A micro-irrigation system consists of a command and control head usually located downstream of the delivery group or the company lifting system, a main pipeline that feeds several secondary pipelines located one for each irrigation sector, each of which feeds different dispensing wings on which the dispensing devices are inserted.
Diagram of a micro-irrigation system
The control head consists of all the equipment that regulates the operation of the system; in particular it carries out the filtration of the water, the possible addition of fertilizing substances, the measurement of the flow rates delivered and the operating pressure of the system and regulates the times required for watering. Downstream of the control head there is a main pipeline that branches off inside the company to be irrigated, feeding the various irrigation sectors. The secondary ducts and therefore the dispensing wings are positioned as a derivation from it.
Sometimes in correspondence of the connections between the secondary pipes and the dispensing wings are installed mesh filters that allow further filtration of the water. The main and secondary ducts can be fixed or mobile and can be made with plastic materials (PVC, polyethylene, etc.) or more rarely in galvanized steel.
The dispensing wings are usually made up of polyethylene pipes with a diameter varying between 16 and 25 mm, in which the dispensing devices are installed.
The various types of dispensers available on the market differ from each other, based on the way in which they are mounted on the dispensing wing (in-line, on-line or dripline drippers), due to their aptitude to deliver constant flow rates. or variable as the hydraulic load varies (self-compensating or common drippers), or due to the flow rate of the water current that passes through them (laminar or turbulent drippers).
Various types of dispensers for micro-irrigation
In particular, the on-line drippers are inserted in derivation with respect to the dispensing wings, the in-line ones are coaxial to them while the dripline ones are factory mounted on the internal walls of the wings, in this case we speak of integral driplines; self-compensating dispensers are generally made with mobile devices or deformable parts which modify the passage sections as the hydraulic load varies so as to keep the delivered flow rate constant; the dispensers operating in laminar regime (microtubes, spiral drippers) are instead characterized by ducts with very small sections (1-3 mm) and of long length (even of the order of a meter) while the dispensers operating in turbulent regime (orifices, double-chamber pipes, labyrinth drippers) have generally larger passage sections.
