Study on direct mixing type axial flow cyclone heat exchanger between gas and particles. 1. Proposal and gas-particle separation performance

A direct mixing type axial flow cyclone heat exchanger between gas and high temperature particles is proposed which serves as particle separator as well. The proposal was motivated by the concept of high temperature nuclear energy conversion system for which dense gas-solid suspension flow is considered as primary coolant. However, it may also be used as a general heat recovery device from various high temperature powdery waste material from conventional industry. In this heat exchanger, the particles, after being mixed directly with gas, transfer their heat to the gas in the form of quasi-counter-flow and are effectively re-separated by centrifugal force due to swirling motion of the gas. The mock-up of the heat exchanger was designed and constructed and its re-separation performance was examined both experimentally and numerically, which is the key to realize such innovative energy conversion systems. (author)