This past week a small ice plant in São Luís – State of Maranhão, Brazil experienced what can only be described at a “catastrophic failure” of a pressure vessel. Details of what/how this happened are sketchy at best; however, the video shows us what anhydrous ammonia can do when it is “blocked-in”. I am assuming this is a “blocked in scenario” leading to hydrostatic expansion with improper or isolated relief protection from the video evidence provided. The vessel shows no fire damage so it does not appear to have been involved in a HOT BLEVE. The vessel was stationary so a COLD BLEVE is highly unlikely; hence I am going with the “blocked-in” scenario. The process was NOT in operation at the time of the event, lending more credence to a “blocked-in” scenario. Unfortunately, we may never know what happened or what caused this devasting event, so just accept the facts as we know them at this time.
Some pics: