Hydrorefining is about to be shut down – any questions?
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The unit is to undergo scheduled shutdown; if blind flanges are installed at the reactor’s inlet and outlet and it is protected with nitrogen after the shutdown, is it still necessary to carry out alkali washing? How should the reactor outlet pipeline up to the cold high-pressure section be handled? If alkaline cleaning is required but there is no alkaline cleaning line, what should be done?
If I remember correctly, the purpose of alkali washing is to prevent corrosion by polyoxysulfuric acid. Our unit was shut down for maintenance last year; no alkali washing was carried out, but nitrogen was continuously supplied to maintain a slight positive pressure.
It depends on what you need to do for parking and maintenance. If the reaction system doesn’t require maintenance, nitrogen is filled into the system, and then a blind flange is installed. If maintenance is required, replacement and purging must be carried out; the specific procedures depend on the process, and it must be separated from the distillation system.