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

THE STEAM PUMP. 153 1909, ozone is obtained in large quantities by means of the silent discharge of electricity which passes between the poles of a powerfully charged magnet. The process appears to be recommended in combination with filtration. Whether it will be useful in removing the taint and odour of distilled water remains to be seen. (b) The Steam Pump. 9. The steam pump, usually included with the dis- tilling apparatus, is made to combine several functions; it generally acts (1) for circulation, (2) for fresh water, and (3) for brine, thus making it of triple-function. The evaporator feed may be supplied to the evaporator by gravitation, but if the evaporator is working at a pressure, there must be another pump (4) to force in the feed-water. 10. In Admiralty ships it is now the practice to divide the pumps of each set of distilling apparatus into two machines—viz., one machine consisting of the circulation and fresh-water pump, while the other machine deals with the evaporator feed and brine. This is a suitable arrange- ment, as the brine and feed-waters can thus be kept at a constant ratio. 11. The Board of Trade rules require that the circula- tion pump should be available as a fire-pump in case of emergency. 12. The pumps should be of the best make throughout. All parts coming in contact with water, such as valves, valve-boxes, plungers, and barrels, should be of Admiralty quality gun-metal. It is well to allow a good margin for the capacity of all the pumps. The pumps should be fitted with suitable relief valves, and air vessels of specified capacity—that is to say, twice the capacity of the pump.