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

156 SEA WATER DISTILLATION. For the Heater.—The usual requirement is a set of coils, ready for fixing in place. 22. For passenger ships and emigrant ships the spare gear is specified by the Regulations of the Board of Trade, and a list may be seen in Seaton and Rounthwaite’s Pocket-book. («) Cleaning the Apparatus. 23. During work, the evaporator coils are constantly accumulating and shedding scale. This scale may bo raked out through a small mud door, until it is convenient to open out the apparatus for cleaning purposes. 24. To clean evaporator coils—First shut off the prim- ary steam valve, and run off all hot brine by the brine valve ; then fill up again rapidly with cold water by opening the filling cock, and re-admit primary steam to the coils. This will loosen the scale left on the coils. Then empty again as before. 25. Next unbolt and swing off the large cleaning door by its tackle (when provided). Then detach coils separ- ately. 26. Take off small door, and rake out deposits. 27. After cleaning coils, replace them, and, before closing up, test joints, which should be all visible, under pressure. 28. Ihe evaporating coils are generally separately de- tachable, and are readily cleaned and replaced inter- changeably. In a very small apparatus there is generally only one coil to remove. 29. The passages for the primary steam into the evap- orator and the outlet for the primary water to coil drain should be carefully cleaned.