Avaliação técnica e de custos do uso de injetor tipo venturi associado à bomba centrífuga versus bomba do tipo pistão na quimigação via pivô central

The use of Venturi injectors is a common practice in chemigation in targeted irrigation systems, which generally operate at low pressures. Their use in larger systems, such as the center pivot, can be seen as an alternative to piston injection pumps, which have been the most used in the market. Thus, this study aimed to evaluate the technical and economical comparison between the system assembled with Venturi injector associated with centrifugal pump and the injection system using piston pump in the center-pivot chemigation. The flow rate of the equipment is 300 m3 h-1 and the irrigated area is 66 ha. The injection system consisted of 1.5-inch Venturi injector associated with a centrifugal pump of 2.2 kW. For technical analysis, the performance parameters of the Venturi injector were injection rates and yield. These data were compared with those provided by the manufacturer of the piston pump. In the economical analysis, fixed and variable costs of both systems were defined.Tests using the Venturi injector had similar performance as compared with that of the piston pump, with injection rate up to 0.621m3 h-1 and yield of 11.13%. As to the economical analysis, the system assembled with the Venturi injector had only 15.9% of the cost of the piston pump.