Patent ID: 8251406

Claim:
A discharge elbow provided with guide vanes, comprising: (a) an elbow of rectangular cross section and magnification f of 1<f≦5; and (b) one or more guide vanes disposed in the elbow, wherein the one or more guide vanes are made of a first curved plate and a pair of flat plates connected to the first curved plate, wherein one of the flat plates is located in front of the first curved plate and the other one of the flat plates is located to the rear of the first curved plate, wherein m number of sub-channels similar to one another are formed in the elbow based on the following formulas (1), (2) and (3), p=h/{[f /( f−r )] m −1} (1), and a n =pr[f /( f−r )] n (2), and b n =a n /f (3), wherein, p is an overhang length at an outlet of the elbow; h is an inlet breadth of the elbow; W is an outlet breadth of the elbow; f is a magnification of the elbow, wherein f=W/h; r is an aspect ratio of the sub-channels, wherein r<f; m is a number of the sub-channels, wherein m≧2; a n is an outlet breadth of an n-th sub-channel, wherein a 0 indicates a radius of curvature of an inner sidewall of the elbow and a m indicates a radius of curvature of an outer sidewall of the elbow; and b n is an inlet breadth of an n-th sub-channel; and wherein the inner sidewall of the elbow is deformed into a second curved plate coaxial with the first curved plate of the adjacent guide vane to deform n=1 sub-channel into a coaxial bend channel provided with a uniform breadth equal to the inlet breadth b 1 of the sub-channel.