초록 ▼

The present invention provides an apparatus and method for accurately controlling the amount of NH.sub.3 to be applied to a field by measuring the NH.sub.3 flow rate without condensing or cooling the NH.sub.3. The system includes a control station 12 on the vehicle with a tachometer 12A or a GPS sys

The present invention provides an apparatus and method for accurately controlling the amount of NH.sub.3 to be applied to a field by measuring the NH.sub.3 flow rate without condensing or cooling the NH.sub.3. The system includes a control station 12 on the vehicle with a tachometer 12A or a GPS system for providing a vehicle speed signal to a control panel 13. The control panel includes a toggle switch 17 for adjusting the opening or closing of a valve 52 in the flow line to regulate the flow through the system, although the control panel alternatively may automatically control the valve 52. The vehicle transports a tank 20 containing liquid NH.sub.3 and a tool bar 30 for distributing the NH.sub.3 to the soil. After flowing through the flow meter 40, 60, 130, the NH.sub.3 is conducted to the soil through a series of hoses, fittings, a distributor, and tubing. The flow meter transmits a signal to the control panel, which is converted to a corrected flow rate signal in response to a fixed value vaporization correction factor. The temperature of the NH.sub.3 is also measured to correct for density variations. An improved variable area meter 60, 130 uses a hall effect sensor 72 and a magnet 68 mounted on a rotatable vane shaft 70 to overcome problems with prior flow meters. The improved meter 60, 130 is ideally suited for measuring the fluid flow of a low temperature vaporization liquid, such as anhydrous ammonia, propane and butane.

대표청구항 ▼

[ What is claimed is:] [1.] A method for controlling the amount of NH.sub.3 applied to a field from a nurse tank located on a vehicle, comprising:withdrawing NH.sub.3 from an outlet of the nurse tank;measuring the flow rate of the NH.sub.3 with a flow meter positioned downstream from the outlet on t

[ What is claimed is:] [1.] A method for controlling the amount of NH.sub.3 applied to a field from a nurse tank located on a vehicle, comprising:withdrawing NH.sub.3 from an outlet of the nurse tank;measuring the flow rate of the NH.sub.3 with a flow meter positioned downstream from the outlet on the nurse tank;comparing the measured NH.sub.3 total flow measured by the flow meter to the actual NH.sub.3 withdrawn from the nurse tank over a time interval;deriving a vaporization correction factor based on measured NH.sub.3 total flow and actual NH.sub.3 total flow;in response to the measured NH.sub.3 flow rate and the derived vaporization correction factor, determining the actual NH.sub.3 flow rate; andadjusting the amount of NH.sub.3 applied to the field in response to the determined actual NH.sub.3 flow rate.