What is a hydraulic injector?
Pressure-proportional hydraulic injectors are internal systems within the irrigation line. Their pressure comes from a small pressure loss in the system. These devices can be installed in two ways:
In-line installation
In an in-line installation, the entire irrigation flow passes through the hydraulic motor of the doser. This easy-to-install system allows for excellent regulation of proportional dosing and offers various percentage options with a moderate pressure loss, although less than with other systems. The greater the irrigation flow, the greater the pressure loss. This system is only suitable for small flows, as the cost increases with the nominal flow rate of the injector.
By-pass installation
In a by-pass installation, only a portion of the flow acts on the pump’s flow. This method allows for injection into large flows at a reduced cost. It is an easy-to-install system, even with large flows, but it generates a pressure loss that, although lower than what a Venturi system would require, affects the entire treated flow. With this installation, we cannot guarantee proportional dosing, as we cannot control which part of the flow passes through each side of the by-pass.
The performance of both installation systems for the proportional hydraulic injector depends on the energy absorbed by the pump in the form of pressure loss, which will vary depending on the flow rate and the network pressure at the point where the dosing pump is located.
How to determine the flow rate of an injector
To determine the flow rate of an injector, it is necessary to evaluate the pressure and system configuration. It is essential to know the technical specifications of the injector and to take precise measurements in the irrigation system.
Diagram of a hydraulic injector
A diagram of a hydraulic injector can be useful for understanding its operation and system configuration. This diagram generally shows the placement of the injector within the irrigation line and the interaction of the different components.
Proportional hydraulics and proportional systems
Proportional hydraulics are essential in irrigation systems as they allow for the uniform distribution of nutrients and water throughout the system. A proportional system ensures that the amount of fertilizer injected is directly proportional to the water flow passing through the injector, thereby optimizing the efficiency of both irrigation and fertilization.
