Vaporizers, unloading with

Ammonia, when released is a toxic gas with little flammability. It is imported by sea into the 14,(XX) tonnes capacity tank at Shell UK Oil where the refrigeration maintains the temperature below the boiling point of the gas (33° C). Three ways were identified whereby several hundred tonnes of liquid ammonia could be released into the river to vaporize and disperse. The worst accident would have an accompanying explosion or fire on an ammonia carrier berthed at the unloading jetty. Next in order of severity is a ship collision and spillage into the river near the unloading jetty. The consequences of a collision between ships occurring within the area but not near the jetty were also calculated. 

Fig. 2.49.2. Schema of a freeze drying production plant with approx. 20 m2 shelf area. The chamber and condenser are in the same vacuum chamber, separated by a wall in which the valve is built, providing the shortest possible path for the water vapor. The condenser and the brine heat exchanger are cooled by LN2. The condenser surface is made from plates (Fig. 2.49.3), its temperature can be controlled between -110 °C and -60 °C. The shelves can be controlled by the circulated brine between -70 °C and +50 °C. The trays with product can be automatically loaded and unloaded from a trolley. The shelves can be pressed together in one block and the trays are loaded to the shelves by pushing one shelf after another in front of the trolley.

Isolator technology is required especially when processing toxic or anti-cancer products and where the operator and his environment must be protected. An automatic loading and unloading system installed in an isolator system can be CIP cleaned and can be sterilized with vaporized hydrogen peroxide (VHP) (Figure 2.74.1). 

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