This research presented the experimental study of improving flow
conditions in pump-sump provided with an axial or mixed pump, and
vertical suction pipe, to ensure reducing the minimum needed
submergence of the sump. A physical model of rectangula
r shaped pumpsump
had been studied, with a scale 1\10 , according to Froude Model.
Three modifications had been added, including: floating element, conical
element, and the third one consists of both of them. The flow had been
watched for vortices observation whether surface or subsurface.
Piezometric pressures had been measured at eight points, distributed
equally on the suction pipe perimeter near pump impeller, in addition to
swirl degree measure near pump impeller too. The results showed that the
floating element, set behind the suction pipe, is the most appropriate and
most effective solution to reduce the submergence in pump-sump in way
which the other hydraulic criterions, which control the flow stability
towards the suction pipe in the sump, don't be affected negatively.
