. Chemical weed-control equipment. Weeds; Spraying; Spraying equipment. Spray liquid is carried in a 100- to 150- gallon tank on fixed-wing planes, and on a tank about half that size for helicopters. Tanks are equipped with an agitation system—generally hydraulic—using the excess flow from a single-stage, centrifu- gal pump, which also provides pressure from 20 to 150 psi to the boom and noz- zles. Booms, pump, and connecting pipe are generally made from aluminum or light metal alloys, and may be bought from manufacturers specializing in air- plane spray equipment, or made up by individual ope
. Chemical weed-control equipment. Weeds; Spraying; Spraying equipment. Spray liquid is carried in a 100- to 150- gallon tank on fixed-wing planes, and on a tank about half that size for helicopters. Tanks are equipped with an agitation system—generally hydraulic—using the excess flow from a single-stage, centrifu- gal pump, which also provides pressure from 20 to 150 psi to the boom and noz- zles. Booms, pump, and connecting pipe are generally made from aluminum or light metal alloys, and may be bought from manufacturers specializing in air- plane spray equipment, or made up by individual operators. The pump may be mounted outside the fuselage and driven by a small propeller, as shown below, or may be mounted in- side and driven by an electric motor. An- other method is to mount the pump behind the main engine and drive it through a V belt power take-off and a clutch. This makes it possible to disengage the pump drive when not in use. The helicopter is entering the weed spraying picture. Users claim it gives better crop penetration because air is mostly forced downward by the rotor in- stead of into a horizontal, high-velocity slipstream such as from the fixed-wing plane. In either case, the amount of dis- placed air is proportional to the weight of the plane and, to a lesser degree, to the horsepower of the engine. The greatest evident factor in favor of the helicopter is its maneuverability in closely bounded fields. This is due to its controllable, low ground speed and ability to rise almost vertically. One factor against widespread use of helicopters is the cost—roughly five times that of a comparable fixed-wing plane. Another is the greater flying skill required, which necessitates using spe- cially trained pilots. The helicopter shown on the following page has a boom with cluster nozzles (no individual control) and side tanks for [38]. Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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Keywords: ., bookcentury1900, bookpubli, booksubjectspraying, booksubjectweeds
