Mercury for the Generation of Light, Heat, and Power

Abstract

Abstract This paper outlines the principles upon which the mercury boiler was first developed and tested in a small unit in 1912. Many difficulties were experienced in units built in succeeding years, the full importance of which was not apparent until the two 20,000-kw units at Schenectady and Kearny were placed in operation in 1932 and 1933, respectively. The major problem from then on was the elimination of mercury attack on the steel tubes, which after short periods of operation became plugged with an iron crystalline deposit. As a result of extensive research, a mercury-sodium-titanium amalgam was discovered which solved the problem of dissolution of the steel. This development combined with the exclusion of oxygen from the boiler, piping, and valves greatly improved the situation. The final solution came in the redesign of the Schenectady plant in 1937 and the construction of an entirely new mercury-vapor unit at Marcus Hook in 1939, in which magnesium and titanium were used in the boiler mercury. Details are also given of the more recently rebuilt plant at Kearny, incorporating all known improvements. This unit, producing 21,000 kw per hr from the mercury turbine and 30,000 kw per hr from by-product steam, operates on 0.5 lb of fuel oil per kwhr. During more than 15 months of operation, this boiler has carried an average hourly load of 205 per cent of the national average for steam-generating units for 1940.