Patent Publication Number: US-2005120654-A1

Title: Wall and/or ceiling structure, wall modules and fastening arrangements therefor and use therof

Description:
FIELD OF THE INVENTION  
      The invention relates to a wall and/or ceiling structure, in particular for a heat treatment installation, to a wall module and a fastening arrangement for the wall structure, as well as to the use of the wall and/or ceiling structure, the wall modules and the fastening arrangement.  
     BACKGROUND OF THE INVENTION  
      A cassette-shaped lining for industrial furnaces is known from DE 37 14 753 A1. This fireproof lining consists of a prefabricated furnace frame with cassettes, which are constructed in the shop and filled with fireproof layers and suspended from the frame. In accordance with one embodiment, anchors are applied to a continuous support plate at the surface facing the furnace interior, which keep a single- or multi-part fireproof layer in place, wherein holders are attached to the other surface of the support plate, by means of which the cassettes are fastened to the furnace frame. It is said that by means of this design it is possible to attach the cassettes by simple means, for example a lifting crane, quickly and dependably to the furnace frame. The transport of the cassettes at the construction site can also take place without problems. The cassettes are prefabricated at lengths of 2 to 3 m or more in a shop. It is disadvantageous with this embodiment that the construction is elaborate and expensive and that, in spite of the cassette construction, a considerable time requirement still exists.  
      A heat insulation element is known from DE 37 00 126 C1. The heat insulation element consists of a heat-resistant fiber mat component, which is maintained on a support element. The heat insulation element consists of several fiber mats, which have been folded once into a U-shape, several of which are placed on top of each other and are fastened at their open ends by means of spiked tapes and fastened to a plate made of a metal mesh. Fastening means are furthermore provided for mounting the heat insulation element in a simple way on a wall or to remove it from the wall. The heat insulation element is intended to be arranged by means of a screw connection on the wall of a furnace or the like, wherein the head of the screw is introduced into a rail and can be displaced on the wall along this rail. It is disadvantageous here that for mounting and dismounting the insulation elements must possibly be displaced over the entire length of the furnace chamber. It is moreover disadvantageous that in connection with rapid mounting systems for fiber elements, the same as with fiber elements in general, environmental protection problems exist in regard to the wearing off of fibers. These fibers are known to enter the lungs and are cause for concern regarding health.  
      Heat insulation elements are furthermore known, which consist of fiber mats and are screwed to the inside of the furnace chamber by means of appropriate retaining clamps.  
     SUMMARY OF THE INVENTION  
      It is an object of the invention to create a wall and/or ceiling structure, in particular for a heat treatment installation which, in contrast to brick or monolithic linings, provides a reduction of assembly time, is rapidly available, and can be assembled particularly simply.  
      It is a further object to create a wall module for the wall and/or ceiling structure.  
      It is still a further object to create a fastening arrangement for the wall and/or ceiling structure.  
      The use of the wall and/or ceiling structure, the module, and the fastening arrangement is another object of the invention.  
      The wall and/or ceiling structure in accordance with at least one embodiment of the invention is embodied in particular in the form of several layers of a lightweight refractory brick on the inside of the furnace and of adjoining heat insulation layers, wherein these heat insulation layers are bordered by a support structure of the furnace and the light refractory brick layer on the side of the fire box. The wall and/or ceiling structure is formed of individual wall modules, and a fastening device for the module is provided. At least a portion of the modules has first retaining devices which keep the module together and act together with second retaining devices arranged on a support structure of the heat treatment installation. The modules are lockingly fastened on the support structure by means of the first and second retaining devices. Because of the lockable connection in accordance with the invention between the first and second retaining devices, the modules can be fastened on the support structure in a particularly simple manner by “clipping” the module to the support structure. It is possible in this case to use modules which are identically constructed.  
      However, it is also possible to use two or more different forms of modules, wherein a portion of the modules is designed as support modules, which support two or several identically or differently formed filler modules on the wall, so that the modules or the wall structure are maintained on the support structure with a reduced assembly outlay.  
      It is advantageous in connection with the invention that the assembly times, and therefore also the idle times, are reduced by up to 70% compared with brick or monolithic linings. Furthermore, the modules can be universally employed in all heat treatment installations with temperatures up to 1200° C., in particular in the chemical and petrochemical industry, in steel and iron production and the heavy clay industry. Moreover, the advantages of the ceramic fiber modules (assembly time) and the conventional lightweight construction (no health risks because of free fibers) are connected with each other in an advantageous manner. In addition, no consoles for supporting the brick lining are required.  
      The invention will be explained by means of examples in the drawings showing several drawing figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic representation of a wall structure in accordance with the invention in a horizontal projection from the furnace interior.  
       FIG. 2  shows a structure in accordance with  FIG. 1  in section along the height of the wall structure.  
       FIG. 3  shows a structure in accordance with  FIG. 1  in longitudinal section along the length of the wall structure.  
       FIG. 4  represents the fastening in accordance with the invention of a module according to  FIG. 2 .  
       FIG. 5  is a horizontal projection of a further embodiment of the invention with identically constructed modules.  
       FIG. 6  is a section through the wall structure in accordance with  FIG. 5  along the wall height.  
       FIG. 7  is a section through the wall structure in accordance with  FIG. 5  along the linear extension of the wall.  
       FIG. 8  is a horizontal projection of a further embodiment of the wall structure of the invention.  
       FIG. 9  is a section through the wall structure of the invention in accordance with  FIG. 8  along the wall height.  
       FIG. 10  is a section through the wall structure of the invention in accordance with  FIG. 8  along the wall length.  
       FIG. 11  shows a first embodiment of a module in accordance with the invention for embodying a wall structure in accordance with  FIG. 1  in a first sectional view, in particular along the length of a furnace.  
       FIG. 12  shows a module in accordance with  FIG. 11  in a second sectional view.  
       FIG. 13  shows a module in accordance with  FIG. 11  in horizontal projection of the side facing away from the furnace chamber with a retaining plate.  
       FIG. 14  is a further embodiment of a module in a lateral view.  
       FIG. 15  shows a module in accordance with  FIG. 14  in a lateral view rotated by 90°.  
       FIG. 16  shows a module in accordance with  FIG. 14  in a horizontal projection of the module side facing away from the furnace chamber.  
       FIG. 17  shows a module for a wall structure in accordance with  FIG. 8  in a lateral view.  
       FIG. 18  shows a module in accordance with  FIG. 17  in a lateral view rotated by 90°.  
       FIG. 19  shows a module in accordance with  FIG. 17  in a horizontal projection of the rear facing away from the furnace chamber.  
       FIG. 20  represents an embodiment of a retaining anchor in accordance with the invention.  
       FIG. 21  is a schematic horizontal projection of a retaining plate in accordance with the invention.  
       FIG. 22  is a cross-section through a retaining plate in accordance with the invention.  
       FIG. 23  is a horizontal projection of a further embodiment of a retaining plate in accordance with the invention.  
       FIG. 24  shows a cross-section through the retaining plate in accordance with  FIG. 23 .  
       FIG. 25  is a horizontal projection of a locking device of the retaining plate in accordance with  FIG. 23 .  
       FIG. 26  represents the retaining device in accordance with the invention in an assembled state in a plan view from a side of the furnace wall.  
       FIG. 27  shows a retaining device in accordance with  FIG. 26  in a lateral view.  
       FIG. 28  shows the retaining device in accordance with  FIG. 26  in a view rotated by  900  with respect to  FIG. 27 .  
       FIG. 29  represents a fastening arrangement in accordance with the invention in a lateral view.  
       FIG. 30  shows the arrangement in accordance with  FIG. 29  in a lateral view rotated by 90°.  
       FIG. 31  is a horizontal projection of the arrangement in accordance with  FIG. 29 .  
       FIG. 32  is a greatly schematized exploded view of a portion of the wall structure in accordance with the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The wall structure  1  in accordance with the invention contains a number of wall modules  2 , which are arranged by means of fastening arrangements  3  on a support structure  4  of a furnace or other heat treatment unit. The wall modules (FIGS.  11  to  18 ) are suitably constructed in multiple layers and have a first layer  5  on the side of the furnace interior or heat side, and at least one second layer  6  adjoining it and facing away from the furnace interior.  
      The first layer  5  suitably is a layer made of a solid rigid material, and in particular a brick layer made of a material which is at least heat-resistant. The heat-resistant material, or its chemical-mineralogical composition, its temperature resistance, as well as the thickness of the layer  5  are arbitrary and are a function of such requirements as temperature, furnace atmosphere, etc. In one embodiment, the first layer consists of a so-called light refractory material, or light refractory brick. Light refractory material is a heat-resistant material of a relatively porous and therefore light structure. However, in case of greater demands made on the temperature resistance, a fire-proof stone material can be used.  
      The second layer  6  suitably is an insulating layer. The insulating layer is composed of a heat-insulating material. For example the insulating layer may be formed of calcium silicate plates customary in the construction of furnaces or fire boxes, or microporous insulating plates. A further insulating layer  7  and, if desired, further layers can be arranged following the second layer  6 . The insulating layer  7  and the possibly further layers can also be embodied as calcium silicate plates or porous or microporous insulating plates. In particular, the porosity of the layers can increase from the layer  6  to the subsequent layers  7  in order to increase the insulating output. Furthermore, the layer  7  and possible further layers can be embodied as fiber mats or fiber plates, in particular made of a nonwoven material and/or a rigid solid fiber plate material.  
      In a horizontal projection, the wall modules may have a four-cornered, in particular square or rectangular, cross-section. Other cross-sections, which permit as nip-free as possible an arrangement with respect to each other, are also possible, for example triangular, hexagonal, or octagonal cross-sectional shapes.  
      In the simplest case, a wall module  2  therefore has a front wall  5   a , a first sidewall  5   b  and a second sidewall  5   c , as well as a rear wall  5   d  of the first layer  5 , a front wall  6   a , a first sidewall  6   b  and a second sidewall  6   c , as well as a rear wall  6   d  of the second layer  6 , and, if desired, a front wall  7   a , a first sidewall  7   b  and a second sidewall  7   c , as well as a rear wall  7   d  of the third layer  7 . If further layers are provided, their arrangement corresponds to the above mentioned layers.  
      The layers  5 ,  6 , and  7 , and possibly further layers, can be arranged to be aligned with each other and to extend in sequence with each other, so that the wall module  2  has a cube-like or cuboid shape.  
      In a further advantageous embodiment (FIGS.  5  to  7 ), the first sidewalls  5   b ,  6   b ,  7   b  of the layers  5 ,  6 ,  7  are aligned, wherein the layers have a step-shaped offset in such a way that the second sidewalls  5   c ,  6   c ,  7   c  are arranged offset with respect to each other. Thus, when arranging these wall modules  2  next to each other, joints  9  extend straight along the wall thickness and joints  10  extend in steps. With a plurality of layers it is also possible to have two layers aligned and to embody only one layer with an offset (FIGS.  14  to  16 ).  
      In a further advantageous embodiment (FIGS.  8  to  10 ,  17  to  19 ), the layers have a step-like offset in such a way that the offset extends diagonally over a corner of adjoining sidewalls.  
      Thus, with this embodiment all joints  9 ,  10  extend stepped in the same way. Therefore, in accordance with the wall structure in accordance with the invention, the wall modules  2  mesh with each other, so that with this embodiment the joint length over the depth of the wall structure, and therefore also the path of the joints, is extended. Furthermore, the support structure  4  is dependably protected against temperatures even in case of slight displacements.  
      In a firther advantageous embodiment of the wall structure  1  of the invention, two different types of wall modules  2 ,  12  are provided. In this case the modules  2  are embodied as retaining modules  2 , and the modules  12  as filler modules  12 , which are alternatingly arranged in the total structure. In cross-section, for example along a longitudinal furnace axis ( FIG. 3 ), the retaining modules  2  are designed in such a way that they are widened in steps from the layer  7  to the layer  5 . In this case the layer  5  can also include an additional step  13 . In a cross-section transverse with respect to the previously described section, each of the modules  2  has a step-shaped offset with, for example, three steps, extending from layer to layer, or in the layer  5  ( FIG. 2 ).  
      The filler modules  12 , which are arranged alternatingly with the retaining modules  2 , have a shape corresponding to that of the retaining modules  2 , which permits a positively connected arrangement of the filler modules  12  and the retaining modules  2 . Thus, in a cross-section in accordance with  FIG. 3 , a filler module  12  tapers in steps in the way the retaining modules  2  are widened. In a cross-section perpendicular with this, the filler modules  12  have the same cross-section as the retaining modules  2 . In connection with the filler modules  12 , the individual layers  5 ,  6 ,  7  are maintained against each other in a suitable manner, in particular the layers are glued together or plugged into each other by means of corresponding elements.  
      The stepped offset can also include an oblique path  14  ( FIGS. 11, 12 ,  17 ,  18 ) which, in particular in the area of the layer  5 , avoids sharp delicate step edges. Furthermore, the steps or offsets can also be embodied to be irregular ( FIGS. 11, 12 ).  
      The modules  2  are arranged on the support structure  4  by means of the fastening arrangement  3 .  
      The fastening arrangement  3  is embodied in several parts and contains at least a retaining device  15 , a retaining plate  16  and a fastening device  17 .  
      The retaining device  15  is used for retaining the modules  2  on a retaining plate  16  and for arranging the layers  5 ,  6 ,  7  against each other. For this purpose the retaining device  15  has an anchor element  18  and a shaft element  19 . For example, the anchor element  18  is designed with two or more arms  21  extending away from a center  20 . Furthermore, the shaft element  19  is arranged acting on the center  20 . The shaft element  19  is embodied in a rod shape. On its free end  22  it has a screw thread  23 . The arms can extend away vertically with respect to the shaft element  19 , or can form an acute angle with the shaft element.  
      Alternatively, instead of an embodiment with arms  21 , the shaft element  19  itself can be embodied as a spiral or corrugated rod (not represented) in place of the arms  21 . The retaining device  15  is made of a ceramic material or heat-resistant metal, for example special steel, and in particular of steel of the grades inconel, 1,4828, 1,4841 and/or 1,4845.  
      The retaining plate  16  ( FIGS. 21, 22 ) is a flat level component. The retaining plate  16  is embodied in particular as a punched sheet metal element made of steel, for example St37 or V4A (1,4301 or similar), or also of a heat-resistant metal like the above mentioned heat-resistant steel. The plate  16  can have a square or polygonal, for example octagonal, basic shape or base area. The retaining plate  16  contains a centered trough  25  in particular. At least one receiving opening  24  is provided adjacent to the trough  25  in the retaining plate  16 , wherein the number of receiving openings  24  is substantially a function of the number of retaining devices  15 .  
      The trough  25  is laterally bordered by a step-shaped wall  26  or a shoulder  26 , wherein the trough  25  has a level trough bottom  27 . The trough  25  can have any arbitrary basic shape. Preferably it is embodied in such a way that the wall  26  extends corresponding to the basic shape of the plate  16 , for example octagonally. At least one first locking device  28  is provided on the trough bottom  27 . The first locking device  28  is, for example, a locking opening  28 . The locking opening  28  is embodied to be rectangular, wherein a circumferential flange  29  extends upward in a direction out of the trough bottom  27  and laterally borders the locking opening  28 . The flange  29  protrudes, for example at approximately right angles, from the trough bottom  27  at the narrow side edges  30  of the locking opening  28 . At the long side edges  31  of the locking opening  28 , the flange  29  forms an obtuse angle  32  with the trough bottom  27 , which narrows the locking opening  28  away from the trough bottom  27 . The angle  32  is approximately 120°, for example.  
      However, the flange  29  can also protrude from the narrow side edges  30 , as well as from the long side edges  31 , at a different angle. This depends in the end on the shaping process. For example, the flange  29  can narrow the locking opening also at the narrow side edges  30  and form an obtuse angle with the trough bottom  27 , for example also 120°.  
      The fastening device  17  (FIGS.  29  to  31 ) is embodied for cooperating in a fastening manner with the retaining plate  16 . The fastening device  17  contains a locking device  35  corresponding to the first locking device  28 . The fastening device  17  has a flat base plate  34 , which is designed to be approximately rectangular. Spring shackles  37  are connected in one piece with the long side  36  of the base plate  35 . In cross-section, the spring shackles  37  extend in an approximate S-shape, wherein they extend from the long side  36  with a first bow  38  converging toward each other and, following a straight portion, which forms an obliquely extending spring shackle wall  39 , they extend away from each other toward the outside and form an undercut protrusion  41  by means of a bow  40 . The height H of the spring shackles  37  from the base plate  35  to the underside of the undercut protrusion  41  substantially corresponds to the height of the flange  29 . The spring shackles  37  form an angle with the base plate  35  which is approximately  1200  or slightly greater, particularly slightly greater than the angle  32  of the flange  29 .  
      The base plate  35  has a preferably centered fastening opening  42 , through which a screw bolt or clinch bolt can be pushed and can be secured by a nut (not shown), if required, in order to fasten the fastening device  17  on a support structure  4 . The opening  42  can be centrally located in a dome-shaped rise  45 .  
      In a further advantageous embodiment (FIGS.  23  to  25 ), at least one first locking device  50  is provided in the trough bottom  27 , wherein the locking device  50  consists of two punched-out locking tongues  51 , which are located on the level of the trough bottom and point toward each other. The locking tongues  51  are fastened along a longitudinal edge  52  of the trough bottom. The locking tongues  51  can taper in the direction toward a free longitudinal edge  53  and to this extent can be embodied in the form of a trapezoid. Between themselves, the free longitudinal edges  53  define a locking joint  54 . A corresponding second locking device (not represented) for acting together with the locking device  50  is a locking protrusion (not represented) arranged on the fastening device  17  or the support structure  4 , for example in the form of a locking plate. Such a locking plate has a thickness which is greater than the locking joint  54 , and is approximately of the length of the locking joint  54 . The locking plate can have channels or grooves extending parallel with the locking tongue edges  53  for the secure fastening of the locking tongues  51 , and in particular their engagement with the locking plate. Furthermore, the locking plate can taper towards its free end in order to be more easily inserted into the joint  54 .  
      It is of course possible to provide any possible type of locking, for example by means of resilient locking hooks, which extend behind an opening edge, on the plate  16 , and correspondingly at the fastening device  17 .  
      The opening  28  can in particular also be embodied to be round, so that the flange  29  is formed as a circumferential conical collar. The respective device  35  is accordingly also designed as a radially circumferential flange (not represented) with individual resilient flange segments, which are separated by slits from each other and otherwise correspond in cross-section to the spring shackles  37 . Such an embodiment is also possible with a square or polygonal opening  28 , wherein the flange is also designed as a circumferential conical collar. The device  35  is correspondingly embodied as a circumferential flange with individual resilient flange segments, which are separated from each other by slits arranged in the corners in particular, and otherwise correspond in cross-section to the spring shackles  37 .  
      The wall modules  2  and the fastening device work together and thus are used in the following manner ( FIG. 32 ).  
      The anchor element  18  of the retaining device  15  is seated in the layer  5 . For this purpose, the anchor element  18  can be cast, cemented, or stuck or pushed into the layer  5 .  
      In a preferred embodiment of the anchor element  18  with the extending arms  21 , the layer  5  is divided in the center and embodied with a cross joint  5   e  ( FIG. 12 ) in such a way that the arms are inserted into corresponding bores  5   e  in the layer halves or oppositely located layer half walls. A semicircular groove  5   f  is provided for the shaft element  19  and extends away from the layer  5  and penetrates the rear wall  5   d  in each one of the layer half walls  5   g  of the layer or brick halves. The shaft element  19  extends through the further layers  6  and  7  and projects sufficiently far out of the rear wall  7   d  of the last layer so that the free end  22  of the shaft element  19  can be inserted into the receiving opening  24  of the retaining plate  16  and fastened on its back. Fastening can be provided by screwing a nut on the thread  23  or by other suitable means, such as welding, locking, etc. In the final assembled state, the retaining plate  16  rests against the rear wall  7   d  of the last layer with its entire surface, except for the trough  25 , and is preferably pressed against it. The layers  5 ,  6 ,  7  and the retaining device  15 , as well as the retaining plate  16 , constitute a wall module  2 .  
      To arrange such a wall module  2  on a support structure  4 , first the fastening devices  17  are placed on the support structure  4  at the prearranged locations, for example by screwing and riveting or welding a bolt through the opening  42 . A locking connection analogous to the locking connection between the plate  16  and the fastening device  17  is possible between the support structure  4  and the fastening device  17 . If filler modules  12  are provided between the wall modules, the distance between the fastening devices is approximately doubled.  
      In connection with a further advantageous embodiment, the fastening device  17  is embodied as a rail or grid of rails (not represented), wherein the locking means, such as locking tongues for example, are formed out of or on the rail.  
      For assembly, the locking opening  28  is placed on the spring shackles  37 , wherein the undercut protrusions  41  are supported on the oblique walls of the flange  29 . By means of the application of pressure to the modules  2 , the protrusions  41  slide along the flanges  29  and are pressed inward in the process. Once the undercut protrusions  41  extend past the free end edges of the flange  29 , they spring or snap outward, so that the protrusions  41  extend behind the flange  29 . Thus, the module  2  is fixedly locked by means of the fastening device  17  against the support structure. A subsequent wall module  2  is placed next to the first wall module  2  in such a way that a positive connection, in particular between the steps of the layers, is achieved. If filler modules  12  are laid in addition, they are maintained by the wall modules  2  on the support structure by the corresponding, positively connecting step shape without being themselves locked to the support structure.  
      An air gap is created in the area of the retaining plate  16  between the wall modules  2  and the support structure which, if required, is filled with suitable materials, for example filled with fed-in or poured-in material.  
      Expandable felt pads (not represented) or other joint-filling materials laid out to be appropriately fire-proof can be arranged between the wall modules  2  and/or  2  and  12 .  
      The locking elements, or the tolerances between the length of the spring shackles and the length of the locking openings, are preferably selected to be such that there is a slight displacement capability in order to be able to optimally match the wall structures to each other.  
      The locking devices  28  and  35  are interchangeable to such an extent that the second locking device  35  can also be arranged on the retaining plate  16  and the first locking device  28  on the fastening device  17 .  
      If only one anchor element  18  extends through a module  2 , the receiving opening  24  is preferably provided centered on the plate  16 , if desired on a rise in a trough, and one or several locking devices ( 28 ,  50 ) are provided in this trough or in separate troughs  25  remote from the center.  
      In connection with the wall structure in accordance with the invention it is advantageous that the assembly times are reduced up to 70% in comparison with brick or monolithic linings. Along with this, the down times are quite considerably shortened and an increase in the production by the operator of the installation is achieved. By means of standardizing the elements as uniform elements  2  or two element shapes  2  and  12 , the elements are rapidly available and the outlay for logistics is considerably lowered. Still, a variation of the layers, and along with this a variation of the insulating output and/or the temperature resistance permits an individual structure of the wall layers in accordance with the requirement profile of the furnace also in a single furnace installation over the length and/or the wall.  
      Moreover, the wall structure in accordance with the invention can be universally employed in all heat treatment installations, in particular up to 1200° C., and is usable for cylindrical, as well as rectangular furnace layouts. It is furthermore advantageous that in corner and joint areas where walls meet, the corners, possibly also with joints with an offset, can be produced by simply cutting the modules  2  or  12 .  
      In addition, it is advantageous that, if the layer facing the fire is embodied in the form of light refractory brick, the possibly provided fiber components of successive insulating layers are shielded to such an extent that the danger to health by flying fiber components during the operation of the furnace and/or the soiling of the fired materials by fibers is prevented. This effect is of course increased if the second and/or further layers comprise calcium silicate plates or microporous insulation plates.  
      Furthermore, it is advantageous that no consoles for supporting the brick lining are required, so that the production costs are also considerably reduced.  
      Typical fields of application of the invention are, for example, in the chemical and petrochemical industry, in particular in cracking installations, thermal exhaust air cleaning, strip annealing, chamber furnaces, roller hearth furnaces, heat treatment furnaces, annealing hoods in the steel or iron processing industry, but also in the heavy clay field, in the fields of pusher furnaces, pusher furnace bogies, roller furnaces, bogie hearth furnaces, and hood-type furnaces.