I have a Centrifugal chiller that was full of water for about six months until the customer decided to call for service to fix it. Did the usual leaking tube replacement, compressor repairs and re-insulated the motor stator. But, now the difficult part is to clean the heat exchanger of all the rust that has formed on the shell surface. I do not want to cut the shell as advised some colleagues and would need advise from Guru's here for any alternative method that will help to rid the shell of maximum amount of rust.

Trenching it out.....