DE2146470A1 - Heat exchanger - Google Patents

Description

United Kingdom Atomic Energy Authority, 11, Gharlee II Street, London S.W 1 / England

For this application, the priority will be taken from the UK Claimed Patent Application No. 44621/70 dated Sept. 18, 1970.

Heat exchanger

The invention relates to heat exchangers and, more particularly, to the type of heat exchanger which generally are referred to as tubular boiler heat exchangers, in which a series of tubes in a jacket arranged, a heat transfer medium is passed through the jacket over the outer surfaces of the tubes and the heat transfer takes place through the tubes to a second medium flowing through the tubes.

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In one embodiment of such a heat exchanger the tubes have a U-shape, which is arranged in the longitudinal direction in the jacket, and are at their ends by welding connected to the tube sheet in the jacket.

The present invention is concerned with problems which occur when such heat exchangers are used, for example, as steam generators or steam superheaters can, in which a liquid metal, e.g. sodium, is used as a heat transfer medium, which is passed through the Jacket is passed over the tube bundle as well, and with the water for steam generation or steam for superheating through the pipes is directed. The heat exchange takes place between media that react violently with each other when they come into direct contact with each other, and it must be particularly ensured that the welds between the tubes and the tubesheet of high quality and easily accessible for inspection and repair during the Maintenance of the heat exchanger.

In addition, provision must be made for an adequate bending possibility of the tubes due to thermal expansion during operation of the heat exchanger and for collection and mitigating the effects of a reaction between the heat transfer media when encountered e.g. should come into contact with each other in the event of a pipe burst.

In accordance with the present invention, a shell type heat exchanger comprises a series of U-shaped tubes arranged lengthwise in the shell, the tubes in a number

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are combined by separate tube bundles and the ends of the tubes with individual tube sheets in separate inlet and outlet headers are connected in an end cap head for the jacket. With this arrangement there is an access to manufacture of the welds between the pipe ends and the pipe sheet readily available ^ during manufacture of the heat exchanger and for subsequent or later repairs or inspections of the pipe welds in operation or during maintenance. In addition, the tube bundle with the end cap of the jacket during the Operation or maintenance of the heat exchanger to inspect the shell and to repair any defective ones Removable tube / tube sheet welding.

In another embodiment of a heat exchanger according to the invention, the ends of the tube bundle extend through a lower tube sheet and are with an upper tube sheet in each inlet and outlet header tube connected in the end caps for the jacket, with the upper and lower tubesheets in each inlet and outlet header tube are separated by a sealed space in the head tube which is used to indicate any leakage to the Pipe / tube sheet connections is monitored.

According to a further feature of the invention, each tube bundle is contained in a single tubular casing, wherein a line is provided for guiding the heat transfer medium from the outside of the jacket in one end of each jacket so that the heat transfer medium passes through the jackets over the surface of the tubes

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flows into the tube bundle and into the jacket of the heat exchanger enters from the other end of the jackets. With this arrangement, each ear bundle is separate from the others Tube bundles separated by its own jacket, so that damage as a result of the reaction between the heat transferring Medium flowing through the pipes and the medium ■ flowing through the pipes is restricted to the pipe bundle, in which the reaction takes place. The sheaths for the tube bundle can be made strong enough to the Shock wave energy releasing to withstand the reaction and there may be devices in the form of a pressure relief device for the withdrawal of the gaseous products of such a reaction from the jackets to the outside of the jacket or boiler be provided.

Another feature of the invention is the tubes arranged in the individual tube bundles at a distance from one another and at intervals along their length through transversely arranged Lattice set, which are supported against each other in an articulated or articulated construction, so that bending the pipes can be absorbed as a result of thermal expansion. The jackets for the tube bundles may comprise individual tubular jackets extending between adjacent grids, so that the sheaths can bend with the tubes of the tube bundles.

A pipe distributor for the heat exchange medium can be provided, which extends longitudinally through the jacket between the Extends tube bundles, the manifold from an inlet port goes out at the lower end of the mantle and has a head

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container at its upper end in the jacket, with the head container openings in its bottom and in its has upper area for the implementation of the legs of the tube bundle, which lead to the outlet nozzle in the upper closure head of the jacket, with jackets or sleeves also provided are that the outlet ports in the upper closure head of the jacket with the corresponding openings in the upper cable of the Head container »connect, with the parts of the sheaths for the legs of the tube bundle, which lead to the outlet nozzle in the closure head of the jacket, at their upper ends with the Openings in the bottom of the head container are in communication and wherein the parts of the sheaths which the legs of the tube bundle which lead from the inlet port in the closure head of the jacket, at their upper ends to the interior of the Are open towards the jacket.

A strong retaining plate may be provided which is mounted within the closure head of the jacket, wherein the retaining plate carries the inlet manifold and the 'grid system and thus the jackets for the tube bundle, so that the arrangement of the Versohlußkopfes the tube bundle and their jackets and the inlet manifold as one closed structural unit is removable from the jacket.

The grids for distributing and fixing the tubes of the tube bundle can be connected to one another by anchor bolts extending between adjacent grids, with the anchor bolts in an articulated construction with the outer frame members of the grid are connected. The top

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Grids on each leg of the tube bundle can be secured by anchor bolts be connected in the same way to the retaining plate in the end closure head of the jacket.

The individual tubular sleeves of the jackets for the tube bundle can be located between cylindrical flanges on the frame members of adjacent grids, each shell at one end with the splash on a grid is welded and with the jacket at its other end with Sezug on the flange of the adjacent grid has a sliding fit.

The lower end of each jacket for the tube bundle can be formed by a U-shaped jacket that surrounds the U-shaped ends of the tubes, the i ^ nden of the U-shaped jacket with the ends of the lowermost tubular Sheath are connected, which form part of the sheath on the upright legs of the tube bundle. A partition plate can also be provided which extends over the lower end of the shell, as well as outlet ports in the U-shaped jackets that form the lower ends of the jackets for the tube bundles that are over Openings in the partition plate are in communication with the space in the jacket below the partition plate and it can also have a -auslaßstutzen with a pressure relief device (e.g. a rupture plate or rupture disc) may be provided in the jacket, which corresponds to the space under the partition plate communicates.

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The invention will now be explained in more detail with reference to the drawing showing it for example shows

Fig. 1 is a longitudinal section along the line I-I in Fig. 3, Fig. 2 is a longitudinal section, partially exploded, showing the main components of the heat exchanger according to the section along the line II-II Fig. 3 illustrates

Fig. 3 is a plan view of the heat exchanger according to Fig. 1, Fig. 4 is an ochnitt along the line IY-IV in Fig. 2, Fig. 5 shows a section along the line Y-V in Fig. 2, Fig. 6 as a detail of the attachment of the distributor for the heat transfer medium,

Fig. 7 is a plan view of the lattice structure used in the heat exchanger;
FIG. 8 shows a detail in section along line VIII-VIII in FIG. 7, while

9 shows a section through a further embodiment of the inlet and outlet headers of the heat exchanger of FIG. 1 illustrated.

The heat exchanger shown in the drawings is particularly useful as a steam generator in which a liquid metal, such as sodium, as a heat transferring Medium is used, and comprises a cylindrical dumbbell 1, which is an arched or dome-shaped has lower end 2. The jacket 1 is provided with a domed closure head 3 which has two water inlet headers or nozzle 4 and two longer steam outlet headers or connector 5 has. The bolt head 3 has an outer

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Splash 6, over which the same is screwed to an outer end flange 7 on the jacket 1 and welded tightly. A seal is attached between the contact surfaces of the planes 6 and 7. The toll oil 1 contains two U-shaped tube bundles 8, which extend longitudinally through the jacket 1 side by side.

According to the Pign. 1 and 2, each tube bundle 8 comprises an array of U-shaped tubes 9 * Pig * 1 shows one of the Tube bundle 8 and the connected water inlet head or nozzle 4 and the steam outlet head or nozzle 5 on Closure head 3 · The tubes 9 in the tube bundle 8 are on one side End with a tube sheet 10 in the water inlet head piece 4 and at the other end with a tube sheet 11 in the steam outlet head piece 5 connected. Similarly, the tubes 9 are in the other tube bundle 8 with the tube sheets 10, 11 in the second Water inlet head or stub 4 and steam outlet head or stub 5 of Verscblußkopfes 3 connected.

A circular or round reinforcement retaining plate 12, which has radial stiffening ribs 13 is screwed tightly to an annular flange 14 within the bolt head 3. The holding plate 12 forms a support for an • "atrium inlet manifold 1.5 and for a cover or a jacket 16 which surrounds the tube bundle 8. According to Pig. 4, the holding plate 12 has openings 17 for carrying out the Water inlet handles of the tube bundle 8 from the inlet headers 4 and openings 18 for the passage of the steam outlet legs the tube bundle 8 to the outlet headers 5.

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According to FIGS. 1, 2 and 5 comprise the inlet manifold 15 a line 19 with a rectangular cross-section, which extends through the jacket 1 between the tube bundles 8. At the top of the inlet manifold 15 leads the line 19 into an upper or head container 20. The distributor 15 is fastened by means of screws to the retaining plate 12 on the head container 20, the upper one Closure plate 21 has openings 22 which the Openings 18 in the holding plate 12 correspond. Openings 23 in the bottom of the head container 20 correspond to the openings 22 in the upper closure plate 21 of the head container 20, so that the steam outlet tube legs of the tube bundle 8 through guide the head container 20. Pig. 6 shows the method for Attach the manifold 15 to the retaining plate 12. Screws 24-, which pass through oversized openings Extending in the retaining plate 12 are screwed into threaded eyes or lugs 26 on the upper Closure plate 21 of the head container are welded. Washers 27 are disposed between the heads of the screws 24 and the retaining plate 12, and there are others Washer 28 made of Stellite (registered trade name) placed on the screws 24 between the holding plate 12 and the eyes 26. Since the openings 25 with reference on which screws 24 are oversized, there is radial thermal expansion of the head container 20 relative to the retaining plate 12 possible.

Each of the Dampfauelaßkopfetüoke 5 on the bolt head 3 is provided with a thermal jacket 29. The thermal jackets 29 extend right down to the

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Openings 18 in the holding plate 12. A flange 30 is round arranged around each of the openings 18 in the retaining plate 12, and the lower end of each thermal jacket 29 is with the flange 30 and around the corresponding opening 18 in the holding plate 12 by a bellows 31.

As in FIGS. 1 and 2, the line 19 of the inlet manifold 15 has a cylindrical shape at its lower end 32. A round partition plate 33 is screwed to the flange 34 within the lower end of the shell 1. The cylindrical lower end 32 of the inlet manifold 15 extends through a central opening 35 in the partition plate 33 into a sodium inlet port 36 at the lower end of the shell 1. The cylindrical lower end 32 of the inlet manifold 15 is slidable within the Inlet connection 36 sealed by piston ring seals 37. A bell-shaped sealing ring 38 is around the opening 35 mounted in the separation plate 33 the sealing ring forms a seal around cylindrical end 32 of inlet manifold 15.

According to FIGS. 1, 7 and 8, the jacket 16 surrounding each of the tube bundles 8 comprises a series of cylindrical ones Jackets 4-0, which extend between the transversely arranged grids 41, which the tubes 9 of the tube bundle 8 at intervals divide and determine their length. As shown in FIGS. 7 and 8, the grid 41 has a circular shape Plate 42 which is provided with an essentially hexagonal opening 43. Holding members 44 for the tubes 9 of the Tube bundles 8 extend over the opening 43 in the plate 42. The holding members 44, which fix the tubes, exist from Ziok-Zaok strip lines 45, which are e.g.

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weld on the surfaces of the upright strip members 46 are attached. Eyes 47 at the ends of the vertically arranged Strip members 46 are used to assemble the members 44 to fix the tubes on the plate 42 by means of hexagon socket screws 48. The tubes 9 of the tube bundle 8 lie in the grooves or troughs of the zigzag strip members 45.

In general, each grille 41 is held in place by the grille 41 immediately above it by anchor bolts 49. 8, the anchor bolts 49 have collared ends 50 which pass through the holes 51 in the plate 42 of each grid 41 pass through. The ends of the anchor bolts 49 provided with a collar are equipped with nuts 52, which have a game with respect to the plates 42 of the grid 41, so that the grid 41 with each other in joint or. Link construction by the anchor bolts 49 are connected to one another. According to Fig. 1, the upper grids are 41 on both the water inlet and outlet legs the tube bundle 8 is suspended from the retaining plate 12 by similar anchor bolts 49.

The cylindrical casing 40 of the casing 16 of the tube bundle 8 each extend between two grids 41. According to Fif _a ·. 8, a cylindrical flange 53 is welded around the edge of the plate 42 of each grid 41. The upper end of each jacket 40 is arranged around the flange 53 of the upper of the two grids 41 and welded to it. The lower end of the jacket 40 extends around the flange 53 of the lower of the two grids 41 and can move freely on the same.

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As can be seen from FIG. 1, the lower end of the sheath 16 for each tube bundle 8 is formed by a U-shaped Sheath 54 is formed, the upper ends of which are formed around the flanges 53 of the lowermost grilles 41 on the water inlet and steam outlet legs of the tube bundle 8 are arranged and welded to the same, - ^ eide U-shaped jacket 54, which the lower Forming the end of the casing 16 for the tube bundle 8, they have an outlet connection 55. The outlet port 55 of the U-shaped Jacket 54 are with openings 56 in the partition plate 33 on The lower end of the jacket 1 is connected in the flange 57 arranged around each of the openings 56 in the partition plate 33, and each flange 57 is with - ^ outlet stubs 55 of the corresponding Sheath 54 connected by a bellows 58. The lower arched or dome-like end 2 of the Shell 1 below the partition plate 33 is provided with an outlet nozzle 53, which is a relief or safety device, for example a fracture plate.

On the water inlet leg of each tube bundle 8, the casing 16 ends at the upper grille 41 below the holding plate 12. At the steam outlet leg of each tube bundle 8, the jacket 16 extends over the upper grille 41 to the bottom of the sodium head container 20 of the sodium inlet manifold 15 through a jacket 60. The Jacket 60 is welded at its upper end around the corresponding opening 23 in the bottom of the head container 20, and the lower end of the jacket 16 extends around the flange 53 of the adjacent upper grid 41 and can freely move on the same move. Sodium outlet ports 61 are provided at the upper end of the shell 1.

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Thermal insulation 62 is within the jacket 16 of the tube bundle 8 is arranged. The thermal insulation can be made in the embodiment as shown by the British Patent 1,098,485 is known. This embodiment of thermal insulation comprises two closely spaced apart metal sheets arranged from one another, which are welded to one another via intersecting seams, around the space between divide the metal sheets into a number of separate, gas-filled spaces. The thermal insulation 62 includes several Layers of this embodiment of thermal insulation within the jacket 40 of the jacket 16 of the tube bundle The thermal insulation 62 extends within the jacket 40 between the plates 42 of the adjacent grids 41 and are defined by brackets 63 as shown in FIG are welded to the plates 42 of the grids 41. The same thermal insulation can be used on the thermal jackets and on line 49 as well as on the head container 20 of the sodium inlet manifold 15.

Fig. 9 shows a further embodiment of the head pieces 4, 5 of the heat exchanger 1 according to FIG forms part of the head piece 69. The gap 67 is filled with argon and fitted with a sampling tube 70, which connects the intermediate space with a monitoring system, which indicates the presence of any water vapor or sodium, which can possibly be exhausted through a defective tube / tubesheet connection or expired. Preferably the pipe / pipe

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Bottom sealing connections in the lower tube sheet 66, while the connections in the upper tube sheet 68 can be produced by flash or explosive welding, fusion welding or soldering. The space 67 can be arranged in an annular, removable inspection cover which is sealed by a sealing ring 72 is, and the upper part of the head piece can, with a removable Dom 73 be provided. This arrangement allows access for inspection and repair purposes on both lines of the upper tube sheet 68 and on the lower side of the lower tube sheet 66 "

If the gas pressure in gap 67 increases to an unacceptable level, for example in the case of a sodium / water reaction as a result of the cornering of the tube / tubesheet connections, this actuates a pressure relief device, e.g. Rupture plate, which releases the gases created by the reaction into the outflow system.

When using the heat exchanger described above, the hot sodium is through the Sodium inlet connection at the lower end 2 of the shell 1 initiates and passed up through line 19 of sodium inlet manifold 15. The hot sodium gets in the head container 20 of the distributor 15 from the line 19. From the head container 20, the hot sodium passes through the openings 23 in the bottom of the head container 20 and flows off down there through the jacket 16, which is the steam outlet leg the tube bundle 8 surrounds. In this way, the hot sodium flows over the in a heat-exchanging manner

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Surface of the tubes 91 which form the tube bundle 8. On the ground the tube bundle 8 reverses the flow of sodium through the TI-shaped jackets 54 which form the lower ends of the jacket 16 on the tube bundles 8. The sodium then flows upwardly through the jacket 16 that forms the water inlet legs surrounds the tube bundle 8, and then flows from the open upper end of this side of the casing 16 into the Shell 1 of the heat exchanger. The cold sodium leaves the jacket 1 through the sodium outlet port 61, albeit one Bypass device can be provided so that the cold sodium flows over the inner surface of the shell 1 before it leaves the jacket 1 through the outlet connection 61.

Water is introduced into the tubes 9 of the tube bundles 8 through the water inlet headers 4-. When flowing through the tubes 9, the water through the heat exchange with the hot sodium, which passes through the tubes 9 the casing 16 of the tube bundle 8 flows, converted into steam. The steam generated in this way leaves the Pipes 9 through the steam outlet head 5

The device according to the invention has the following advantages in comparison with known embodiments of FIG Sodium / water heat exchangers on:

The arrangement of individual water inlet head pieces 4 and steam outlet head pieces 5 in the closure head 3 is permitted easy access to the tube sheets 10.11 in the joints 4 and 5. Thus, the welds between the tubes 9 of the tube bundle 8 and the tube sheets 10 and 11 quickly inspected and repaired on the spot will.

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The entire arrangement of the closure head 3 of the tube bundle 8 and the inlet manifold 15 can be removed from the jacket and, if necessary, after a certain period of use or in the event of mechanical damage Failure can be exchanged during operation.

Since the grids 41 for the tube bundle 8 are suspended in an articulated or articulated construction, an unhindered one Thermal expansion of the tube bundle 8 allows. In particular is the thermal expansion of the steam outlet leg of the Tube bundle 8 be larger in the longitudinal direction than the thermal elongation of the water inlet leg of the tube bundle 8, there the steam outlet legs of the tube bundle 8 first come into contact with the hot sodium which is in the tube bundle 8 enters from the head container 20. As a result, the tube bundles 8 tend to have a "hockey stick" or J-shaped configuration and the flexible grid mounting system permits such a design.

One of the most difficult problems that can arise with such a sodium / steam generator heat exchanger is to be prepared for an incidental sodium / water or sodium / steam reaction that can occur if a failure occurs allows a jet of water or steam to escape into the surrounding sodium in one of the heat exchange tubes. The thus occurring sodium / water or sodium / steam reaction may be extremely violent and with a release of large amounts of energy and the generation of large volumes of gas with a high pressure, ie, _e is hydrogen be accompanied.

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In the construction of the present invention, by the individual inclusion of each tube bundle 8 in the jacket 16, the effects of the reaction on the tube bundle 8 which contains the defective tube 9 is limited. The individual jackets 40 of the jacket 16 for each tube bundle 8 can be designed with sufficient strength to absorb the energy released so that the reaction released gases are fluted or guided through the casing 16 of the defective tube bundle 8 and through the Outlet connection 55 at the bottom of the casing 16 into the lower, curved end of the casing 1 below the partition plate 33 reach. The reaction gases are fed into an outflow system through the outflow opening or nozzle 59 at the lower end 2 of the jacket 1 released by the breakage of the rupture plate in the outflow opening 59. In this context is still mentions that the thermal insulation 62 within the jacket 16 of the tube bundle 8 also for the absorption of the Btoßwelle energy by the collapse of the individual chambers of the insulation under the shock wave load.

The invention also relates to modifications of the embodiment outlined in the appended claim 1 and refers above all to all features of the invention, which individually - or in combination - in the entire description and drawing are described.

Claims

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Claims (1)

2U6470 71 071 ptt / h. 15. SER1971 Claims I 1 "! Heat exchanger with a jacket, characterized by a series of U-shaped tubes (9)" which are arranged in the longitudinal direction in the jacket (1), the tubes (9) being arranged in a number of separate tube bundles (8) and the ends of the tubes (9) are connected to individual tube sheets (10, 11) in separate inlet and outlet headers (4) and (5) respectively in an end closure head (3) for the jacket (1). 2. Heat exchanger according to claim 1, characterized in that the ends of the tube bundle (8) through a extend lower tube sheet and with an upper tube sheet in each of the Eiriaß- and outlet header tubes in the End capping heads for the jacket are connected and that the upper and lower tube sheets in each inlet and outlet header tube are separated by a sealed space in the header tube. 3. Heat exchanger according to claim 2, characterized by means for monitoring the atmosphere in the Space between the top and bottom tube sheets of the head tubes to indicate a leak at the joints occurs between the tubes and the lower tube sheet. 4β heat exchanger according to claim 2, characterized in that an end closure at each inlet and outlet 209813/1154 2U6470 head tube and a removable cover are provided that the Access to the space in the inlet and outlet head pipes between the upper and lower tube sheets. 5. Heat exchanger according to claim 1, characterized in that that each tube bundle (8) is arranged in a single tubular casing (16), that also one Conduit is provided for guiding the heat transfer medium from the outside of the jacket into one end of each Sheathing, so that the heat transfer medium through the sheaths (16) over the surfaces of the tubes (9) in the tube bundle (8) passes and into the jacket (1) of the heat exchanger enters from the other end of the wrappings (16). 6. Heat exchanger according to claim 5, characterized by a pressure relief device (at 59) for venting the sheaths (16) of the tube bundle (8) to the outside of the shell (1). 7ο heat exchanger according to claim 5, characterized in that that the line for supplying the heat transfer medium from the outside of the jacket (1) in one end of a each jacket (16) comprises an inlet manifold (15) extending longitudinally through the jacket (1) between the Tube bundles (8) extends that the manifold (15) extends from an inlet connection (36) at the upper end of the jacket (1) and to the upper or head container (20) at its upper end in the jacket that the head container (20) has openings (22,23) 20981 3/1154 2U6470 in its bottom and in its upper part for implementation the tube leg of the tube bundle (8) which leads to the outlet nozzle in the upper closure head of the jacket lead that further jacket are provided which the outlet nozzle in the upper closure head of the jacket with the corresponding Openings in the upper part of the head container connect, the parts of the jackets that the Surrounding legs of the tube bundle, which lead to the outlet connection in the closure head of the jacket, at their upper Ends are connected to the openings in the bottom of the head container, and wherein the parts of the casing which the Surrounding the legs of the tube bundle and extending from the inlet connection in the closure head of the jacket, at their upper ones Ends are open to the interior of the jacket. 8. Heat exchanger according to claim 7, characterized in that that a retaining plate (12) is disposed within the end closure head of the jacket, the retaining plate (12) the inlet manifold (15) and the jackets (16) for the tube bundle (8) and wherein the arrangement of the Closure head, the tube bundle of their sheaths and the inlet manifold can be removed as a structural unit from the jacket (1) is. 9. Heat exchanger according to claim 5, characterized in that that the tubes (9) in the individual tube bundles (8) arranged at a distance from one another and at intervals their length are set by transversely arranged grids (41), which are spaced apart in an articulated or articulated construction, so that a bending of the tubes (9) due to thermal expansion is added can be. 209813/1154 10. Heat exchanger according to claim 9 »characterized in that that the jackets (16) for the tube bundle (8) comprise individual tubular jackets (40) which extend between the adjacent grids (41) extend so that the sheaths (16) with the tubes (9) of the tube bundle (8) can bend. 11. Heat exchanger according to claim 9, characterized in that the grids (41) by anchor screws (49) to each other are connected extending between adjacent grids (41), the anchor bolts (49) in articulated to the outer frame members of the grids (41). 12. Heat exchanger according to claim 11, characterized in that the upper grid (41) on each leg of the Tube bundle (8) is connected by anchor bolts in an articulated design with a retaining plate, which is located inside the sealing head of the jacket is arranged. 13. Heat exchanger according to claim 9 or 10, characterized characterized in that there are individual tubular jackets (40) which form the jackets (16) for the tube bundle (8) form, extend between the cylindrical flanges (53) on outer frame members (42) of adjacent grids (41), wherein each jacket is welded at one end to the puddle (53) on the one grid (41) and has a sliding fit on its other end with respect to the splash on the adjacent grid forms. 209813/1164 14. Heat exchanger according to one or more of claims 10 to 13 »characterized in that the lower end each jacket (16) for the tube bundle (8) is formed by a U-shaped jacket (54-), which is the lower U-shaped Ends of the tubes (9) surrounds, and that the ends of the U-shaped jacket with the ends of the lowermost tubular jacket in Are connected, which are part of the jacket on the vertical legs of the tube bundle (8). 15o heat exchanger according to claim 14-, characterized in that that a baffle or separation plate (33) is provided, which extends over the lower end (2) of the shell (1) extends, and that outlet nozzles (55) are provided in the U-shaped jackets (54) which the lower ends of the Form sheaths (16) for the tube bundle (8), the outlet connection (55) through openings in the separating plate (33) with the space in the jacket below the Separation plate (33) are connected, and that an outlet connection (59) with a pressure relief device in the jacket is provided, which is in communication with the space (36) below the partition plate (33). 209813/1154 , 13., Blank page