Rainguns are high performance impact sprinklers designed for a variety of uses and applications where relatively high flows and extended radius of throw are desired.
Rainguns are available with operating pressure of 2.0 to 7.5 kg/cm2 and flows of 3 to 30lps usually with nozzle diameters ranging from 10 to 30 mm and with a wetting radius of 27 to 60 metre.
Spring loaded
These type of sprinklers have a spring loaded element which is forced to rotate by the flowing water jet. Raingun sprinkler irrigation is recommended for field crops such as sugarcane, pulses, oil seeds, cereals, tea, coffee and vegetables.
It has also wide application in large turfs, lawns and playgrounds.
A raingun may be permanent or portable. In a permanent raingun the gun riser stands are permanently fitted on the pipeline network.
It can also be supported by cement concrete block around the riser.
In portable rainguna, the entire pipeline network along with the gun riser stand can be shifted from one location to another.
One raingun can cover upto 4 hectare (10 acre) of land. With raingun water saving of 30 to 50 per cent has been reported in different crops.
Uses
It saves labour and electricity. Pests and insects get washed away during raingun irrigation. In one and half hours about 0.50 acre can be irrigated by this sprinkler.
A recently conducted field experiment at the Agricultural Engineering College &
Research Institute, Kumulur Tamil Nadu Agricultural University revealed that raingun irrigation can be economically used for irrigating cluster beans. Performance of a raingun may be affected by wind. The cost of a single raingun varies from Rs. 25,000 to 50,000 according to the wetting radius.
(A. Tajuddin, Dean and S. Somasundaram, Asst Prof, Tamil Nadu Agricultural University, Agricultural Engineering College & Research, Institute, Kumulur, Tiruchi, email: deancaekum@tnau.ac.in, phone: 0431-2912359.)
