Comparative Advantages of Axial - Flow Pumps Over Centrifugal Pumps for Low - Lift Irrigation
Centrifugal pumps are commonly used in the Philippines for low-lift irrigation whereas axial-flow pumps have proven more acceptable in Thailand and Vietnam. This study compares centrifugal and axial-flow pumps in terms of performance and cost. The pumping efficiency of the axial-flow pump is substantially higher than that of the centrifugal pump for lifts (static heads) of three meters or less. Therefore, the fuel required to pump a specified quantity of water is lower for the axial-flow pump than for the centrifugal pump. This, and the fact that the initial costs of the two pumping units are approximately equal, are considered in an economic analysis which demonstrates that axial-flow pumps have significantly lower total annual costs than centrifugal pumps for lifts of three meters or less. It is recommended that a promotional campaign be carried out in the Philippines to inform farmers, manufacturers, and extension workers of the comparative advantages of axial-flow pumps relative to centrifugal pumps for low-lift irrigation. (Author abstract).