US2404187A - Tubular heat exchange apparatus - Google Patents

Description

Julyv 16, 1946.

w. H. MILLENER TUBULAR HEAT EXCHANGE APPARTUS 5 sheets-sheet i Inventor /Wr//eHe/f.

ttorney Filed July 25, 1.944

July 1 6, 1946.

Filed July 25, 1944 TUYBULAR HEAT EXCHANGE APPARATUS MILLENER 2,404,187

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TUBULAR HEAT EXCHANGE APPARATUS l File@ July 25, 1944 5 sheets-sheet s lNvEN'ToR WITNESSIESI WILL [my H {VILLENER @uw A @www ATTORNEY July 16, A1946.

w. H. MILLENER l TUBULAR HEAT' EXCHANGE"APPARA'TUS' A 'Filed Jply 25,` 1944 5 sheets-shed@ WILLIAM 6'. {VILLE/VAT.

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Patented July 16, 1946 UNITED STATES PATENT j 'OFFICElv 'y 2,404,187 Y A i TUBULAR HEAT EXCHAN APPARATUS William Henry Millener, Guildford, England, as-

signor to Woodall-Duckham (1920) Limited, Guildford, England, a; British company Application July 25, 194'4,`Serial/No. 546,492 In Great Britain August 27, 1943 12 claims. (01.257-222) This invention relates to improvements in tubular apparatus for effecting heat exchange between fluids, such as heat exchangers and condensers. It is applied to apparatus of the floating-head type; and in which each of the fluids makes "at least two parallel passes through the apparatus, the paths of the fluids inside and outside the tubes being essentially parallel.

In heat exchange apparatus of the floatinghead type, the tubes conveying one of the fluids are built up into an integral assembly with the supply and exit manifolds at one and. the same end, and with a transfer header or headers connecting the various banks of tubes at the other end, so that the complete tube assembly can be` inserted into an enclosing shell through which the second uid flows. In systems in which the fluid flowing outside the tubes makes two or more passes over the tubes, pass plates are inserted between the banks of tubes to guide the fluid in the appropriate paths. In a two-or four-pass system, the inlet and exit ports for the fluid flowing over the tubes can both be situated at the same end of the enclosing shell as the connections to the tubes.

lIt is often desirable that the exterior ofl the tubes should be cleaned and in such cases a construction in which good access can be obtained to all parts of the tube assembly after Withdrawal from the shell will have important advantages over any arrangement in which the pass plates or baffles and their supports make the 'complete cleaning of the tube surfaces diicult or impossible. 'Ihe closer the outer edges of the pass plates can -be extended to the interior of the shell, the less will be the amount of short circuiting of the externally-flowing fluid between the various passes, with a consequent improvement in efficiency. In the known constructions, there has of necessity been av certain gap between the 'edges of the pass plates and the shell, to permit the tube assembly being inserted in and withdrawn The usual arrangement of the tube assembly in s transfer. Any arrangement which reduces sub- 2 ,4 stantially Vthis by-passing of the tubes byi the externally-flowing fluid will consequently. be ad' vantagcous and lead to an improved efliciency.

The present invention has each of the desirable features referred to in the three immediately pre,- Y

ceding paragraphs. Firstly, free access,unre stricted by the presence of pass plates or baiiles, can be obtained to the outsides of thev tubes for cleaning when withdrawn from the -shellgsince the pass plates andbaffles can becompletely dismantled from the tubeA assembly. Secondly, the outer edges of thefpass plates can be extended into direct contact with the interior ofthe shell, which substantially prevents short-circuitingof the externally-flowing fluid between Adifferent passes. Thirdly, the space between ythe outer,- most tubes and the shell can be adequately baflled to reduce the bypassing of the tubes by the fluid flowing in this space.' v

Various forms of the invention will now be described by Way of example with reference to the accompanying drawings, in which: Figure 1 is a vertical section through a fourpass condenser; y Y Figure 2 is a cross-section on the lined-"2 of Figure 1; l A l.

Figure 3 is an enlarged view of a detail of the device of Figure 1; Figure 4 is an enlarged sectional detailshowing spring-loaded pass plates applied to a `four,-

pass arrangement;

Figure 5 is a View perpendicular to that of Figure 4; f Y Figure 6 is a cross-sectional vieW of a modifica,- tion disclosing a two-pass condenser vhaving ja single pass plate; l n 1 Figure 7 is an enlarged view of a detail of Figure 6;` ,Y

Figure 8 is a cross-sectional view of a two-pass condenser embodying a spring-loaded pass plate; and j Figure 9 is an enlarged viewof a detail of Figure 8.

Referring to Figures 1, 2 and 3;, the condenser comprises an outer enclosing shell III witll-l an inlet I I and an outlet I2 for the fluid which flows externally over the tubes through which thesecrond fluid flows. The tube assembly comprises inlet and outlet manifolds I3 and I4 respectively, transfer headers I5, and banks of tubes :I6 connecting the manifolds `and the headers. The manifolds, tubes and headers are arranged to provide the desired number of passes for the internally-flowing fluid. :The manifolds,k tubes and headers form a unitary 'assembly whichcan be inserted into and withdrawn Yfrom the shell I Il, in which the tube assembly is mounted by the flanges 9.

In order to provide the requisiteV number of passes for the externally-flowing fluid through the shell between the inlet and outlet, pass plates are arranged between the banks of tubes. In the construction shown, the externally-owing fluid makes four passes, and two pass plates are therefore provided, arranged perpendicularly to each other across the interior of the'shell, thus divid- I ing the space into four quadrantal sections. Each pass plate comprises two iparts I1 and I'Ia, and I 8 and I 8a respectively. The inner portions of the two parts of each pass plate overlap as shown 1 in Figures 2 and 3, thus bearing on each other at right angles round the central longitudinal axis of the condenser. Holes 2| are provided in the pass plates as shown in Figure 1 to transferv f Qthe iluid4 to successive passes.

1f From Figure 2, it is seenY that if the two inner `portions of the plate II and Ila are moved towards each other, the eiect will be to move the outeredges of the two plates I8 and I8a out- `wards towards the inner surface of the shell I9, l and 'similarly movement of the inner portions of `theplates I 8 and Ia together moves the youter edges of the parts I'I and IIainto contact with the shell.` By moving the edges of the pass plates The parts of the pass plates are held together I and moved when required by means of two sets of Ybolts as 'shown in detail inFigure 3. The bolts I9 act on the Vplates I'I and the bolts 20 on the plates I8. Each bolt passes through an aperture in one ofthe parts of the pass plate, and screws into a nut portion I9a or 20a respectively welded to the otherY part of the pass plate.

The pass plates are placed in positionY between the tube-s when the tube assembly is withdrawn from the shell and lthe bolts I9 and 20 are screwed in loosely, so that the Vparts of the plates may be moved inwards a suilicient distance to `enable the whole assembly to be inserted in the shell. When in position in the shell, the bolts are then tightened by means of a long-handled box spanner 22 inserted through closable apertures 23 in the shell I0, as shown in Figure 1. The positions 'of the Various apertures 23 are arranged tp correspond to the positions of the bolts. The

l outer edges of the Apass plates are thereby moved outwards into contact with the interior of the 3 shell, forming an effective seal between the varil ous passes, While short-circuiting of fluid through the region where the pass plates meet on the axis is substantially prevented by their contact here, 'as shown in Figure 3. Conversely, when it is desired to remove the tube assembly from the shell, the bolts I 9 and 2U are first loosened with the spanner through the apertures 23, so that the pass plates are withdrawn from Vcontact with the shell, whereupon the whole assembly can be dir rectly extracted from the shell.

In order to minimize by-passing of the tube by 4iiuid flowing through the spaces between the banks of tubes and the surfaces of the pass plates,

(subsidiary baiiles 24 are provided at intervals across the'spacesj The baffles 24 are attached perpendicularly to the surfaces of the pass plates.

Further, in order to minimize by-passing of the tubes by fluid flowing through the space lbetween the outermost tubes and the inner surface of the shell (which space is caused by the size of the rim of the tube plate and the transfer headers I5); baille rings are provided at intervals across this space. These baille rings are formed of quadrantal sections 25 attached by pin and slot connections between the outer portion of each subsidiary baille 24 and a suitable projection 26 on the back of the adjacent part of the pass plate, as shown in Figure'2. The pin and slot connections permit the baille ring sections 25 to move out towards the inner surface ofthe shell when the pass plates are extended into position, and Vice versa.

It is seen that by removing the bolts I9 and 2li and the quadrantal baffle rings 25, the pass plates can be dismantled completely from thel tube assembly when the latter is removed from the enclosing shell, leaving the entire tube surface freely accessible for cleaning.

Figures 4 and 5 show amodiiication of the apparatus of Figures 1, 2 and 3, in which the bolts I9 and 2!) are dispensed with, and the pass, plates are extended into contact withl the shell by means of springs. The springs 21 areA flat L-shaped members, having one arm attached to the subsidiary baille 24 while the other arm bears freely on the inner portion of the adjacent partof a pass plate. As seen from Figure 5, the springs 21 tend to move the inner portions of each part of a pass plate together, and so the effect is the same as rthat of the boltsk I9 and 29. The parts of the pass plates are placed in position in the tube assembly and the quadrantalY baiile rings 25 are attached before the assembly is inserted into the shell.V The edges of the pass plates near the head are then pressed in towards the axis sufficiently far to enable the head to be inserted into the opening of the shell, and .the remainder of the tube assembly can then be pushed into the. shell, the compression of the springs 2'! acting to keep the outer edges of the pass plates pressed intocontact with the inside of the shell. In the same way as in Figures 1, 2 and 3, the pass plates and baiiles can be dismantled completely from the tube assembly.

f Figures 6, 7, 8 and 9 show the present invention applied to a condenser in which the externally-flowing fluid makesl two passes over the tubes. y

Figures 6 and 7 show an arrangement in which the two parts of the pass plate are connected together and moved relatively to each other by screwedV bolts., The pass plate is formed of two parts, one of which 28 extends diametrically acrossfnearly the whole of the internal width of the shellV I0, while the remaining part 29 is much narrower and serves to close rthe remaining gap. The part v29 is of L-section as shown clearly in Figure 7, and the part 28 has its edge 28a turned up at right angles. Screwed studs 30 are mounted inthe part 29 as shown, and pass freely through apertures in the edgeZSa. Ro.

tation of a nut on stud 30 causes the vertical portion of part 29 to move towards part 28a, and so presses the edge 29a into contact with the inner surface of shell I0, and the remote edge` of the pass plate into contact with the opposite side of the shell.

Barile rings 3l which baiile the space between the outermost tubes and the .shell as in the preceding -constructions are now practically' semicircular. The ends of the lower. sections of the baffles 3| are attached to at longitudinal members 32 extending over the length ofthe tubes (see Figure 7). The ends of the upper sections remote from the part 29 of the pass plate are attached to a similar longitudinal member 32a, while the other ends are attached to the part 29. Bolts 33 pass freely through apertures in the memberv 32 adjacent to the part 29 and screw into a nut portion 33a welded to the part 29. A

The assembly and operation are very similar to those of Figures 1, 2 and 3. Th'e two parts of the pass plate together with the baille rings 3| are first mounted on the tube assembly with the nut on stud and the bolt 33 loose, and the assembly is inserted in the shell. Access to the nuts and bolts is then obtainable through the closable apertures 2 3 in the shell (Figure 6). Tightening the nut onstud 30 extends the two edges of the pass plate into contact with' the interior surface of the shell, while tightening the bolt 33 brings the edge of the part 29 into contact with the part 28 and so prevents iluid shortcircuiting between the passes at this point. The bolt 33 also holdsgthe annular bailles 3| in position. Before withdrawal of the assembly from the shell, the nuts and bolts are slackened through the apertures 23 and the whole assembly can then be freely withdrawn. By removing the nuts and bolts, the pass plate and the baille rings can be completely dismantled from the tube yassembly, leaving the latter fully accessible for cleanlng.

Figures 8 and 9 show an arrangement, comparable to that of Figures 6 and '7, in which the nuts and bolts are replaced by springs. The passA plate is again formed of two parts 34 and 35, of which the part 34 extends across nearly the whole diameter of the shell I0 while the part 35 closes th'e space between the part 34 and the shell. yPart 35 is slidably mounted on the edge of part 34 by means' of fthe bolts 36 which pass through slots in the part 35 as shown in Figure 9. Between parts 34 and 35 are springs 31 which bear against the up-turned edge 35a, and act to move th'e two sections of the pass plate apart, thus pressing the edge 35a into contact with the shell at one side, and the remote edge of part 34 into contact` with the shell on the opposite side.

Semi-circular baille rings 3| are provided as in the preceding case. The ends of th'e lower sections of the bales are attached at one end to a longitudinal member 38 which itself is attached to the part 34 of the pass plate; the other ends of these bailles are attached to a longitudinal member 39 on which the part 35 slides freely. The ends of the upper sections of the baffles 3| are attached to a similar longitudinal member 40 resting freely on the part 34, while the ends adjacent the part 35 are attached thereto as shown in Figure 9.

Insertion of the tube assembly and bailles in the shell is effected in a manner similar to that used for the arrangement of Figures 4 and 5. The two parts of the pass plate near the head of the tube assembly are first compressed until the head can be inserted in the shell opening, and the assembly is then pushed into position, the springs 3l operating to hold the edges of the pass plate against the inner surface of the shell. When withdrawn from the shell, the baille rings and pass plate can be dismantled completely from the tube assembly to render the tubes freely accessible for cleaning.

, 6 What I claim is 1. Tubular apparatus of the floating-head rtype for effecting heat exchange between fluids wherein the fluid flowing outside the tubes makes four parallel passes through the apparatus, including in combination a cylindrical enclosing shell of uniform diameter permanently closed at one end, a tube assembly incorporating four tube banks Vbetween inlet and outlet manifolds and a iioating head, which tube assembly is insertable in and removable from the enclosing shell through the end opposite to the closed end, two pass plates arranged perpendicularly to one another across the interior of the shell, each of said pass plates being formed of two relatively movable and separable parts inserted between the tube banks with their inner portions overlapping, the inner edges of the parts of one pass plate bearing perpendicularly on the inner portions of the parts of thev th'e enclosing shell when the tube assembly and the pass plates are inserted in the shell.

2. Heat exchange apparatus as claimed in claim 12, in which the two parts of a pass plate are held together and moved relatively to each other by means of bolts accessible through closable apertures in the enclosing shell.

3. Heat exchange apparatus as claimed in claim 1, in which the two parts of each pass plate are held together and moved relatively to each other by means of bolts accessible through closable apertures in the enclosing shell.

4. Heat exchange apparatus as claimed in claim 1, in which the two parts of each Apass plate are held together and are moved relatively to each other by means of bolts accessible through closable apertures in the enclosing shell, which bolts are operated by means of a long-handled spanner inserted through the said apertures.

5. Heat exchange apparatus as claimed in claim 12, including a spring operative to press the outer edge of each part of a pass plate into contact with the enclosing shell.

6. Heat exchange apparatus as claimed in claim 1, including springs carried by the two parts of one pass plate and operative to press the inner portions of the two parts of the other pass plate towards each other.

7. Heat exchange apparatus as claimed in claim 12, including a longitudinal member joining the ends of each arcuate baille remote `from the ends connected to a part of a pass plate, said longitudinal member bearing on the other part of the said pass plate.

V8. Heat exchange apparatus as claimed in claim 1, including quadrantal baffles bailling the space between the outermost tubes of the tube assembly s andthe interior of the enclosing shell arranged at intervals along the length of the tubes, and a nonrigid connection between the end of each quadrantal baille and the adjacent part of a pass plate.A

9. Heat exchange apparatus as claimed in claim 12, including subsidiary bailles .projecting from the parts of a pass plate arranged at intervals along the length of the tubes and bailling the space between the tube banks.

10. Heat exchange apparatus as claimed in claim .1, including subsidiary bailles projecting from the parts of the pass plates arranged at 11. Heat Vexchange apparatus as claimed in.

claim yl, including `subsidiary baffles projecting fro-m the parts of the pass plates arranged at intervals along the length of the tubes and baiilng the space between the tube banks, quadrantal baies baiiling the space between the outermost tubes of the tube assembly and the enclosing shell, a non-rigid attachment between the outer end of a subsidiary bafle and one end of each quadrantal baille, and a non-rigid attachment between the other end of each quadrantal balile and the adjacent part of a pass plate.

12. Tubular apparatus of the oating-head type for effecting heat exchange between uids,

Vwherein each of the fluids makes at least two 8 iioating head, which tube assembly is insertable in and removable from the enclosingI shell through the end opposite to the closed end;` a pass plate formed of two relatively movable and separable parts inserted between the tube banks, each of said pass plate parts being entirely unattached to the tube assembly; arcuate baiiles baiiling the space between the outermost tubes of the tube assembly and the interior of the enclosing shell, arranged at intervals along the length of the tubes; a connection between one end of each of said arcuate bafes and a part of a pass plate; means to support the other 'end of each arcuate baile adjacent to the edge of a pass plate and to the interior of the enclosing shell; and means to efectthe movement .of the two parts of the pass plate into contact with the interior of the enclosing shell when the tube assembly, the pass plate parts, and the arcuate baffles are inserted into the shell, while maintaining a seal between WILLIAM HENRY MILLENER.4

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