SOAP AS CONDENSER

Otago Daily Times, Issue 22504, 23 February 1935, Page 18

SOAP AS CONDENSER

LESSON FROM A MIRROR ENGINEERS’ DISCOVERY. Mirrors and window panes are coated with a'film of moisture on frosty mornings. The surface of the glass is cold and the moisture somewhat warmer. Considering this explanation, three German engineers did a little reasoning. They were interested in condensing steam alter it had done its work in the engines of a powerhouse or of a steamer. Engineers want enormous surfaces for condensation at the exhaust end of a turbine. High heat at the entrance, the lowest possible temperature at the exhaust—such is their technical ideal. “ Temperature drop,” they call it. As in the case of a waterfall, the greater the fall in temperature in running a power plant, the higher the efficiency. Hence the importance of the condenser at the exhaust end.

It occurred to these engineers that, instead of letting the steam from an engine collect in the form of a film which would wet the outer surface of tubes through which cold water Is pumped, they might obtain better results if they applied the household mirror lesson. Drs. T. B. Drew and W. M. Nagle, two American engineers, agreed and thought that good results could be obtained with soap as a coating for condensing surfaces. Drew and Nagle found that after they had been washed with soap copper and brass surfaces were better drop collectors. The active agents turned out to be oleic and stearic acids, the important ingredients of most soaps. A mere trace of either acid on copper, brass, nickel or stainless steel was enough to increase the misting of a surface. Moreover, the acids could not be easily washed off. Now Drew and Nagle see the possibility of reducing the size of the surface condensers of steamships and power plants by one-third to a half.