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

6; CHAPTER VI . THE EVAPORATOR. (A) General Outline—Steam Coil. 1. The term evaporator, as before-mentioned, is mostly applied to an apparatus which generates steam from sea water by the agency of steam heat, as distinguished from fire. Evaporators, therefore, are constructed with a coil or other form of heating surface, so arranged that steam, of a desired pressure, shall pass into the coil and then give out its heat to the surrounding sea water contained in a shell or casing. The steam inside the coil (called for convenience “ primary ” steam) in the act of giving up its heat, is itself condensed into “ primary water,” whilst the sea water is evaporated into steam (called for convenience “ secondary ” steam), and the saline matter is left behind. 2. Only a suitable part of the sea water is evaporated, and the portion that is not evaporated (usually called “ brine ”) is thus rendered stronger by the salinity of that portion which lias been evaporated. 3. These are the main outlines of an evaporator, but connected with this is the method of supplying such primary steam to best advantage—i.e., as to its pressure, and as to the discharge of the primary water from the interior of the coil, also as to the best manner of feeding and brining the evaporator, and many other points of a like nature, as to which various makers of evaporators have their own system. On main points, however, their