HEAT-RESISTANT BROAD-BANDWIDTH LIQUID DROPLET GENERATORS

摘要

Apparatus and methods for making uniformly-sized and predictably-spaced droplets from high-temperature liquids. Liquid droplet generators having electromechanical driving elements (16) are coupled to a power supply (17) to apply pulsed excitation forces through a wall of the delivery tube (14) to a high-temperature liquid, e.g., a liquid metal, epoxy, or polymer. The excitation forces generated by the driver (16) induce capillary vibrations in the liquid within the delivery tube (14). Liquid jet streams having capillary vibrations when exiting an orifice (22) break up into groups of substantially uniformly-sized liquid droplets (26) shortly after leaving the orifice (22). Droplets (26) may be produced in a uniformly-spaced series, or individually on demand in response to a single burst of force from the driving element (16). A heat source (18) is also thermally coupled to the delivery tube (14) to maintain the liquid in a high-temperature state. Embodiments using heat-sensitive elements thermally insulate those elements from the wall of the heated delivery tube (14) and may also effectively cool the elements by one or more heat exchangers. A magnetohydrodynamic embodiment couples a magnetic field, having spaced points of maximum intensity, to a fluid stream exiting an orifice (22), causing the stream to break into droplets (26) in response to the periodic magnetic field.