EP0618418B1 - Process to dry and fire tiles and means for its realisation - Google Patents

Abstract

The subject of the invention is a process for drying and firing green bricks in one operation, in which the green bricks, after pressing, are put directly onto a hearth car and then transported through a combined drying and firing oven (kiln). In order also to be able to dry and fire economically, and in one pass, large-sized green bricks produced by the soft-pressing process, the green bricks (1) are stacked on the hearth car in a plurality of layers (1a, 1b, 1c) and the individual layers are spaced apart from one another by interposed perforated insertion elements (2). Uniform airing of the mutually facing bearing surfaces is thus guaranteed. The insertion elements are preferably designed in the form of rods with a perforation. <IMAGE>

Description

The invention relates to an insert element for use in drying and Firing brick moldings according to the preamble of claim 1 and one Process for drying and firing in a soft pressing process large-sized brick moldings in one operation, in which the Brick moldings have a higher proportion of holes of 20 to 50% and after pressing wet on a bogie wagon without reloading by a combined Dryer and kiln can be transported.

Drying and firing of moldings is usually done in the brick and tile industry in different process sections on spatially separate Plant parts. The moldings must be between the individual system parts reloaded, stored, placed in special arrangements and treated will. These operations not only waste time, but also there are additional means of transport, grouping systems, setting grabs and the like. required, which increase the price of the end product.

Control devices are also used to coordinate the individual work steps needed, which is also expensive and moreover often are also prone to failure.

Finally, the energy from the ovens is also poorly used, since the drying oven and the kiln is heated and operated independently have to.

To improve the overall efficiency of the plant, it is known to be stiff to stack pressed moldings after pressing on bogie wagons and without interruption as well as without reloading in one pass through a dryer and to drive the kiln. However, this procedure is only for generation small-format masonry brick (normal format) can be used according to the rigid press method, because these bricks have a small percentage of holes from 0 to 10% and be pressed so stiffly that they can be deformed in several without the risk of deformation Layers were stacked directly on top of the bogie and in the described Art can be treated further.

This method has not been applicable to large-sized moldings since such moldings without exception with a higher proportion of holes of 20 to 50% be manufactured, which is only possible with the soft pressing process. You can also such moldings in the manner described on a bogie without Reloaded after drying through a dryer and kiln However, only one layer of moldings may be placed on the wagon to be ordered.

Although also soft-pressed brick moldings in terms of stability for one Stacking in two or more layers on top of one another is drying and immediately following firing in this arrangement possible. When drying and firing, they are in direct contact with each other Contact surfaces of the moldings to a considerably smaller extent ventilated than the exposed outer surfaces and the inner sides of the holes, thereby different moisture contents and material temperatures on the contact surfaces adjust that negatively affect the quality of the end products impact.

To avoid such damage, the lead time would have to be increased to a degree be that compared to the single-layer arrangement on the bogie Advantage more can be achieved.

From FR-A 668 136 it is known for drying and firing brick moldings to stack them after pressing on a bogie and each other spaced from each other by large-area floor elements. The relatively narrow bricks are largely due to the large floor elements kept stable and can be stacked on top of each other in several layers be, the risk of tipping the individual bricks by the weight the overlying layer is reduced.

From GB-A 191 734 floor elements are also known on which the Lay the bricks over the entire surface. Run through the floor elements Passages, which are arranged in the direction of the end faces, so that they during of drying are arranged transversely to the direction of flow.

The invention has for its object to provide a method that Drying and firing soft-pressed, large-sized brick moldings in one pass without reloading after drying and without additional Time expenditure with the best possible use of the tunnel cross section of Allows dryer and oven. Furthermore, to carry out the procedure appropriate means are given.

The object is achieved in that the bricks in two or more layers arranged on the bogie and the individual Layers are spaced apart by interposed insert elements.

The brick moldings are preferably in two or more layers arranged one above the other.

The insert elements are designed according to the features of claim 1. Particularly suitable as a refractory material Fireclay or metal. The bars are perforated and become like this placed between the stacked brick moldings that the cavities the rods are aligned parallel to the cavities of the moldings and the Contact surfaces between the moldings in the same way as the inside of the Moldings can be ventilated. The fireproof material of the insert elements is chosen in a quality that is multiple Reuse allowed.

Fig. 1

zwei übereinanderliegende Ziegelformlinge mit dazwischengelegten Einlageelementen im Aufriß,

Fig. 2

drei übereinanderliegende Ziegelformlinge mit dazwischengelegten Einlageelementen im Aufriß,

Fig. 3

zwei übereinanderliegende Ziegelformlinge mit rillenartigen Auflageflächen und dazwischengelegten Einlageelementen im Aufriß,

Fig. 4

einen Ziegelformling mit aufgelegten Einlageelementen in Draufsicht,

Fig. 5

verschieden gestaltete perforierte Einlageelemente in perspektivischer Ansicht,

Fig. 6 und 7

verschieden gestaltete perforierte Einlageelemente in Draufsicht.

Further details and advantages of the invention result from the following description of preferred embodiments of the method according to the invention and the insert elements with reference to the drawing. In this show:

Fig. 1

two stacked brick moldings with insert elements in between, in elevation,

Fig. 2

three stacked brick moldings with insert elements in between, in elevation,

Fig. 3

two stacked brick moldings with groove-like contact surfaces and insert elements in between, in elevation,

Fig. 4

a brick form with inserted insert elements in top view,

Fig. 5

differently designed perforated insert elements in perspective view,

6 and 7

differently designed perforated insert elements in top view.

According to the invention, between the stacked one above the other Layers of brick moldings 1 narrow insert elements 2 interposed, through which the mutually facing bearing surfaces the moldings are kept at a distance from each other. In Fig. 1 are two superimposed moldings 1a, 1b 2, while FIG. 2 shows a stack of three moldings 1a, 1b, 1c shows. Depending on the nature of the bricks and Resilience of the wet moldings can even more layers be provided.

Rod-shaped insert elements 2, which keep the contact surfaces at a distance from one another, have been introduced between the contact surfaces. The drying and oven air, favored by the perforation of the insert elements, can circulate unhindered between the insert elements along the contact surfaces of the bricks. The insert elements with a square or rectangular cross section and perforation are arranged according to FIG. 3 so that they carry the moldings as evenly as possible, transversely to the direction of the holes in the moldings. The holes in the insert elements run parallel to the holes in the moldings, so that the dry air and the furnace air are passed through the moldings and along the support surfaces through the insert elements.

Fig. 3 shows moldings with a toothed, groove-like contact surface, which is fully supported by the transverse insert elements.

Fig. 4 shows a top view of the insert elements on the contact surface of a molding.

5 shows a perspective view of insert elements with different perforations, namely in the form of perforations with a square and a round cross section.

6 and 7 show insert elements with different angles of the perforation in plan view.

The bars forming the insert elements can have a greater width than height, so that there is a larger contact surface for the brick moldings. The insert elements can also take the form of plates. Furthermore, several rods or plates can be connected to one another, e.g. be hooked to fix them against each other.

In the case of very narrow blanks, it may be necessary to use a fuse to prevent tilting. This can take the form of Holders happen that are attached to the insert elements are and grasp the edges of the moldings.

It is important in any case that there is good ventilation between the facing surfaces of the bricks is guaranteed.

Claims (7)

1. Insertion element for use in drying and firing large semi-finished bricks, produced in a soft pressing process, in a procedure in which the semi-finished bricks have a relatively high proportion of holes of 20 to 50% and are transferred damp, after the pressing process, on a furnace truck through a combined drying and firing furnace without transloading, which element is constructed as a bar (2) with a rectangular, particularly square, cross-section and a length which is less than the breadth of the contact surface of the semi-finished bricks (1), characterised in that the bars of rectangular or square cross-section have openings, which are constituted by perforations which are arranged transversely or obliquely to the longitudinal axis of the bars, and the bars are manufactured from refractory material.
2. Insertion element as claimed in Claim 1, characterised in that the insertion element comprises two bars intersecting in an X shape.
3. Insertion element as claimed in one of Claims 1 or 2, characterised in that the perforation comprises openings of square cross-section.
4. Insertion element as claimed in one of Claims 1 or 2, characterised in that the perforation comprises openings of round cross-section.
5. Method of drying and firing large semi-finished bricks, produced in a soft pressing process, in a procedure in which the semi-finished bricks have a relatively high proportion of holes of 20 to 50% and are transported damp, after the pressing process, on a furnace truck through a combined drying and firing furnace without transloading, the semi-finished bricks (1) being arranged above one another in a plurality of layers (1a, 1b, 1c) on the furnace truck and the individual layers are spaced from one another by a plurality of rod-shaped insertion elements (2) as claimed in one of the preceding Claims 1 to 4, and the insertion elements (2) being so constructed and arranged parallel to one another that they make a flow of the drying air and of the furnace air possible between the layers of the semi-finished bricks along the contact surfaces of the insertion elements substantially in the direction of the holes in the semi-finished bricks (1).
6. Method as claimed in Claim 5, characterised in that the bar-shaped insertion elements (2) are arranged parallel to the direction of the holes in the semi-finished bricks.
7. Method as claimed in Claim 5, characterised in that the bar-shaped insertion elements (2) are arranged transversely to the direction of the holes in the semi-finished bricks (1) and are so constructed that drying air and furnace air can flow through them.

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