Experiment and Analysis on Control Performance of Venturi Injector

Abstract：In order to obtain an optimal a regulating and controlling method of the Venturi injector in the water-fertilizer drip irrigation integration facility, based on a one-inch parallel Venturi injector, one test was conducted by installing respectively three valves at the input, the output and the juncture to the water pile of the Venturi injector to modify the corresponding differential pressures. The results showed that the fertilizer concentration could not be regulated lower than 13% by regulating the differential pressure at the intake. Though the fertilizer concentration could be change accordingly while modifying the pressure at the pile juncture, the no linear relationship could be found between the input and output flow and the differential pressure when the pressure-differential was higher than 0.10 MPa. Eventually, the fertilizer concentrations varied in accordance ranging from 0% to 10% and the relationship between the concentration and the pressure ratio fits in a Square Polynomial by regulating the differential pressure at the outlet. Besides, the input flowing was linearly related to the multiplication of the input pressure and the differential pressure. It＇s concluded that the suction amount and fertilizer concentration of the Venturi injector can be controlled by regulating the differential pressure at the intake outlet.