GB916025A - Spraying apparatus - Google Patents

Abstract

916,025. Spraying apparatus. FISONS PEST CONTROL Ltd. Feb. 7, 1961 [Nov. 17, 1959], No. 38872/59. Class 69 (3). In a process and apparatus for spraying agricultural chemicals from a moving vehicle, a mixture of a solution or suspension of an agricultural chemical and water is forced to spray nozzles by a main pump, the pump drawing water from a main tank and the solution or suspension from a metering pump which forces the solution or suspension to the main pump from a subsidiary tank, the metering pump being driven in direct proportion to the speed of the moving vehicle. Thus the amount of chemical supplied per unit area of land sprayed is maintained constant and independent of vehicle speed. The vehicle may comprise a railway train in which case the main tank consists of a tanker. The metering pump operates at a rate considerably below that of the main pump whereby the variation in the volume of liquid fed by the metering pump makes no appreciable difference in the volume of liquid forced by the main pump to the nozzles. In the Figure a main pump 4 draws water from a main tank, not shown, along a line 7 and forces it through a three-way valve 8 and line 9 to nozzles 6. The metering pump 3, geared to a landwheel of the vehicle on which the apparatus is carried, draws chemical in solution or suspension from tank 1 through three-way valve 18 and line 10 into line 7. The nozzles always spray the liquid at optimum pressure but the chemical concentration varies. A mixing tank 2, a subsidiary pump 5 and interconnecting lines and three-way valves 15, 16, 18 and 19 are provided whereby during spraying, with the valves appropriately adjusted, the pump 5 draws liquid from tank 2 and feeds it to tank 1 which is kept full, and excess liquid flows back to tank 2 through an overflow pipe 25. In order to spray the contents from both tanks 1 and 2 at the end of a run, a valve 22 in a line 21 is opened. To replenish the tank 2 the various valves are appropriately adjusted whereby water is supplied from the main tank to the tank 2, and fresh chemical simultaneously supplied. By suitable adjustment of the valves the system may be rinsed through with water from the main tank. During temporary stops the valves 8 and 12 are adjusted so that the pumps 3 and 4 operate in closed circuit, a drive from pump 4 being connected to pump 3 when the vehicle is at rest.