On board commercial shipping
makers are more common then reversed osmosis
units. They are cheaper and require a lot less maintenance
For those unfamiliar with the principle:
A closed steel
bowl filled with feed water
is pulled vacuum til about 0.1 bar absolute pressure. At this pressure water will boil at 45°C. The heat is usual provided by free hot cooling
water running trough a coil at the bottom of the bowl. The water evaporates goes trough a steel
wool filter to stop any droplets caught in the damp stream. On top there is a water cooled pipe cooler and a scale to catch the condensate fresh water. You need 3 pumps, one too remove the brine at the bottom. One to extract the fresh water and one air pump
to get the unit to vacuum. A feed pump
is optional as the vacuum already pulls in feed water and it has to be restricted.
I prefer these units over a reversed osmosis
any time, low maintenance
and high production.
Disadvantage: the water is pure condensate so you need to ad minerals too make it taste proper.
Has anyone ever seen an evaporation unit on a cruiser?
I've been thinking about building one of these and using a sunboiler to provide the necessary heat so you don't have to run the engine
Any ideas, suggestions ?