A Practical Manual On Sea Water Distillation
With A Description Of The Necessary Machinery For The Process

1T4 SEA WATER DISTILLATION. 100. In steam ships, where the steam for the evaporator is taken directly from the boiler, a feed regulator of this description (Fig. 12) is not so much needed as when the steam is taken from the exhaust steam pipes, because the former steam has steady pressure, but the exhaust steam is at all manner of pressures, and the production of secondary water consequently variable ; therefore, an automatic feed regulator would be far more useful. On the other hand, if the feed-water is made very hot before being fed into the evaporator, its quantity, or rather its excess of quantity, is not of very much importance, as little or no heat is taken to heat it, and the quantity of primary water will therefore never be abnormally in excess of the secondary water. 101. The feed regulator, therefore, has two objects— first, it constantly keeps the brine at a proper strength, and secondly, it obviates waste of heat by an excessive feed, when the production of gained water is reduced. Materials Used for Regulator. 102. The boxes containing the floats are usually made of cast iron galvanised, when large, but if small they may be made of gun-metal. The floats are usually made of copper tinned, and should be tested to see they are water-tight. The fittings, such as the branches and the castings for the ferrule holes, should be of gun-metal. The feed regulator is also fitted with two gauge glasses, one to each float box, so that the levels of the sea water and fresh water can be seen without opening the lid. The feed regulator is usually covered with a hinged lid,