EP2984437B1 - Pipe grouping apparatus and its use - Google Patents

Description

The invention relates to a tube bundle apparatus having the features in the preamble of claim 1. The invention is further based on a use of the tube bundle apparatus.

Tube bundle apparatuses are generally used where heat transfer from a first medium to a second medium has to take place. Corresponding apparatus are, for example, heat exchangers or reactors. In the tube bundle apparatus, the first medium flows through the tubes and the second medium through the space surrounding the tubes. The fluid guide can be done in cocurrent, countercurrent, crosscurrent or cross-countercurrent. For a flow guidance in the cross-flow or cross-countercurrent, the individual tubes of the tube bundle apparatus are guided by baffles, with which the second medium flowing around the tubes is deflected. By deflecting along the baffles results in a meandering flow pattern for the medium flowing around the tubes.

In order to avoid a mixing of the first medium and the second medium, the tubes are usually fluid-tightly received with their ends in a tube plate. The tubesheets are in turn also fluid-tightly connected to a shell of the tube bundle apparatus.

In currently used tube bundle apparatus, the first tube plate and the second tube plate are each fixedly secured in the housing of the tube bundle apparatus, for which purpose usually flange connections are used. Common designs of tubesheets and their mounting are, for example, in Perry's Chemical Engineer's Handbook, Eighth Edition, pages 11-34 shown.

Disadvantage of the known tube bundle apparatuses is that, in particular at large temperature differences between the medium flowing through the tubes and the medium flowing around the tubes length expansions of the tubes and the shell are different, so that the tubes can deform in the tube bundle apparatus. In addition, it is generally not possible to replace tubes in a simple manner from the tube bundle, if necessary, or to carry out cleaning work on the tube bundle or on the jacket. To avoid these deformations are usually used on the shell side of the apparatus compensators, but only for apparatus with limited wall thickness in the low pressure range can be used. These compensators are a known vulnerability of such Constructions, a failure leads to a leakage of the medium in the shell space into the environment. This is a non-tolerable emission in cases where process chemicals are handled on the shell side.

The object of the present invention is therefore to provide a tube bundle apparatus which does not have the disadvantages known from the prior art.

The problem is solved by a tube bundle apparatus according to claim 1. By fixing the first tube sheet to the stop is avoided that the tube bundle can move during operation of the tube bundle reactor within the housing. The leadership of the second tube sheet with a sealing element in the housing allows that, for example, at a different elongation of pipes and housing, especially at very different temperatures of the guided in the pipes medium and the medium flowing around the pipes, the tube sheet within the housing shift and can be compensated in this way different elongations due to temperature differences. The sealing of the second tube plate with a gland seal allows on the one hand a displacement of the tube bottom within the housing and on the other hand seals the separated by the tube plate spaces within the housing from each other. This ensures that a fluid from the space, which is delimited by the tube plate and a housing cover, flows into the tubes and continue to get into the housing added medium flowing around the tubes, not in the inlet into the tubes.

In order to avoid on the side at which the tube plate is fixed to the stop, that a fluid from the space between tube plate and housing cover in the space defined by the housing shell and the two tubesheets, the space surrounding the tubes can flow and on the other hand, the fluid from the space surrounding the tubes can flow into the space between the tube sheet and the housing cover, and the first tube sheet is preferably sealed relative to the housing, here also a stuffing box gasket can be used.

The use of a sealing element designed as a stuffing box has the advantage that even when using media under high pressure, for example, a pressure of more than 100 bar and in particular with large pressure differences between the medium flowing through the pipes and the medium flowing around the pipes sufficient tightness between the spaces separated by the respective tubesheet can be ensured.

The use of a sealing element designed as a stuffing box has in particular the advantage that media with higher pressure differences between shell and tube side can be separated without causing a mixing of the streams. At the same time, the stuffing box packing, with sufficient dimensioning via compression, is able to absorb the thermal growth of the tube bundle with respect to the casing during thermal stress. This is especially necessary in apparatuses with large wall thickness, as they are mainly used in the medium and high pressure area, on the shell side, since here at unsteady heating or cooling processes, the tube side heats up much faster than the coat. According to claim 1, the stop against which the first tube sheet is supported comprises a split ring which is received in a groove in the housing. Here, the ring may be divided into two or more segments. The division of the ring into two or more segments makes it possible to remove the individual segments from the housing, so that the tube plate and thus the tube bundle is freely displaceable in the housing after removal of the stop. This has the advantage that the tube bundle can be removed from both sides of the housing. So it is on the one hand possible to pull the tube bundle out of the housing, on the other hand, the tube bundle can also be pushed out of the housing.

To fix the first tube sheet detachably against the stop, it is preferred if the first tube sheet is fixed with a counter element against the stop. The counter element is, for example, another ring, the outer diameter of which corresponds to the inner diameter of the jacket, which bears against the stop on the side opposite the tubesheet. The connection of the counter element with the tube sheet takes place for example with clamping screws. For this purpose, it is for example possible that in the tube bottom threaded openings are formed, into which the clamping screws are screwed. Alternatively, it is also possible to form threaded rods, for example, on the tubesheet, which are guided through corresponding openings in the counter element and fixed with suitable nuts. Alternatively to a designed in the form of a ring counter element, it is also possible to provide a plurality of counter elements. Thus, for example, it is also possible to provide a counter element, for example in the form of a clamping hook, in each case in the region of a fixing, for example a clamping screw or a threaded rod. Alternatively, it is also possible to use, for example, a corresponding disc which bears against the stop on the side opposite the tubesheet. It is possible, for example, to provide a disk for each clamping screw or each threaded rod. It is also possible to make the discs so that several clamping screws or threaded rods are passed through a disc. In this case, it is necessary in each case for the disks to be designed so that the feed to the individual pipes of the tube bundle remains free.

In order to avoid that the medium that is to be passed through the pipes, comes into the area that surrounds the pipes, or in the opposite direction, the medium from the space surrounding the pipes in the area in which the pipes open . It is necessary that the first tube sheet is mounted fluid-tight in the housing. In one embodiment of the invention, it is possible, for example, that the first tube sheet is pressed against the stop with a second sealing element. As a sealing element is suitable in this case, for example, a flat gasket or a correspondingly sized O-ring. Alternatively, it is also possible to make the second sealing element, with which the first tube sheet is sealed relative to the housing, as a stuffing box. Here, for example, the stop or the counter element can be used to fix the stuffing box.

By using two tubesheets mounted on opposite sides of the housing, it is possible to use straight, that is unbent, tubes. This has the advantage that the pipes can be inspected, tested and cleaned without removal from the tube bundle apparatus. Another advantage of using straight tubes with opposite tubesheets in which the respective ends of the tubes are mounted, has the advantage that the respective tube plates have a uniform temperature profile and thus no faults can occur, leading to leaks. In contrast, in U-shaped tubes due to the temperature difference between inlet and outlet from the pipes and the installation of inlet and outlet in the same tube sheet would be a temperature gradient in the tube sheet, which can lead to dislocations.

By using straight pipes it is possible, for example for testing or cleaning, to push a straight cleaning lance through the pipe. In addition, a tube bundle with straight tubes can be made easier than a tube bundle with bent tubes, since a bending of the tubes is not necessary and the tubes can be easily threaded into the tubesheets.

Another advantage of the tube bundle apparatus according to the invention is that a cylindrical housing can be used by the use of two tube plates and straight tubes, so that the tube bundle can be pulled out of the housing on both sides or alternatively pushed out.

Through the use of the two tubesheets of the tube bundle apparatus is divided into three separate areas. Each at the end faces results in a space in the pipes open, with one forms the inlet to the pipes and the other the drain from the pipes. In the middle there is another area surrounding the tubes, where a second medium can flow.

The design of the tube bundle apparatus such that the second tubesheet is guided with a sealing element in the housing, has the advantage that, for example, for housing and tubes different materials can be used with different thermal expansion and always by the displaceability of the tube plate with a suitable sealing element a seal between the individual areas, in which the tube bundle apparatus is separated, is ensured. For different linear expansion, for example At high temperatures, the second tubesheet shifts in the housing, so that it does not come to a tensile or compressive load on pipes or housing and possibly resulting in deformations. Another advantage is that even large lengths of the pipes are possible by the displaceable tube sheet, without it during operation of the tube bundle apparatus, for example, under high pressure or at high temperatures to deformation of the tubes or the housing.

The tube bundle apparatus according to the invention is usually used in systems in which a gaseous or liquid material flow has to be heated or cooled at a higher operating pressure. Here, the tube bundle apparatus can be used either as a tube bundle reactor or preferably as a heat exchanger or recuperator in a heat integration. The tube bundle apparatus according to the invention is particularly suitable when large dimensions, such as long tubes, are required. Also, the tube bundle apparatus according to the invention is particularly advantageous to use when high temperature differences occur between the guided in the tube bundle media media or the media are passed through the tube bundle apparatus at high temperatures. Under high temperature differences across the apparatus while temperature differences in the range of 50 to 350 ° C, preferably in the range of 50 to 200 ° C understood. High temperatures in the context of the present invention are temperatures in the range of 100 to 500 ° C, preferably in the range of 100 to 350 ° C.

In the context of the present invention, "higher operating pressure" is to be understood as meaning pressures in which the tube bundle apparatus can be operated in a constructively advantageous manner. These are, for example, in the range of 60 to 500 bar, preferably in the range of 100 to 350 bar. Differential pressures between jacket and pipe side can be up to 100 bar.

Of course, the tube bundle apparatus according to the invention can also be operated at low temperature differences or low temperatures or low pressure differences or low pressures. The operation of the reactor according to the invention is not limited to processes in which high pressure or temperature differences or high pressures or temperatures occur. Due to its design, however, it is particularly suitable for operation at high pressures and / or temperatures.

The tube bundle apparatus according to the invention is particularly suitable in processes in which the heat of reaction of an exothermic reaction of an adiabatically operated reactor system is intended to heat the reactor feed to the reaction temperature. In this arrangement, the reaction enthalpy containing reactor effluent is fed to one of the two sides of the tube bundle apparatus, while on the other side of the reactor inlet is supplied under heating to the system.

Particularly suitable is the apparatus according to the invention for use as a heat exchanger, for example in a process for the preparation of tertiary butylamine. Here, the tube bundle apparatus is used as a heat exchanger for heating the educt streams to the intended Reactor inlet temperature in the range of 230 to 320 ° C, for example, 300 ° C used. The educt streams are each heated in a heat exchanger to the reactor inlet temperature and fed to the reactor. The reaction then takes place in the reactor to tertiary butylamine.

Embodiments of the invention are illustrated in the figures and are explained in more detail in the following description.

Figur 1

eine Schnittdarstellung eines Rohrbündelapparates,

Figur 2

einen Ausschnitt des an einem Anschlag fixierten Rohrbodens,

Figur 3

einen Abschnitt des im Gehäuse geführten Rohrbodens.

Show it:

FIG. 1

a sectional view of a tube bundle apparatus,

FIG. 2

a detail of the fixed to a stop tube sheet,

FIG. 3

a portion of the guided in the housing tubesheet.

In FIG. 1 a tube bundle apparatus is shown in section.

A tube bundle apparatus 1 comprises a housing 3, which comprises a jacket 5, which is closed on both sides with a respective cover 7. The jacket 5 is usually designed cylindrical, but can also take any other cross-section in addition to a circular cross section.

The cover 7 are usually attached to the jacket 5 each with a flange connection.

In the housing 3, a tube bundle 9 is received. The tube bundle 9 comprises a first tube plate 11, a second tube plate 13 and tubes 15. The tubes 15 are each fastened with their ends in one of the tube plates 11, 13. Here, the tubes 15 are preferably secured in the tube sheets 11, 13, that they each flush with the tube sheet 11, 13 ends. As a result, it is avoided during operation of the tube bundle apparatus 1 that liquid remains on the tubesheet and can not flow into the tubes 15.

The tube sheets 11, 13 are fluid-tightly connected to the housing 3. According to the invention, in this case the first tube sheet 11 is detachably fixed to the housing 3 and the second tube sheet 13 is displaceably positioned in the casing 5 of the housing 3. Through the tube sheets 11, 13, the housing 3 is divided into three areas. A first region 17 and a second region 19 lie on the outer sides of the apparatus, respectively, so that the tubes 15 each open into one of the two regions 17, 19. In each case on both sides through the first tube sheet 11 and the second tubesheet is completed a central region 21st

For operation of the tube bundle apparatus 1, a connection 23 is provided in each of the lids 7. Here, a first fluid, which may be liquid or gaseous, through one of the two Connections 23 supplied, passes into the first region 17 and second region 19 and from there into the tubes 15. The medium flows through the tubes and enters the respective other region 19, 17 and leaves the tube bundle apparatus through the second port 23. A second medium , which flows around the tubes via an inlet 25 which opens into the surrounding the tubes central region 21, fed and removed via a drain 27 from the central region.

When the tube bundle apparatus 1 is used as a heat exchanger, it is possible, for example, to heat or cool the first medium flowing through the tubes. For this purpose, a temperature control medium is passed through the central region 21. When the medium to be heated in the tubes is to be heated, the medium passed through the middle portion has a higher temperature than the medium to be heated, and when the medium to be cooled is cooled, the temperature of the medium passed through the central portion 21 is lower. The guided through the tube bundle apparatus 1 media can be performed in cocurrent, countercurrent or crosscurrent or cross-countercurrent. If a current flow is provided in the cross-direct current or in the cross-countercurrent, deflection plates 29 are usually provided in the central region 21, around which the fluid is deflected.

So that the tube bundle is not displaced within the housing 3 during operation, it is necessary that one of the two tube plates 11, 13 is fixed to the housing 3. A section of a tube bottom fixed in a housing by means of a stop is exemplary in FIG FIG. 2 shown. In order to fix the first tubesheet 11 on the housing 3, preferably on the jacket 5, the first tubesheet 11 is fixed against a stop 31. The stopper 31 may, for example, as in FIG. 2 represented, may be formed as a ring which is guided in a groove 33. In order to allow easy mounting of the stopper 31 and the first tube plate 11, it is preferred if the stopper 31 is formed as a split ring. In this case, the stop 31 may have two or more segments. It is preferred if the stop 31 has more than two segments, as in this case a simpler installation is possible.

In order to fix the first tube sheet 11 to the stop 31, a counter element 35 is positioned on the side of the stop 31 opposite the first tube plate 11. By counter-element 35, for example, clamping screws 37 are guided, which are screwed into a thread in the first tube sheet 11. Alternatively, it is also possible to form threaded rods on the first tube sheet, which are guided through a hole in the counter element 35 and fixed with a nut. The attachment with clamping screws 37 or via a threaded rod allows easy disassembly of the tube sheet, for example, to remove the tube bundle from the housing 3.

In order to obtain a fluid-tight connection between tube sheet 11 and housing 3 or casing 5, the first tube sheet 11 is provided with a sealing element 39. The sealing element 39 may be, for example, a flat gasket or an O-ring or as in FIG. 2 shown, a stuffing box packing. In this case, designed as a stuffing box packing sealing element 39 is guided in a groove of the tube sheet and pressed against the stop 31, so that a fluid-tight connection between tube sheet 11 and shell 5 is generated. This avoids, on the one hand, that fluid from the first or second region, into which the tubes 15, which are led through the tubesheet 11, can flow into the middle region 21 or liquid from the middle region 21 into the first or second region into which the pipes open, can enter.

According to the second tube sheet 13 is slidably mounted in the housing 3. This is exemplary in FIG. 3 shown.

In contrast to the first tube sheet 11, which is fixed to the housing, the second tube sheet 13 is slidably mounted in the housing.

In order to avoid that fluid from the central region in the outer region, in which the pipes 15 open, can pass or can flow from the outer region in the central region 21, the second tube sheet 13 is guided with a sealing element 41 in the jacket 5 , The sealing element 41 rests with one side on the jacket 5. As a sealing element 41 is suitable, for example, a stuffing box, which is pressed with a stuffing box 43. As a result, is pressed by the stuffing box packing of the sealing element against the housing shell 5, thus achieving a fluid-tight connection. Nevertheless, the tube plate 13 is still displaceable in the jacket, so that, for example due to pressure or temperature differences occurring changes in length of the tubes 15 can be compensated by moving the second tube plate 13. This allows in particular the construction of tube bundle apparatuses with very long tubes or with tubes and housings of different materials, which have different temperature elongations.

In order to remove the tube bundle from the tube bundle apparatus 1, the connection produced by the clamping screw 37 or the threaded rod is released, the counter element 35 is removed and the stopper 31 is removed from the groove. Now, the first tube sheet 11 is slidable in the housing, so that the tube bundle 9 can be pulled or pushed out of the jacket 5.

The material for the pipes is any material from which pipes can be made. If the tube bundle apparatus 1 is to be used as a heat exchanger, it is preferred to use a material for the tubes, which is highly thermally conductive. It is preferred to use a metal. Suitable metals for the tubes 15 of the tube bundle are, for example, ferrous metals such as steels or also copper or aluminum. The housing may also be made of corresponding metals. In addition to metals, however, the tubes and the housing can also be made of plastic, glass or ceramic. The suitable material for pipes and housing is also dependent on the media to be passed through the pipes or through the central region in the housing.

LIST OF REFERENCE NUMBERS

1

Tube apparatus

3

casing

5

coat

7

cover

9

tube bundle

11

first tube sheet

13

second tube sheet

15

pipe

17

first area

19

second area

21

middle area

23

connection

25

Intake

27

procedure

29

baffle

31

attack

33

groove

35

counter element

37

clamping screw

39

sealing element

41

sealing element

43

gland

Claims (9)

1. A shell-and-tube apparatus comprising a housing (3) having a bundle (9) of tubes accommodated therein, where the tubes (15) are joined on one side to a first tube plate (11) and on the side opposite the first tube plate (11) to a second tube plate (13), with the first and second tube plates (11, 13) being fastened detachably in the housing and the side of the first tube plate (11) opposite the tubes (15) resting against a stop (31) on the housing (3) and being fixed on the stop (31) and the second tube plate (13) being installed with a sealing element (41) in the housing (3), wherein the stop (31) comprises a divided ring which is accommodated in a groove (33) in the housing.
2. The shell-and-tube apparatus according to claim 1, wherein the sealing element (41) with which the second tube plate (13) is installed in the housing (3) is configured as gland packing.
3. The shell-and-tube apparatus according to either of claims 1 and 2, wherein the first tube plate (11) is fixed by means of a locking element (35) against the stop (31).
4. The shell-and-tube apparatus according to claim 3, wherein the locking element (35) is a ring which is connected by means of clamping screws (37) to the tube plate (11) in such a way that the tube plate (11) is fixed on one side against the stop (31) and the locking element (35) rests against the stop (31) on the side opposite the tube plate (11).
5. The shell-and-tube apparatus according to any of claims 1 to 4, wherein the first tube plate (11) is pressed with a second sealing element (39) against the stop (31).
6. The shell-and-tube apparatus according to claim 5, wherein the second sealing element (39) is configured as gland packing.
7. The use of a shell-and-tube apparatus according to any of claims 1 to 6 as heat exchanger or recuperator in heat integration.
8. The use of a shell-and-tube apparatus according to claim 7, wherein at least one medium flowing through the heat exchanger has a temperature in the range from 100 to 500°C.
9. The use of a shell-and-tube apparatus according to claim 7 or 8, wherein at least one medium flowing through the heat exchanger has a pressure in the range from 60 to 500 bar.

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