Rigorous Design Process for a Groundwater Pump for Low-Yield Water Wells: A Case Study

Abstract

Ground-water pumping in remote areas, such as Australian farms, was for many years traditionally done by wind pumps in order to satisfy the needs of stock. Since the 1980’s solar pumps of varying designs have become popular for pumping water from farm dams and tube wells. Wind pumps, solar pumps, engine or electric motor driven pumps and even animal/human powered pumps have a future in many remote situations in the world for stock watering, irrigation and for village water supply in developing countries. In these markets there is a wide-spread view that local manufacture of the pumps is preferable, as is well documented in the literature on village water supply in developing countries. Submersible pumps that are either of the multi-stage centrifugal class or that use the progressive cavity principle have increased in popularity in the low well yield environment. However, where well yields are extremely low the efficiency of these pumps also becomes low and oversized pumps of these kinds are often inappropriately applied. Quite often in the low yield situation, tube wells are also oversized in that they are drilled to large diameters and depths so as to provide storage in order to accommodate the water demand requirements of the user. This practice leads to unnecessary deterioration of both pump and well. Designing for low production volume manufacture presents unique challenges for the designer in attempting to design a robust, versatile but cost-effective product. The design challenges include, achievement of: - high efficiency, reliability, longevity, simplicity, versatility with a minimum parts count, and all this at a low cost. A case study is presented in this paper in which the design issues are outlined. A rigorous design process has been applied in this case study.