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

48 SEA WATER DISTILLATION. account the above multipliers will not be required. Thus— 1st case, . 946 units of latent heat. Add, . 27 units sensible heat (239-212—27). 973 B.T.U., total. 2nd case, . 927 units of latent heat. Add, . 54 units sensible heat (266- 212 = 54). 981 B.T.U., total. 3rd case, . 889 units of latent heat. Add, . 108 units sensible heat (320-212= 108). 997 B.T.U., total. Feed Temperature. 27. It must be borne in mind that in the above calcu- lations no allowance has been made for waste of heat, nor for the heat required to heat the feed-water up to the boiling point. The object has been to show as clearly as possible the efficiency of various pressures, without being obscured by minor details. 28. In practice, the feed is 1| times the evaporation, and its temperature (as it enters the evaporator) about 150° or more, so that to meet these conditions an ad- justment is necessary. Thus, the feed, being half as much again as the evaporation, there is, first of all, a quantity of 1| lbs. of water to be heated up from 150° to 212°, i.e., 62 x 1| = 93 units + 966 (latent heat) = 1,059 units, in each case, instead of only 966 units, the heat