Development and Hydraulic Characteristics of the Pipe Bend for Chemigation System

Abstract

The increasing use of drip and sprinkler irrigation system have shown that applycation of fertilizer are desirable to along with irrigation water. In agricultural facilities, low cost and low energy are requested to reduce production cost of agriculture. When the water passes through a pipe bend in irrigation system, by the centrifugal force of the flowing water, the water pressure of the outside of curved pipe is higher than that of the inside. If the inside and outside of the curved pipe are connected by the pipe, the bypass flow is generated in this route. If the fertilizer tank is connected in the bypass route, the fetilizer is injected automatically in irrigation system without additional energy.
In this paper, the hydrulic design procedure of chemical injection system in irrigation facility by thr use of pipe bend was shown. The characterristis of byppas flow in bend pipe was shown. By the increasing of bypass flow rate, the pressure differrence between inside and outside in curved pipe is greatly reduce. This point is the defect of application of curved pipe in chemical injection system by the use of pipe bend. The increase method of bypass flow wasproposed and effect of this method was shown by the use of chracteristics of centrifugal force line. The design procedure of chemical injection system was also shown.