GUIDE DEVICE FOR CENTRIFUGAL MULTI-STAGE PUMP Russian patent published in 2019 - IPC F04D29/44 

FIELD: pump engineering.

SUBSTANCE: invention relates to pump engineering. Guide device of the centrifugal multistage pump contains a disk with guide blades (GB) made on one side of the disk, and back blades (BB) made on the other side of the disk. Each BB is conjugated along the outer diameter of the disk with the corresponding BB with the formation of guide and reverse channels on opposite sides of the disk. Entrance edges GB are located along the circumference (C) with the formation of the input sections of the guide channels, covering with a gap output sections of the channels formed by the blades of the impeller of the pump. In cross section, the GB profile is made with inlet, middle and output sections. Entrance section is made at an acute angle to the tangent to C, along which the entrance edges of the GB are located. In cross section, the entrance edge of each GB is formed by the arc of C, mated with straight lines forming the inlet section of the concave and convex sides of the GB and made at an angle to each other with the formation of increasing in thickness from the entrance edge of the inlet section of the GB. Straight line forming the convex side of the GB, with the radius of C, along which the entrance edges of the GB are located, forms an angle α. Middle section of the concave and convex sides of the GB is formed by arcs of C, with the radius of the arc of C, forming the middle section of the convex side of the GB, 1.7–1.8 times less than the radius of the arc of C, forming the middle section of the concave side of the GB. Output section of the concave side of the NL is formed by a straight line forming with the radius of C, along which the entrance edges of the GB are located, the angle β. Straight line of the entrance section of the convex side of the GB makes with the straight line of the output section of the concave side of the neighboring GB γ with the formation of an expanding along the flow section of the guide channel. Output edges of the BB are located along C with the formation of output sections of the return channels. In the cross section, the output edge of each BB is formed by an arc of C connected with arcs of C forming the output and inlet portions of the concave and convex sides of the BB. Radius of the arc of C, forming the output section of the convex side of the BB, is 2.6–2.7 times greater than the radius of the arc of C, forming the input section of the convex side of the BB. Guide device is designed as a single part with six GB and BB uniformly spaced around the circumference. Radii passing through the input and output edges of each GB, form an angle λ.

EFFECT: invention is aimed at reducing the hydraulic resistance in the flow part of the guide device.

1 cl, 3 dwg