Shepelenko O. Application of the Impeller Split Blades to Increase the Borehole Screw-Type Pump Stages' Head Pressure .

The increase of the borehole pump screw-type stages' head pressure has been achieved on the basis of the split-bladed screw being applied as an impeller. The obtained solution enables the impeller to increase the circulation difference between inlets and outlets so far as it adds the angular disparity between the first and the second row of blades to the incidence angle, as opposed to a fixed lead screw in the stage head pressure equation. With that the occurrence of an additional hydraulic factor is to be considered in the process of operation that is the occurrence of a high-speed jet which flows out of the gap between the rows of blades and exercises significant influence on the flow structure of the impeller and, as a result, the pump stage's characteristics integrally. The patterns of flow in a screw-type split-bladed impeller have been obtained on the relevant numerical schemes so that the velocity and pressure distribution field patterns in the pump stage can be qualitatively evaluated. The geometrics exerting the most impact upon the energy characteristics of the stage can be identified as well. The main optimal correlated geometrics have been found experimentally which allows increasing the stage's head pressure by 40 per cent as opposed to the initial one under the same affordability and manufacturability terms. The effect of the separate split-bladed impeller's geometrics upon the stage's characteristics has been ascertained which allows optimization in various directions according to definite requirements and specifications. The engineering methodology of the screw-type pump stages calculation considering the operation characteristics of the screw-type split-bladed impeller has been complemented and expanded.