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

66 SEA WATER DISTILLATION. pose. Thus, if 1 lb. of water at a certain temperature requires, say, 1,000 B.T.U. to convert it into 1 lb. weight of steam, and 1 lb. of a particular fuel is capable of im- parting, say, 10,000 B.T.U. when burnt, the ratio will be one of fuel to ten of distilled water. Heat from Coal, &c. 25. It should be mentioned that the results obtained by Dulong (stated on p. 53) are not quite the same as those of some other analysts. Thus in burning hydrogen no more than 39,000 to 42,000 B.T.U. have been obtained, against Dulong’s 62,535 B.T.U., by some analysts, whilst other reports practically agree with Dulong’s analysis. Economy of Working. 26. The “ economy ” of working distilling machinery is the amount of distilled water that can be produced by the fuel used or consumed—i.e., weight for weight. There are, therefore, two points to consider—1st, the efficiency of the distilling apparatus, and 2nd, the heating power of the fuel. The heating power of various fuels has just been dealt with in this chapter, the efficiency of the dis- tilling machinery will be dealt with as we consider the different types of apparatus.