Commissioning of the gas separation unit
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Excuse me, is this how gas separation units are normally started up? First, cold propylene is introduced into the propylene column; then pressure is applied to the depropanization column, feedstock is added, the bottom of the column is heated, and the vapor at the top is condensed. This process is repeated until stability is achieved, after which the material is fed into the deethanization column and the ethylene column... Is this the standard way to start up gas separation units? Are there any other ways to drive? Please!
Proceed according to the process: once the analysis of the previous tower is successful, move on to the next tower one by one; feed material to the next tower only after the analysis of that tower is also successful
We also follow the established process: first desulfurization, then washing, followed by gas fractionation. Once the products from each column meet the required standards, we proceed to the next stage of the process. Construction usually takes 2 to 3 days.
Excuse me, it’s still a matter of pressure: the nitrogen with a pressure of 4.0 Mpa used in starting up the project is said to be for \"air-tightness testing\", that is, to check whether there are leaks in the tower It is said that stamping is required before feeding the equipment (because the heat absorbed by the evaporation of LPG can freeze the equipment!) ), but the utility supply only provides nitrogen at a low pressure of 0.8 Mpa. For devices like the “depropanization tower,” the normal operating pressure is higher than 1.0 Mpa. The question now is: how much pressure of nitrogen should be used to purge the equipment?
Generally, the pressure used for gas tightness testing is 1.25 to 1.5 times the operating pressure. The operating pressure of our depropanization tower is 1.85 MPa, while the pressure used during gas tightness testing is around 2.3 MPa.
How is displacement carried out when the tower top cooler is put into use? Should the gas from the reflux tank be used for displacement, or not?
If you use nitrogen displacement, it doesn’t matter; if air is introduced into the tower, it can be vented directly from the top of the reflux tank. If steam replacement is to be used, stop the circulating water flowing into the condenser, empty the tube side, drain the water, and then introduce steam.