Elbow for a Tube Bundle Heat Exchanger for Large Product Pressures, Method for Producing a Tube Bundle Heat Exchanger Comprising such an Elbow, and Use of a Tube Bundle Heat Exchanger for Large Product Pressures with such an Elbow in a Spray Drying System

Abstract

A manifold with a circular cross-section having a deviation angle of 180 degrees for a tube bundle heat exchanger for large product pressures has a first and second flange on each inlet and outlet. The manifold has two manifold halves respectively made of a single piece, and each half comprises a joining point on an end facing away from a flange. The manifold halves are connected together on the associated joining point. Extension of the passage cross-section of each manifold half is formed by rotationally symmetrical through openings, from which at least one of the flanges and at least one of the joining points extends in the respective coaxial arrangement on rotational axes. First and second axes of through openings of the first manifold halves and third and fourth axes of through openings of the second manifold halves extend on a common plane representing a meridian plane for each flange.

Claims

1. An elbow with a circular cross-section having a deflection angle of 180 degrees for a tube bundle heat exchanger for large product pressures, having a first and a second flange on each inlet and outlet of the elbow, wherein: the elbow comprises two one-piece elbow halves, each elbow half has a connecting point at its end facing away from the flange, the elbow halves are integrally bonded to each other at the associated connecting point, a progression of passage cross-sections of each elbow half is formed by rotationally symmetrical passages, of which at least one extends from the flange, and at least one extends from the associated connecting point in a coaxial arrangement on rotational comprising first, second, third and fourth rotational axes, the first and second rotational axes of first and second passages of the first elbow half, and the third and fourth rotational axes of third and fourth pas sages of the second elbow half, run in a common plane that represents a meridian plane for each flange, the first and second rotational axes intersect at a first intersection, and the third and fourth rotational axes intersect at a second intersection, the first intersection is associated with a penetrating first passage on the first rotational axis, and a penetrating second passage on the second rotational axis that each penetrate each other on one side, and the second intersection is associated with a penetrating third passage on the third rotational axis, and a penetrating fourth passage on the fourth rotational axis that each penetrate each other on one side.

2. The elbow according to claim 1, wherein: at the first to fourth passages that penetrate each other in pairs, a convex rounding with an outer curvature radius is provided in the radially exterior progression of the associated passage cross-section of the respective elbow half, and a concave rounding with an inner curvature radius is provided in the radially interior progression of the associated passage cross-section.

3. The elbow according to claim 1, wherein: the first to fourth passages are each designed in the shape of a conical frustum, and their respective tapering is oriented toward the associated first or second intersection.

4. The elbow according to claim 1, wherein: a peak cross section of each elbow half is expanded relative to the peak cross-section of adjacent passage cross-sections on both sides.

5. The elbow according to claim 1, wherein: the rotationally symmetrical passages are lined up with the same diameter at their respective transition point to an adjacent passage.

6. The elbow according to claim 5, wherein: the transition points are consistently designed curved.

7. The elbow according to claim 1, wherein: the rotational axes each run in a straight line.

8. The elbow according to claim 1, wherein: the first and second rotational axes, and the third and fourth rotational axes each intersect at an angle of 90 degrees.

9. The elbow according to claim 1, wherein: the elbow halves are designed congruent.

10. The elbow according to claim 1, wherein: an integral bond of the connecting points is a weld connection.

11. The elbow according to claim 10, wherein: the weld connection is formed in a multilayer orbital manner.

12. The elbow according to claim 1, wherein: a contact surface is provided on the flange, which is oriented in a plane parallel to an end face of the connecting point and that stands back by a degree of shrinkage from the end face.

13. A production method for an elbow according to claim 1, comprising: producing the respective elbow half from round material and from a whole piece by machining, wherein an inner contour consisting of rotationally symmetrical passages and a first outer contour that is not directly adapted to the tube bundle heat exchanger, or respectively its tube bundles, are provided with a respective end contour, and a second outer contour is processed beforehand that is directly adapted to the tube bundle heat exchanger, or respectively its tube bundles; integrally bonding the two elbow halves to each other at their respective connecting point to the elbow; and adapting the second outer contour to the tube bundle heat exchanger, or respectively its tube bundles, by machining an end contour.

14. The production method according to claim 13, wherein integrally bonding the two elbow halves comprises: producing an integral bond of the two elbow halves by an orbital welding method.

15. The production method according to claim 14, wherein: the orbital welding method is performed in multiple layers.

16. The production method according to claim 14, performing stress-relief annealing at least once following conclusion of the orbital welding method, or during a multi-layer orbital welding method.

17. The production method according to claim 13 wherein: a contact surface provided on each of the first and second flange is positioned by a degree of shrinkage such that, after integrally bonding, a mutual contacting of the contact surfaces resulting from contraction by cooling regions of the elbow heated during integral bonding ensures that the second outer contour is produced with the dimensionally accurate end contour.

18. A tube bundle heat exchanger for large product pressures with series-connected tube bundles arranged in parallel, wherein a product flows through inner tubes of the tube bundle and, viewed in the direction of flow of the product and with reference to any desired tube bundle, an outlet of the tube bundle is fluidically connected to an inlet of an adjacent downstream tube bundle and, alternatingly, an inlet of the tube bundle is fluidically connected to an outlet of an adjacent, upstream tube bundle via an elbow with a deflection angle of 180 degrees according to claim 1.

19. A use of a tube bundle heat exchanger for large product pressures according to claim 18 in a spray drying system directly before or at a short distance from the nozzle in the drying tower.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG. 1 shows a middle section of a so-called tube bundle as a modular part of a tube bundle heat exchanger which may consist of a plurality of such tube bundles, wherein a well-known, commercially available elbow in the form of a circular connecting bend is arranged on each side.

[0037] A detailed representation of the invention is given in the following description and the accompanying figures of the drawing and from the claims. Whereas the invention is realized in a wide variety of embodiments, the drawing depicts a preferred exemplary embodiment of the elbow for large product pressures according to the invention and will be described below with regard to its design, production method and use in a high-pressure tube bundle heat exchanger.

[0038] FIG. 2 shows a meridian section of a preferred embodiment of an elbow half of the elbow according to the invention according to a section identified as C-D in FIG. 4.

[0039] FIG. 3 shows a perspective representation of an elbow half according to FIG. 2 parted in the meridian section.

[0040] FIG. 4 shows a perspective representation of a view of the elbow half according to FIG. 2.

[0041] FIG. 5 shows a meridian section of the elbow according to the invention joined with two congruently designed elbow halves according to FIG. 2.

[0042] FIG. 6 shows a meridian view and section of the inner contour of the elbow half according to FIG. 2 at the deflection region.

[0043] FIG. 7 shows a perspective representation of the parted elbow half according to FIG. 2 in the meridian section at the deflection region to depict the penetration in the region of the inner curvature.

DETAILED DESCRIPTION

[0044] The middle part of a tube bundle heat exchanger 100, which is normally composed of a plurality (a number n) of tube bundles 100.1 to 100.n (generally: 100.1, 100.2, . . . , 100.i−1, 100.i, 100.i+1, . . . , 100.n−1, 100.n) in the prior art is shown in FIG. 1. The bundle 100.i designates an arbitrary tube bundle (see also DE 94 03 913 U1) consisting of an outer jacket 200 bordering an outer channel 200* with a fixed-bearing-side outer jacket flange 200a arranged on the left side with reference to the depicted position, and a floating-bearing-side outer jacket flange 200b arranged on the right side. Abutting the latter is a first cross channel 400a*, which is bordered by a first housing 400.1 and has a first coupling 400a, and a second cross channel 400b*, which is bordered by a second housing 400.2 and has a second coupling 400b and abuts the fixed-bearing-side outer jacket flange 200a. A number of inner tubes 300, which extend axially parallel with the outer jacket 200 through the outer channel 200* and jointly form an inner channel 300* and each have a tube inner diameter D.sub.i, said number starting for example with four and then also increasing up to 19 and possibly more in number, is braced at the end in each case in a fixed-bearing-side tube carrier plate 700, or respectively a floating-bearing-side tube carrier plate 800 (both of which are also designated a tube mirror plate), where they are sealingly welded therein. This overall arrangement is introduced through an opening (not shown) in a second housing 400.2 into the outer jacket 200 and clamped by means of a fixed-bearing-side exchanger flange 500 to the second housing 400.2 with an intermediate seal 900 in each case, preferably a flat seal (fixed bearing 500, 700, 400.2).

[0045] The two housings 400.1, 400.2 are also sealed with a seal 900 against the adjacent outer jacket flange 200b, 200a, wherein the first housing 400.1 arranged on the right side in conjunction with the outer jacket 200 is pressed against the fixed bearing 500, 700, and the second housing 400.2 is arranged on the left side by means of a floating-bearing-side exchanger flange 600 with an intermediate, preferably O-ring 910. The floating-bearing-side tube carrier plate 800 extends through a hole (not shown) in the floating-bearing-side exchanger flange 600 and is sealed against the latter by means of the dynamically stressed O-ring 910 that moreover statically seals the first housing 400.1 against the floating-bearing-side exchanger flange 600. The latter and the floating-bearing-side tube carrier plate 800 form a so-called floating bearing 600, 800 that permits the changes in length of the inner tubes 300 welded in the floating-bearing-side tube carrier plate 800 that arise from a change in temperature in both axial directions.

[0046] Depending on the arrangement of the respective tube bundle 100.1 to 100.n in the tube bundle heat exchanger 100 and its respective configuration, a product P can flow through the inner tubes 300 from left to right or vice versa relative to the depicted position, wherein the average flow speed in the inner tube 300, and hence in the inner channel 200* is designated v. The cross section is generally designed so that this average flow speed v also exists in a connecting bend 1000 that is connected on the one hand to the fixed-bearing-side exchanger flange 500, and on the other hand directly to a floating-bearing-side coupling 800d that is securely connected to the floating-bearing-side tube carrier plate 800. By means of the two connecting bends 1000 (so-called 180 degree elbows), one half of each is depicted in FIG. 1, a relevant tube bundle 100.i is series-connected to an adjacent tube bundle 100.i−1, or respectively 100.i+1. The fixed-bearing-side exchanger flange 500 therefore first forms an inlet E for the product P, and the floating-bearing-side coupling 800d accommodates an associated outlet A. With each adjacent tube bundle 100.i−1, or respectively 100.i+1, this inlet and outlet configuration correspondingly reverses.

[0047] The fixed-bearing-side exchanger flange 500 has a first connection opening 500a that corresponds to a nominal diameter DN. Hence, a corresponding nominal passage cross-section of the connecting bend 1000 connected at that location, and which is generally dimensioned so that the existing flow speed at that location, corresponds to the average flow speed v within the inner tube 300, or respectively inner channel 300*. A second connection opening 800a in the floating-bearing-side coupling 800d is also dimensioned in the same manner, wherein the respective connection opening 500a, or respectively 800a expands to an expanded first 500c, or respectively expanded second passage cross-section 800c in the region of the adjacent tube carrier plate 700, or respectively 800, by a conical first 500b, or respectively a conical second transition 800b.

[0048] Depending on the direction of the flow speed v in the inner tube 300, or respectively inner channel 300*, the product P to be treated either flows through the first connection opening 500a or the second connection opening 800a toward the tube bundle 100.1 to 100.n, so that the flow is either toward the fixed-bearing-side tube carrier plate 700, or the floating-bearing-side tube carrier plate 800. Because in each case heat is exchanged between the product P in the inner tubes 300, or respectively the inner channels 300*, and a heat carrier medium W is in a countercurrent in the outer jacket 200, or respectively in the outer channel 200*, this heat carrier medium W either flows toward the first coupling 400a or toward the second coupling 400b at a flow speed c, which exists in the outer jacket 200.

[0049] The tube bundle heat exchanger 100 according to the prior art described above with its exemplary design is an embodiment that has been known for decades. Many design alterations with regard to bearing and sealing the tube bundle 100.i are known. The present disclosure needs only a number n of parallel-arranged, series-connected tube bundles 100.i (with i=1 to n). A product P flows through inner tubes 300 of the respective tube bundle 100.i. Viewed in the direction of flow of the product P and with reference to any desired tube bundle 100.i, an outlet A of the tube bundle 100.i is fluidically connected to an inlet E of an adjacent, downstream tube bundle 100.i+1 by an elbow with a deflection angle of 180 degrees. In the same manner, an inlet E of the tube bundle 100.i is connected to an outlet A of an adjacent, upstream tube bundle 100.i−1.

[0050] A finished elbow 1 (see FIG. 5) consists of two single-part, preferably congruent elbow halves, a first elbow half 1.1 and a second elbow half 1.2 (see FIGS. 2 to 7). The first elbow half 1.1 is associated with a first flange 2, and the second elbow half 1.2 is associated with a second flange 3. Each elbow half 1.1, 1.2 has a connecting point V on its end facing away from the flange 2, 3. The elbow halves 1.1, 1.2 at the connecting point V are bonded integrally to each other. The integral bond is preferably a weld seam 4, which is preferably performed in a multilayer orbital manner. Each flange 2, 3 can either accommodate the inlet E or the outlet A for the product P, which determines the respective relevant assignment of the flow direction of the product P.

[0051] The progression of the passage cross-sections of each elbow half 1.1, 1.2 is formed by rotationally symmetrical passages. On the one hand, at least one passage extends from the first flange 2 in a coaxial arrangement on a first rotational axis X1.1, and on the other hand at least one passage extends from the associated connecting point V in a coaxial arrangement on a second rotational axis Y1.1. In the same manner, at least one passage extends on the one hand from the second flange 3 in a coaxial arrangement on a third rotational axis X1.2, and at least one passage extends on a fourth rotational axis Y1.2 (see FIGS. 2 to 7). In the exemplary embodiment, only one penetrating first passage 5 and one penetrating second passage 6 are indicated in the first elbow half 1.1, and one penetrating third passage 7 and one penetrating forth passage 8 are indicated in the second elbow half 1.2 of these passages in the sequence of the above citation.

[0052] The first and second rotational axis X1.1, Y1.1 of the passages 5, 6 of the first elbow half 1.1, and the third and fourth rotational axis X1.2, Y1.2 of the passages 7, 8 of the second elbow half 1.2, run in a common plane that represents a meridian plane M for each flange 2, 3, and they preferably run in a straight line. The first and the second rotational axis X1.1, Y1.2 intersect at a first intersection P1, and the third and the fourth rotational axis X1.2, Y1.2 intersect at a second intersection P2, preferably always at a right angle, i.e., an angle of 90 degrees.

[0053] The first intersection P1 is associated with the penetrating first passage 5 on the first rotational axis X1.1 and the penetrating second passage 6 on the second rotational axis Y1.1 that each penetrate each other on one side. In the same manner, the second intersection P2 is assigned to the penetrating third passage 7 on the third rotational axis X1.2, and a penetrating fourth passage 8 on the fourth rotational axis Y1.2 that also each penetrate each other on one side. The first to fourth passages 5, 6 and 7, 8 that each penetrate each other on one side are preferably each designed in the shape of a conical frustum, and their respective tapering is oriented toward the associated first or second intersection P1, P2.

[0054] At the first to fourth passages 5, 6 and 7, 8 that penetrate each other, a first convex rounding 16, or respectively a second convex rounding 18 with an outer curvature radius R is provided in the radially exterior progression of the associated passage cross-section of the respective elbow half 1.1, 1.2, and a first concave rounding 17, or respectively a second concave rounding 19 with an inner curvature radius r is provided in the radially interior progression of the associated passage cross-section (see FIG. 2).

[0055] The rotationally symmetrical passages of the respective elbow halves 1.1 and 1.2 are lined up with the same diameter at their respective transition point to an adjacent passage to prevent sudden loss-associated cross-sectional transitions, wherein it is moreover advantageous to design these transition points with a continuous curve as provided as an example in the region of the flanges 2, 3 at one point (see FIGS. 2, 5).

[0056] The first and second elbow halves 1.1, 1.2 are preferably composed of the following geometric main bodies in the following sequence (see in particular FIG. 4 in conjunction with FIG. 5): the circular cylindrical first flange 2, or respectively circular cylindrical second flange 3, a cylindrical first section 9, or respectively cylindrical fourth section 13, a prismatic second section 10, or respectively prismatic fifth section 14, and a cylindrical third section 11, or respectively a cylindrical sixth section 15.

[0057] A contact surface 12 is provided on the first flange 2 and the second flange 3 (see in particular FIG. 2 in conjunction with FIGS. 4 and 5) and is oriented in a plane parallel to an end face B of the connecting point V and stands back by a degree of shrinkage “a” from the end face B. Before the production of the weld seam 4 and in the adjusted end position of the elbow halves 1.1, 1.2, the contact surfaces 12 are distant from each other by double the degree of shrinkage 2a (see FIG. 5). This double degree of shrinkage 2a is dimensioned so that, after the produced weld seam 4 has cooled, the contact surfaces 12 lie on each other, and an immovable and undeformable spacing between the two flanges 2, 3 accordingly exists for their dimensional end processing.

[0058] FIG. 6 shows details of an inner contour i of the elbow halves 1.1, 1.2 at their respective deflection region. A “normal” elbow, or respectively a so-called standard bend with a 180 degree deflection with the same inlet and outlet cross-section that is characterized in each case by a diameter Ød, possesses an outer radius R2 (convex rounding) and an inner radius R1 (concave rounding), wherein both differ from each other by the diameter Ød (geometric condition R2=R1+Ød). In contrast to this “normal” elbow, the first elbow half 1.1 has the penetrating first and penetrating second passage 5, 6, each designed in the shape of a conical frustum, which penetrate each other on one side. The geometric relationships in the second elbow half 1.2 with the third and fourth passages 7, 8 that penetrate each other on one side are configured in the same manner. It is apparent that a respective cross-sectional tapering toward a respective peak cross-section S of the elbow half 1.1, 1.2 is established by the respective frusticonical design of the passages 5 to 8 with an expected consequence in terms of fluid mechanics, which has already been addressed above. In order to realize the condition of an equivalent passage cross-section in the region of penetration of the penetrating first passage with the penetrating second passage 5,6, or respectively the penetrating third with the penetrating fourth passage 7, 8, i.e., in the overall peak region of the respective elbow half 1.1, 1.2, said elbow half should be provided with a convex rounding with a radius of a constant passage cross-section R3 in the respective radially exterior progression of the associated passage cross-section, and with a concave rounding in the radially interior progression with the inner curvature radius r.

[0059] The design of the inner contour i in the deflection region contrastingly provides expanding the peak cross section S of the elbow half 1.1, 1.2 relative to the peak cross-section S of adjacent passage cross-sections on both sides, which is illustrated by the representation in FIG. 6. The conical, mutually penetrating first to fourth passages 5, 6 and 7, 8 are each concavely rounded with the outer curvature radius R (R<R3) that extends in each case to intersection PI, or respectively P2, which clearly leads to an expansion of the peak cross section S because the first, or respectively second convex rounding 16, 18, extends further to the outside relative to an inner contour established by the radius of a constant passage cross-section R3.

[0060] FIG. 7 shows a perspective representation of the penetrating region of the penetrating first with the penetrating second passage opening 5, 6, or respectively the penetrating third with the penetrating fourth passage opening 7, 8 in the radially interior progression of the passage cross-section of the respective elbow half 1.1, 1.2. Without the concave rounding with the inner curvature radius r, a sharp-edge penetrating line would result, which would manifest itself in the meridian plane M in FIG. 6 as a penetration point P3. In any event, in the region of curvature of the elbow, such a sharp-edge penetrating line would cause the flow to be interrupted and hence cause increased elbow loss. To reduce this loss, it is particularly useful when this penetrating line, as shown clearly in FIG. 7, is only partial with varying sharpness over the perimeter, and is concavely rounded over the entire extent of its shape with the inner curvature radius r.

[0061] A production method for an elbow 1 having the above-described features includes producing the respective elbow half 1.1, 1.2 from a round material in a first production step, and from a whole piece by machining. An inner contour i consisting of rotationally symmetrical passages and a first outer contour al that is not directly adapted to the tube bundle heat exchanger 100, or respectively its tube bundles 100.1 to 100.n, are provided with a respective end contour. A second outer contour a2 is processed beforehand that is directly adapted to the tube bundle heat exchanger 100. Machining is preferably carried out in this case on a multi-axis machining center on which the flange 2, 3 and cylindrical sections 9, 13 and 11, 15 are turned, the prismatic sections 10, 14 and the contact surfaces 12 are milled, and the passages associated with the rotational axes X1.1, X1.2, Y1.1, Y1.2 are drilled and/or turned.

[0062] In a second production step, the two elbow halves 1.1, 1.2 are integrally bonded to each other at their respective connecting point V to the elbow 1. The integral bond is preferably produced by a manual or mechanical orbital welding method which can be carried out in one or more layers.

[0063] In a third production step, the second outer contour a2 adapted with the tube bundle heat exchanger 100, or respectively its tube bundles 100.1 to 100.n which expediently also comprises the end-side part of the inlet E or the outlet A is provided with an end contour by machining. In this end contour, the machining of the first and second connection opening 500a, 800a, the conical first and second transition 500b, 800b and the expanded first and expanded second passage cross-section 500c, 800c as described above in conjunction with FIG. 1 are expediently included.

[0064] The design of the tube bundle heat exchanger 100 according to FIG. 1 is only to be understood as a possible exemplary embodiment. The invention can be used for any tube bundle heat exchanger that is suitable for large product pressures in which a product flows through inner tubes of a tube bundle, and in which the tube bundles are arranged in parallel and series-connected in a known manner. In such an arrangement viewed in the direction of flow of the product and with reference to any desired tube bundle, an outlet of the tube bundle is fluidically connected to an inlet of an adjacent downstream tube bundle and, alternatingly, an inlet of the tube bundle is fluidically connected to an outlet of an adjacent, preceding tube bundle via an elbow with a deflection angle of 180 degrees. According to the invention, an elbow is used in each case that has the above-described features.

[0065] A reference list for the abbreviations and drawing labels is as follows: [0066] 1 Elbow [0067] 1.1 First elbow half [0068] 1.2 Second elbow half [0069] 2 First flange [0070] 3 Second flange [0071] 4 Weld seam [0072] 5 Penetrating first passage [0073] 6 Penetrating second passage [0074] 7 Penetrating third passage [0075] 8 Penetrating fourth passage [0076] 9 Cylindrical first section [0077] 10 Prismatic second section [0078] 11 Cylindrical third section [0079] 12 Contact surface [0080] 13 Cylindrical fourth section [0081] 14 Prismatic fifth section [0082] 15 Cylindrical sixth section [0083] 16 First convex rounding [0084] 17 First concave rounding [0085] 18 Second convex rounding [0086] 19 Second concave rounding [0087] a Degree of shrinkage [0088] a1 First outer contour [0089] a2 Second outer contour [0090] Ød Diameter [0091] i Inner contour [0092] r Inner curvature radius [0093] A Outlet (out of flange 2, 3) [0094] B End face [0095] E Inlet (into flange 2, 3) [0096] M Meridian plane [0097] P1 First intersection [0098] P2 Second intersection [0099] P3 Penetration point [0100] R Outer curvature radius [0101] R1 Inner radius of the normal elbow [0102] R1 Outer radius of the normal elbow [0103] R3 Radius of a constant passage cross-section [0104] S Peak cross section [0105] V Connecting point [0106] X1.1 First rotational axis [0107] X1.2 Third rotational axis [0108] Y1.1 Second rotational axis [0109] Y1.2 Fourth rotational axis [0110] 100 Tube bundle heat exchanger [0111] 100.1 First tube bundle [0112] 100.2 Second tube bundle [0113] 100.i i-th tube bundle [0114] 100.i−1 Tube bundle upstream from tube bundle 100.i [0115] 100.i+1 Tube bundle downstream from tube bundle 100.i [0116] 100.n−1 Tube bundle upstream from tube bundle 100.n [0117] 100.n n-th tube bundle [0118] 200 Outer jacket [0119] 200* Outer channel [0120] 200a Fixed-bearing-side outer jacket flange [0121] 200b Floating-bearing-side outer jacket flange [0122] 300 Inner tube [0123] 300* Inner channel [0124] 400.1 First housing [0125] 400a First coupling [0126] 400a* First cross channel [0127] 400.2 Second housing [0128] 400b Second coupling [0129] 400b* Second cross channel [0130] 500 (Fixed-bearing-side) exchanger flange [0131] 500a First connection opening [0132] 500b Conical first transition [0133] 500c Expanded first passage cross-section [0134] 600 Floating-bearing-side exchanger flange [0135] 700 Fixed-bearing-side tube carrier plate (tube mirror plate) [0136] 800 Floating-bearing-side tube carrier plate (tube mirror plate) [0137] 800a Second connection opening [0138] 800b Conical second transition [0139] 800c Expanded second passage cross-section [0140] 800d (Floating-bearing-side) coupling [0141] 900 Seal (Flat seal) [0142] 910 O-ring [0143] 1000 Connecting bend [0144] c Flow speed in the outer jacket [0145] n Number of tube bundles (generally: 100.1, 100.2, . . . , 100.i−1, 100.i, 100.i+1, . . . , 100.n−1, 100.n) [0146] v Average flows speed in the inner tube [0147] A Outlet (outflow side of the tube carrier plate 700, 800) [0148] DTube inner diameter (inner tube 300) [0149] DN Nominal diameter of the connecting bend [0150] E Inlet (inflow side of the tube carrier plate 700, 800) [0151] W Heat carrier medium, general [0152] P Product (temperature-treated side)