Heat exchanger with electrohydrodynamic effect

A heat exchanger comprising:

• a shell-type casing;
• a plurality of parallel tubes arranged within and passing through said casing and separated from each other by first clearances, whereby heat exchange may take place through the walls of said tubes between a first fluid medium within said tubes and a second medium outside them but within said casing, said tubes being arranged so that, when viewed in transverse section, they lie at the vertices or intersections of a grid-like regular pattern;
• means to enhance the rate of said heat exchange by electrohydrodynamic effect, said means comprising an electrode located within said casing but insulated from both said casing and said tubes and capable of being excitd to high voltage, said electrode comprising:
• a first sheet-form member forming a sheath around said plurality of tubes throughout their length;
• a plurality of parallel second sheet-form members, separated from each other by second clearances and running lengthwise of said plurality of tubes through said first clearances between said tubes, and
• parallel third members also running lengthwise of said plurality of tubes, said third members being disposed in the space common to said first and second clearances,
• said first, said second and third electrode members being electrically connected to each other.