EP3355015B1 - Support elements for a tunnel furnace cart or carriage, tunnel furnace cart or carriage with such support elements and tunnel furnace with such a tunnel furnace cart or carriage - Google Patents

Description

The present invention relates to a support element for a tunnel kiln car or carriage for the transport of fuel by a tunnel kiln preferably for the ceramic, preferably coarse ceramic, industry, especially for brickwork, a tunnel kiln car or carriage with such support elements and a tunnel kiln with at least one such tunnel kiln car or sled.

In known tunnel kilns, the kiln is driven on tunnel kiln car through the tunnel kiln. The firing material is placed on stacked firewood carriers, in particular in the form of H or U cassettes, which in turn are mounted with their bearing feet on the tunnel kiln car. During the kiln journey, the tunnel kiln car and also the kiln furniture are exposed to large temperature fluctuations, which leads to Temperarturdehnungen. Since the kiln furniture receiving components of the tunnel kiln car and the kiln furniture consist of materials with different coefficients of thermal expansion, there is a risk that the sensitive bearing feet are damaged by different thermal expansions.

The FR 2 866 418 B1 discloses such a generic kiln, especially for the clay industry. The kiln has several kiln cars for the transport of kiln through the kiln. The kiln cars each have a carriage body carried by wheels which travel on rails in the kiln. The kiln is stored on carriers, for example in the form of H-cassettes, which are stacked on top of each other. According to the FR 2 866 418 B1 is located under each stack, ie between the bottom bracket and the car body, an intermediate piece. The intermediate piece is made of a material whose coefficient of thermal expansion substantially corresponds to the thermal expansion coefficient of the carrier. As a result, relative movements are limited due to the different dimensions between the lowermost support and the intermediate piece and the wear of the carrier due to friction significantly reduced.

The intermediate piece itself rests on supports, which are firmly connected to the car undercarriage of the tunnel kiln car. The spacers represent a flat, upper wall of the kiln car, which is easy to clean. They also protect optionally arranged under the spacers insulating material. To limit the amount of material can be present in the upper and / or lower sides of the spacers recesses.

According to the FR 2 866 418 B1 In addition, the intermediate pieces form a thermal insulation ventilated on both sides between the kiln car and the lowermost beam, whereby a better homogeneity of the burning of the mounted on the lowermost carrier fuel is achieved.

The ES 2 351 810 B1 discloses a carriage floor for a kiln car for firing ceramic parts, which consists of a plurality of support elements made of refractory material, which are intended to receive stacks of stackable support members for the kiln. According to the ES 2 351 810 B1 the support elements are factory equipped with flat and coplanar surfaces on which the bottom support elements are arranged. In this case, each lowermost support element rests on only one and not on a plurality of support elements.

DE 20 2009 015 250 U1 discloses a kiln car with a support beam; an intermediate burner plate carried by the support beams; and a cassette carried by one of the intermediate burners.

The object of the invention is to provide a support member for the formation of an upper carriage or carriage cover of a tunnel kiln car or carriage, the low wear of the lowest Brenngutträgers of stacked Brenngutträgern formed Brenngutträgerstapels, and at the same time a high quality of combustion of the fuel while low energy consumption Fire guaranteed.

Further objects are the provision of a tunnel kiln car with such supporting elements and a tunnel kiln with at least one such tunnel kiln car.

These objects are achieved by a support element having the features of claim 1, a tunnel kiln car having the features of claim 12 and a tunnel kiln having the features of claim 19.

Figur 1:

Perspektivisch einen Teil eines erfindungsgemäßen Tunnelofenwagens

Figur 2:

Eine perspektivische Ansicht von erfindungsgemäßen Tragelementen mit darauf angeordneten H-Kassetten

Figur 3:

Eine perspektivische Ansicht eines Tragrahmens ohne Abdeckplatten

Figur 4:

Eine perspektivische Ansicht eines Tragrahmens mit einer Abdeckplatte

Figur 5:

Eine perspektivische Ansicht einer H-Kassette

Figur 6:

Schematisch stark vereinfacht einen Querschnitt eines erfindungsgemäßen Tunnelofens mit einem schematisch dargestellten Tunnelofenwagen

In the following the invention will be explained in more detail by way of example with reference to a drawing. Show it:

FIG. 1:

Perspective part of a tunnel kiln car according to the invention

FIG. 2:

A perspective view of support elements according to the invention with H-cassettes arranged thereon

FIG. 3:

A perspective view of a support frame without cover plates

FIG. 4:

A perspective view of a support frame with a cover plate

FIG. 5:

A perspective view of an H-cassette

FIG. 6:

Schematically greatly simplified a cross section of a tunnel kiln according to the invention with a tunnel kiln car shown schematically

The tunnel kiln 1 (according to the invention) Fig. 6 ) has an oven tunnel 2 and at least one tunnel kiln car or carriage 3 according to the invention for the transport of fuel, in particular of bricks, in particular roof tiles, or other coarse ceramic shaped bricks through the furnace tunnel 2.

The furnace tunnel 2 has two tunnel side walls 4, a tunnel foundation plate 5 and a tunnel ceiling 6, in particular a suspended ceiling. The furnace tunnel 2 also has a horizontal tunnel longitudinal direction 2 a, a horizontal tunnel width direction 2 b perpendicular thereto, and a vertical tunnel height direction 2 c. Rails (not shown) are arranged on or in the tunnel foundation plate 5 in a manner known per se, on which the tunnel kiln carriages or carriages 3 pass through the kiln tunnel 2 with the kiln goods arranged thereon.

The two tunnel side walls 4, the tunnel kiln car or carriage 3 and the tunnel ceiling 6 delimit a combustion chamber or combustion channel 7.

The tunnel kiln car or carriage 3 according to the invention comprises a, preferably metallic, carriage or carriage undercarriage or carriage or carriage chassis 8 and a carriage or carriage superstructure or carriage or carriage superstructure 9 arranged thereon for thermal insulation of the carriage or carriage undercarriage 8 from the combustion chamber 7 and serves to hold the fuel. In particular, the carriage or carriage superstructure 9 serves to receive stacked firing supports 35, 35a, which respectively carry the firing products.

In addition, the, preferably cuboid, tunnel kiln car or carriage 3 has a horizontal, parallel to the tunnel longitudinal direction 2a, carriage or carriage longitudinal direction 3a, a perpendicular, horizontal, transverse to the tunnel transverse direction 2b, carriage or carriage transverse direction 3b and a vertical, parallel to the tunnel height direction 2c , Carriage or carriage height direction 3c on. The direction of travel of the tunnel kiln car or carriage 3 is parallel to the carriage or carriage longitudinal direction 3a. As used in the art, the terms "carriage or carriage longitudinal direction 3a" or "carriage or carriage transverse direction 3b" refer to the extension of the tunnel kiln car or carriage 3 in the tunnel longitudinal direction 2a or tunnel transverse direction 2b. This does not mean that the extension of the Tunnel kiln car or carriage 3 in the carriage or carriage longitudinal direction 3a is greater than in the carriage or carriage transverse direction 3b.

The carriage or carriage base 8 serves on the one hand for receiving the carriage or slide superstructure 9 and on the other hand for transportable in the tunnel longitudinal direction 2a storage of the tunnel kiln car or carriage 3 on the tunnel foundation plate 5. The tunnel kiln car or carriage 3 is in the tunnel kiln 1 slidably or roller bearings. For this purpose, the carriage base 8, for example, wheels 10 ( Fig. 6 ) on. The carriage base has z. B. runners (not shown).

Furthermore, the carriage or carriage subframe 8 has one or more horizontal floor panels 11, a plurality of transverse support beams 12 and a plurality of longitudinal support beams 13. The bottom plates 11 are preferably corrugated sheets or trapezoidal sheets. The floor panels 11 rest on the transverse support beams 12, which extend in the carriage or carriage transverse direction 3b. Preferably, the transverse support beams 12 are I-beams or double T-beams. The longitudinal support bars 13 are attached to the underside of the transverse support beams 12 and extending in the carriage or carriage longitudinal direction 3a. Preferably, the longitudinal beams 13 are C-beam or I-beam or double T-beam. The floor panels 11, the transverse support beams 12 and the longitudinal support bars 13 are made of metal, in particular steel.

The wheels 10 and skids are arranged below the floor panels 11 and in particular fastened respectively to two longitudinal support beams 13.

The carriage or slide superstructure 9 preferably has at least one layer 14, 15 of mineral material arranged on the base plates 11, a plurality of vertical columns or supports 16 and a plurality of support elements or support elements 17 according to the invention.

Preferably, the carriage or carriage superstructure 9 in a conventional manner a compensation layer or layer 14 and a Isolierplattenlage arranged thereon 15 on. The leveling layer or layer 14 is used for leveling and creating a flat, horizontal layer surface. The leveling layer 14 is arranged directly on the bottom plates 11. It preferably consists of several juxtaposed layer sections of pressure-resistant material, preferably made of pressure-resistant insulating concrete.

The Isolierplattenlage 15 is, preferably arranged directly on the leveling layer 14. It consists of several, juxtaposed and adjoining insulating panels. The insulating panels are plates made of heat-resistant and mechanically strong insulating material.

As already explained, the carriage or slide superstructure 9 also has a plurality of vertical, preferably tubular, supports 16. The supports 16 are each arranged on the Isolierplattenlage 15 and stand from this vertically upwards. The supports 16 are preferably arranged side by side and spaced from one another in rows in the carriage or carriage transverse direction 3b and in the carriage or carriage longitudinal direction 3a.

In addition, the supports 16 are each preferably hollow on the inside and have a tubular support wall 18 and an inner support cavity 19. The tubular, vertically extending support wall 18 is preferably formed in a cuboid in cross section. It has a wall outer surface 18a, a wall inner surface 18b and a lower wall end surface 18c and an upper wall end surface 18d. In addition, the support wall 18 has two opposite longitudinal wall sections 20 and two opposite transverse wall sections 21.

The support wall 18 is made of refractory, preferably ceramic fired material, preferably of chamotte according to DIN EN ISO 10081-1: 2005 or a cordierite mullite material.

Refractory according to the invention means material with a printer softening point T _0.5 according to DIN EN ISO 1893: 2009-09 of at least 1200 ° C.

Preferably, the printer softening point T _{0.5 of} the material of the support wall is 1280 ° C to 1380 ° C according to DIN EN ISO 1893: 2009-09.

The support elements 17 according to the invention have a lower grid-like support frame or a grid or a framework 22 and a cover plate 23 mounted thereon.

The support frame 22 has two extending in one, in particular horizontal frame longitudinal direction 22a and in a, in particular horizontal, transverse frame direction 22b opposite longitudinal frame members or frame longitudinal beam 24. In addition, the support frame 22 has a central grid element 25 arranged between the two frame longitudinal beams 24. In addition, the support frame 22 on a support frame top side 30a and one of these opposite support frame bottom side 30b.

The two frame longitudinal beams 24 each have a planar top surface 24a and one of these in a frame height direction 22c opposite, in particular planar, beam underside 24b. The upper sides of the beams 24a serve to receive the lowermost combustible carrier 35a. And the two beam bottoms 24b are used to support the support frame 22 on the supports 16. In addition, the two frame longitudinal beams 24 each have a the other longitudinal frame beam 24 facing bar inside 24c and the other frame longitudinal beam 24 facing away from the beam outside 24d.

The grid element 25 has a, in particular planar and horizontal, grid element upper side 25a and one of these in frame height direction 22c opposite grid element bottom 25b. The grid element upper side 25a is offset in the frame height direction 22c relative to the bar top sides 24a downwards or arranged lower than this.

The grid element bottom side 25b is preferably flush with the beam bottoms 24b and / or coplanar with respect to the frame height direction 22c. The two bar undersides 24b and the grid element bottom side 25b thus form a planar support element support surface 42 for supporting the support frame 22 on the supports 16.

In addition, the support frame 22 thus preferably has a U-shaped cross-section.

The grid element 25 also has continuous grid recesses 26 from the support frame upper side 30a or grid element upper side 25a to the support frame lower side 30b or grid element lower side 25b. The lattice recesses 26 are preferably of cuboid shape, so that transverse struts or transverse webs 27 extending between the individual lattice recesses 26 are respectively provided in the transverse direction 22b of the frame.

Furthermore, a support frame 22 preferably has a plurality of hold-downs 28 for holding down the cover plate 23. The hold-downs 28 are preferably hold-down lugs 29. The hold-down lugs 29 each extend away from or away from the inner sides 24c of the frame longitudinal beams 24. In this case, per frame longitudinal beam 24 preferably more Niederhalternasen 29 are present, which are arranged adjacent to each other in the frame longitudinal direction 22a. The hold-down lugs 29 are spaced from the lattice element upper side 25a, so that a slot for receiving the cover plate 23 is formed between the hold-down lugs 29 and the lattice element upper side 25a. The hold-down lugs 29 collar over the grid element top 25a.

A support frame 22 also has in each case two longitudinal strips 31 extending in the longitudinal direction 22a of the frame. The longitudinal strips 31 each preferably protrude from one of the two beam bottoms 24b. The longitudinal strips 31 are each between the two frame end ends 32a; b arranged or spaced therefrom. A longitudinal strip 31 in each case has two strip end faces 33 lying opposite one another in the longitudinal direction 22a of the frame. The ledge end faces 33 are preferably planar and perpendicular to the frame longitudinal direction 22a. In addition, the ledge end surfaces 33 preferably pass over a recessed radius 34 into the underside of the frame 24b. The radius 34 serves as a free cut, so that the lower side of the beam 24b and the ledge end faces 33 can be machined by grinding.

In addition, the support frame 22, in particular the frame longitudinal beams 24 and the grid element 25, preferably material recesses 37, which serve to save weight.

The support frame 22 is preferably formed in one piece and consists of refractory, in particular ceramic burned, material, preferably with direct ceramic bond. Preferably, the support frame 22 is made of a cordierite material or a SiC material.

According to an advantageous aspect of the invention, the support frame 22 has a linear thermal expansion of 0.2 to 0.35 lin .-% according to DIN EN 51045-4: 2007-01 at 1000 ° C.

The support frame 22 is preferably made by casting.

The cuboid cover plate 23 has a, in particular planar and horizontal, Abdeckplattenoberseite 23a, one of these in frame height direction 22c opposite, especially planar and horizontal, Abdeckplattenunterseite 23b, and four, in particular planar and vertical, plate edge surfaces 23c, which abut in pairs.

Since the cover plate 23 carries no further external mechanical loads, so neither directly nor indirectly the Brenngutträger 35, carries 35a, but only serves to cover the support frame 22, in particular the lattice recesses 26, It can be made very thin. It preferably has a thickness of 8 to 20 mm, preferably 10 to 12 mm.

The cover plate 23 is made of refractory material. Preferably, the cover plate 23 is made of ceramic fired material, preferably with direct ceramic bond, preferably from a Cordieritwerktstoff or a SiC material or a chamotte material. The cover plate 23 is preferably a drawn plate. However, the cover plate 23 may also be a ceramic fiber plate made of pressed ceramic fibers.

The cover plate 23 is preferably made of a different material than the support frame 22, so that the respective material properties are optimally adapted to the respective requirements of the cover plate 23 and the support frame 22. The material may differ in that it is made of a different material or, although it may be made of the same material, it may have been manufactured differently, which also results in a different material with different properties.

The support frame 22 are mounted directly on the supports 16. In this case, the support frame 22 with its support element bearing surface 42, ie with the beam undersides 24b of the longitudinal frame beam 24 and with the grid element bottom 25b on the upper wall end faces 18d of the support walls 18. In addition, the longitudinal strips 31 engage with a small clearance in a form-fitting manner into the respective support cavity 19. As a result, the support frames 22 are secured or locked in relation to the supports 16 in the carriage or carriage longitudinal direction 3 a, but are detachably connected to the supports 16. In the carriage or carriage transverse direction 3b, the longitudinal strips 31 are preferably spaced from the support wall 18. In the carriage or carriage transverse direction 3b, the support frames 22 are preferably limitedly displaceable in relation to the supports 16.

In this case, a support frame 22 is in each case on two adjacent to each other in carriage or carriage transverse direction 3b supports 16. Between the support frame 22 and the supports 16 is preferably a ceramic fiber mat for sealing present. The support frame 22 are arranged adjacent to one another in both the carriage or carriage transverse direction 3b and in the carriage or carriage longitudinal direction 3a. At least one compressible, ceramic fiber mat is preferably arranged in each case between two carrier frames 22 which are adjacent to one another in the carriage or carriage transverse direction 3b to each other (not shown). The carrier elements 17, which are arranged adjacent to one another in the carriage or carriage longitudinal direction 3a, are preferably spaced from one another, wherein slot covering plates are present in the intermediate space or burning slot. The ceramic fiber mats are used in particular for mechanical sealing, so that no abrasion or similar material can penetrate into the interior of the tunnel kiln car or carriage 3 and to increase the insulating effect. The ceramic fiber mats are preferably each made of ceramic high-temperature wool according to DIN EN 1094-1: 2008-09.

As already explained, the cover plates 23 serve only or exclusively for covering the support frame 22. For this purpose, at least one cover plates 23 are each arranged on a support frame 22 such that they cover the latter, in particular the lattice recesses 26, from above and close. In this case, the cover plates 23 each lie with their cover plate bottoms 23b on the grating element upper side 25a. In addition, the cover plates 23 are inserted into the slots between the hold-down lugs 29 and the lattice-element upper face 25a. This ensures that they are not sucked away when cleaning the tunnel kiln car or carriage 3 by means of a vacuum suction device.

The cover plates 23 are releasably and replaceably connected to the support frame 22.

The cover plate tops 23a are also offset downwardly with respect to the beam tops 24a of the frame rails 24.

The support elements 17 thus form a major part of a substantially continuous or closed, refractory carriage or carriage cover 43 of the tunnel kiln car or carriage 3 according to the invention with a substantially closed carriage or carriage top 44. Usually, the carriage or slide cover 43 as already explained in a conventional manner also the Schlitzabdeckplatten to cover the burning slots between two adjacent, spaced-apart support elements 17. The carriage cover or carriage cover 43 or the support elements 17 delimit the combustion chamber 7 of the tunnel kiln 1 or close the tunnel kiln car or carriage 3 upwards to the combustion chamber 7. The carriage or carriage cover 43 and the support members 17 are therefore also used to protect the underlying components of the tunnel kiln car or carriage 3 against the flame impact of the ceiling burner of the tunnel kiln. 1

Preferably, moreover, the cavities between the individual supports 16 and the support cavities 19 and also the grid recesses 26 are filled with suitable insulating insulation material. As a result, the carriage or carriage base 8 is thermally insulated from the combustion chamber 7. The insulating material is, for example, a loose or bound bulk insulation.

As already explained, the support elements 17 are used according to the invention for the direct reception of the stacked tray 35; 35.

The firing supports 35, 35a are preferably U-cassettes known per se (not shown) or H-cassettes 38, 38a (FIG. Fig. 1-5 ). The H-cassettes 38, 38a have, in a manner known per se, two spaced-apart support webs 39 and an intermediate, grid-like one arranged therebetween Brenngutaufnahmeelement 40 on. The support webs 39 preferably each have two lower and two upper bearing feet 41. The two lower bearing feet 41 serve to support the H-cassette 38, 38a on the support frame 22 and on the underlying H-cassette 38, 38a. As a result, the upper bearing feet 41 serve to support the lower bearing feet 41 of the H-cassette 38, 38a of the stack of fuel stacks 36 arranged above them.

bevorzugt $$\left|{\mathrm{Wärmedehnung}}_{\mathrm{Brenngutträger}}-{\mathrm{Wärmedehnung}}_{\mathrm{Tragrahmen}}\right|\le \mathrm{0,025}\mathrm{lin}\mathrm{.}-\%,$$

insbesondere Wärmedehnung Brenngutträger = Wärmedehnung TragrahmenThe Brenngutträger 35, 35a, in particular the H-cassettes 38, 38a, according to the invention have a linear thermal expansion according to DIN EN 51045-4: 2007-01 at 1000 ° C, which corresponds to the linear thermal expansion of the support frame 22 and not significantly from this is different. That is, it applies to the linear thermal expansion according to DIN EN 51045-4: 2007-01 at 1000 ° C: $$\left|{\mathrm{thermal\; expansion}}_{\mathrm{Firing\; Tray}}-{\mathrm{thermal\; expansion}}_{\mathrm{supporting\; frame}}\right|\le 0.05\mathrm{lin}\mathrm{,}-\%.$$

prefers $$\left|{\mathrm{thermal\; expansion}}_{\mathrm{Firing\; Tray}}-{\mathrm{thermal\; expansion}}_{\mathrm{supporting\; frame}}\right|\le \mathrm{0,025}\mathrm{lin}\mathrm{,}-\%.$$

in particular thermal expansion of the firing tray = thermal expansion of the supporting frame

To determine whether the above conditions are met, the measurements of the linear thermal expansions on any of the identical firing tray 35, 35a and any of the identical support frame 22 of the tunnel kiln car or carriage 3 can be made and compared with each other, since the firing 35th 35a and / or the support frame 22 can occupy a different place on the tunnel kiln car or carriage 3 in each furnace trip. In particular, however, a support element 22 and a bottom firing tray 35a arranged thereon are compared with one another.

Preferably, the Brenngutträger 35, 35a of the same material as the support frame 22. The material can also differ, for example Although made of the same material, but have been produced differently.

As already explained, according to the invention the lowest firing tray 35a, in particular the lowermost H-cassette 38a, of a stack of firing material 36 is mounted exclusively directly on the supporting frame 22 of a supporting element 17. In particular, the lowest firing tray 35a is mounted exclusively directly on the two frame longitudinal beams 24, preferably on the beam tops 24a. The bearing feet 41 of the lowermost H-cassette 38a are supported directly on the beam tops 24a.

Since the H-cassette 38a and the support frame 22 have a substantially same linear thermal expansion, in particular consist of identical material, foot chipping the sensitive bearing feet 41 are almost avoided. The wear level is shifted from the bearing feet 41 to the stable support frame 22.

Since the support frame 22 of the support member 17 according to the invention is formed lattice-like with a plurality of grid recesses 26, and the cover plates 23 are very light due to their small thickness, the support members 17 have a total of a relatively light weight and low mass, which must be heated during the fire. The support frame 22 has only in the areas supporting components, where this is necessary for a sufficient stability. The other areas are left out. The cover plates 23 are exclusively for covering, take no external loads, and can therefore be made very thin and made of lightweight material. This leads to a considerable energy saving, since less mass has to be heated during the fire.

Since the cover plate tops 23a of the cover plates 23 are offset downwardly with respect to the beam tops 24a of the frame rails 24, a continuous flow passage 45 extending in the frame longitudinal direction 22 is provided between the lowermost H cassette 38a and the support member 17 ( Fig. 2 ), which serves to ventilate the lowermost H-cassette and the combustion material arranged thereon and for cooling the support element 17. The cooling of the carriage or slide superstructure 9, in particular of the support elements 17, is necessary in order to prevent the tunnel kiln cars or carriages 1, which are still warm from the previous firing cycle, from heating up the lowermost combustibles too quickly. Because can lead to cracking of the fuel.

In addition, the heat storage of the support elements 17 of the invention is very low due to their low mass, which ensures good heat exchange during firing. This also ensures a lower difference in the temperatures of the lower and upper fuels, ie a homogenization of the temperatures and a good quality of combustion.

In the grid recesses 26 also, as explained, insulating material can be introduced, whereby the carriage or carriage base 3 is thermally insulated from the combustion chamber 7 very well.

Since the support element 17 according to the invention, which is in particular mounted directly on the supports 16, the surface of the tunnel kiln car of the carriage 3 forms and serves directly to receive the lowermost Brenngutträgers 35 a, the structure is very low and it can, for example, compared to the known constructions. a layer of firing supports 35, 35a more of the tunnel kiln car or carriage 3 are added. The capacity of the tunnel kiln 1 according to the invention is thereby increased.

In addition, an automated cleaning of the tunnel kiln car or carriage 3 according to the invention is possible.

In the context of the invention, it is of course also that the positive securing of the support frame 22 is realized differently on the supports 16, for example by the supports 16 have protruding elements which engage positively in recesses in the support frame 22.

A support frame 22 may also be mounted only on a single support 16, respectively.

Also, the support element 17 according to the invention may be mounted on other components than the supports 16, e.g. on the uppermost layer in the case of a layered wagon or sled superstructure. It is only important that the juxtaposed support elements 17 demarcate the tunnel kiln car or - carriage 3 from the combustion chamber 7 and form the carriage or carriage top, are placed directly on the lowest Brenngutträger 35 a.

Also, a support frame 22 can accommodate a plurality of juxtaposed bottom firing tray 35a.

Furthermore, it is within the scope of the invention that the cover plates 23 cover the support frame 22 from below. However, a cover from above is preferred.

Claims (19)

1. A carrying element (17) for forming an upper car or carriage cover (43) of a tunnel kiln car or carriage (3) for directly mounting a bottom firing tray (35a) of a firing tray stack (36) formed from firing trays (35; 35a) stacked on top of one another, wherein the carrying element (17) has a lattice-like carrying frame (22) having one or more continuous lattice opening(s) (26) from a carrying frame upper side (30a) to a carrying frame underside (30b),
   characterised in that
   the carrying element (17) has at least one cover plate (23) covering and closing the lattice opening(s) (26) from above, wherein the cover plate(s) (23) lie(s) on the carrying frame (22) and a cover plate (23) is detachably connected to the carrying frame (22) in each case and the carrying frame (22) has means for holding down the cover plate(s) (23).
2. The carrying element (17) according to Claim 1,
   characterised in that
   the cover plate(s) has/have a thickness of 8 to 20 mm, preferably 10 to 12 mm.
3. The carrying element (17) according to Claim 1 or 2,
   characterised in that
   the carrying frame (22) and the cover plate(s) (23) are made from different materials.
4. The carrying element (17) according to one of the preceding claims,
   characterised in that
   the carrying frame (22) is made from refractory, in particular ceramic, material, preferably from a cordierite material or a SiC material,
   and/or
   the carrying frame (22) has a linear thermal expansion according to DIN EN 51045-4:2007-01 of 0.2 to 0.35 lin.% at 1000°C.
5. The carrying element (17) according to one of the preceding claims,
   characterised in that
   the cover plate(s) (23) is/are made from refractory material, preferably in each case from a cordierite material or a fire clay material or a SiC material, wherein the cover plate(s) (23) is/are preferably drawn.
6. The carrying element (17) according to one of the preceding claims,
   
   characterised in that
   the cover plate(s) does not/do not carry external mechanical loads.
7. The carrying element (17) according to one of the preceding claims,
   characterised in that
   the carrying frame (22) has two frame longitudinal beams (24) which extend in an, in particular horizontal, frame longitudinal direction (22a) and are opposite one another in an, in particular horizontal, frame transverse direction (22b) and a central lattice element (25) which is arranged between the two frame longitudinal beams (24) and has a plurality of transverse struts (27) extending in the frame transverse direction (22b),
   wherein the two frame longitudinal beams (24) preferably each have a, preferably planar, beam upper side (24a) and an, in particular planar, beam underside (24b) which is opposite the beam upper side in a frame vertical direction (22c),
   and/or
   wherein the lattice element (25) preferably has an, in particular planar and horizontal, lattice element upper side (25a) and a lattice element underside (25b) opposite the lattice element upper side in the frame vertical direction (22c),
   wherein the lattice element upper side (25a), as seen in the frame vertical direction (22c), is preferably arranged such that it is offset downwards relative to the beam upper sides (24a).
8. The carrying element (17) according to Claim 7,
   characterised in that
   cover plate upper sides (23a) of the cover plates (23) are offset downwards with respect to the beam upper sides (24a) of the frame longitudinal beams (24).
9. The carrying element (17) according to Claim 7 or 8,
   characterised in that
   the lattice element (25) has the continuous lattice cutout(s) (26) from the lattice element upper side (25a) to the lattice element underside (25b).
10. The carrying element (17) according to one of the preceding claims,
    characterised in that
    the carrying frame (22) has a plurality of holding-down lugs (29), which extend in each case away from a beam inner side (24c) of the frame longitudinal beam (24) and are spaced from the lattice element upper side (25a) so that, between the holding-down lugs (29) and the lattice element upper side (25a), a slot is present in which the cover plate(s) (23) is/are arranged.
11. A tunnel kiln car or carriage (3) for transporting firing goods through a tunnel kiln (1),
    wherein the tunnel kiln car or carriage (3) has a car or carriage underframe (8) and a car or carriage superstructure, arranged thereon, with a car or carriage cover (43) for mounting firing trays (35; 35a) and for delimiting a firing space (7) of the tunnel kiln (1),
    characterised in that
    the car or carriage cover (43) has one or more adjacently arranged carrying elements (17) according to one of the preceding claims.
12. The tunnel kiln car or carriage (3) according to Claim 11 having at least one firing tray stack (36) which is arranged on the car or carriage cover (43) and comprises firing trays (35; 35a) stacked on top of one another,
    characterised in that
    the bottom firing tray (35a) of a firing tray stack (36) is mounted directly on at least one of the carrying frames (22) of one of the carrying elements (17), and has a thermal expansion according to DIN EN 51045-4:2007-01 at 1000°C which corresponds substantially to the thermal expansion according to DIN EN 51045-4:2007-01 of the carrying frame (22) at 1000°C,
    wherein, for the linear thermal expansions according to DIN EN 51045-4:2007-01 of at least one carrying element (22) and a bottom firing tray (25a) arranged thereon at 1000°C, the following preferably applies: $$\left|\mathrm{thermal}{\mathrm{expansion}}_{\mathrm{firing}\mathrm{tray}}-\mathrm{thermal}{\mathrm{expansion}}_{\mathrm{carrying}\mathrm{frame}}\right|\le 0.05\mathrm{lin}.\%,$$

    

    preferably $$\left|\mathrm{thermal}{\mathrm{expansion}}_{\mathrm{firing}\mathrm{tray}}-\mathrm{thermal}{\mathrm{expansion}}_{\mathrm{carrying}\mathrm{frame}}\right|\le 0.025\mathrm{lin}.\%,$$

    

    in particular
    thermal expansion _{firing tray} = thermal expansion _{carrying frame}
    and/or wherein the firing trays (35; 35a) are preferably made from an identical material to the carrying frames (22).
13. The tunnel kiln car or carriage (3) according to Claim 12,
    characterised in that
    the bottom firing trays (35a) are mounted in each case directly on the two frame longitudinal beams (24), in particular in each case on the beam upper side (24a) thereof.
14. The tunnel kiln car or carriage (3) according to Claim 12 or 13,
    characterised in that
    the car or carriage superstructure (9) has a plurality of vertical, preferably tubular, supports (16) for receiving the car or carriage cover (43), wherein the carrying elements (17), in particular with the carrying frame (22), are mounted directly or indirectly on the supports (16).
15. The tunnel kiln car or carriage (3) according to one of Claims 12 to 14,
    characterised in that
    the cover plates (23) carry the mechanical loads of the firing trays (35; 35a) neither directly nor indirectly.
16. The tunnel kiln car or carriage (3) according to Claim 14 or 15,
    characterised in that
    the carrying frame (22) and/or the supports (16) have means for the, in particular form-fitting and detachable, locking of the carrying element (17) in a car or carriage longitudinal direction (3a) with respect to the supports (16),
    wherein the carrying frames (22) preferably have, on the underside, in each case two longitudinal strips (31) which extend in the frame longitudinal direction (22a) and each engage with form fit in a support cavity (19) of the hollow supports (16), so that the carrying frames (22) are locked with respect to the supports (16) in the car or carriage longitudinal direction (3a),
17. The tunnel kiln car or carriage (3) according to one of Claims 11 to 16,
    characterised in that
    the lattice openings (26) and/or cavities present between the individual supports (16) and/or support cavities (19) of the supports (16) are filled with heat-insulating material.
18. The tunnel kiln car or carriage (3) according to one of Claims 11 to 17,
    characterised in that
    the tunnel kiln car or carriage (3) serves for transporting firing goods through a tunnel kiln (1) for the ceramics, preferably heavy ceramics, industry, in particular for brickworks.
19. A tunnel kiln (1) having a kiln tunnel (2) and at least one tunnel kiln car or carriage (3) for transporting firing goods arranged on firing trays (35; 35a) through the kiln tunnel (2),
    characterised in that
    the tunnel kiln (1) has at least one tunnel kiln car or carriage (3) according to one of Claims 11 to 18.

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