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

MULTIPLE DISTILLATION. jgr but the actual results obtained after continued working of the apparatus are the only reliable test of its value. (C) DETAILED DESCRIPTION OF LAND APPARATUS. (a) THE BOILER—Generally. 38. The boiler, being of predominant importance, will be dealt with first. 39. The boiler intended to work with a sea-water feed is the only kind that calls for notice in this treatise. 40. The first thing to be considered is the type of boiler best suited for sea water distillation. As on steam ships distilling apparatus is worked by the greasy steam on board, which, after use, is returned as so much greasy water, the boiler (as part of the distilling apparatus) is of much the same type as that used on land. 1. Type of Boiler. 41. Water-tube boilers, in which the water is evapor- ated inside the tubes, are obviously not suited for sea water distilling machinery ; such a boiler can only be worked if fed with the returned primary water, but this involves the loss of economy already pointed out. 42. The boiler best suited for this purpose is the tank boiler of Cornish or Lancashire type, the former up to a certain size, say 5 to 6 feet in diameter, and the latter of a diameter exceeding 6 feet. A large Lancashire boiler is, of course, more economical in its working than a small one, and the same may be said of the Cornish type, which is also always rather less economical of fuel than the Lancashire boiler of the same power with its double flues. 43. For large installations, boilers of Lancashire or Cornish type are best, but if absolutely necessary, a boiler