FIELD: mechanical engineering; ambient air delivery to centrifugal fan impeller. SUBSTANCE: inlet bell has conical inlet portion 12, 21 tapering towards impeller 15, 24 and neck 13,22 connected with inlet portion. Ring-shaped flow guide 16,23 is placed in point of intersection between inlet portion and inlet bell neck. Ring-shaped guide is formed inside neck 13,22 by bevelled end of inlet portion. The latter is partially fitted in neck. In second design version neck is made conical. Ring-shaped guide is made in form of edge 23b formed in place of butt joint by smaller bases of inlet portion 21 and neck 22. Angle between walls of two members is at least 230 degrees. Edge 23b serves to provide division of flow coming out of inlet portion of bell with minimum perturbation of flow. EFFECT: provision of non-expensive bell with good performance characteristics. 9 cl, 8 dwg
