Patent Publication Number: US-2011048674-A1

Title: Holding module for heat exchanger tubes

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of priority of German Application No. 102009039816.3, filed Sep. 2, 2009. The entire text of the priority application is incorporated herein by reference in its entirety. 
     FIELD OF THE DISCLOSURE 
     The disclosure relates to a holding module for heat exchanger tubes, a rack for heat exchanger tubes with several holding modules as well as a method for setting up a rack for heat exchanger tubes. 
     BACKGROUND 
     The use of heat exchangers, in particular tubular heat exchangers, for transmitting thermal energy from one medium to a second medium is widely spread. Depending on application, several tubular heat exchangers are combined in individual sections. The tubular heat exchangers e.g. comprise, as will be illustrated more in detail hereinafter, a heat exchanger tube, i.e. a casing tube in which a plurality of internal tubes is arranged, at least, however, one internal tube. The heat exchanger tubes are held by means of frames and shelf racks. 
     The conventional racks, however, require a lot of space, and the manufacture of such racks and their equipment are moreover complex and expensive. The size of the known racks is fixed and they cannot be flexibly extended. 
     SUMMARY OF THE DISCLOSURE 
     Starting from this situation, an aspect underlying the present disclosure is to provide a device and a method by means of which heat exchanger tubes can be held in a simpler, more space-saving and cheaper manner, where the device can be in particular flexibly extended. 
     According to the present disclosure, individual holding modules for the heat exchanger tubes are used for the modularly assembled rack. A holding module comprises a lower module half with several recesses into each of which one heat exchanger tube can be placed, as well as an upper holding module half which also comprises several recesses and which can be placed onto the lower holding module half, such that its recesses are lying opposite to the recesses of the lower holding module half, such that the heat exchanger tubes are held in the recesses. 
     A connecting element connects the upper and the lower halves. Thus, the heat exchanger tube can be simply placed into the holding module, and the second half can then be placed on top. The rack is assembled in steps together with the piling up of the heat exchanger tubes. Level by level is piled up until a certain rack height is reached. 
     According to the present disclosure, a very compact construction can be achieved. By the modular structure, the height can be flexibly adapted to certain requirements. The height of the system can also be subsequently flexibly extended. The system can be extended as desired. The rack according to the disclosure is clearly less expensive than the known frame racks. The assembly of the individual modules is also very simple and quick. Moreover, an improved design results. 
     Advantageously, the connecting element which connects the upper and the lower holding module half is a plug-in element that can be plugged onto the lower holding module half, while the upper holding module half is plugged onto the plug-in element. Such a connecting element is inexpensive and moreover permits an easy assembly. 
     The plug-in element preferably extends in the longitudinal direction of the heat exchanger tubes and provides a stable connection. 
     Advantageously, the upper and lower holding module halves are constructed in the same way. Thus, the complete holding module can be manufactured very inexpensively. 
     According to a preferred embodiment of the holding module, the upper and/or lower holding module half is embodied such that it comprises an essentially U-shaped cross-section with two opposite side walls and an intermediate bottom, the recesses being embodied in the side walls. Thus, each module half comprises two support surfaces for the heat exchanger tube and permits a good support for the heat exchanger tube. By the U-shaped embodiment, the weight of the holding module can be essentially reduced. 
     The plug-in element can be embodied e.g. such that it comprises at least two upper and/or at least two lower openings into which the side walls of the upper or the lower holding module half can be inserted, or else the lower holding module half and/or the upper holding module half is embodied such that they comprise openings in the side walls into which the plug-in element can be inserted. 
     A rack for the heat exchanger tubes comprises at least one first and one second unit in which several modules each are arranged one upon the other, where then the heat exchanger tubes arranged in parallel to each other are held by the first and the at least second unit. Depending on the length of the tubes, a varying number of units can be employed. Equally, depending on the diameter and number of the heat exchanger tubes, each level can be differently equipped. The units do not have to be filled completely. The modules arranged one upon the other in the units can be fixed to each other by a fixing means. To fix the modules in a respective unit, the modules can comprise e.g. through openings arranged one upon the other into which a fixing rod can then be inserted from above. Thus, the individual modules arranged one upon the other remain in correct orientation with respect to each other. For even better fixing, lateral crossbars can be arranged between the holding element units for bracing. 
     The lowermost holding module half of each holding module unit can be firmly connected to a bottom frame. Thus, the lowermost holding module half has a stable grip and permits secure assembly of the modules to be arranged thereabove. 
     In the method according to the disclosure, several holding module halves spaced apart are provided (step a). Then, the heat exchanger tubes are placed into the recesses of the lower holding module halves (step b). Finally, the several upper holding module halves are placed onto the tubes, such that the recesses face the tubes and receive them (step c). A lower holding module half can then be placed again on the upper side of the now already installed upper holding module half to produce a further module (step d). Steps d, b, c can be repeated as often as desired until a desired rack height is reached. 
     After step a or b, the holding module halves are fixed. For this, after step a or b, at least one plug-in element can be inserted into the lower holding module half, and the upper holding module half can be placed onto the at least one plug-in element in step c. Thus, a simple self-supporting modular system is formed. The modules arranged one upon the other in one unit can then be also fixed again to each other to achieve an altogether stable system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will be illustrated below in greater detail with reference to the following figures: 
         FIG. 1  shows a holding module according to the present disclosure in a perspective representation; 
         FIG. 2  shows a lower holding module half with inserted plug-in element in a perspective representation; 
         FIG. 3  schematically shows a front view of a plug-in element according to the present disclosure; 
         FIG. 4  shows a perspective representation of three holding modules according to the present disclosure arranged one upon the other; 
         FIG. 5  shows a schematic perspective representation in partial elevation of a rack according to the present disclosure, wherein the heat exchanger tubes are not represented; 
         FIG. 6  schematically shows an example of a heat exchanger tube; 
         FIG. 7  shows a rack according to the present disclosure in a perspective representation. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 6  shows the basic structure of a heat exchanger tube  12 . The heat exchanger tube  12  here comprises a casing or external tube  18  with an inlet  13  on the secondary side and an outlet  14  on the secondary side. In the casing tube  18 , several internal tubes, at least, however, one internal tube or bank of tubes  17 , respectively, are arranged which comprise a corresponding inlet  15  and outlet  16  on the primary side. The individual heat exchanger tubes  12  can be interconnected in individual sections, i.e. then, for example, the outlet  16  of a first heat exchanger tube is connected to the inlet  15  of a subsequent heat exchanger tube, e.g. arranged in parallel to it, and the outlet  14  is connected to the inlet  13  of a subsequent tube. The inlets  15  and outlets  16  can be interconnected, for example, via tube bends. The outlets  14  and the inlets  13  can also be connected by corresponding tube connections. 
       FIG. 1  shows in a perspective representation a holding module for holding several heat exchanger tubes  12  extending in parallel with respect to each other, which are not represented here for the sake of simplicity. A holding module  1  comprises a lower holding module half  1   b  which comprises several recesses  3   b  into each of which one heat exchanger tube  12  can be placed, and an upper holding module half  1   a  which comprises several recesses  3   a  and which can be placed onto the lower holding module half  1   b  such that the recesses  3   a  are lying opposite to the recesses  3   b , such that the heat exchanger tube can be firmly held in the recesses  3   a, b . The inner diameter of the essentially circular recess  3   a, b  here essentially corresponds to the outer diameter of the heat exchanger tube  12 , such that the tube is held to be protected from shifting. 
     Normally, the holding modules are designed such that one of the units  30 ,  31 ,  32 ,  33  serve as fixed, and the other ones as loose bedding, so that the different thermal expansions of the individual heat exchanger tubes with respect to the rack are compensated. 
     As can be taken in particular from  FIG. 2 , each holding module half is embodied such that it has a U-shaped cross-section, so that the holding module  1  is embodied to be hollow inside and only has a low weight. The openings  3   a, b  are embodied in the opposite side walls  5   a, b  and  6   a, b  of the module halves  1   a, b . One bottom  7   a, b  each is situated between the side walls  5   a, b  and  6   a, b . In this example, six recesses  3   a, b  for six heat exchanger tubes arranged in parallel to each other in one level are provided. Advantageously, approximately two to ten such openings are provided next to each other. Angles  8   a, b  are shaped to the front and end side of the holding module  1 , so that after the set up of the individual holding modules, crossbars and/or a covering, as will be illustrated more in detail below, can be arranged. In both bottoms  7   a, b , opposite openings  9   a, b  are provided into which a fixing rod  20  (see  FIG. 5 ) can be inserted for fixing holding modules arranged one upon the other. 
     To connect the two holding module halves  1   a, b  with each other, a connecting element, preferably a plug-in element  11 , is provided. The plug-in element can be plugged onto the lower holding module half  1   b , while the holding module half  1   a  is plugged onto the plug-in element  1 . Here, a holding module  3  comprises such plug-in elements  11 . The number of plug-in elements  11  depends on the size of the holding module. 
     As can be in particular also taken from  FIG. 2 , the plug-in element extends in the longitudinal direction of the heat exchanger tubes  12 . Here, the plug-in element comprises two openings  19   a  at the upper side and two openings  19   b  at the bottom side. The side walls  6   a, b  and  5   a, b  can be inserted into these openings. As an alternative to this, the lower holding module half  1   b  and the upper holding module half  1   a  can also comprise openings in the side walls into which the plug-in element  11 , which then does not require any corresponding openings, can be inserted. Thus, a secure grip of the two holding module halves is ensured. Several holding modules  1  can be arranged one upon the other, as can be taken from  FIG. 4 . 
       FIG. 4  shows, for example, three holding modules  1  which are arranged one upon the other, where three heat exchanger tubes  12  have been inserted and the individual halves have been connected to each other by means of the plug-in elements  11  during the assembly. This results in a self-supporting unit. 
     In  FIG. 5 , a rack for heat exchanger tubes with several holding modules  1 , as described above, are shown. The holding modules  1  correspond to the above described holding modules. For the sake of simplicity, the heat exchanger tubes  12  are not represented in  FIG. 5 . The rack comprises several units  30 ,  31 ,  32  in which several holding modules  1  are arranged one upon the other. In this embodiment, four units are provided. The heat exchanger tubes  12  arranged in parallel are held by the holding modules in the respective units  30 ,  31 ,  32 ,  33 . The lowermost holding module half  1   b  of each holding module unit  30  to  33  can be firmly fixed to a frame  27  which can stand on corresponding feet. Then, so many heat module halves and heat exchanger tubes are piled up level by level until a desired height is reached. If a desired height is reached, the modules  1  arranged one upon the other of each unit can be fixed to each other by a fixing means  9 ,  20 . For this, a through opening  9  (openings  9   a, b , in the bottom of the holding module halves) is provided in each module  1 , as already described above. A fixing rod  20  is pushed through the openings and for example fixed by screwing. Here, there are two fixing means  20 ,  9  per unit. The holding modules  1  piled one upon the other can then be braced between the units  30 ,  31 ,  32 ,  33 , e.g. with crossbars  23 . The crossbars  23  can be placed either directly at the modules (not represented), or else with frame parts  26  which are fixed between the units. In addition, side covering parts  21 ,  22  can be attached to the open sides of the rack. An upper covering  24  can also be arranged between the individual units. Here, the upper coverings  24 , which comprise openings  25  above the corresponding openings  9 , are also held by the fixing rod  20 .  FIG. 7  shows a rack with a covering. 
     The system according to the disclosure brings about the advantage that the number of heat exchanger tubes arranged in one level can be varied, i.e. that for example not all recesses must be occupied by tubes. The number of modules or tubes, respectively, arranged one upon the other can also be simply varied by stacking the desired number of modules one upon the other. 
     At the front sides of the rack, the heat exchanger tubes  12  project (not represented) and can be connected to each other via corresponding tube bends or connecting elements depending on the interconnection, as was also described in connection with  FIG. 6 . Here, they can be connected vertically as well as horizontally. The center distance of the openings is identical in identical units. 
     In the method according to the disclosure for setting up the rack shown in  FIG. 5 , first in a step a, several lower holding module halves  1   b  that are spaced apart are provided. Here, the holding module halves  1   b  are fixed to the frame  27 . In a next step b, the heat exchanger tubes  12  are placed into the lowermost heat exchanger half  1   b  of each unit  30 ,  31 ,  32 ,  33  (step b). In each unit  30 ,  31 ,  32 ,  33 , an upper holding module half  1   a  is now placed onto the tubes, such that the recesses  3   a  are facing the tubes  12  and receive and hold the same. After step a or b, here the plug-in element  11  is inserted into the lower holding module half  1   b , the upper holding module half  1   a  being plugged into the plug-in element  11  in step c. 
     Then, a lower holding module half  1   b  of a further module can be placed onto the upper side of the upper holding module half  1   a , so that the bottom  7   b  comes to lie on the bottom  7   a.    
     Steps a, b, c can be repeated as often as desired until a predetermined rack height is reached. Then, the modules arranged one upon the other in the individual units  30 ,  31 ,  32 ,  33 , can be fixed to each other via the fixing means  20 ,  9 , as illustrated before, by passing the rod  20  through the openings  9  and screwing it down. Finally, cross bracings can be arranged and the longitudinal covering elements  21 , the upper covering elements  24 , and the lateral covering elements  22  can be arranged as desired. Frame parts  26  can be arranged between the individual units. 
     In this manner, the heat exchanger tubes can be very easily mounted. An attractive design results. The height of the modular structure can be flexibly extended. The compact design is extremely space-saving.