AN INTAKE CHANNEL ARRANGEMENT FOR A VOLUTE CASING OF A CENTRIFUGAL PUMP, A FLANGE MEMBER, A VOLUTE CASING FOR A CENTRIFUGAL PUMP AND A CENTRIFUGAL PUMP

摘要

The present invention relates to an intake channel arrangement for a volute casing of a centrifugal pump, the intake channel (12) comprising a first end (54; 540) with a first inner diameter D1 and a second end (58; 580) with a second inner diameter D2, the second inner diameter D2 being smaller than the first inner diameter D1, the intake channel having a cross-sectional flow area and an adapter section (56; 560) arranged between the first end (54; 540) and the second end (58; 580), the intake channel (12) has a first channel portion (50; 500) with a surface (50'; 500') and the first inner diameter D1; and an annular convex curvature surface (S) joining at an angle (±) to the surface (50'; 500') of the first channel portion (50; 500), the angle (±) being in a range of 90° - 110° between the surface (50'; 500') of the first channel portion (50; 500) and a tangent (T) of the convex curvature surface (S) having a tangent point in an intersection (11) of the surface (50'; 500') of the first channel portion (50; 500) and the convex curvature surface (S), the annular convex curvature surface (S) reducing the cross-sectional flow area from the first inner diameter D1 to the second inner diameter D2 and that the first inner diameter D1 is chosen to correspond to a first available standard pipeline inner diameter greater than the second diameter D2. The invention further relates to a flange member for positioning between an inlet pipeline and an inlet flange of a centrifugal pump, a volute casing of a centrifugal pump and a centrifugal pump.