EP0089623A2 - Coke oven - Google Patents

Abstract

In a coking oven (1) with walls (2) between heating trains (3) and coke chambers (4) made of refractory material, the heat transfer through the walls (2) is achieved with the substantial exclusion of reversible thermal expansion above about 1000 ° C in that the walls (2) from an approximately lattice-shaped frame structure (5) made of known refractory stones (6) and the frame-filling plates (7) - also made of refractory material - with a relatively high heat transfer coefficient. The plates (7) preferably have better thermal conductivity than the refractory bricks (6) of the frame structure (5); Joints (8) between the plates (7) and the refractory bricks (6) of the frame construction (5) equalize different thermal expansions between these construction elements, whereby elastic sealing materials (11) cavities (10) between the different construction parts in the area of the joint end faces (9 ) to complete.

Description

The invention relates to a coking oven with walls between heating trains and coke chambers made of refractory material.

So-called horizontal chamber coking ovens are particularly affected by the invention. In order to operate coking ovens economically, the coking (cooking) process must be as short as possible; forth flow of heat between the heating flues and coking chambers required _- therefore an HO possible is. With this heat flow, the thermal resistance of the heating walls (walls between heating trains and coke chambers) must be overcome.

As is known, the heat flow can be increased by increasing the heating train temperatures and / or by using refractory bricks with higher thermal conductivity instead of the conventional silica material or particularly thin bricks made from such silica material (DE-PS 21 61 980).

The increase in heating cable temperatures are about the z. Currently, technical limits have been reached, the exceeding of which would unacceptably reduce the durability of coke ovens.

A further reduction in the heating wall thickness is not justifiable for mechanical, especially structural reasons.

The use of refractory material with higher thermal conductivity has been tried - unsuccessfully. So z. B. a large-scale experiment with so-called magnesite stones because of Inability to control the high reversible thermal expansion of this material failed. In contrast to silica bricks, which after reaching a stone temperature of approx.1,000 ° C with process-related temperature changes above this limit no longer show any reversible thermal expansion, all other refractory materials are also subject to reversible thermal expansion above 1,000 ° C, even if they are not as large as with magnesite stones. - This applies e.g. B. also for silicon carbide (SiC), which is the one with the highest thermal conductivity among the most common refractory materials. According to the experience with magnesite stones, using such stones as the exclusive building material for coke chamber walls seems too risky, even if the reversible thermal expansion of SiC is only half as large as that of magnesite.

From DT-PS 1 43 332, a refractory retort module is known from a thin-walled main surface with a solid, tongue and groove frame. Such retort modules have an improved heat transfer coefficient compared to uniformly thick modules, but the material thickness of the thin-walled main surfaces cannot be chosen to be as thin as desired, because otherwise different thermal expansions between the main surface and the frame lead to stress cracks. In particular, the size of such stones is limited because of their one-piece construction. Particular difficulties arise when such stones are used for the walls of coke oven chambers, since they are poorly suited for the interlocking of runner and binder stones.

| The invention is therefore based on the object to provide a coking oven of the type mentioned with heating walls with higher heat transfer rates and at the same time to avoid reversible thermal expansion of the heating walls as a whole at temperatures above 1000 ° C., and a solid connection between the binding stones separating the heating cables from one another and to ensure the runner blocks separating the coke oven chambers from the heating trains.

This object is achieved in a coking oven of the type mentioned by the features of claim 1. Further developments of the invention result from the subclaims.

The invention is based on the basic idea of filling a self-supporting serum made of refractory bricks of the material composition "A" in the form of a lattice of the material composition "A" with thin plates of the material composition "B" filling the free lattice areas and serving only the highest possible heat transfer . This separation of the supporting function from the function of heat conduction allows the two functional elements to be optimally designed. The resulting frontal joints at the plate edges in relation to the frame construction allow a different thermal expansion between the two functional elements, free of stress cracks.

Refractory bricks have proven to be particularly favorable with regard to the stability of the lattice-shaped frame construction, which at the same time separate the individual heating trains of a heating wall of the coking oven lying side by side separate others. In this case, preferably two horizontally juxtaposed refractory bricks of two opposite heating walls form the binding stones which separate the heating trains from one another. This results in a particularly high strength of the frame construction.

Accordingly, the thermal transmittance through the heating walls is improved in that they are created from a strong horizontal and vertical continuous latticework made of fireproof stones known per se and suitable for heating walls, in particular from silica bricks, and plates from a likewise refractory material are more justifiable Enclose size and comparatively high heat transfer coefficient. The last-mentioned panels can include, in comparison to the prior art, relatively thin panels made of the same material from which the lattice-shaped frame construction is made.

It is preferred according to the invention to use such filling plates made of refractory material, the thermal conductivity of which is higher than that of the stones used for the frame construction, e.g. B. SiC stones or SiC-containing plates (see DE-PS 20 19 078) in a frame construction made of silica stones.

The growth and shrinkage of the panels is thus absorbed in the connecting joints surrounding them to the lattice-shaped frame construction. According to the invention, the panel format should not be larger than a tolerably tight joint can compensate for absolute length and width changes resulting from the format dimensions. This largely prevents mechanical stress on the frame structure from the plates. - In order to keep the masonry structure of the frame construction rigid and to keep the joints tight against the panels, suitable tongue and groove connections should be provided between these areas. It is recommended that the side surfaces beveled only slightly by tongue and groove or possibly even designing them at right angles to the head surfaces and mortaring them. - So there is only a minimal change in the joint width when moving the tongue relative to the groove, so that the joint remains practically tight.

According to a further development of the invention, the joints mentioned can be filled with an easily deformable sealing material in the region of their end faces lying opposite one another transversely to the wall plane. in particular, cavities formed by the joints should be provided with such material. For example, the top surfaces of the tongues and the bottom surfaces of the groove can be sealed against one another when bricked up by ceramic fibers or possibly cardboard strips in order to keep a space for the reversible expansion of the plates after the coking oven has been heated up.

The proposed construction enables the heating walls to be easily installed on a conventional substructure (sub-furnace); therefore, it can also be used in a coking oven to be repaired from the chamber bottom, e.g. H. be retrofitted.

Designed to the heating walls terms of surface area to approximately 50% of silicon carbide, at least containing plates and the balance of a grid-shaped frame made of silica stones, then, chamber-side Heizwandtemperatur increases the mean at the same Heizzugtemperatur to about 100 ⁰ C over a heating wall of silica stones with the same average wall thickness.

Thanks to the new, lattice-shaped frame construction, it is also possible to manufacture and use the filling panels from approximately 50 mm thick silica panels, and thus to achieve the smallest wall thicknesses known to date from this material in a coking oven.

Further objectives, features, advantages and possible uses of the present invention result from the following description of an exemplary embodiment with reference to the accompanying drawings. All of the described and / or depicted features, alone or in any meaningful combination, form the subject matter of the present invention, regardless of how they are summarized in the claims or their relationship.

• Fig. 1 einen Ausschnitt eines horizontalen Verkokungsofens im Horzizontalschnitt;
• Fig. 2 einen Ausschnitt aus einer Heizwand gemäß Fig. 1 in der Ansicht;
• Fig. 3 eine Mauerwerkfuge in einem vergrößerten Ausschnitt aus Fig. 1.

The drawing shows:

• 1 shows a section of a horizontal coking furnace in the horizontal section;
• FIG. 2 shows a detail of a heating wall according to FIG. 1 in the view;
• 3 shows a masonry joint in an enlarged detail from FIG. 1.

In Fig. 1, 1 shows a section of a horizontal coking furnace with walls (heating walls) 2 between heating trains 3 and coke chambers 4. The heating walls 2 consist of a lattice-shaped frame construction 5, of known, refractory stones 6 and the frame-filling plates 7 with a relatively high heat transfer coefficient, for. B. silicon carbide. These stones can also be known, heating draw-side cavities 7a for further improvement of the heat transfer coefficient, in particular they can be made comparatively thin compared to the previously known so-called runner stones and also consist of the same material as the refractory bricks 6 of the frame structure 5.

Refractory bricks 6, which form the verticals of the frame structure 5, have a depth across the heating walls 2 such that opposing refractory bricks meet two heating walls and thus form the heating blocks 3 separating binding stones. Different depths of the opposing refractory bricks allow a solid interlocking when laid alternately.

Fig. 2 illustrates the lattice-shaped frame construction in which, for. B. horizontally several refractory bricks 6 are layered on top of one another and possibly mortarized, while vertical refractory bricks 6 bridge the spaces between the vertical columns in a yoke-like manner, toothings 6a oinon securely holding the frame construction against shear and tensile forces at the intersection points of the latticework.

3 shows a possible design of the joints between the refractory bricks 6 of the frame structure 5 and the plates 7. Here, a tongue and _F ederge- staltung was chosen only slightly bevelled side surfaces of the grooves 8a and 8b of the springs. The joint 8 runs through the wall 2 from surface to surface and is with mortar; backfilled. An end surface 9 of the refractory bricks 6 and the plates lying opposite one another transversely to the wall plane can also be completely or partially filled with an elastic sealing material 11; this applies in particular to cavities 10, as shown on the bottom of the groove 8.

Claims (5)

1. coking oven (1) with walls (2) between heating trains (3) and coke chambers (4) made of refractory material, characterized in that the walls (2) from an approximately lattice-shaped frame structure (5) made of known refractory stones ( 6) and the frame-filling, in particular single-stage, plates (7) are also made of refractory material with a relatively high heat transfer coefficient. 2. Coking furnace according to claim 1, characterized in that the plates (7) consist of a refractory material with a better thermal conductivity than the frame structure (5). 3. coking furnace according to claim 1 or 2, characterized by different thermal expansion between the plates (7) and the frame structure (5) compensating joints (8). 4. coking furnace according to claim 3, characterized by joints (8) with approximately transversely to the wall plane opposite end faces (9) with intermediate, by an easily deformable sealing material (11) filled cavities (10). 5. coking furnace, according to one or more of claims 1 to 4, characterized in that the refractory bricks (6) of the approximately lattice-shaped frame construction (5) serve simultaneously as the heating cables (3), so-called binding stones.

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