US2887304A

US2887304A - Heat exchangers

Info

Publication number: US2887304A
Application number: US602003A
Authority: US
Inventors: Hilliard Alfred
Original assignee: Carbone Lorraine SA
Current assignee: Mersen SA
Priority date: 1955-08-15
Filing date: 1956-08-03
Publication date: 1959-05-19
Anticipated expiration: 1976-05-19

Description

May 19, 1959 A. HILLIARD HEAT EXCHANGERS Filed Aug; 3, 1956 5 Sheets-Sheet 1 ATTOR/VEXS May 19, 1959 A. HILLIARD 7 2,887,304

7 HEAT EXCHANGERS Filed Aug. 3, 1956 5 Sheets-Sheet 2 6 72 60\6l fla 63 67 Flinn a. 9 Fag]. I 70 .-:6 68 g 64 7 go v AM Pet-p r9014 04/610 ATTQRAEXS.

United StateS Pa efl Q 2,887,304 p I v 1 HEAT EXCHANGERS Alfred Hilliard, London, England, assignor tiiISociete Le Carbone-Lorraine, Paris, France, a French com 1, Application August3, 19s6,seria1No.,6o2,q0;s

Claims priority, application Great Britain i August 15, 1955 H t t 5 Claims. c1. 2s7--241 This invention relates to heat exchangerszof .the kind in-.which-a plurality of sets of ducts for passage .there-;

through of two heatexchange media respectively are provided in a block of material in heat exchange relational ship :with each other. described in British patent specifications 739,906, 756,327 and 756,240.

Heat exchangers of this kind are Nos. 736,305;

block to the next. Said shell which completely surrounded the column of blocks, involved the provision of a sliding joint to accommodate differential expansion between the casing (usually made from metal) and the column of blocks which may be made from graphite.

"Alternatively, if lateral headers were used instead of the aforesaid shell to convey the second heat exchange medium from one block to the next, the gaskets of the latter had to cross the gaskets relating to thefirst series of passages, which involved danger of leakage and necessitated careful and costly manufacture. -1If;the' second heat exchange medium was corrosive, and

ifythe aforesaid shell or the headers were made from metal, the latter had to be provided with corrosion resistant linings.

It was necessary to remove the shell or the lateral ersto locate leakage of a gasket. 1

The main object of the present invention is to provide heat exchangers which can be built uptfrom blocks to form a column without involving crossing gaskets, which do notrrequire the use of an outer shell or external lateral headers for the conveyanceof the second heat exchange fluid from one block to the next, and which permit visual observation of at least some of the gaskets between the blocks.

head- A further object of the invention is to obviate the use of a sliding joint to allow for difierential thermal expansionof the materials of construction.

According to the present invention a heat exchange blo ck is provided in which at least one end of, the block has; at least two openings for different heat exchange media whereby they can be surrounded by gaskets that do notpcross each other, said openings communicating through the block by means of at least two corresponding sets of ducts which extend transversely across each other in the block. t p t .;By such a construction a heat exchanger can be made byconnectingtwo ormore blocks end to end whereby the heat exchange media can flow through the blocks 'with out requiring an outer casing for conducting fluidfrom one-block to the next and without gaskets crossingover each other.

fee

2,887,304 Pstse i x .1 259,

The invention also otters other advantages: for. ex-' ample the outer gaskets can be visible which facilitates detection of leaksydifierent flow arrangements can be achieved with a given form of block; easier dismantling and reassembly is possible; and metal strengthening bands around the blocks will not need protectionagainst corrosive fluids. Y Y

Any convenient shape and number of blocks, e.g. cylin-L- drical orrectang ular blocks of graphite orother material preferably of high heat conductivity, may be mounted to forina column with gaskets between adjacent blocks orsev'eral columns side by side secured together by tie bars or other means; and: provided with headersat'the ends of thecolumn and inlet and outlet means for the medi H p j Some constructionalforms of the'invention will nowbe described by way of exa ple with reference to the accompanying diagrammatic drawings wherein:

Figure 1 is a perspective view ofa column made in accordance with the invention;

igure '2 is a view of said column partly in side eleva 1 tion aridfpartly in section; 1

-Fig'u re 3"shows similar blocks having amodified form of ducting; p p i e Figure 4is a viewpartly in section and partly in perspective of a similar column with a further modified form 05 ducting; j

Figure 5-is asectional view of another form of block;

Figure6' shows the block of Figure 5 in plan;

-Figure 7 is a view partlyin" section and partly'in per-f spectiv e showing cylindrical blocks; i

Figures 9 and 10 are sectional views on lines 9 9 andj10-10 respectively on Figure 8; Figure9 has been rotatedthrough about degrees inthe clockwise direc tion in relation to the section 9-9; and t Figures 11 and 12'ar e sectional views of heat exchangers made with cylindrical blocks and illustrating difierent flow paths achieved-with the same standard blocks.

In theconstruction shown in Figures 1 and 2 blocks 10 11,12 z'ire showhf disposed in the form of a column with g'askets13, 14between adjacent blocks. .A similar gasket 15 is shown on the top'block 10. Each gasket surrounds separate

rectangular areas

17, 18, 19, 20, 21, 221 Openings in the top surface of the block 10 are formed by the ends of ducts 23 that extend through the block to the opposite end surface into the area .corre spending to 18'thereby extending transversely across. ducts 24 the ends of which form openings injthe arealSl Thejduets 2,4extend through the block to form openings of blocks inthe area of the'opposite surface corresponding to area 17. In the next block 11 the ducts change direction and again crossfleach other, and soon. By suitable header means the

ducts

23, 24. at the lower surface of the block 12 cannbeconnected with the next adjacent sets of ducts 26,127 andfromihe top surface of block 10 the

ducts

26,,27 communicate with

ducts

28, 29. Thus the dash lines 30 in Figure 2 show"the path of one medium and th'e d'ot and dasli'li'nes 31 show the path of the other medium. The blocks may be clamped between header plates, by means. of tie-bars.

The arrangement of the ducts leaves the strongest parts of the blocks at and near their side surfaces which ensures best mechanical strength to withstand clamping pressure of the tie-bars.

In the modification shown in Figure 3 the ducts are of etchelon shape giving a similar effect.

In the alternative construction shown in Figure 4 ducts 30 pass through the blocks from end to end and other ducts 31 are drilled through the 'blocks in the direction from side to side of the blocks at right angles to the ducts 30 and have their ends blocked by

plates

32, 33 and communicate with

manifolds

35, 36 which provide openings in the end surfaces of the blocks in I.

areas separate from the openings of the ducts 30 so that the separate areas can be surrounded by gaskets 34, 39

which do not cross. These manifolds open into the upperand

lower end surfaces

37, 38 respectively of the block. One heat exchange fluid flows through the ducts 30. The other fluid flows through the manifolds 36 into the ducts 31, and into the manifolds 35. This fluid then flows into the manifold corresponding to 36 of the next block. Suitable gaskets are provided as before.

Another constructional form of the invention is shown in Figures and 6 which show a block having a manifold 40 at one end opening into the top end surface and branching at 41 so as to open out into the side face 42. Another manifold 44 at the other end of the block opens into the bottom end face of the block and branching at 45 into the surface 42. Ducts 47 are drilled transversely through the block. Other ducts 48 are drilled through the block at right angles to the ducts 47. A header plate 50 connects the manifold branch 45 to one half of the ducts 47 on the side 42. A header plate 51 connects the manifold branch 41 to the other half of the ducts 47 on the same side 42. A header plate 54 connects all the ducts to each other on the opposite side of the block. Thus one fluid passes from

manifold

44, 45, header 50, right hand ducts 47 into header 54. The fluid then flows through the other half of the ducts 47 to header into the manifold 40, 41 and then intothe manifold corresponding to 44 of the next block which is reversed end to end in relation to the first block. The header plates may be replaced by flat plates and the blocks recessed to form header spaces. The other fluid flows through the ducts 48 of one block into similar holes in the nex block.

Thus gaskets or packing rings 43, 46 can surround different areas on the same end surface of the block without crossing each other, the areas leading to separate series of ducts 47, 48 which extend transversely across each other in the block.

In the construction shown in Figure 7 of the accompanying drawings the blocks 60 are cylindrical and their end flat faces 61, 62 abut, i.e. are parallel to and adjacent the similar faces of adjacent blocks. These flat faces are formed with deep frustoconical recesses or

manifolds

63, 64 separated from each other by a wall 65. Near the periphery of the block and parallel to the axis thereof are an upper series of manifold recesses 67 in line with a similar lower series of manifold recesses 68, each forming openings in the end surfaces of the blocks in areas separate from the areas of the openings in said end surfaces formed by the manifolds or recesses 63, 64. Two series of

ducts

69, 70 are drilled from the The fluid media from 63 passes through A t and manifold 64 into the next manifold such as 63 and so on. A third set of ducts 72 are drilled through the block parallel to the axis thereof. The blocks are somewhat spaced apart from each other and provided with

gaskets

73, 74, 75, the outer one (73) of which can be seen through the gap between the blocks which facilitates detectionofleaks. The second heat exchange fluid passes through these ducts from one block into the space between adjacent blocks surrounded by the gaskets 74, and into the corresponding ducts of the next block.

The

gasket

74 or 75 may be omitted if the same fluid passes through the

ducts

70 and 72 or 69 and 72 respectively.

The construction shown in Figures 8, 9 and 10 is in general similar to that of Figure 7 but the grouping of the ducts is more precise. Thus the ducts 72 are arranged in triangular shaped radial groups spaced apart from each other and the sets of

ducts

69, 70 are disposed between the said groups. The manifold 67 has branches 80, 81-, to provide ample cross-sectional area for flow of fluid.

Figures 11 and 12 show a complete heat exchanger consisting of four

blocks

89, 90, 91, 92 arranged end to end in a vertical column with an upper header 94 and a lower header 95 and top and

bottom plates

96, 97 connected together by tie-bars 98 so as to clamp the wholeheat exchanger together. The blocks are cylindrical asin Figures 7 to 10. The vertical ducts 72 are connected at the interfaces of the blocks by turbulence spaces 99. The header 95 provides two inlet or

outlet openings

100, 101 and the header 94 has

similar openings

102, 103.

In Figures 11 and 12 the blocks are of identical shape except for the gasket grooves which in Figure 11 are arranged so that one heat exchange medium enters from 103 and passes through an opening 104 in the header into a manifold 105 and a turbulence chamber 106 so that this medium passes through two sets of ducts and leaves in a similar manner through the outlet 101 in the bottom header. The other medium enters at 100 and passes by the third set of ducts to the outlet 102.

In Figure 12 the gaskets are differently arranged and a hole 110 is bored centrally through the top block and a similar hole 111 is bored centrally through the bottom block. The set of passages 69 is omittedin the first block 89 and the set of passages 70 is omitted in the last block 92. In this case the medium entering at 100 divides into two streams passing through the two set of crossing ducts and uniting again in a common stream leaving at 102. The other medium passes from 103 through the ducts 72 to the outlet 101.

If the two sets of crossing ducts have a different heat exchange area and/or different cross-sectional areas, a third combination becomes possible.

Further by using these three combinations with a polypass system many other arrangements are possible.

The blocks may be formed of metal, graphite or other material.

In all constructions the sets of ducts are brought either directly or by manifold to separate areas on the same face of the block whereby the two fluids from one block flow from one face of one block into ducts or manifolds in the abutting face of the next block thereby avoiding the use of gaskets which cross each other.

As no shell is required, this reduces not only the respective cost of the assembly (a stainless steel shell, for'example, can be very expensive) but also makes the assembly much lighter and more handleable. makes it practicable to use larger blocks and assemble a greater number of blocks together than would be convenient if the additional weight of the shell had to be contended with. The absence of an outer shell further obviates the necessity for floating headers or other arrangements to compensate for differential expansion between This in turn I heat exchanger and shell which can be costly and troublesome.

Another important practical advantage of the invention is that it permits accommodation of very large heat exchange areas in a single heat exchanger and that the blocks are detachable, which not only facilitates cleaning and repairing (if this should ever be necessary) but if any block is accidentally damaged it can be replaced at a much lower cost than if the assembled blocks were cemented together or otherwise fixed together non-detachably.

If the blocks are made from graphite then the orientation of the graphite crystals can be controlled to ensure best heat transfer conditions between the sets of heat exchange passages.

I claim:

1. A heat exchanger comprising a homogeneous solid block having two openings for different heat exchange media in each of the end surfaces thereof, said openings being positioned in first and second areasof each of said surfaces, said openings communicating with at least two corresponding sets of ducts which extend transversely across each other in the block and are separated from each other, said ducts comprising short straight drilled holes within the solid block and the ducts of one set being closely adjacent the ducts of the other set where the ducts of the first set cross the ducts of the second set with opposite ends of said one set of ducts communicating with the opening of the first area of said one end surface and the opening of said second area of said second end surface, and the opposite ends of said second set of ducts communicating with the opening of said second area of said one end surface and the opening of said first area of said second end surface, the ducts of each set being interposed between the ducts of the other set whereby simple headers may be used at the opposite ends of the solid blocks.

2. A block as claimed in claim 1 wherein the block is rectangular and at least one set of the ducts extends therein in the direction from side to side of the block but opens into manifold recesses which constitute said openings in the ends of the block.

3. A block in which at least one end surface of the block has at least two openings for different heat exchange media, said openings being positioned in different areas of said surface such that they can be surrounded by gaskets that do not cross each other, said openings communicating with at least two corresponding sets of ducts which extend transversely across each other in the block and are separated from each other, said ducts comprising short, straight drilled holes, the ducts of one set being closely adjacent the ducts of the other set where the ducts of the first set cross the ducts of the second set, the ducts of each set being interposed between the ducts of the other set, said openings being spaced apart over the major part of the areas of said surface; said block being cylindrical and has a central manifold recess at each end and a circular series of manifold recesses at each end around the central manifold recess, said recesses forming said openings in the ends of the block and each set of ducts opens at one end into the central manifold recess and opens at the other end into the series of manifold recesses.

4. A block as claimed in claim 3 wherein each of the two sets of ducts opening into the manifold recesses is arranged in a series of groups around the axis of the block and another set of ducts is located between adjacent groups and passes directly from end to end through the block.

5. A heat exchanger comprising at least two solid homogeneous blocks each having in each of two opposite surfaces at least two openings for different heat exchange media, said openings being spaced over substantially the whole area of said surfaces, all four said surfaces being parallel to each other, one of said surfaces of the first block being disposed closely to one of the surfaces of the second block, so that these two surfaces are adjacent each other while the other two surfaces are remote from each other, the openings in one of the surfaces in each block 1 being connected respectively to the openings in the other surface of said block by two sets of ducts which extend transversely across each other in the block, whereby heat exchange occurs between one set of ducts and the other set through the solid material of the block, the ducts comprising straight drilled holes, each duct extending from one opening at one end of a block to an opening at the other end of the same block, the ducts of one set being closely adjacent of the other set where the ducts of the first set cross the ducts of the second set, the ducts of each set being interposed between ducts of the other set, said openings being spaced apart over the major part of the area of said surface, packing between said adjacent surfaces which separates the openings in each surface from each other but permits media from the two openings in one surface to pass respectively to the two openings of the other adjacent surfaces, means to conduct the media respectively to the openings in one of said remote surfaces, and means to conduct said media respectively away from the openings in the other remote surface.

References Cited in the file of this patent UNITED STATES PATENTS 106,686 Gee Aug. 23, 1870 1,571,068 Stancliffe Jan. 26, 1926 1,799,626 Keith Jr Apr. 7, 1931 2,466,676 Boling et a1 Apr. 12, 1949 2,499,448 Axelson et a1. Mar. 7, 1950 2,699,325 Hedin Jan. 11, 1955