Forced convection boiling of potassium‐mercury systems

Abstract

Many investigations are currently being conducted to obtain forced convection boiling heat transfer information for Iiquid metal systems; however only limited results have been published, and no information is available regarding a binary metallic system.This study was initiated to obtain the boiling heat transfer characteristics of M e r e n t compositions of potasium amalgams. The information is required for the proper design of a thermal regenerator in a liquid metal electrochemical cell system (1 ) . Initial results of the first series of experiments with a 44.5% K (by weight) amalgam were previously reported (2). This paper presents, in addlition to the previously reported data, the results of a second series of experiments with a 44.5% K amalgam and the experiments with a 14.7% amalgam. Studies made with boiling binary systems of water and organic liquids (3, 4, 5) indicate that the critical heat flux for boiling binary mixtures may be higher than that of either component. In addition the boiling heat transfer coefficient of certain compositions reaches a miniirnum value lower than thdt of either component. This finding is in accordance with the theoretical prediction of Sciriven ( 6 ) based upon an evaluation of the bubble growth coefficients. It is therefore conceivable that the same phenomenon may exist in a binary liquid metal system, and the boiling characteristics of pure components can not be used as limits for mixtures of these components.