WO2009080839A1

WO2009080839A1 - Compact shell and tube heat exchanger

Info

Publication number: WO2009080839A1
Application number: PCT/ES2007/000748
Authority: WO
Inventors: Jesus Miguel Pagan Duran
Original assignee: Hrs Spiratube, S.L.
Priority date: 2007-12-20
Filing date: 2007-12-20
Publication date: 2009-07-02

Abstract

The invention relates to a heat exchanger which is rendered compact by providing intermediate heads at the ends of the surrounding shells which are bonded to the exchange tubes, said heads including holes establishing a connection with the surrounding fluid which flows through the shells outside the inner exchange tubes. In addition, hollow end heads are joined to the intermediate heads, connected contiguously in pairs, and form part of adjacent shells by means of ducts transverse to the axes of the shells, by means of which the fluid cascades through the shells forming the exchanger. The invention is based on providing flow diverters or deflectors joined to an axis that may or may not be common to the tubes of the exchanger. The invention also relates to a method for assembling the heat exchanger.

Description

HEAT EXCHANGER OF HOUSING AND COMPACT PIPES

OBJECT OF THE INVENTION

The object of the present invention relates to a shell and tube heat exchanger. In this type of exchangers that are very widely used in industry, there is a fluid that flows inside the tubes, while the second fluid is forced through the housing and on the outside of the tubes.

To ensure that the fluid on the side of the housing flows through the tubes and induces greater heat transfer, baffles are placed that increase the turbulence and create the cross flow between the tubes.

The invention focuses on several aspects, such as, on the one hand, a simplification of the connection means of the terminal ends of the housing, connection means of the exchanger housings, an improved placement of the internal baffles, as well as The invention focuses on the mounting frame of the housings that make the assembly a very compact heat exchanger.

BACKGROUND OF THE INVENTION

As mentioned previously, heat exchangers of the shell and tube type are widely used in the industry for both cooling and heating of liquids, for example in the dairy industry, juice industry, etc.

These casing and tube heat exchangers are formed in their most basic conception by a series of parallel tubes supported on both end plates, flowing a liquid to be heated inside or cooling, while this whole set of tubes is enclosed by an outer casing between whose inner plates a second fluid is passed that completely surrounds the tubes, carrying out a heat transfer between the inner and outer fluids of the tubes that will determine the cooling of one of the liquids and the heating of the other trying to find a thermal equilibrium of the fluids between them.

In general, these exchangers are arranged in multi-casing batteries with their tubes inside, in order to constitute a stepped and continuous flow of the fluids when cooled or heated since once the fluid leaves one of these! Exchangers go on to the next one and so on, since just passing through one of them would not be enough to achieve the purpose of the necessary exchange.

The European patent EP-0865601 in favor of TETRA LAVAL is known

HOLDINGS & FINANCE S.A. which reflects a typical shell and tube heat exchanger, in which the connection between the ends of the enclosing shells of the tubes, formed by 180 ° cords that occupy a large length, necessary to give the housing the connection Ia necessary with the adjacent housing. Due to the diameter of the housings, the length of the bending is important, leading to a loss of fluid load in the system that although small when the number of tubes is considerable in an exchanger, it is no longer negligible.

The connection between the enclosures is made through welded tubes transversely to the shells themselves, placing the inlet and outlet of fluid in locations as far apart as possible from each other. While the flow of the second fluid passes through the outside of the tubes, a cross flow is ensured through all the tubes by means of incorporating welded baffles into the tubes themselves, thus ensuring a turbulence of the fluid and the cross flow of this fluid. to The length of all the tubes.

A second example of realization of the state of the art is found in European patent EP-1234154 in favor of TETRA LAVAL HOLDINGS & 5 FINANCE S.A. which also highlights the lateral connection of the enclosures of two adjacent tubes and as here, in order to reduce the distance between housings there has been a considerable narrowing of the bending in its central part which leads to a reduction in diameter in passing and consequent loss of load. The solution offered by this exchanger is oriented to the absorption of the forces that are exerted by the thermal expansion produced by the high temperatures of the fluid that crosses the exchanger.

DESCRIPTION OF THE INVENTION 5

The present invention relates to a shell and tube heat exchanger that provides significant structural and functional advantages over the state of the art. On the one hand, the purpose of the invention is the realization of an extremely compact and efficient exchanger while being simple to carry out and easy to maintain. This improvement is translated into the execution of several improvements that will be explained throughout the descriptive report.

^{! Í} On the other hand, it is the purpose of the invention to carry out baffles or 5 flow diverters, joined together and not rigidly connected to the exchanger tubes or to the inside of the housings, which allow easy replacement thereof in case of any eventuality.

Thirdly, it is the purpose of the invention to construct for this system so compact, an appropriate frame for this compact assembly that brings together the housings of this exchanger in a simple and efficient way. The purpose of the invention is an improved connection system between adjacent enclosing housings for the passage of fluid between them.

It is also the purpose of the invention a highly fast and efficient compact shell and tube heat exchanger assembly procedure.

With the purpose of making this heat exchanger a compact construction, the ends of the enclosures that bind to the exchange tubes are provided with intermediate heads that carry the connection holes between the enveloping fluid that passes through the outer casings to the inner exchange tubes and attached to said intermediate heads, the end heads are placed hollowly, connected two to two in an adjacent manner that will be those belonging to adjacent carcasses, by means of transverse ducts to the carcass axes, through which will flow through the cascading fluid through the housings that form the exchanger.

These end heads on the one hand are connected directly to the intermediate heads and these to the enclosing housings or through the fixing plates of the tubes and have at their end face a hole through which it crosses an inner shaft with double threaded in its ends for fixing this housing or cap to the plate fixing the exchanger tubes. With this construction two effects are achieved, as they are, in the first place that the construction is very compact since the dimensions of these caps will be shorter in relation to the traditional couplings and secondly that the load loss is smaller.

A second improvement of the invention is in the fastening of the baffles, since the end heads being subject to the inner plates supporting the inner tubes from its central part through a threaded shaft, it is evident that the central tube that could have the configuration of tubes of the exchanger must disappear, since in that position is the fastening of the end heads , so that said central tube coinciding with the axis of the enclosure housing will be replaced by an axis that stiffens the assembly and also constitutes a fastening or fixing element on which the deflectors are placed, which also allow the deflectors to be truly independent. of the tubes of the exchanger and can be removed as a whole independently from the tubes themselves.

The third improvement included in the present invention translates into the realization of an exchange frame for such a compact construction, for which it has at least two base profiles, which can be fixing profiles of different sections as they will serve as support elements of the whole set. On both ends of each support profile, the pieces that will support and embrace the enclosures of the exchangers, formed by initial pieces of flat base and upper end of half circumference, coinciding with the diameter of the housings that are held, are held vertically. They have to hold. On both sides of these pieces there are two holes that will allow the passage of assembly rods that will be described later.

Next to this piece that has been described to support the first of the housings there is another upper envelope in the form of "H" with half circumferences both upper and lower, so that each housing will be fixed by the confluence of two of these pieces. These "H" shaped pieces also have side holes in coincidence with those of the lower part described above and as many of these pieces will be placed as vertical housings provided by the exchanger in question. All these pieces will be stacked in a column and will be finished in a piece with flattened end as indicated in the first place and that served as support for the whole. All this stacked set of supports is held by means of the incorporation of two rods that cross the lateral holes placed in alignment with each other and are secured by means of link nuts. The fixation to the lower profiles is achieved by means of signs that prevent the breakage of these elements and stiffen the entire assembly.

A third improvement consists in the connection between enveloping housings through the intermediate heads. To achieve this purpose, these intermediate heads consist of cylindrical tubes from which laterally welded couplings arise perpendicularly to these intermediate heads, said heads joining together by means of a tongue and groove connection of two concentric rings with the corresponding sealing joints between them.

The fixing of these connections is carried out through the frame, since the fixing system allows all the housings to be tightened together and, therefore, the sealing between said intermediate heads.

A fourth improvement consists in the assembly procedure of the heat exchanger of the invention, which comprises the following operations:

-Fixing inside the enclosures of the heat exchanger tube bundles.

-Fixing to the enclosures on both ends of the intermediate connection heads for the circulation of the fluid that passes through the interior of the enclosure, but externally to the interior heat exchange tubes. - Superimposed placement of the enclosures and fit one over the other, through the tongue and groove connection of the ducts flow union between housings.

-Placement of the fastener frame of the exchanger and tighten it, intercalating between housings, separation and support pieces thereof, holding by its ends to form a compact assembly, avoiding the separation of the tongue and groove joints of the intermediate joining heads between enveloping housings -Final positioning of the extreme heads and screwed them.

BRIEF DESCRIPTION OF THE DRAWINGS

Next, a preferred embodiment is described by means of the contribution of the attached figures, in which by way of example a preferred embodiment has been described, thus

Figure 1 represents a perspective view of an embodiment with eight enclosing housings that constitute a shell and tube heat exchanger.

Figure 2 represents a section of an end head placed at the ends of the enclosures

Figure 3 represents a similar sectional view and offering a sectional cut of the same head of Figure 2.

Figure 4 represents the isolated placement of two end heads joined together from both a perspective view and a sectional view and profile view of these heads.

Figure 5 represents the tongue and groove joint of two intermediate heads that on the one hand join the enclosures and on the opposite side the extreme heads. Figure 6 represents a perspective view or raised elevational views of the set of inner exchange tubes to the enclosure housing in which the arrangement and placement of the baffles that create the cross flow that passes through the outside of the tubes is shown.

Figure 7 represents an exploded view of a construction of an eight-element heat exchanger in which its construction details and the placement of the flow inlet holes are observed, both through the end heads and inside the housing envelope

Figure 8 represents the construction detail of the mounting frame of the heat exchanger of the invention, showing in several representations both mounted the frame but without the enclosures as in an exploded view to observe the constituent parts thereof.

DESCRIPTION OF A PREFERRED FORM OF EMBODIMENT

Figure 1 shows a perspective view of an assembled shell and tube heat exchanger (1), formed by eight enclosures (2), although the number of these housings will depend on the application to which said exchanger is destined. , in which the inlet or outlet connection tubes of the fluids to the exchanger, the intermediate heads (23) and the end heads (5) are observed. The conduit (3) is the fluid inlet conduit to the enclosure (2) and said fluid flows into the interior of the housing and outside the inner exchange tubes, which in this figure are not shown, the fluid it reaches the end of the enclosure and through the communication through the intermediate heads (23) the fluid passes to the lower enclosure and so on until it reaches the bottom that communicates with the parallel from where this cascade ascends in cascade. fluid to finally leave the fluid through the hole (24). In the position (4), the inlet or outlet port of the second fluid that runs from the end heads (5) into the interior interchange tubes of this fluid is shown to reach the end head (5) and of there it passes to the lower enclosure housing by cascading down the fluid until it reaches the lower enclosure casing that communicates with the adjacent parallel casing from where it rises in cascade until exiting through the hole (25).

Figure 2 shows the detail of the end head (5) of the enclosures (2), whose representation has been omitted, which constitute the heat exchanger of the invention. In said figure, the fixing plate (6) of the inner tubes of the exchanger is represented and as the end head (5) formed in this case by a cylindrical body closed at its end by a cover (7) is attached. . As a link means of this assembly, there is a stepped shaft (8) and threaded at its ends that are joined by a part in the tube fixing plate

(6) and on the other in the extreme cover (7). The tubular body that forms the end head (5) has an orifice (9) of passage of the fluid through which it links with another adjacent end head, the fluid being the one that passes through the plate (6) for fixing the exchanger tubes of heat

Figure 3 is a sectional view but also in perspective of the same head (5) for which the same references explained above are valid, this view being the one showing the holes (10) of fluid flow through the exchanger tubes. In this figure it is observed how the possible tube that the plate (6) could carry in the center cannot be included when this area is occupied by the connection of the axis (8) on the plate (6).

Figure 4 shows the connection of two end heads (5), coupled together by means of a connection through the transverse ducts (9). This connection allows the distance between the heads (5) and therefore the enclosures between them is minimal. To remove these heads, the axle nuts attached to each of the heads must simply be loosened and this connection will be removed, while traditional systems should be removed from each flange of the connections, which would imply a more considerable loss of time than only the removal of two nuts as in the present invention. These end heads (5) are double and joined by welding through a connecting separator tube (32).

Figure 5 shows the intermediate heads formed by cylindrical bodies that, at one of its ends, joins the enclosure and the opposite of the corresponding end head (5).

For joining these intermediate heads together, there are transverse holes (26) and (27) that are joined by welding to two concentric rings (28) and (29) of tongue and groove coupling with sealing gaskets (30) and (31). The pressure of the fluid inside the tubes would force that the tongue and groove joint to separate, which is prevented by the fixing frame that packages all the enclosures, preventing their separation.

Figure 6 shows the assembly formed by the heat exchange tubes (11) attached between each fixing plate (6), which have holes (10) through which the fluid from the end heads (5) passes through ). In the central part of the plates (6) a rod is fastened from which the baffles (12) that conveniently placed between the tubes leave allow to increase the turbulence of the fluid and create a cross flow that facilitates the passage through all the tubes exchange (11). These baffles will contact the inside of the enclosure (2) preventing fluid flow through that space. Figure 7 represents an exploded view of a construction of an eight-element heat exchanger in which the enclosures (2) are shown inside which are the exchange tubes and the fixing plates of such tubes. On both sides of these housings the extreme heads (5) that incorporate the holes are placed

(4) fluid passage through the interior of the heat exchange tubes. In the enclosing housings there are holes (3) at both ends of said housings through which the fluid that surrounds the inner heat exchange tubes flows externally. In this exchanger two flows are created that do not mix between the one that passes through the inside of the exchange tubes and the flow that passes through the outside of them.

Finally, Figure 8 represents the construction detail of the mounting frame of the heat exchanger of the invention, formed by a support profile (13) on which at both ends the support structure of the heat exchanger is arranged. The support structure is formed by two pieces (14) and (15), the first (14) that supports the upper and lower end tubes and that only has a recessed area (16) in the form of a semicircle, while the opposite side is plane (17) that will serve as a flat support area. The second of the pieces involved in the realization of the frame are the pieces (15) in the form of "H" with curved areas (16) at both ends for the placement of the upper and lower tubes on these curved areas.

Both the pieces (14) and (15) have drilled areas (18) and (19) on both sides that overlap and through which the rods (20) are fixed at their ends by nuts (21) that assemble the entire set. To achieve a rigid support of this frame, posters (22) are placed in confluence with the support profile (13) that stiffen the structural assembly thus formed. Referring, for example, to Figure 1 thereof, it should be noted that the intermediate and extreme heads vary between those that are intermediate and extreme, whose representations have been described with Figures 5 and 4 respectively and those heads that have the inlet and outlet orifices of refrigerant fluid or to be cooled, since, for example, in the extreme heads instead of being a double body as shown in Figure 4, the body is simple with a hole for the inlet and / or fluid outlet In the intermediate heads the same would happen, since instead of carrying that tongue and groove closure arrangement described in Figure 5, the connection will be through a welded tube perpendicular to the axis of said head, which will be attached to the connection means of the Hydraulic circuit for cooling inlet and outlet or to be cooled.

The invention also refers to the assembly procedure of the exchanger of the invention, since as such assembly is advantageous with respect to the state of the art and provides simplicity of assembly, saving assembly times, as well as disassembly thereof.

This procedure consists of the following operational phases: - Fixing inside the enclosures (2) of the tube bundles of the color exchanger.

-Fixing to the enclosing housings (2) at both ends of the intermediate connecting heads (23) for the circulation of the fluid that passes through the interior of the housing. -Fixing inside the enclosures of the heat exchanger tube bundles.

-Fixing to the enclosures on both ends of the intermediate connection heads for the circulation of the fluid that passes through the interior of

The enclosure shell, but externally to the indoor heat exchange tubes.

- Overlapping of the enclosures and fit of some over others, by means of the tongue and groove connection of the flow connection ducts between housings.

-Placement of the fastener frame of the exchanger and tighten it, intercalating between housings, separation and support pieces thereof, holding by its ends to form a compact assembly, avoiding the separation of the tongue and groove joints of the intermediate joining heads between enveloping housings

-Final positioning of the extreme heads and screwed them.

Claims

1.- Compact shell and tube heat exchanger formed by one or multiple enclosing housings, inside which one or multiple heat exchange tubes are disposed, characterized in that the enclosing housings that form the heat exchanger comprise at least one of its ends an end head which in its lateral periphery includes a connection hole between two adjacent enclosures, or the connection hole to the external hydraulic connection means.

2.- Compact shell and tube heat exchanger according to claim 1 characterized in that each enclosure has two end heads, one on each side of the enclosure, which constitute the heat exchanger

3. - Compact shell and tube heat exchanger according to claim 1, characterized in that the end head includes a retaining element in coincidence with the axis of the casing housing of the exchange tubes that constitute the heat exchange.

4. Compact shell and tube heat exchanger according to claims 1 to 3, characterized in that the retaining element joins the end head to the junction plate of the inner heat transmission tubes.

5.- Compact shell and tube heat exchanger according to claims 1 to 4, characterized in that in the joint between the retaining element and the end head there are sealing elements of said joint.

6.- Compact shell and tube heat exchanger according to Ia claim 5 characterized in that in the connection between the end head and the fixing plate of the heat exchange tubes it has sealing elements of said union.

5. A compact shell and tube heat exchanger according to claims 1 to 6, characterized in that the retaining element consists of a shaft threaded at both ends for attachment to the fixing plate and the terminal end head 0

8.- Compact shell and tube heat exchanger according to claim 1 characterized in that between the fixing plates of the transmission tubes and in coincidence with its axis, it has a rod on which the baffles that ensure that the fluid are joined of exchange that flows inside the housing and externally to the heat transmission tubes 5 runs externally to the transmission tubes.

9. - Compact shell and tube heat exchanger according to claim 1, characterized in that the end heads are grouped two by two connected in solidarity by joining the 0 side connection holes.

10. - Compact shell and tube heat exchanger according to claim 1, characterized in that the connecting and / or fluid outlet end connection heads are simple heads. 5

- • ^; 11.- Shell and tube heat exchanger, formed by one or multiple enclosing housings, inside which one or multiple heat exchange tubes are disposed, characterized in that between the enclosing housings that form the exchanger and the end heads, 0 they have the intermediate heads that include a connection hole through which the fluid circulating between the housing and the inner tubes of heat exchange

12. - Compact shell and tube heat exchanger according to claim 11, characterized in that the intermediate heads that have two enclosures adjacent to each other through which the cascade fluid circulates are joined by tongue and groove coupling.

13.- Compact shell and tube heat exchanger according to claim 12, characterized in that the tongue and groove coupling is carried out by means of the fitting of two concentric rings and spacer from each other by the incorporation of sealing gaskets.

14.- Compact shell and tube heat exchanger according to claims 11 to 13, characterized in that the intermediate inlet and / or fluid outlet connection heads are simple heads that are attached to the external hydraulic connection means.

15.- Frame for fixing tubes or enveloping sleeves of shell and tube heat exchangers comprising:

At least one horizontal support support of the exchanger assembly.

At least one semi-circumferential shaped part where one of the tubes or enclosures that form the heat exchanger is supported or hugged

16.- Frame for fixing tubes or enveloping sleeves of shell and tube heat exchangers according to claim 9, characterized in that the support or embracing parts of the tubes or enclosures that form the exchanger have hollow areas laterally by which cross the connecting rods of the successive support and hugging parts of the tubes or enclosures.

17.- Frame for fixing tubes or sheaths of casing and tube heat exchangers according to claim 9, characterized in that the support or embraced parts of the enclosing housings that are constituted as end pieces, only have a form of semi-circumference while its opposite end is flat.

18.- Frame for fixing tubes or sheaths of casing and tube heat exchangers according to claim 9, characterized in that the intermediate support or embraced parts of the enclosing shells have opposing sections in the form of a semicircle for support and / or hugging the enclosures of the heat exchanger.

19.- Frame for fixing tubes or sheaths of casing and tube heat exchangers according to claim 9, characterized by having connecting rods that allow the stacking of the successive support and / or embracing pieces of the enclosures , this assembly being held stacked by appropriate retention elements.

20.- Assembly procedure of a compact shell and tube heat exchanger comprising:

-Fixing inside the enclosures (2) of the tube bundles of the color exchanger.

-Fixing to the enclosing housings (2) at both ends of the intermediate connecting heads (23) for the circulation of the fluid that passes through the interior of the housing.

-Fixing inside the enclosures of the tube bundles of the heat exchanger.

-Fixing to the enclosures on both ends of the intermediate connection heads for the circulation of the fluid that passes through the interior of the enclosure, but externally to the interior heat exchange tubes.

- Superimposed placement of the enclosures and fit one over the other, by means of the tongue and groove connection of the flow connection ducts between housings. -Placement of the fastener frame of the exchanger and tighten it, intercalating between housings, separation and support pieces thereof, holding by its ends to form a compact assembly, avoiding the separation of the tongue and groove joints of the intermediate joining heads between enveloping housings -Final positioning of the extreme heads and screwed them.