Heat exchanger with electrohydrodynamic effect

• US 4,651,806 A
• Filed: 09/18/1985
• Issued: 03/24/1987
• Est. Priority Date: 09/24/1984
• Status: Expired due to Fees

• Current Assignee: National Research Development Corporation
• Original Assignee: National Research Development Corporation
• Inventors: Cooper, Paul, Allen, Peter H. G.
• Primary Examiner(s): Davis, Jr., Albert W.
• Assistant Examiner(s): Smith, Randolph A.
• Application Number:
  US06/777,456
• Time in Patent Office: 552 Days
• Field of Search: 165/1, 165/2, 165/96, 165/110, 165/109.1, 165/134.1
• US Class Current: 165/96
• CPC Class Codes: F28F 13/16 by applying an electrostatic field to the body of the heat-exchange medium

Abstract

A heat exchanger comprising a casing through which pass a plurality of spaced-apart tubes. Heat exchange takes place through the tube walls between a first fluid within the tubes and a second fluid outside them but within the casing. The rate of heat exchange is enhanced by electrohydrodynamic effect by means of an electrode comprising a sheet-form first part which encompasses the tubes, and connected second parts which run lengthwise through the spaces between the tubes. The first part may be mesh-like and the second parts may be mesh-like and/or rod-like. The electrode is excited to high voltage and the casing and tubes are grounded. The effect of the second parts is to make the electric field around the individual tubes more uniform than would be the case if the electrode consisted of the first part alone.

Claims

1. 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.

2. A heat exchanger according to claim 1 in which said first member of said electrode is of mesh or other open-work form.

3. A heat exchanger according to claim 1 in which said second members include at least one sheet-form member of mesh or other open-work form.

4. A heat exchanger according to claim 1 in which said third members include rods.

5. A heat exchanger comprising:

a shell-type casing;

a plurality of spaced-apart tubes arranged within and passing through said casing, 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;

and 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 excited to high voltage, said electrode comprising a substantially sheet-form first member which encompasses said tubes and second members running lengthwise through said tubes and to which said first part is electrically connected;

in which said electrode comprises two opposite end frames, between which said end frames both said first and said second members are supported;

in which said end frames each comprise an outer boundary, in which crossmembers arranged in grid-like formation span each said outer boundary, in which said first member of said electrode is attached to said outer boundary, in which the ends of said second members are supported on said crossmembers of said gird, and in which said tubes pass through the voids of said formation.