Hot water or vapour at low pressure, whichever the means used, goes through the “U” tubes of the heat exchanger placed on the lower part of the unit a. At this point the engine cooling sea water loses about 7°, enough heat to produce fresh water suitably.

The cooling sea water, sent by the pump, goes through the condenser tubes, placed on the upper part b.

A small amount of water coming out from the condenser passes through the valve of feeding water to the generator. The level of feeding water is automatically maintained by means of a level baffle above the exchanger tubes. The rest of water flow produced by the pump goes through the ejector generating vacuum inside the body of the generator and takes the waste brine from the equipment.

The heat exchanger rises the water temperature surrounding the tubes about 46°C, at this point, due to the vacuum effect, the water begins boiling. This low boiling temperature helps to minimize the formation of calcareous deposits. The vapour produced rises to the upper part of the casing going through the monel screen separator (demister).

Water drops are coalesced in the lower part while pure vapour goes through the demister. Vapour gets condensed when in contact with the cool condenser tubes. A tray placed under the condenser collects the distilled water drops produced by the generator constantly.
The extracting pump sends the water produced from the generator to the storage tank.

The salinometer analyses the whole water produced by the equipment, and checks that only pure water is kept in the tank, showing the total amount of disolved solids in water in p.p.m.

Supposing that the amount of disolved solids in water exceeds 4 p.p.m., the two-way solenoid valve will be electrically opened, sending the impure water to the bilge.