EP3117168B1

EP3117168B1 - Ceramic assembly

Info

Publication number: EP3117168B1
Application number: EP15707988.0A
Authority: EP
Inventors: Sándor KISS; Manuel BOURDELY
Original assignee: Imerys Kiln Furniture Hungary Ltd
Current assignee: Imertech SAS
Priority date: 2014-03-14
Filing date: 2015-03-06
Publication date: 2018-07-18
Anticipated expiration: 2035-03-06
Also published as: EP3117168A1; WO2015135846A1; HUE039759T2

Description

FIELD OF THE INVENTION

The present invention relates to ceramic assemblies used for supporting products to be treated in a kiln.

BACKGROUND OF THE INVENTION

According to the current practice of firing fine or heavy-clay ceramic products, racks are required for loading the products to be treated in a kiln. Such racks are known in the art. The base elements of the racks are commonly adapted in shape to the objects to be treated in a kiln in order to save space and improve efficiency.
WO 2007/132276 A1 discloses ceramic assemblies for providing racks, consisting of ceramic base elements and ceramic functional auxiliary elements connected to the base elements. The base elements are used to support objects to be treated and the auxiliary elements act as feet and spacers for the base elements, such that several assemblies may be stacked on top of each other and the spacing between base elements may be adjusted by selecting appropriate auxiliary elements, depending on the nature and shape of objects to be fired.
DE 20 2010 005 560 U1 also discloses ceramic assemblies for providing racks, consisting of base elements and spacers, wherein the base elements are used for stacking objects to be treated in a kiln and the spacers act as feet such that several assemblies may be stacked on top of each other.
When loading the ceramic racks with objects to be treated in a kiln, such as for example green ceramic tableware products, it is not always possible to fill up an entire kiln car with objects to be treated. For economic reasons, it is often not feasible to build up a whole set of ceramic racks prior to each treatment run and to dismantle the set after the run. It is therefore common practice to leave ceramic racks on a kiln car and to load and unload them in the built up state. The drawback of this practice is that the kiln cars cannot be fully loaded with racks, in order to maintain accessibility to the racks for the loading and unloading of objects to be treated in the kiln, as illustrated by Figs. 1 and 2. While these represent the maximal loading of kiln cars with stacked racks for maintaining all the stacked racks accessible during loading and unloading of objects to be treated onto the racks, substantial void volumes are left on the kiln cars if such a loading mode is selected, leading to a loss of capacity and reduction of economic efficiency.
The state of the art therefore constitutes a problem. The present invention aims at improving efficiency of kiln treatment operation by reducing void spaces on kiln carts during use while at the same time minimising or avoiding the need for build up and dismantling of racks prior and after use. Furthermore, it is an object of the invention to improve efficiency of the loading and unloading of kiln cars.
EP 0989378 A1 discloses a kiln car comprising a car frame having a mounting surface and stacks of positioning shelves arranged on the mounting surface, wherein each stack of positioning shelves has a central support/fixation point. The central support comprises a center pedestal which passes through the individual positioning shelves in the stack.

SHORT DESCRIPTION OF THE INVENTION

The present invention is defined in the appended claims.
The problems of the prior art are solved by the provision of an assembly for carrying objects to be treated in a kiln, comprising a rod-shaped central prop and a plurality of setters, the setters being configured for being mounted around the rod-like central prop such that each setter is freely rotatable around the longitudinal axis of the central prop. The setters are further configured for carrying a plurality of objects to be treated in a kiln, such as at least two objects.
In one embodiment of the invention, the assembly further comprises at least one spacer, configured for being mounted around the rod-like central prop. The spacers are preferably mounted around the central prop between adjacent setters, such as to keep the setters at a set distance between each other, depending on the nature and shape of the objects to be treated in the kiln.
In one embodiment of the invention, the assembly further comprises a foot for carrying the rod-like central prop. The foot is intended to improve stability of the rod when the foot and the rod are connected, either alone, or in combination with setters and/or spacers. The rod-like central prop and the foot may form one integral part. Alternatively, the rod-like central prop and the foot may be securely assembled, either through use of ceramic nut and pin or screw and/or ceramic glue.
In one embodiment, the foot may have a basic shape which is essentially square or circular, or represent a rotationally symmetrical array of rods joined at a central point. The foot may be shaped such that it extends further from its central point than an expected centre of gravity of the assembly in its assembled state extends from the said rod-shaped central prop at full or partial loading of the assembly in an assembled state. This adds stability to the assembly during loading and unloading with objects.
In one embodiment, the setters are configured for carrying n objects to be treated. In this case they preferably have n-rotational symmetry, n being a integer of 2 or more, such as for example 2, 3, 4, 5 or 6. Rotationally symmetrical setters provide assemblies which in their assembled state are easier to stack on a kiln car, while maintaining their free rotation around the central prop.
In one embodiment, the spacers are shaped such as to intimately surround the central prop and as to be placed on top of and in contact with each other in an assembled state. In this configuration, each of the setters rests on one spacer without being in contact with the central prop in an assembled state. With this configuration, in an assembled state, each spacer carries the load of the superposed spacers and setters, while each setter only carries the load of the objects to be treated.
In one embodiment, the said spacers comprise extensions configured to carry the said setters in an assembled state. These extensions add to the stability of the assembly as a whole in an assembled state, while at the same time improving load bearing strength of the spacers.
In one embodiment, the central prop of the assembly comprises a hole adapted for lifting the said central prop using a hook or similar tool. The hole is preferably located in the vicinity of the end of the prop which is opposite the end intended to be connected to the foot in an assembled position. This hole makes it easier to place the assembly in an assembled or partially assembled state on a kiln rack. The hole is preferably configured such that the assembly in a fully or partially assembled state may be carried using said hole without damaging the central prop. In an alternative embodiment, one or several other applications for lifting or hoisting the assembly in its assembled state, as known to the skilled person, may be used, such as for example one or several hooks, handles, grips or knobs.

SHORT DESCRIPTION OF THE FIGURES

The invention will be further illustrated by reference to the following figures:

Fig. 1: represents a first exemplary configuration of a loaded kiln car for use without build up and dismantling of racks prior and after each treatment run, according to the state of the art;
Fig. 2: represents a second exemplary configuration of a loaded kiln car for use without build up and dismantling of racks prior and after each treatment run, according to the state of the art;
Fig. 3: represents a central prop and setters in a partially assembled state with a hole for lifting the assembly;
Fig. 4: represents an exploded view of an assembly according to one embodiment of the present invention;
Figs. 5a to 5d: represent various possible shapes for a foot of the assembly according to embodiments of the present invention;
Fig. 6: represents a view of a foot and central prop of an assembly according to one embodiment of the present invention, in an assembled state;
Fig. 7: represents a cut through the foot and central prop of an assembly of Fig. 5, according to one embodiment of the present invention;
Figs. 8a to 8c: represent various possible shapes for setters of the assembly according to embodiments of the present invention;
Fig. 9a: represents an exemplary shape of a spacer of the assembly according to an embodiment of the present invention;
Fig. 9b: represents an enlargement of the highlighted portion of the spacer represented in Fig. 8a;
Fig. 10: represents a turn-table rack assembled from an assembly according to an embodiment of the present invention;
Fig. 11: represents a third exemplary configuration of a loaded kiln car for use without build up and dismantling of racks prior and after each treatment run, using assemblies according to an embodiment of the present invention;
Fig. 12: represents a fourth exemplary configuration of a loaded kiln car for use without build up and dismantling of racks prior and after each treatment run, using exclusively assemblies according to an embodiment of the present invention.

It is understood that the following description and references to the figures concern exemplary embodiments of the present invention and shall not be limiting the scope of the claims.

DETAILED DESCRIPTION OF THE INVENTION

The present invention according to the appended claims provides for an assembly of parts, intended to be connected in order to form a rack for storing multiple objects to be treated in a kiln. Kiln treatment is understood to include firing of green ceramic materials, such as for example table ware, as well as drying, baking and other types of thermal treatment.
Figs. 1 and 2 show possibilities for configuring racks for loading objects for kiln treatment, without requiring the build up and dismantling of stacked racks after each treatment run. The racks may be loaded and unloaded without dismantling, once installed on a kiln car. All the rack surfaces are accessible for loading and unloading. The presence of void spaces renders this way of stacking both energetically and temporally inefficient, since the loading amount per treatment run is reduced by the need for accessing each rack in the stacks.
This problem is solved by the assemblies according to the embodiments of the present invention. According to one embodiment, the assembly 1 comprises a central prop 2 and a number of setters 3. In the simplest form of the invention, as shown for example in Fig. 3, a number of setters 3 are stacked on a central prop 2. The setters 3 are freely rotatable around the central prop 2, and therefore allow easy loading and unloading with objects for thermal treatment, even when installed on a kiln car. During loading and unloading, the setters 3 may be rotated around the central prop 2, allowing access to setters 3 which on a loaded kiln car may normally be inaccessible.
According to the present invention, the central prop is rod-shaped. According to the present invention, "rod-shaped" designates an elongated shape with a constant cross-section which has a regular or irregular geometric shape, such as round, triangular, square, rectangular, hexagonal or any other geometric shape, provided that setters 3 and/or spacers 7 may freely rotate around the rod-shaped central prop 2 in an assembled state.
In order to assemble a stacked rack with rotatable setters using the assembly 1 according to the present invention, the foot 4 and central prop 2 are secured to each other as described above. Next, setters 3 are stacked onto the central prop 4, such that they are fully rotatable around the said central prop 4. The setters 3 may be shaped such that when stacked on top of each other around the central prop 3, they provide sufficient space between two adjacent setters 3, in order to allow objects to be fired to fit between a setter 3 and its adjacent setter. Various types and sizes of setters 3 may be used depending on the type of object to be treated in a kiln.
Optionally, the setters 3 are separated from each other using spacers 7. If spacers 7 are used, they may be configured such that the space between adjacent setters 3 is sufficient for an object to be treated in a kiln to fit. Various types and sizes of spacers 7 may be used depending on the type of object to be treated in a kiln.
When spacers 7 are employed, they may have a shape configured such that in an assembled state, each spacer 7 carries the load of one setter 3 in addition to the load of an adjacent spacer 7. In such a configuration, the setters 3 are shaped such that they are not in contact with the central prop 2 in an assembled state, while the spacers 7 are in close connection with the central prop 2, while still being freely rotatable around the central prop 2.
According to one embodiment of the invention, the parts of the assembly 1 may be assembled as shown in Fig. 4. A central prop 2 is connected to a foot 4 using a nut 5 and a pin or screw 6. A central prop 2 and foot 4 in an assembled state without any other elements of the assembly 1 according to the invention is represented in Fig. 6. In addition, setters 3 and spacers 7 are alternately mounted onto the central prop 2. The said setters 3 may be loaded with objects to be fired, such as for example green ceramic tableware, such as green ceramic plates 9. The foot 4 may be set on an additional stabiliser 10.
Figs. 5a to 5d represent various shapes for the foot 4 which may be used in the assembly according to embodiments of the invention. It is understood that the mentioned shapes are exemplary and not to be considered limiting to the invention. In one embodiment, the foot 4 extends further away from its centre than a centre of gravity of the assembly 1 in an assembled position, when fully or partially loaded. This ensures that the stability of an assembled rack is increased and that it does not tilt over during loading or in operation.
Figs. 6 and 7 illustrate the connection of the centre prop 2 and foot 4 of the assembly 1 in an assembled state. The connection is ensured using a nut 5 and a pin or screw 6, which may or may not be used in connection with ceramic glue in order to fill any gaps left after assembly. Alternatively, the connection may be effected using only ceramic glue and a tight fitting connection between foot 4 and central prop 2. In a further alternative embodiment, the foot 4 and the central prop 2 may form a single, integral part.
Figs. 8a to 8c illustrate various possible shapes and configurations of setters 3 for use in the assembly 1 according to the present invention. It is understood that the mentioned shapes are exemplary and not to be considered limiting to the invention. In one embodiment, the setters 3 have rotational symmetry with n rotations, n being a positive integer of 2 or more. In the embodiments represented in Figs. 8a and 8b, n=4. In the embodiment represented in Fig. 8c, n=5. The number of objects to be carried by each setter normally corresponds to n. It is also possible to use setters of different shapes, where n=2, 3, 6 or more.
Fig. 9a shows one embodiment of a spacer 7 for use in an assembly 1 of the present invention. It is understood that the mentioned shapes are exemplary and not to be considered limiting to the invention. The spacer 7 has extensions 11, which in an assembled state extend outwardly from the central prop and are intended to carry a setter 3. In order to limit the contact area between a spacer 7 and a setter 3, each extension 11 is provided with a nib pointing upwards in an assembled state. This is shown in Fig. 9b, as an enlargement of the circled portion of an extension 11 as shown in Fig. 9a.
According to one embodiment of the present invention, the various components of the assembly may be made of high temperature resistant ceramics used as kiln furniture as known to the skilled person These materials may include for example nitride bonded SiC (NSiC), siliconised SiC (SiSiC), recrystallised SiC (RSiC), oxide bonded SiC (OSiC), cordierite, cordierite-mullite, mullite, aluminasilicate, aluminiumtitanate, aluminiumtitanate-mullite, Al₂O₃, Al₂O₃-MgO, MgO, ZrO₂, Al₂O₃-ZrO₂, ZrSiO₂, fused SiO₂, and mixtures and/or combinations of any of these.

EXAMPLES

In use, the stacked racks formed from assemblies 1 according to the present invention may be employed in connection with traditional racks as shown in Figs. 1 and 11. In this case, a kiln car is loaded with racks as shown in Fig. 1. Prior to a treatment cycle, the racks are loaded with objects to be thermally treated. Next, stacks formed from assemblies 1 are loaded onto the kiln car and these stacks are then loaded with further objects to be treated in a kiln. The said stacks formed form assemblies 1 of the present invention may be hoisted onto the kiln cars using a crane hook with hole 13 of the central prop 2. The stacks may then be loaded setter by setter by rotating each setter 3 around their respective central prop 4, rendering all the loading surfaces of the setters accessible from the outside of the kiln car. Alternatively, the said stacks have already been pre-loaded with objects to be fired before loading onto the kiln car.
In a separate use, the stacked racks formed from assemblies 1 according to the present invention may be employed exclusively, as shown in Fig. 12. In this particular use, the stacks do not need to be removed from the kiln car after use, but may be loaded and unloaded with objects to be treated in a kiln as described above.
It is clear that with the use of assemblies 1 according to the present invention, kiln cars may be loaded more efficiently, by allowing the treatment of more separate object in each treatment run, without the need for removing or disassembling racks from the kiln car.

Claims

Ceramic assembly (1) for supporting products to be treated in a kiln, comprising
a rod-shaped central prop (2); and

a plurality of setters (3), configured for being mounted around the said rod-like central prop (2) such that each setter is freely rotatable around the longitudinal axis of the said central prop (2);

wherein each setter (3) is configured for carrying a plurality of objects to be treated;

wherein the ceramic assembly (1) further comprises a number of spacers (7), configured for being mounted around the said rod-like central prop (2) between setters (3), such that each spacer (7) is freely rotatable around the longitudinal axis of the said central prop (2), and

wherein the said spacers (7) are shaped such as to intimately surround the central prop (2) and as to be placed on top of and in contact with each other in an assembled state, and wherein each of the said setters (3) rests on one of the said spacers (7) without being in contact with the said central prop (2) in an assembled state.
Ceramic assembly (1) according to any one of the previous claims, further comprising a foot (4) for carrying the said rod-shaped central prop (2).
Ceramic assembly (1) according to claim 2, wherein the said rod-like central prop (2) and the said foot (4) form one integral part.
Ceramic assembly (1) according to claim 2, wherein the said rod-like central prop (2) and the said foot (4) are separate parts which are configured to be securely assembled using ceramic pin or screw (6) and nut (5) and/or ceramic glue.
Ceramic assembly (1) according to any one of claims 2 to 4, wherein the said foot (4) has a square or circular shape, or represents a rotationally symmetrical array of rods conjoined at a central point, such as a cross.
Ceramic assembly (1) according to claim 5, wherein the said foot (4) extends further from its central point than an expected centre of gravity of the assembly (1) in its assembled state extends from a longitudinal axis of the said rod-shaped central prop (2) at full or partial loading of the assembly (1) in an assembled state.
Ceramic assembly (1) according to any one of the previous claims, wherein the said setters (3) are configured for each carrying n objects to be treated and have n-rotational symmetry, n being an integer of 2 or more, such as for example 2, 3, 4, 5 or 6.
Ceramic assembly (1) according to any one of claims 1 to 7, wherein the said spacers (7) comprise extensions (11) configured to carry the said setters (3) in an assembled state.
Ceramic assembly according to any one of the previous claims, wherein the said central prop (2) comprises a hole (13) adapted for lifting the said central prop using a hook or similar tool.
Ceramic assembly according to any one of the previous claims, wherein the said central prop (2) has a rod-shape, defined as an elongated shape with a constant cross-section which has a regular or irregular geometric shape, such as round, triangular, square, rectangular, hexagonal or any other geometric shape, wherein, in an assembled state, setters (3) and/or spacers (7) may freely rotate around the rod-shaped central prop (2).
Ceramic assembly according to any one of the previous claims, wherein the elements thereof are made from high temperature resistant ceramics, such as selected from the group consisting of nitride bonded SiC (NSiC), siliconised SiC (SiSiC), recrystallised SiC (RSiC), oxide bonded SiC (OSiC), cordierite, cordierite-mullite, mullite, aluminasilicate, aluminiumtitanate, aluminiumtitanate-mullite, Al₂O₃, Al₂O₃-MgO, MgO, ZrO₂, Al₂O₃-ZrO₂, ZrSiO₂, fused SiO₂, and mixtures and/or combinations of any of these.