Acid seepage at the seal of the backup host enclosure
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Acid is seeping from the seal of the backup host’s enclosure. It’s due to a leak in the inlet and outlet valves – where lies the problem?
What specific equipment, is it a fan?
Recently, our factory has encountered similar problems. I have analyzed the causes as follows: 1. The drying conditions at the inlet of the main fan are caused by moisture, acid mist, and condensed acid. Laboratory tests are used to determine the cause. 2. The system load is too high, resulting in an excessive operating gas velocity in the drying tower, reduced efficiency of the demister, and the carryaway of acid foam.
Is it because the inlet and outlet valves of the backup fan aren’t sealing properly? At present, no valve manufacturer is able to meet the requirements for the sealing performance of large-diameter valves in sulfuric acid environments. We used to use valve switching as well, but now we have switched to using blind flanges.
To switch the fan, the plant has to be shut down and the blind flanges removed; I wonder how it’s possible to reduce the shutdown time so significantly?
The only option is to use a mass approach, by preparing in advance (in terms of personnel and materials) and carefully planning the parking transitions.
I think it’s possible to reduce the time required for removing and installing blind flanges, for example by removing and installing the inlet and outlet blind flanges simultaneously (i.e., removing and installing them twice each), by using orifice plates (which do not have a throttling function) for easier removal and installation, and by having both an orifice plate and a blind flange available at each location.