Process environment effects on heat pipes for fluid-bed gasification of coal

The Bureau of Mines is evaluating sodium-type heat pipes for the isothermal transport of heat at 2,000 F from a fluid-bed coal-air combustor to a fluid-bed coal-steam gasifier. Tests were conducted to determine the physical and chemical effects of combustion-gasification atmospheres on Inconel 601 pipe. A prototype pipe exposed to such an environment for 522 hours functioned acceptably and remains operable. Tests with this pipe and five pipes of the same design are continuing. Results of initial tests of the six pipes are presented and the pipes and gasification concept are described.