Motorized rope pump
The motor rope pump is one of the application of the ‘rope and washer’ pumping principle, powered by an electrical, petrol or small diesel motor. The main application of this pump is as a deepwell irrigation pump for small scale irrigation.
The context
In those parts of the world where the climate has distinct dry periods, many small farmers earn additional income by growing additional crops in the dry season using simple irrigation techniques. When farmers have access to shallow wells with a water table of no more than 7m, pumping is usually done with suction pumps that are powered by a diesel or gasoline engine. For pumping from deeper wells, submersible electrical pumps are often used. However many small farmers in developing countries have no access to electricity and alternatives such as a generator sets with a submersible pumps or long-shaft diesel pumps are expensive and complex to operate and maintain.
The motor rope pump is a low cost alternative for making productive use of water from deeper wells for irrigation.
The technology
The pump part of a motorised rope pump is similar to that of a hand rope pump. Critical parts have been adapted to the higher load and PVC tubing and pistons are larger. The rotating shaft of the pump is connected with the shaft of the engine with V belts or a Polyurethane round belt, using a large pulley transmission to adjust the RPM of the engine to the low RPM of the rope pump. Where there is access to electricity the pump can be driven by an electric motor, or else it can be driven by a small diesel or gasoline engine of 1 to 2HP.
The application
Most motorised rope pumps are used for irrigation purposes; in Nicaragua they are also used for domestic water supply. As in the case of the hand rope pump, the basic model of the motorized pump cannot pump higher than just below the pump shaft, which makes the pump most suitable for low pressure irrigation. To pump to tanks of 3 to 5m high, an additional post must be added. Motorised rope pumps are recommended for depths up to 60m. In Nicaragua however, some pumps are installed on wells with depths exceeding 80m.
Motor rope pumps have been applied in Nicaragua, Senegal and Burkina Faso. The pump is produced locally, using simple techniques and materials that are locally available. The engines are either purchased on the local marked or imported.
The facts
| Range of depth | 7 – 60 m |
| Yield | 120 Litres/min at 10m 60 Litres/min at 20m 20 Litres/min at 60m |
| Fuel consumption | 0.4 litres/hour, depending on model and engine |
| Cost | €350 – €550 depending on country of implementation |
| Numbers | 300 produced in Nicaragua (different models) 30 produced in Burkina Faso and Senegal (gasoline model) |
Training and introduction
PRACTICA can assist local manufacturers with starting up production. For training of manufactures, PRACTICA has developed a set of workshop drawings, a production manual, installation manual and maintenance sheets, spare parts, etc. PRACTICA also gives assistance with importing low cost petrol engines for the motor rope pump, as well as assistance with the promotional activities.
