FROM TUBES TO PLATES

摘要

There was a small celebration in the Alfa Laval freshwater distiller factory near Copenhagen, recently. This was because plate type distiller number 10 000 had just rolled off the production line. The unit was a DPU-36-C100 model with Grade 1 titanium plates and capable of producing 30m~3 of fresh water per day. It has now been installed in a 62 000dwt containership in service for a European shipping line. Freshwater is a crucial commodity aboard all ships and freshwater distillers have been in use for many years ― Alfa Laval began making them in 1955, although development of its present type of plate distiller started in 1967. Essentially all freshwater distillers use the same basic technique. Seawater runs over a heated surface inside a vessel that is under vacuum and then some of the water evaporates and is condensed either within the vessel or in a subsequent condensing stage. Normally, distillers use waste heat sources such as hot water in cooling circuits or low-pressure steam as the driving energy.