German Reich

[emblem]

 

                                                              German Patent Office

 

                                                                        Patent

 

                                                                    No. 516 682

                                                                Class 17f Group 5

 W 83820 I / 17f

                                                         issued on January 26, 1931

 

                          Date of publication regarding the grant of the patent: January 8, 1931

 

 

                                            Wehrle Werke A.G. in Emmendingen, Baden

 

                        Heat Exchanger comprising a Tube Bundle, mounted in the Shell,

                        and Lateral Baffle Surfaces, fastened between Transverse Plates

 

                                                          Addition to patent 515 761

 

                             Patented in the German Reich starting from September 28, 1929.

                                        The parent patent commenced on January 4, 1929.

 

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            The invention relates to an additional embodiment of a heat exchanger, as claimed in patent 515 761, where the one heat exchange medium flows through a tube bundle, which is housed in a shell, and the other heat exchange medium is conveyed in a zigzag through intermediate partition walls, which are situated transversely to the direction of the tubes. Such heat exchangers are intended chiefly for use as oil coolers and vapor condensers. In the device, according to the parent patent, the cross flow chambers, formed by the intermediate partition walls, are terminated laterally by baffles, which are adapted to the tube bundle. On the one hand, only the center sections of the baffles are attached to the intermediate partition walls; and on the other hand, the front and rear edges of the baffles rest in a freely resilient manner against the internal wall of the shell, enveloping the device, so that the transversely flowing heat exchange fluid does not make any contact whatsoever with the sides of the outer shell. The configuration, according to the parent patent, has already demonstrated the key advantage that owing to the arrangement and elasticity of flexure of the baffles along the straight edges, the baffles form a seal against the internal wall of the outer shell, even if this shell is not turned and machined internally. Moreover, this configuration of the parent patent has also demonstrated the advantage that the edges of the intermediate partition walls do not have to be adapted to the desired shape of the baffles, because the baffles are not continuous. However, in the case of the configuration of the parent patent, it is still necessary to adapt the edges of the intermediate partition walls exactly to the circularity of the internal wall of the outer shell, so that no axial through-flow from a transverse flow chamber to the adjacent chamber on the outer edge can occur. Therefore, the present invention provides that resilient end plates are also installed on the edge between the intermediate partition walls in the transverse direction - that is, transversely to the baffles. However, each of these transversely lying end plates or cover plates exhibits twice the height of a transverse flow chamber, since said plates come to rest in the reversal chambers, where the central intermediate partition wall is cut out. These sheet metal plates, which rest outwards only with one rib in a resilient manner against the internal wall of the shell and with their lateral edges against the ends of the lateral baffle surfaces, terminate the transverse flow chambers in the direction of the transverse sides, so that there would be no further need for a circular machining of the edges of the intermediate partition walls for the purpose of adapting to the shell, which is to be machined so as to match. Therefore, it is now possible to use as the shell for the device a rough cast or rough machined tube by constructing now the actual shell of the system out of the resilient metal sheet plates, which rest against each other with flat edges. In addition, the edges of the intermediate partition walls do not need to experience any exact circular machining, since now it no longer depends on the width of the distance of the edges from the internal wall of the shell. The whole internal system of tubes, intermediate partition walls, baffles and end plates can be assembled and screwed together as a homogeneous body before insertion into the shell, in order then to be slid as a monolith into the shell. At the same time the parts rest against each other in a resilient and sealing manner; and, in particular, they rest along the flat edges, which can be cleanly machined in a simple way.

            The drawings depict one embodiment of a heat exchanger of the invention in a longitudinal section (Figure 1) and a cross section (Figure 2); and, in particular, the embodiment shows a heat exchanger that is intended for use as a kettle vapor condenser. The device consists of a system of parallel longitudinal tubes 1, which are installed into front bottoms 2 and 3. Onto the tubes 1 are slid at regular intervals the sheet metal plates 4, which serve as the intermediate partition walls and which are cut out alternatingly at the top and the bottom, so that in this way chambers are generated for the transverse flow of the coolant in a zigzag. The sides of these cross flow chambers 5 are covered by baffles 6, which extend, therefore, vertically in the present case. As a result, their front and rear edges rest on the sheet metal plates 4; and the baffles are fastened in their center so that the top and bottom ends 7 of these baffles are outwardly resilient. Therefore, in the present case the end plates 9 are installed at the top and the bottom into the reversal chambers 8 in the transverse direction to the baffles 6. The front and the rear edges of the end plates rest against the plates 4, whereas the linear side edges 10 press in a resilient manner against the lateral baffles 7, which lie in the region of the side edges. These end plates 9 are provided externally with a welded-on rib 11, which extends from the front to the rear in the longitudinal direction. If this system of tubes 11 comprising intermediate plates 4, lateral baffles 6 and transversely lying cover plates 9 is tightened with continuous threaded bolts 12, the result is a homogeneous body, which can be slid into the shell 13 of the device, which is  provided with inlet and outlet adapters 14 and 15 for the coolant. Attached to the tube bottoms 2 and 3 are the front chambers or rather covers and hoods 16  and 17 for the feed and discharge of the kettle vapor that is to be condensed. In order to insert the tube system into the shell 13, the end plates 9 are compressed in a resilient manner to the extent that the ends 10 rest snugly against the ends 7 of the baffles. These baffle ends 7 in turn rest snugly against the internal wall of the shell 13. In this way a system is provided that exhibits flow chambers that are adequately sealed against each other, so that there are no machined surfaces or edges other than the linearly planar ones.

 

                                                                   Patent Claim:

 

            Heat exchanger, which comprises a tube bundle, mounted in the shell, and lateral baffle surfaces, fastened between transverse plates, and which is claimed in patent 515 761, characterized in that resilient, outwardly delimiting cover plates (9) are slid into the reversal chambers between the intermediate partition walls (4), said cover plates resting outwardly with a central rib (11) against the internal wall of the shell (13) and with the lateral edges (10) against the ends of the lateral baffles (6).

 

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                                                                1 sheet of drawings

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                                                           Berlin, printed in the German Government Printing Office


key to the figures

 

With respect to patent 516682

Class 17f Group 5

 

Figure 1

            [see drawing]

 

Figure 2

            [see drawing]