Читать книгу Agitator Design for Gas-Liquid Fermenters and Bioreactors - Gregory T. Benz - Страница 78

I am adding this in the hopes it may amuse readers as well as to forewarn them about a potential hazard involving holdup. A project team I led designed a fermentation system for a 250 m³ working volume fermenter (full volume about 350 m³) that was designed to have up to 1.5 VVM of airflow and was equipped with a 750 kW agitator. The projected holdup based on the working volume was close to 40%, or 100 m³. During mechanical commissioning, the customer test crew decided to fill the tank with water to the brim and then start it up with 100% airflow and agitation. Luckily, they left the manway open! Within seconds of start‐up, we estimate that about 100 m³ of water, with a whole lot of entrained air, came out of the manway and hit the ceiling, then rained down on structures and people below. Fortunately, there were no injuries, though a few people got very wet. Had there been anyone looking into the manway or even on the catwalk close to the manway, serious injuries, or even a fatality could have occurred. So, test your fermenters at the operating volume, not with a full tank!