GB2279731A - Support structure for ceramic articles - Google Patents

Description

1 Design for a Firing Table is 2279731 The present invention pertains to a

design for a firing table for receiving ceramic material to be fired, especially tableware. Various types of kilns have been known for firing ceramic materials to be fired, especially tableware. Tunnel kilns and roller kilns as representatives of continuously operating kilns, as well as hood type kilns or shuttle kilns as representatives of batch type kilns are of particular interest.

There is a special problem during the loading and unloading of the material to be fired onto or from a corresponding support especially when sensitive materials, such as tableware, e.g., porcelain, are fired. The support usually consists of a kiln car in the case of a tunnel kiln and of, e.g., a plate in the case of a roller kiln. The various supports will hereinafter be generally 2 called a firing table.

Various designs have been known for this purpose; they consist essentially of props, on which lie plates, on which the material to be fired is placed. A plurality of such units of props and plates are assembled one on top of another (prospectus of Gbbel-Werk GmbH, Grossalmerode, 1985).

Loading and unloading are always performed manually. Loading and removal are especially difficult in the case of the parts to be fired which are located in the center, because the distance between the individual plates is selected to be as short as possible in order to increase the amount of material that can be charged in for firing. It is sometimes even necessary to build up a new the socalled kiln furniture, i.e., the props and plates, for each kiln run, and to remove them at the end of the kiln.

Besides the above-mentioned firing table design, encapsulation of the material to be fired has been known as well. In this case, e.g., plates are placed individually into a capsule, and a plurality of capsules may be arranged one on.top of another. It is obvious that this process for charging a firing table is also extremely expensive 3 0 and can usually be performed only manually.

Props for placing on ceramic materials to be fired have been known from, e.g., U.S. Patent No. 3,137,910 A, German Offenlegungsschrift No. DE 28, 44,281 Al and German Offenlegungsschrift No. DE 35,16,490 Al. Every individual part is placed on a separate prop, which may have the form of, e.g., a tripod.

A support bottom for ceramic materials to be fired has been known from German Patent No. DE 39,23,564 Cl; it consists of a plurality of individual elements, each of which consists of a lower foot section lying on a bottom and of an upwardly extending, pin-shaped section, whose front surfaces, which are used as the contact surface for the material to be fired, are flush with one another, and the foot sections have a larger crosssectional area than the corresponding upper sections associated with them, and the elements are positioned relative to one another at their foot sections. Even though this support bottom simplifies the placing on of the materials to be fired, the charge can be introduced in one layer only with such a support bottom, as a result of which the throughput capacity of a kiln is again limited.

Ad - 0 The basic task of the present invention is therefore to provide a firing table design which makes it possible to accommodate the largest possible amount of materials to be fired, on the one hand, and, on the other hand, simplifies the loading and unloading of the material to be fired, so that it can preferably also be performed automatically.

The present invention is based on the consideration that this goal can be accomplished if the material to be fired is placed on support plates, and the support plates lie on corresponding lateral guide rails, so that it can be charged in and removed automatically with, e.g., a kind of forklift.

The advantage of the firing table design according to the present invention is the fact that a larger number of parts to be fired can be placed on the individual support plates, and a plurality of such support plates can be arranged one on top of another and possibly even next to each other on a firing table.

Thus, the new firing table design combines in itself the advantages of a high charging density with the possibility of automatic loading and unloading.

It its most general embodiment, the present invention pertains to a design for a firing table for receiving ceramic materials to be fired, especially porcelain, with the following features: at least four props, which are made of a temperature-resistant material, are arranged at spaced locations from one another, vertically upwardly project from the firing table, and are fastened to the firing table, each prop has a plurality of slots arranged vertically one on top of another, the slots are used to accommodate profiled rails, which extend, opposing each other in pairs, between adjacent props, and the profiled rails opposing each other in pairs are used to support plates, on which the material to be fired can be placed. Insofar as the props are to be fastened to the firing table, this can be done in the simplest case by the props having a corresponding foot, which stands on the firing table. To optimize the stability of the props, an alternative embodiment provides for the props being inserted into corresponding holes on the surface of the firing table. Providing other possibilities of fastening the props on the firing table, e.g., by pin v,, - is 6 connections, bonding, or the like, is also within the scope of the present invention.

The number of props arranged on a firing table depends especially on the following parameters: The size of the firing table, the size and number of the parts to be fired, as well as the local conditions for a possibility of loading and unloading. For example, four props can be arranged on each side in the case of a firing car with a length of 2.100 mm and a width of 1.895 mm (both overall sizes), when viewed in the longitudinal direction, and the profiled rails are inserted into slots of two adjacent props at right angles to the longitudinal direction, so that a total of three loading planes are available one behind the other in the direction of transport. Depending on the size of the kiln, especially the clearance, a plurality of profiled rails can be inserted one on top of another between adjacent props, so that a corresponding number of loading planes, e.g., 7, and consequently a total of 21 loading plates, can be provided for the material to be fired.

In such an embodiment, at least the props arranged between the corner props have the said slots on diametrically opposed surface sections, so that the profiled rails can be hung on both sides of 7 the corresponding props.

The specific design of the slots may vary. According to one embodiment, the slots have a rectangular shape and undercuts on the outer section of the upper edge of the slot. The lower edge of the slot thus forms a contact surface for the profiled rail and, by means of the undercuts, an anchor in the upper area of the slot. This type of design of the slot permits a particularly reliable and simple fixation of the support profiles for the plates.

The props themselves may have various designs. They are preferably cylindrical, and the cross section of the cylinder may be round, oval, or rectangular, the term "rectangular" always being defined according to the present invention as a shape that also comprises quadratic shapes. Solid profiles are also possible.

In the case of slots with rectangular cross sections, the slots are preferably arranged in the corner area, so that one slot extends over two lateral surfaces of the prop, and the lower, bentoff edge of the slot is used as a contact surface for the profiled rail.

8 Both the props and the profiled rails are made of temperature-resistant materials, where "temperature-resistant" means that these materials have a corresponding dimensional stability at the maximum temperatures prevailing in the kiln.

Materials based on silicon carbide, e.g., SiSiC, have proved to be particularly suitable.

The size and shape of the plates, on which the material to be fired is placed, depends on the local conditions, especially the size and the number of the parts to be fired. Placing a continuous plate on two opposite profiled rails, e.g., L-shaped rails, is, in principle, within the scope of the present invention. In the exemplary embodiment described at the beginning, the plate would extend over the entire width of the kiln car. Since only a relatively small surface is usually needed as a contact surface for the material to be fired, the consequence of this embodiment would be that a considerable, technically nonutilized portion of the mass of the plate(s) would also have to be heated up in the kiln, which is not very logical from the viewpoint of energy.

The car design according to the present invention also makes it possible to arrange individual, discrete plate elements at spaced 9 locations next to one another between adjacent profiled rails, so that the surface areas and the weight of the corresponding firing aids are reduced, and free spaces, which promote the convective flow in the kiln and consequently the homogenization of the temperatures around the material being fired, are formed between the individual plate elements. Plates with recesses, and even grid plates or honeycomb plates are advantageous in this sense.

According to one exemplary embodiment, the edges of the plates are waveshaped and adapted to the geometry of the material to be fired.

Conventional refractory materials, e.g., those based on SiC, SiSiC. but even other oxidic and nonoxidic materials, such as cordierite, can be considered for use as plate materials.

The task of the profiled rails is to laterally support the "plates." Their shape is to be adapted to this task. Even though angle sections, e. g., those with an L-shaped cross section, are simple and inexpensive, it is also possible to use other rail shapes, and even solid profiles. Via recesses in the profiled rails, the said profiled rails can be anchored on corresponding pins in the area of the slots of the props.

Additional features of the present invention will become apparent from the features of the subclaims as well as from the other application documents. The present invention will be explained in greater detail below on the basis of an exemplary embodiment. In schematic representations, Figure 1 shows a perspective view of a car design according to the present invention, Figure 2 shows a top view of a car design according to the present invention, Figure 3 shows a side view of the car design according to Figure 2, Figure 4 shows a sectional view of a prop, and Figure 5 shows an example of the design of a slot in a prop.

Identical or functionally identical components are designated by the same reference numerals in the figures.

The reference numeral 10 is used to designate a firing table. The firing table has a length L and a width B. As is shown especially by a comparison of Figures 1 and 3, a total of eight props 12a-h are arranged on the said firing table, with four said props 12a-d and 12e-h each being arranged at spaced locations next to one another in the longitudinal direction L. The said props 12a-h are inserted into 11 is corresponding holes of the said firing table 10.

The shape of the said props 12a-h can be determined especially from Figure 4. According to this representation, each of the said cylindrical props 12a-h of round cross section has, on opposite surface sections, six slots 14 arranged at spaced locations one on top of another, whose shape is schematically represented in Figure 5. Undercuts (recesses) 16 in the outer upper edge area are characteristic of the said slots 14.

The said slots 14 are used to support profiled rails 18, which have an Lshaped cross section here. The said profiles 18 are inserted slightly tilted into the said slots 14 of said adjacent props 12a,e; 12b,f; 12c,g; 12d,h, and they are then tilted into the end position represented in Figure 4, and the said profiles lie with their horizontally extending legs on the lower edge 14u of the said recess 14, and they extend with their vertical legs into said undercuts 16 of the said slots 14, so that a reliable and stationary anchoring is guaranteed.

The vertical distance between the said slots 14, the number of said slots 14, as well as the size of the said profiles 18 depend on the local conditions, especially on the size and the height of the parts to be fired.

12 - 1) Thus, two said profiled rails 18a, b are always located opposite each other in pairs at spaced locations, and corresponding support plates 20 can now be placed on the said profiles 18 with their outer edges.

Figure 2 shows as an example various shapes of the said plates 20. The plate 20a between the said props 12a,b,f,e is designed as a one-part plate and extends over the entire surface covered by the said props and lies at its edges on the said rails 18a, b.

The plate 20b, which lies on the said rails 18a,b in the area of the said props 12b,c,f,g, consists of an essentially circular central section, from which narrow webs extend to the said rails 18a,b. The central surface is used here, e.g., to support a plate of a corresponding size (represented in broken line), while the end-side, narrow sections only have to assume the function of supporting the said plate 20b on the said rails laa,b.

If a plurality of said plates 20b are arranged next to each other, free spaces are automatically formed between the said plates 20b, so that combustion air is able to flow through the said free spaces and to homogenize the temperatures within the car structure. The said plates 20b also offer the 1) A is advantage that a much smaller mass of kiln furniture must be heated up and cooled.

The plate shape 20c represented in the lower part of Figure 2 represents another possible alternative, which is used, e.g., to support a total of three cups (also represented in broken lines) here.

The plate 20d represented in Figure 1 has waveshaped side edges and recesses 21. This also creates convection areas for the kiln air.

While the car design remains unchanged over a plurality of firing cycles in terms of the said props 12 and the said rails 18, only the said plates 20 loaded with the material to be fired are placed according to the present invention on the said rails 18 in front of the kiln for loading the said firing table 10, and they are removed from the said firing table 10 after the firing process. Based on the "storage" of the said plates 20 on the said rails 18 according to the present invention, both loading and unloading can now also be performed without problems by means of automatic setting devices, e.g., robots. These robots may have, e.g., actuating arms in the manner of a forklift, and the arms of the forklift pick up the said plates 20, move them to or remove them from the desired position of the firing table 14 design. Another advantage is the fact that a plurality of such said plates 20 (both horizontally and vertically adjacent plates 20) can be inserted or removed in a single operation.

The advantages described are appreciable especially in the case of the once firing or glost firing of tableware, where large numbers of very sensitive parts must be arranged on a firing table or firing table design. Both assembly and loading and unloading are markedly simplified according to the present invention.

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Claims (1)

1. Claims

   1. Design for a firing table for receiving ceramic materials to be fired, especially tableware, with the following features:

   1.1. at least four props made of a temperature-resistant material, which are arranged at spaced locations from one another, project vertically upward from the firing table and are fastened to the firing table, 1.2. each prop has a plurality of slots arranged vertically one on top of another, 1.3. the slots are used to accommodate profiled rails, which extend opposite each other in pairs between adjacent props.

   1.4. the profiled rails opposing each other in pairs are used to receive plates on which the material to be fired can be placed.

   Design in accordance with claim 1, in which th slots have a rectangular shape and undercuts on the outer sections of the upper edge.

   16 3.

   4 5.

   6.

   7.

   Design in accordance with claim 1 or 2, in which the props are of a cylindrical shape.

   Design props Design props Design slots props.

   Design in accordance with claim 1, in which the props, the profiled rails or the plates consist of a material based on silicon carbide.

   8. Design in accordance with claim 1, in which the props have the said slots on diametrically opposed surface sections.

   9. Design in accordance with claim 1, in which the plates have a shape adapted to the material to be fired.

   10. Design in accordance with claim 9, in which the plates have narrow edge-side sections and an enlarged middle area.

   Design in accordance with claim 1, in which the plates have wave-shaped side edges.

   in accordance with claim 3, in which the have a round cross section. in accordance with claim 3, in which the have a rectangular cross section. in accordance with claim 5, in which the extend in the corner area of the 17 12. Design in accordance with claim 1, in which the plates have recesses (holes).

   13. Design in accordance with claim 1, in which the profiled rails are formed by angle sections.

   14. Design in accordance with claim 13, in which the angle sections have an L-shaped or U shaped cross section.

   15. Design in accordance with claim 1, in which the props are designed for insertion into corresponding holes on the surface of the firing table, 16. Design for a firing table for receiving ceramic materials to be fired, substantially as hereinbefore desdrib6d with reference to-the accompanying drawings.