GB620675A - Improvements in or relating to methods of applying powders used in agriculture - Google Patents

Abstract

A mobile or portable agricultural machine for applying insecticidal, fungicidal or herbicidal powders to plants by the method of the parent Specification has mounted thereon means for imparting an electric charge to the powder particles. The machine may be of the blower type, having in front of the powder ejecting nozzle an insulated grid comprising a number of fine wires charged to a high voltage, arranged either horizontally or vertically to the ground and perpendicularly to the direction of movement of the machine; or the powder may be ejected rearwardly to the right and left through two inclined jets, the wires being arranged in two vertical banks. In these constructions the nozzle may be made of insulating material or may be insulated and raised to the same potential as the wires. According to a modification the powder is distributed by a vibrating screen, the powder on falling passing close to a wire or wires which are perpendicular to the direction of movement. According to another modification an electrically charged nozzle supported by a tubular insulating handle is used. The nozzle may have attached thereto a triangular leaf over which the powder jet is spread, the side of the triangle facing the plant being formed with saw teeth in order to facilitate brush discharge. Other forms of nozzles are provided with one or more needle points with a spiral wire ending in a point, or with perpendicular or inclined wires remote from the nozzle and near the plants being treated. In a further modification, the powder to be dispersed is disposed on an insulated support which is raised to a high potential, the powder being driven off the plate by electrostatic action. The powder for electrification may be in the form of a fume or smoke produced by the incomplete combustion of a cartridge or by heat-volatilization, electrification being effected by one of the above devices. Electric potentials of 15,000-60,000 volts may be used. Specification 626,296 is referred to.ALSO:A mobile or portable agricultural machine for applying insecticidal, fungicidal or herbicidal powders to plants by the method of the parent Specification has mounted thereon means for imparting an electric charge to the powder particles. The machine may be of the blower type, having in front of the powder ejecting nozzle an insulating grid comprising a number of fine wires charged to a high voltage, arranged either horizontally or vertically to the ground and perpendicularly to the direction of movement of the machine; or the powder may be ejected rearwardly to the right and left through two inclined jets, the wires being arranged in two vertical banks. In these constructions the nozzle may be made of insulating material or may be insulated and raised to the same potential as the wires. According to a modification the powder is distributed by a vibrating screen, the powder on falling passing close to a wire or wires which are perpendicular to the direction of movement. According to another modification an electrically charged nozzle supported by a tubular insulating handle is used. The nozzle may have attached thereto a triangular leaf over which the powder jet is spread, the side of the triangle facing the plant being formed with saw teeth in order to facilitate brush discharge. Other forms of nozzles are provided with one or more needle points, with a spiral wire ending in a point, or with perpendicular or inclined wires remote from the nozzle and near the plants being treated. In a further modification, the powder to be dispersed is disposed on an insulating support which is raised to a high potential, the powder being driven off the plate by electrostatic action. The powder for electrification may be in the form of a fume or smoke produced by the incomplete combustion of a cartridge or by heat-volatization, electrification being effected by one of the above devices. Electric potentials of 15,000-60,000 volts may be used. Specification 626,296 is referred to.