LIQUID DELIVERY SYSTEM
    6.
    发明申请

    公开(公告)号:US20120168011A1

    公开(公告)日:2012-07-05

    申请号:US12983443

    申请日:2011-01-03

    IPC分类号: F15D1/00

    CPC分类号: A01C23/042 Y10T137/85978

    摘要: A liquid delivery system comprises a tank containing a supply of a first liquid. A positive displacement pump operates to withdraw the first liquid from the tank via a suction conduit and to deliver a pressurized flow of the first liquid via a delivery conduit. An adjustable metering orifice in the delivery conduit serves to control the flow of the first liquid through the delivery conduit. A normally closed first valve located in the delivery conduit between the pump and the metering orifice is opened in response to a pressure of the first liquid exceeding a threshold level, and is operative when open to deliver the first liquid to the metering orifice at a substantially constant pressure. A bypass conduit communicates with the tank and with the delivery conduit at a location between the pump and the first valve. A second valve in the bypass conduit is adjustable to accommodate a controlled return flow of the first liquid from the delivery conduit to the tank, thereby modulating the pressure of the first liquid being delivered to the first valve.