US2721730A - Heat exchanger - Google Patents

Description

Oct 25, 1955 J. CLAUSE ETAL HEAT EXCHANGER Filed 00'0. 29. 1952 2 Sheets-Sheet l ttorneys Oct. 25, 1955 J, CLAUSE ET Ax.

HEAT EXCHANGER 2 Sheets-Sheet 2 Filed Oct. 29, 1952 A ttorneys.

71 wm/ T lmp 7 N R ENA funn@ bw SAA a J om..v no; MIME a wat United States Patent() HEAT EXCHANGER Jean Clause, Paris, .lean Parisot, Argenteuil, and Charles Roos, Paris, France, aud Alfred Hilliard, Brockwell Park, London, and Francis Ferdinand Jaray, Kingswood, Martley, Engiand, assignors to Societe le Carbone-Lorraine, Paris, France, a French body corporate Application octsba- 29, 1952, serial No. 317,464 Claims priority, application Great Britain April 22, 1952 5 Claims. (Cl. 257-104) This invention relates to heat exchanging apparatus.

The main factors affecting heat transfer eciency are the thermal conductivity of the material from which the heat transferring elements of the apparatus are made, the film effect viz., the tendency of a fluidto form a more or less stagnant film on the heat transfer surfaces of the elements, and streamlining which is the tendency of a uid to flow through a channel less rapidly nearest the walls of the tube. The most pronounced of these factors is generally the lm effect. A Well known heat exchanging process consists in pumping the fluid through stationary channels in counter-current to a heat exchanging medium flowing in adjacent channels but in this process it is difficult to overcome the disadvantages of film effect and streamlining, and moreover when corrosive fluids are involved the construction of pumps for pumping the liquid under treatment is costly and generally less efficient.

According to the present'invention the apparatus comprises a member having at least one passage therethrough for each heat exchange fluid With heat exchange .between the fluids through the material of the member, means for continuously driving said member when .immersed in the second of said fluids, said member carrying surfaces which propel the second iluid through its passage in said member.

The apparatus may be immersed in the fluidthe temperature of which is to be controlled, or for example when with a heat pump, the said fluid may be circulated within the apparatus While the latter is immersed in a body of liquid such as a lake with which heat exchange is to be effected.

The member maybe rotary and the passages `for the second uid may be disposed transversely of theuaxis of rotation thereby providingrheat transfer surfaces lwhich rotate the second fluid and impel it centrifugally-past those surfaces to effect a circulatory motion from the body of the second fluid Apast said surfaces and back into the body of said second fluid.

The rotatable member or ycylinder is preferably constructed of graphite, which material has high thermal conductivity and is 'resistant `to chemical attack by most fluids. The member may have a simple rotary motion or may have a planetary motion or a combined rotary and reciprocatory motion.

The speed at which the member rotates or otherwise moves, may vary for any given process, depending upon the nature of the fluid which is to be heated or cooled, its viscosity, its tendency to wet or not to wet the material from which the heat transfer member is made, whether the fluid contains gas or vapours in solution, or carries solid particles in suspension, and if so, upon their concentration and particle size.

The invention provides an apparatus which obviates the need for a pump for effecting movement of the liquid surrounding the heat exchangers, is more compact than normal tube type heat exchangers, enables short blocks to be used for the heat exchange surfaces with consequent ice less liability to fracture, provides turbulence and rapid iiow past the heat exchange surfaces, Vaccessibility for cleaning and repair, acts as a mixer, is suitable `for highly viscous and corrosive fluids, and can be made of graphite blocks in which case the orientation of the graphite crystals can be arranged favourably for Vheat transfer.

The heat exchange member may be rotated about a vertical axis in the Vessel containing the fluid which is to be heated or cooled, or be used horizontally, or in any other convenient position. When the member is rotated about a horizontal axis, each end of a central tube which carries the member may be suspended and suitably supported in opposite walls of the vessel in which the fluid is contained. The heat transfer member is situated either at the centre or at any other convenient place on the supporting tube, the latter 'being sheathed by a second tube made from carbon or another vcorrosion resistant material. The heating or cooling medium may be passed into one end of the tube, from there into one header, then through the heat transfer channels into the second header, and from there out through the same end or the other end of the tube.

The invention will now be further described by way of example with reference to the accompanying diagrammatic drawings wherein:

Figure l is a vertical sectional view of one form of heat exchange apparatus; and

Figure 2 is va sectional View von the line 2 2 on Figure l.

A hollow steel shaft 1G carries at its upper end oppositeiy disposed frusto-conical or frusto-spherical bearing members 11, 12, made of hard carbon. The member 12 is fixed to the shaft and the member 11 is slidable thereon, and a spring 13 urges them apart to seat respectively on correspondingly shaped bearing elements 15, 16 made of graphite. The elements 15, 16 are mounted on plates 17, 18 that are fixed to the opposite ends of a tubular member 20 that is provided with a connecting pipe 19. The upper plate 17 carries an outlet fitting 21 to which a connecting pipe 22 is connected. The member 29 has a horizontal annular flange 24 which is connected to but spaced from a horizontal plate 25 by bolts 26. The shaft 10 has openings 28 at its upper end and carries a pulley 29, between the parts l24, 25, whereby the shaft can be rotated.

A tube 30 of metal, hard resin composition, or other rigid material, is disposed within the shaft 10 and spaced from it and its upper end passes through the bearing member 11 and is xed to it. One of the two fluids between which exchange of heat is to be effected can pass from the pipe 22 to the tube 3i), and eventually is returned through the space between the shaft 1t) and tube 30 into the member 20 and out through the pipe 19, or this direction of flow 'may be reversed.

A strong steel tube 32 surrounds the shaft 10 and has its upper end welded or bolted tothe plate 25 with ball or roller bearings 33, 34 between the tube 32 and shaft 16.

The plate 25, carries a depending ring 36 which carries a graphite sealing ring 37 which seats on a carbon ring 38 carried by a ring 39 that is fixed on to the upper end of a sheath 40 that surrounds the tube 30 and is made of carbon or rubber-covered steel or other protective material. The lower end of this sheath is attached to the heat exchange device which will now be described. If desired the ring 39 may be carried by the tube 32. A spring washer or a coil spring may be inserted as shown at 90.

The heat exchange device comprises a thick walled cylinder 70, and upper and lower header blocks 71, 72 cemented to the cylinder, or clamped to the cylinder with the interposition of sealing gaskets. The headers are also bolted to the cylinder by bolts 73 the heads and nuts of which are disposed in recesses filled with a heavily grogged cement 76. The bearing 34 is supported by a ring 64 which is carried by a cap 65 that ts over the lower end of the tube 32 and may be welded to the tube 10. Thus the part 32 is stationary and the parts 40, 65, 10, 30, 71, 66, rotate in unison. The cylinder is made of graphite and the blocks are made of carbon or other suitable materials. A metal plate 67 engages the underside of the header plate 71 and bolts 66 pass through the plate 67, and header plate 71, and screw into the cap 65 whereby the heat exchange device is attached to the tube 32. The upper header block has two series of horizontal radial channels 74, 75, the upper set 74 communicating with the space between the shaft and the tube 30 and the other series 75 being in communication with the interior of the pipe 30. The radial channels are extended through a right angle as at 77, 78 and continue down to the under surface of the header where they communicate with corresponding vertical downow and upow channels 79, 80 in the cylinder, which channels are arranged in a number of sets which extend outwardly either radially or at some other desired disposition. Between each adjacent pair of sets there are a series of bores or slots 82 that extend from the interior of the cylinder to the outside thereof, these holes or slots being radial or at some suitable angle to the radial. The surfaces of these radial bores or slots constitute the main heat exchange surfaces which extend radially and vertically so as to rotate the streams of liquid therein which are discharged centrifugally and fed from the vertical stream in the interior of the cylinder. The lower header has radial channels 84 in its upper surface that connect each of the downflow channels with its corresponding up-flow channel whereby a circulation of the heat exchange medium is established from the shaft 10, through headers and cylinder back to the outflow pipe 30 or vice versa. The lower header is in the form of a ring through the central opening of which liquid ows from the body of the liquid under treatment.

If desired the walls of each of the slots may be divergent in plan view so as to increase the speed of ow at the inside and to produce a turbulence or in certain cases may converge.

Instead of making parts of the heat exchanger of carbon, they may be made of metal e. g. stainless steel, copper, or Monel metal, as may be desirable for the particular purposes involved.

We claim:

l. In or for a heat exchange device, a hollow body having a plurality of sets of first passages therein and extending therethrough for passage of one heat exchange fluid, and a plurality of sets of second passages therein which passages are separate from each other and extend through the wall of the hollow body from the hollow interior to the outer surface thereof transversely of the sets of first passages and passing between but not into the said first passages and suitable for the passage therethrough of another heat exchange uid, each set of second passages being disposed between adjacent sets of rst passages.

2. In or for a heat exchange device, a hollow graphite cylinder having a plurality of sets of first passages therethrough parallel to the axis of the cylinder, said sets being spaced apart from each other around the axis of the cylinder, and a plurality of sets of second passages each of which sets of second passages is disposed through the cylinder from the interior thereof to the cylindrical exterior wall thereof and disposed between adjacent sets of first passages.

3. In or for a heat exchange device, a hollow thick walled graphite block having a plurality of sets of rst bored holes therethrough between opposed parallel surfaces of the block, said sets being spaced apart from each other, and a plurality of sets of second bored holes extending transversely of the rst bored holes, each of which sets of second bored holes is disposed through the block from the interior thereof to the exterior wall thereof and disposed between adjacent sets of rst bored holes.

4. A heat exchange apparatus comprising a hollow member, an upper header plate on said hollow member, a lower header ring on said hollow member providing an opening to the interior of the hollow member, said upper header plate having inlet and exhaust ducts for a first heat exchange uid, sets of vertically extending passages in said hollow member comprising downow passages and upflow passages spaced at intervals around said member, the downow passages communicating with said inlet duct and the upow passages communieating with said exhaust duct, said lower header ring having channels therein connecting the lower ends of the downilow passages respectively to the lower ends of the upflow passages, said hollow member having a series of rows of transverse passages for a second heat exchange fluid including at least one row between adjacent sets of vertical passages, said transverse passages opening at their inner ends to the interior of said member and opening at their outer ends at the outside surface of said member.

5. An apparatus as claimed in claim 4 wherein the hollow member is mounted on a vertical rotatable shaft having passages concentric therewith communicating respectively with the inlet and exhaust ducts in the upper header plate.

References Cited in the le of this patent UNITED STATES PATENTS 99,070 Dittmar Jan. 25, 1870 436,337 Cochrane Sept. 16, 1890 781,529 Jensen Jan. 31, 1905 924,233 Jensen June 8, 1909 1,281,351 Groch Oct. 15, 1918 1,645,614 Monahan Oct. 18, 1927 1,854,213 Modine Apr. 19, 1932 FOREIGN PATENTS 664,464 Great Britain Jan. 9, 1952 805,638 Germany May 25,- 1951,

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