Characterization of the hydraulic performance of self-compensating emitters with water of different salt concentrations

Abstract

The aim of the present study was to evaluate hydraulic characteristics such as manufacturing and flow variation coefficient, characteristic equation of self-compensating emitters and the variation between nominal flow and that obtained by the emitter equation using waters of different salt concentrations. The research was conducted in the greenhouse of the Academic Unit of the Agricultural Engineering, Federal University of Campina Grande-PB. Treatments consisted of five salinity levels in the irrigation water (ECwi) (0.6; 1.5; 2.5; 3.5 and 4.5 dS m-1 at 25 ° C) and four working pressures (60, 100, 140, and 160 kPa), with three replicates. The flow variations of emitters were considered small over time, being within recommendation of ± 7% of the nominal flow with “x” exponent values between 0.02 and 0.09, as recommended by the manufacturer, which was classified as self-compensating. The manufacturing and flow variation coefficients were considered excellent in all evaluations and the operating time did not influence the hydraulic performance of emitters. At pressure of 60 kPa and electric conductivity of 0.6 dS m-1, flow rates near values provided by the manufacturer and more economically viable to the farmer were obtained.