HEAT EXCHAGER FOR COOLING REACTION GAS

PURPOSE: To suppress the installation cost of a heat exchanger while keeping good process conditions and cooling conditions by intercoupling outer tubes surrounding a single tube and a jacket surrounding a tube bundle and providing a coupling for supplying or discharging cooling medium. CONSTITUTION: A single tube 1 has a gas outlet side end opening to a distribution chamber 5 defined by a tube plate 6. Tubes 2 in a tube bundle have gas outlet side ends welded gas tightly to the tube plate 6 and a second tube plate 7. In order to discharge cooled decomposed gas, a gas outlet chamber 8 is coupled with the tube plate 7. High pressure water being fed through one or a plurality of inlet side coupling 13 to a heat exchanger is used as cooling medium. The water evaporates by receiving heat from the decomposed gas flowing through the single tube 1, the distribution chamber 5 and the tubes 2 and mixture of water and steam flows out through a plurality of outlet side couplings 14.