Irrigation pumps are pumps that are used to water the farmland during farming. These pumps can mostly only pump water from shallow wells at a steady pace with low pressure. When choosing a pump for irrigation,you need to choose one that best suits the water source available. Irrigation pumps can be either centrifugal pumps, propeller pumps, deep-well-turbine or submersible pumps.
You must consider the source of water, total dynamic head, total suction head and the required flow rate of the pump before choosing an irrigation pump. Centrifugal pumps are used to pump water from shallow water sources like lakes or streams. These pumps when used as irrigation pumps or other applications must be primed before they can function efficiently. Centrifugal irrigation pumps can be either vertical or horizontal pumps. The horizontal centrifugal pumps are the most common irrigation pumps and they have a vertical impeller attached to the horizontal shaft. The horizontal centrifugal pump is mostly used in irrigation because it costs little to acquire and install, and it is very low maintenance.
The vertical centrifugal pump is also used as an irrigation pump, especially in areas where a floating pump is needed. The impeller of this pump can stay underwater for long periods of time and it is a type of self priming centrifugal pump. This type of pump, when used for irrigation, needs a lot of maintenance because the operating parts are always underwater. Hence, the vertical centrifugal pump is not very popular as an irrigation pump.
The deep-well turbine pump is used as an irrigation pump in areas where the water surface is deep. This type of pump is also suitable for use with shallow water surfaces as well. The operating parts of this irrigation pump are always underwater, so it is a self priming pump. Deep-well turbine pumps are more efficient for irrigation than centrifugal pumps, but they are more expensive to buy, install and maintain. The parts which make up this type of pump include the head, the shaft and the pump bowl. The head of the pump is usually made from cast iron and it serves as a support for the other parts of the irrigation pump. The shaft on the other hand connects the head to the pump bowl and the impellers to the motor, while the column moves the water to the surface. The pump bowl serves as a cocoon for the impellers of the pump. The shaft of this irrigation pump can be lubricated with oil or water depending on what type of farming the pump is needed. For example, if the pump is for watering the farmland you can opt for an oil lubricated pump but for livestock farming, the water lubrication is more suitable.
Another type of irrigation pump is the submersible pump which is a turbine pump, but has a submersible electric motor attached to it. The impellers in this pump are enclosed because the heat from the electric motor could cause the impellers to lose efficiency. Submersible pumps are less efficient as irrigation pumps, than centrifugal pumps and deep-well turbine pumps, because their head is smaller in diameter. If there is no lightning protection in the connection box, the submersible pump is highly susceptible to lightning. In areas where the water levels are unsteady and fluctuate, submersible pumps can be used to boost suction in the suction lines of centrifugal pumps.
The propeller pump is a type of irrigation pump that is used for systems that require high flow rate and low suction lift. Propeller pumps are usually mounted horizontally and need their head to be totally submerged in the water source to operate effectively.
Irrigation pumps are one of the mechanized features that make farming and other agricultural processes faster and easier, especially in places where the water source is not directly on the farmland.