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

THE DISTILLING CONDENSER. J43 16. In the ordinary surface condenser for condensing the exhaust steam from the engine, the usual allowance is 30 lbs. of circulation water per 1 lb. weight of steam. This would, therefore, involve a larger circulation pump and a smaller amount of surface than above given. Some condenser makers arrange their condensers to work with less circulation water, say 18 to 1. Other makers allow 25 to 1, which is a still greater allowance of circulation water than is stated above for a distilling condenser. Books of reference give other ratios, such as so many units of heat per square foot of surface, but this depends much on circumstances, such as the nature of the cooling surface, its material and thickness, the temperature at which the circulation water enters and leaves, &c. 2. Surface—Condensing and Cooling. 17. The surface to be allowed per square foot depends on so many considerations, that no rule is applicable to all cases. The surface must be sufficient to allow the circulation water to abstract all the latent heat of the secondary steam, and the heat necessary to cool the water produced to the desired temperature. 18. Condenser makers have different rules to work by for the surface they allow. Some makers allow more circulation water, in order to reduce the surface area, and, consequently, the size of the condenser, but this requires a larger pump. Others reverse this, and allow plenty of suiface and a reduced circulation. 19. Sometimes an allowance of 1 square foot of surface (brass tubes) is allowed per 25 lbs. weight of steam, on the assumption that the circulation water is 30 times that of the steam (30 x 25= 750 lbs. of circulation water), and its inlet temperature is 60°.