Performance evaluation of a modified axial flow water Lifting pump for small to medium irrigation in Nigeria.

Most irrigation pumps used in Nigeria are imported. Consequently, the challenges farmers faced in using these pumps include but not limited to the following; priming before operation, relatively low-capacity delivery at low head and high price which is often time not affordable by peasant farmers. The objective of this research was to develop an axial flow pump with locally sourced materials and affordable by farmers for small to medium scale irrigation in Nigeria. The design of the pump for the study was adopted from an existing and functioning axial pumping machine, developed by Agricultural Machinery and Mechatronics Department, Kasetsart University, Thailand. The pump was fabricated at the workshop of National Centre for Agricultural Mechanization (NCAM), Ilorin, Nigeria. Diesel fuel was used in powering the pump because of higher torque deliverable. The developed pump based on its capacity can be used to irrigate one hectare in one hour at 16.2 mm depth of water using 2000 rpm at 1m head and 9.6 mm depth of water using 1000 rpm at 3 m head. The maximum water discharge of 162 m3/h (45 l/s) was at 1m using a speed of 2000 rpm with water to fuel delivery of 124.29 l/s. The maximum water discharge of 162 m3/h (45 l/s) was at 1m using a speed of 2000 rpm with water to fuel delivery of 119.57m3/L. And the least water discharge of 59.30 m3/h (28 l/s) and water delivery per fuel was 41.0m3/L at 3 m head at 1000 rpm.  Therefore, the developed pump operates best at lower head of 1m featuring a 3kW prime mover. The developed pump based on its capacity can be used to irrigate one hectare in one hour at 16.2 mm depth of water using 2000rpm at 1m head and 9.6 mm depth of water using 1000rpm at 3m head at a moisture content of 45% on a sand-loamy soil. Statistical analysis reveals relationships between pump speed, head, fuel consumption, and various performance indicators. The centrifugal pumps were found to produce lower discharge than axial flow pumps at different water heads evaluated. Comparative economic analysis demonstrates the pump's superiority over conventional centrifugal pumps in terms of water-fuel delivery efficiency and operational cost. This study introduced a locally modified axial flow pump as a practical, cost-effective, and efficient solution to irrigation challenges faced by small and medium-scale farmers in Nigeria. This pump has higher capacity delivery, spare parts are readily available at local market, it is appropriate for use where the irrigation head requirements are low and large volumes of water is required to be lifted at low pressure, it is appropriate where water can be lifted from rivers and canals and then directed to farmers' fields for irrigation. It is also applicable in rice farm flooding and flood drainage. This type of pump is good for flood (surface) irrigation system, which include furrow, border, basin irrigation and uncontrolled flooding in loamy and clay soils for rice production and sugarcane productions.  The pump's adoption and economic viability positions it as a potential catalyst for increased food production, income, and food security in the country.