Development of a Low-Torque Progressive Cavity Pumps Using Inter-Crosslinking Network Structure Gels

Abstract

Progressive cavity pumps (PCPs) consist of a rotor and a stator. The extrusion process of PCPs is governed by a single-helical rotor which rotates eccentrically within a double-helical stator of twice the pitch length. Between the seal lines (the contact lines of rotor and stator), there are cavities which are constantly moved towards the discharge end of the pump. As one cavity is eliminated, another cavity develops, keeping the cross-sectional area of the cavities constant. The process makes a continuous non-pulsating flow in the PCPs. The developed pushing–and–suction action allows PCPs to exert significantly lower shear rates on the pumped material, compared to other pump types, such as membrane pumps or peristaltic pumps. However, the sliding of the rotor and stator in the pump causes a biting phenomenon [1-3]. Therefore, the destruction of particles in the fluid occurs. In this study, we adopted a flexible, low-friction gels as the stator material. By using gels materials as stator, we could make a pump that could discharge at low torque as previously reported by our group [4]. In this work, the commercial rubber stator and the gels stator were compared and evaluated in a torque test.