The Malone Liquid Engine
Virtually all prime-mover engines work with gases (such as hot-air engines) or gas and liquid. (such as steam engines) There have also been solid-expansion engines based on the expansion of solid material. But in one unique case, liquid alone was used; the expansion of water when heated under high pressure was used to drive a piston. Behold the Malone liquid engine:
Left: Malone's first large liquid engine: 1925
Malone experimented on the the thermal-expansion coefficients and compressibilities of a range of liquids, including mercury, liquid carbon dioxide, liquid sulphur dioxide, and various hydrocarbons. However he, no doubt wisely, choose water as the operating fluid for his liquid engines.
The following description is taken from Time magazine for Monday, 3rd August 1931:
"By surrounding two cylinders with high pressure boilers, by filling the boiler coils with water and then sealing them hermetically, Engineer J. F. J. Malone of Newcastle-on-Tyne, England has made an effective heat engine. Last week he demonstrated it.
"A furnace heats the base of one boiler-cylinder to 900°F. (688° above water's normal boiling point). The superheated water expands (but cannot change to steam because it is too closely confined) and pushes a piston at the far end of this cylinder. Cold water or air, applied against the piston end of the boiler, cools the confined water sufficiently to make it contract and suck the piston back to its original position. The external cold water or air is shut off, the cooled water in the boiler coils passes into the second cylinder, and newly heated water comes from the furnace to push the piston of the first cylinder again. Thus heat energy carried by the water changes to mechanical energy in that piston.
"The cooled water which left the first cylinder for the second is still much above the boiling point. It carries a certain amount of heat energy which it transfers to the second piston upon its being cooled and contracted a second time.
"After the second cooling the confined water returns to the furnace for reheating to 900°. The circulation of the water through the coils of the two cylinders is on the same principle as the circulation of water through the radiators of a residential hot-water heating system. Heated water rises from the furnace; cold water drops to the furnace.
"Claimed thermal efficiency of the Malone engine is 27%. Superheated steam locomotives are 8% efficient; steam marine engines 14.7%; gasoline engines 26%,; Diesels 47%. Once filled the Malone engine needs no more water for long periods of time."
This describes what is essentially a Stirling-cycle hot-air engine with the air replaced by water, which is kept under such high pressure that it cannot boil even at the high temperatures used.
There seems to have been little contemporary interest in the idea, and Malone appears to have abandoned work on his liquid engine in the mid 1930's, turning his attention to a regenerative gas machine. To this end he formed the The New Engine Company Limited.
Interest in the Malone cycle disappeared for decades but then revived; in the 1970's John Wheatley at the University of California resumed the study of liquid-based engines. In 1992 the Los Alamos group was working on refigeration cycles based on Malone's work. using liquid carbon dioxide as the working fluid.
BIOGRAPHY OF JOHN MALONE
John Fox Jenkins Malone was born in Wallsend on Tyne, England in 1880. He served at sea with the merchant marine for foutreen years, during which period he was apparently wounded seventeen times in Arab and Latin-American wars. Having no doubt got fed up with this, he abandoned the sea and founded the Sentinel Instrument Company in 1912, and later the Fox Instrument Company. He died on the 16th of June, 1959.