Liquid spraying device

Claim 1

A liquid spraying device, comprising: a first tube made of electrically conducting material and having at a front end thereof a flared, bell-shaped opening having a concavely conical front surface which diverges forward in the direction of liquid spray, at a specific vertex angle; vortex flow means located within said first tube and defining, with said wall of said first tube, a primary air flow passage, said vortex flow means having a forward head portion having a shape for ejecting primary air flowing through said air passages and causing said air to flow vortically in the shape of a cone along said concavely conical front surface; a second tube, made of electrically conducting material, being coaxially disposed around said first tube and defining together therewith a liquid passage through which liquid flows, said second tube having at a front end thereof a flared, bell-shaped opening having a concavely frusto-conical front surface around said first tube concavely conical front surface, whereby liquid flowing through said liquid passage forms a cone-shaped thin film on said frusto-conical front surface, said frusto-conical front surface diverging forward at a vertex angle smaller than said vertex angle of said first tube front surface, the forward edge of said first tube conical front surface being disposed axially to the rear of the forward edge of said second tube frusto-conical front surface whereby said vortically flowing air collides against said thin film of liquid for causing said film to vibrate; a third tube coaxially disposed around said second tube for defining together therewith a secondary air flow passage, said third tube having a front end disposed around said front end of said second tube and having vortical flow means for causing secondary air to flow vortically in the same direction as said vortically flowing primary air from said primary air flow passage; air supply means for supplying primary and secondary air flows under pressure through said primary and secondary air flow passages respectively to said front ends thereof; liquid supply means for supplying said liquid under a pressure through said liquid passage to said front end thereof; and voltage means for applying a high voltage of one polarity to said first and second tubes for creating respective electrostatic fields for cooperating with said vortical flows of primary and secondary air for promoting atomization and spraying of the liquid.