Avaliação do escorregamento em bombas de cavidades progressivas com dados de teste de bancada

Abstract

The Progressive Cavity Pump (PCP) was proposed by Rene Moineau in 1930, from the principle of creating helical volumes formed between rotor and stator surfaces, in which the number of stages determines the pressure capacity. When the system pressure exceeds the pump's sealing limit, available for a stages number, there is a flow reduction which is called slip, which implies in the reduction of flow and volumetric efficiency. In this context, this search proposes to evaluate the influence of the rotation and pressure on slip and what is the influence on pump’s efficiency with bench test data. For that, evaluated five sets of bench test result for five PCP’s models and with them, calculated the slip at each test pressure, observing the slip behavior with increasing test pressure, comparing the differences between splipes at the same pressure and different rotations and flow behavior in the performance curve considering the effect of slip. In addition, it was evaluated the influence of the error in the flow measurement by the instrument used. Based on the data studied, there is a tendency for a significant increase in slip with increasing test pressure, and a practically negligible difference at different rotations. It is also possible to observe a trend of similarity lines in the performance curves, and that the pumps are more efficient when operating at higher speeds.