Hi ,Im still a bit of a novice at the industrial ammonia plant that I'm required to operate single handed as one of two shift engineers at a meat freezing works and still getting to grips with the theory of our two stage/pressure system .My main concern is in the event of an electrical failure [happens sometimes here ] after power is restored . Which stage compressors should be put online first and why??
We have combinations of screw and reciprocating type on both high and low pressure stages? we have two "pots' for each stage and operate at 200kpa and 10kpa respectively supplying liquid refrig to both higher and lower temp chillers blast freezers and cold stores. This place is a bit of a museum with lots of "additions" to the plant over about 100 yrs[yes true!] of continuos service . The newest piece of equipment is 1970 howden screw compressor all the way down to 1917 Haslam horizontal recip compressor . So anyone out there that can put up with a green horn ex marine engineer asking basic questions on refrigeration ,Id be most grateful for the help.