An electrostatic atomizer has a power source powering a charge injection device. The power source is arranged to vary the net charge injected by the charge injection device cyclically in accordance with a pattern of variation so that the net charge repeatedly increases to a higher value at or above a long-term breakdown value. The net charge injected is reduced by the power source to a lower value below the long-term breakdown value so that corona-induced breakdown is reduced. A method for electrostatically atomizing a fluent material is provided. The method includes the step of cyclically varying the net charge injected to reduce the occurrence of corona-induced breakdown.
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims benefit of U.S. Provisional Application Ser. No. 60/106,420, filed Oct. 30, 1998, the disclosure of which is hereby incorporated by reference herein.
In a powder coating apparatus a pulse signal S2 of a low voltage generated by a pulse signal generation circuit (7) is boosted to a high voltage by means of a high voltage impression circuit (8), so that it is impressed upon corona electrodes (5). As a result, a corona discharge is intermittently generated from the corona electrodes (5) toward an object to be coated, whereby powder coating material sprayed from a nozzle opening of a gun main body in a forward direction is charged with negative ions developed by the corona discharge, whereafter it is directed toward the object to be coated, and is deposited on a surface of the object.
Fluids are atomized using a miniaturized electrostatic microinjector. The microinjectors are capable of producing uniform droplets in several spray modes, and metering and dispersing very small volume fluids. The atomizer is useful in carburetion systems for internal combustion engines, to prepare samples for analytical methods such as MALDI, for fluid filtration and separation, and in other applications.
An apparatus for dispersing fluent material comprises a body defining a plurality of orifices arranged around a central axis and a charge injection device arranged on the central axis.
A fiber is formed by providing a stream of a solidifiable fluid, injecting the stream with a net charge so as to disrupt the stream and allowing the stream to solidify to form fibers.
Fluids are atomized using a miniaturized electrostatic microinjector. The microinjectors are capable of producing uniform droplets in several spray modes, and metering and dispersing very small volume fluids. The atomizer is useful in carburetion systems for internal combustion engines, to prepare samples for analytical methods such as MALDI, for fluid filtration and separation, and in other applications.
