Mercury into Power

More successful and profitable than attempts to create gold from mercury is the actual creation of electricity at Hartford, Conn. The Hartford Electric Light Co. has been using a mercury-vapor turbine to run its generators since 1923. That turbine was shut down while last week a second was prepared for operation. William Le Roy Emmet of General Electric Co. invented and developed the machines. General Electric built them.

Steam, or water vapor, operates a piston or turbine by the fall in its temperature. The higher the vapor is heated, the greater the pressure which must be controlled and the work the steam can do. Engineer Emmet sought a material whose vapor could carry great quantities of heat at relatively low pressures. He found mercury the best. It boils at 675DEG F., instead of at 212DEG F. for water. At 884DEG F. pressure is only 70 lbs. on a gauge, at 1,000DEG F. only 180 lbs. Those pressures are sufficient to run turbines. After the hot mercury vapor has done its work by revolving the turbine, the temperature of the exhaust mercury vapor is about 435DEG F., enough to heat water into steam at about 300 lbs. pressure. That mercury-vapor-heated steam operates, in the Emmet machine, a second turbine until its heat falls too low to do more work. Mechanically efficient as the Emmet apparatus is, not many similar plants exist. Mercury vapor is poisonous and it is difficult to prevent its escape.