Exhaust gas return duct for engine, made of gray cast iron and provided with ribbed inner and outer pattern

摘要

The exhaust gas return duct (5) connects the exhaust pipe with the air intake of the generator. The pipe (5) is made of a gray cast iron and has circular ribs (11) positioned along its outer surface (10). The inner surface is divided into alternating rings with bigger (12a) and smaller diameters (12b). Each of the rings (12a, 12b) is provided with a row of individual axially positioned stepped ribs (14a, 14b). Each rib (14a, 14b) at one of the rings (12a, 12b) is positioned opposite a plane area at the adjacent ring (12a, 12b).