HEAT-EXCHANGE TUBE FOR HEATING BOILER Russian patent published in 1999 - IPC

FIELD: heat-power engineering. SUBSTANCE: heat-exchange tube consists of cylindrical steel smooth-wall outer tube 1 with profiled insert 2 inside it. Insert 2 is formed by two half-ferrules 3 and 4 entering each other by their longitudinal edges due to recesses 7 and projections 8. Both half-ferrules 3 and 4 have longitudinal fins 5 on their inner surfaces which are so positioned that each half-ferrule forms profile together with its fins which is open on one side. EFFECT: intensified exchange of heat and facilitated manufacture of tubes. 7 cl, 3 dwg