| 摘要 |
<p>A device for the automatic and pulsed delivery of an irrigation liquid, which can be connected, at its upstream side, to a source liquid under a constant or substantially constant pressure, and at its downstream side, to a distribution network equipped with pressure-responding valves. These valves are capable of closing, during the step charging of the distribution system, at a pressure equal to, or substantially equal to, the liquid feed pressure, and of opening, during irrigation liquid expelling, when the pressure decreases under said value. The device comprises a Venturi device, fed with the same irrigation liquid, from whose region of constricted stream a duct is branched off, to transmit to a sliding member depressure generated by the Venturi. As a function of such a depressure, a sliding member reciprocatingly shifts between a position of opening of the irrigation liquid delivery port, and a position of closure of said port and of simultaneous or subsequent venting towards the atmosphere, so as to cause a pressure drop and the explusion of the irrgation liquid from the distribution network, and the beginning again of the cycle. An irrigation facility incorporating this device is connected to a distribution network equipped with a plurality of pressure-responding valves, each one of which is provided with a delivery nozzle.</p> |
