water cannot drain completely in some areas, and freezing may occur there as well! But our flowchart doesn’t have insulation.
Because the temperature of the desalinated water entering the tower is relatively high, at 40 degrees; the dry gas exiting the tower has been washed, so its temperature is lower. In winter, if operations are stopped, the reversal of gas flow within the six towers occurs too late, resulting in even lower temperatures and an increased risk of freezing
It is mainly based on considerations for winter anti-freezing!
I think the main consideration is the exhaust gas scrubber; during shutdown, since there is no medium for heat exchange with the exhaust gas, the temperature of the exhaust gas entering the scrubber is very low. As a result, the temperature of the water used for scrubbing also drops, so steam heating should be applied