| 摘要 |
PROBLEM TO BE SOLVED: To reduce the adhesion of soot to pipe wall surfaces and thereby to secure stable heat transmission performance over a long period even in an operation region having a small exhaust gas flow rate. SOLUTION: Projecting ribs 45 for hastening the flow of an exhaust gas flowing along the tube wall surface 49 and for forming an eddy current are discontinuously formed in plural tubes 29 for heat exchange mounted in a heat exchange body 23 along their circumferential direction, and a current having a high flow velocity is formed by the eddy current even in the operation region having the small exhaust gas flow rate, so that the adhesion of,soot to the tube wall surface 49 is prevented. |
