EP0163773B1 - Door for a coke oven with horizontal chambers - Google Patents

Description

The invention relates to a coke oven door for a horizontal chamber coking oven with a one-piece or multi-part protective shield, which at the same time serves as heat protection and protrudes into the oven chamber and is connected to the door body, by means of which the oven filling is held at a certain distance from the door body, the door body being held during the Coking process is pressed against the door frame of the furnace with at least one locking device. Such coke oven doors are also included in DE-A-33 27 337. This proposal is aimed at a novel design of the door body with the associated sealing device. The new door body is characterized in particular by its lightweight construction, price advantages compared to conventional doors and by its high, permanent sealing effect. According to P 33 27 337.5, the new door body is partially combined with conventional fire-resistant door plugs.

DE-C-238 363 also discloses a door for coke ovens with an adjustable protective shield attached to the rear wall, the protective shield being connected to the rear of the door by articulated intermediate members and being able to move relative to the door. The protective shield connected by articulated intermediate elements to the rear of the door should be lockable from the outside in its respective position by an adjusting device. According to the presentation of the embodiments of this patent, the protective shield is designed as a flat, one-piece plate with rear stiffening ribs.

In such a coke oven door with a flat, one-piece plate extending over the door height, it has been shown that the metallic design of this protective shield has so far not caused any sore difficulties. The strong deformation of the one-piece protective shield is particularly striking. Due to a large temperature gradient of the coke-side protective shield surface compared to the door body-side protective shield surface, there is a very strong curvature.

At the time of filing the German patent 23 83 63, the usual heights of coke ovens were 1.5 to 2 m. With such low door heights, the overall deformation of the protective shield may still be within the tolerance range. With today's coke oven heights of 4 m, 6 m and in the future 8 m and more, the overall deformation of the protective shield would either lead to openings between the furnace sole and protective shield and between the protective shield and chamber walls such that excessive amounts of coal penetrate between the protective shield and the door body. This would affect dry coking coal. especially preheated coal, still significantly strengthened.

More recently, the idea of a metallic protective shield has been taken up again. Two approaches have been tackled.

An example of one solution is US-A-4 086 145. It attempts to counteract the faults by connecting and supporting the protective shield on the furnace body as intensively as possible. Intensive means here: The protective shield is connected to the door body via at least one web running the entire length of the protective shield. In one embodiment, support rods are provided on both sides of the web. In another embodiment, two webs running at a distance from one another are provided, which are additionally stiffened by lateral ribs. However, this solution has above all thermal disadvantages, in that contact heat is conducted through the webs, ribs and support rods into the door body. The associated heating of the door body easily leads to undesirable leaks.

DE-A-31 05 703 is an example of the other approach taken: a protective shield is shown there, which is constructed in a scale-like manner, i.e. H. consists of a large number of smaller, overlapping individual parts. Each item is attached separately. The smaller individual parts are subject to the same overall thermal expansion as a one-piece protective shield. The absolute degree of thermal expansion of each individual part is, however, much lower than that of a one-piece protective shield. Due to the individual suspension of the various individual parts and the overlapping arrangement of the individual parts, the thermal deformation of each individual part does not have an excessive effect on the other individual parts. The total heat deformation is within acceptable limits.

• Durch die Aggressivität des Sauerstoffs kann eine schleichende Zerstörung am heißen Kopfmauerwerk der Ofenkammer eintreten ; bei starken Undichtigkeiten kann an der Koksofentür das metallische Schutzschild mit seinen Befestigungen am Türkörper zum Schmelzen bzw. zur Zerstörung gebracht werden. Der Effekt wäre vergleichbar einer Brennschweißung.

The invention takes a different route either while maintaining a one-piece protective shield. Or, using a multi-part protective shield, adverse heat loads should be avoided. The invention is based on the following considerations: Operating difficulties can arise in the raw gas duct between the door body and the protective shield. This is considered returned that the raw gas in such doors is totally extended and then adjusting gas pressure averaged according to vehicle original pressure at the coke oven battery, more or less in a short Garungsdaüer on the door height of positive transfers to _/ negative values, ie of its original pressure negative pressure then arises. This creates suction. If the coke oven doors are not sufficiently tight, this phenomenon inevitably leads to the intake of atmospheric air between the chamber frame and the door body. The air penetrates into the raw gas duct and causes, among other things, the following faults:

• The aggressiveness of the oxygen can result in a gradual destruction on the hot brickwork of the furnace chamber; In the event of severe leaks, the metallic protective shield with its fastenings on the door body can be melted or destroyed on the coke oven door. The effect would be comparable to flame welding.

Operating difficulties from existing temperature gradients are also seen according to the invention. It is assumed that the resulting raw gas temperatures in the totally expanded raw gas duct over the distances between the protective shield and the door body and between the chamber walls are around 500 to 700 ° C, depending on the cooking state and driving style of the coke oven. ,

At coke temperatures of around 1,100 ° C, there is a temperature jump from the protective shield to the raw gas duct of around 400 to 600 ° C. This phenomenon inevitably leads to an influence on the expansion or to inadmissible tensions between the relatively cold masonry in the area of the raw gas duct and the relatively hot masonry in contact with coal or relatively cold furnace frame. Unpredictable wall damage in the area of the head masonry is to be expected from this. Furthermore, the gas permeability in the stone material increases considerably because of the low wall temperatures, the surface structure of the stone material increasingly changing negatively with the running time of the coke oven and tending to flake and crack.

The invention further assumes that in a coke oven not filled with coking coal or in a protruding coke oven (the coke pressing has been delayed) the protective shield used heats up to such an extent in a short time that increased heat radiation via the protective shield unhindered both on the door body and also acts on the chamber frame. The effect of heat leads to uncontrolled deformation on the one hand on the conventionally cast door body (thereby causing door leakage) and on the other on the chamber frame. Due to the increasing bending of the chamber frame, the frame joint between the masonry and the chamber frame is exposed on the chamber frame. A so-called frame joint leakage occurs.

Finally, the invention takes into account the fact that, at the usual coke oven temperatures, the protective shield explained above tends to warp continuously over the height of the coke oven due to its geometry as a flat, one-piece surface. This causes the already explained risk that when a coke oven door is inserted or removed, the protective shield will cling to the oven walls and be torn off. The consequences are also damage to the furnace walls. Furthermore, the distortion of the shield that occurs increases the opening width of the two gaps between the shield and the coke oven walls. This increases the unwanted amount of coal in the raw gas channel. With low water contents (less than 10% by weight H ₂ 0) of the input coal mixture, the coal accumulation in the expanded raw gas channel is particularly large. There, the coal leads to disadvantages of the uncontrolled formation of condensate in the area of the door seal due to the low head temperatures or forms a semi-coke plug of different heights, which has to be removed manually and time-consuming by the operating personnel after each furnace run.

According to the invention, all of these difficulties are avoided either while maintaining a one-part or using a multi-part protective shield extending over the door height by arranging at least one further one-part or multi-part shield between the protective shield and the door body.

The one additional shield creates two raw gas channels, which can be called the inner, coke-side raw gas channel and the outer, door body-side raw gas channel. With several additional shields, more raw gas channels are created.

With the help of the inner and outer raw gas channel, the raw gas discharge quantity can be controlled or equalized in such a way that the raw gas pressure on the sealing surface between the coke oven door and the chamber frame is optimized in the measurable positive range.

The heat radiation of the door body to the outside is reduced by the protective shield facing the door body acting as an crane. Optionally, additional protective shields (ecranes) are arranged between the coke-side protective shield and the door body. In addition to a saving in insulating material on the door body, the high heat radiation which arises is kept away from the door body and from the chamber frame, in particular by the ecranization effect in the case of protruding or empty coke ovens. The ecranization effect ensures a uniform temperature drop along the head masonry, starting from the protective shield in contact with the coal or coke towards the door body.

Compared to the known, flat and one-piece protective shields made of heat-resistant metallic material, the usual high coke oven temperatures result in a much greater dimensional stability. One reason for this is the low temperature gradient on the coke-side protective shield due to the thin-walled protective shield, and secondly the special profile of the protective shield. Otherwise, the additional protective shield counteracts deformation and bulging of the protective shield on the coke side. As a result, the wall thicknesses of the protective shields according to the invention can be made considerably thinner than known protective shields. This has two main advantages: firstly, that reduces the temperature gradient in the above sense, secondly, the invention is moderate protective shields with sufficient dimensional stability overall lighter than the known protective shields.

The connection of the same protective shields is particularly advantageous. According to the invention, these are then preferably arranged in mirror symmetry. This gives the protective shields additional dimensional stability. The protective shield on the door body counteracts any deformation and bulging of the coke-side protective shield. Cross-sectional geometries with different moments of resistance are preferably selected according to the invention. This means that the protective shield on the door body side has a greater section modulus than in the opposite direction against deformation directed away from the coke. This gives the restoring forces of the additional protective shield an additional effect.

As a result of the mirror-symmetrical design of the protective shields, the coke-side protective shield can be replaced if damaged against the door body-side protective shield and vice versa.

Different profiles can also be combined with one another. This can be used to increase the resistance moments of the protective shield on the door body side.

Because of the light construction and the problem-free manufacture of the shield construction, the protective shields according to the invention are generally less expensive than known other protective shields.

When using multi-part molded sections composed of wefts there are similar advantages according to the invention. A gas channel open on the narrow sides is created between the shields. The profiles forming the shields are advantageously arranged in such a way that - seen in longitudinal section - at least two protective shields composed of wefts are arranged one behind the other. The other versions refer to two shields, but apply accordingly to 3 or more shields or corresponding shots with the same number of profiles.

Using at least two profiles according to the invention, the shots can be made considerably longer compared to the multi-part protective shield known from DE-A-31 05 703. While in contemporary coke ovens with a furnace height of 6 to 7 m, a maximum length of about 1 m is considered to be reliable for the shots of a known sign, shots according to the invention have a multiple of this length, e.g. B. only three shots for an 8 meter high door. This has considerable manufacturing and handling advantages.

The other explanations apply equally to one-piece and multi-piece protective shields.

A further reduction in costs can be achieved by using cross-sectional profiles for the protective shields, which correspond to the profiles of commercially available steel sheet piling or light profiles or panel profiles.

It has proven to be advantageous according to the invention to arrange the protective shields parallel to one another or inclined to one another over their entire height. In the case of an inclined arrangement, the coke-side protective shield is again arranged vertically so that only the shield on the door body side is inclined. With the inclined arrangement, the different gas pressure in the gas discharge duct can be taken into account. According to the invention, the inclination is chosen such that a pressure loss of 1 mm water column is compensated for every running meter of furnace height.

In addition, in particular the distance between the protective shields can be made changeable by interchangeable spacers which are evenly distributed over the height of the protective shields. Depending on the normal operating conditions, the gas discharge quantities in the gas discharge duct between the two protective shields can also be regulated. Likewise, changing the distance between the protective shields and the door body can influence its temperature load, i. H. a certain desired or permissible door body temperature can be ensured by appropriate distance. On the other hand, the overall distance from the door body can be changed while the distance between the protective shields remains the same, in the same or opposite sense. This allows the flow conditions in both gas discharge channels to be optimized.

To seal the gap between the protective shields and the adjacent chamber walls, it is expedient to movably fasten at least one sealing plate on the sides of the two protective shields, which bears against the chamber walls when the protective shields are lowered. Special sealing plates with obliquely rising oblong holes can be used, through which bolts or spacers are passed between the two protective shields. To simplify assembly and replacement, the sealing plates are optionally provided with open slots on the side towards the middle of the chamber and have bolts or spacers for hanging them up.

For a correct insertion of the coke oven door according to the invention, it is advantageous if the sealing plates in the raised state of the protective shields are moved laterally inwards in the elongated holes or slots; ie are sunk between the protective shields. The sealing plates then move outwards against the chamber walls when the protective shields are put on. This happens, for example, in that the sealing plates protrude below between the protective shields or are provided with a suitable foot or plunger or the like, which forces the shaped profiles when the protective shields are put on, due to the guidance in the oblique slots or elongated holes to the outside on the chamber wall to move. Applying the sealing strips creates an advantageous seal between the protective shields and chamber walls.

The sealing plates are bent or bent sideways on their contact surface with the chamber walls. In a horizontal section through a sealing plate, this results in an S-shaped or Z-shaped or angular cross section. The beveled or bent leg of this cross-section ensures gentle contact with the chamber walls and at the same time gives the sealing plates excellent dimensional stability in the longitudinal direction.

• Figur 1 zeigt einen waagerechten Schnitt durch die erfindungsgemäß in eine Kammeröffnung eingesetzte Tür.
• Figur 2 zeigt einen senkrechten Schnitt durch einen Teil der erfindungsgemäßen Tür.
• Figur 3 zeigt eine Reihe erfindungsgemäß einsetzbarer Schutzschilde im Querschnitt.
• Figuren 4 und 5 zeigen im senkrechten Schnitt die Koksofentür mit verschiedenen Abständen zwischen den Schutzschilden.
• Figur 5a zeigt eine erfindungsgemäße Tür mit mehrteiligen Schutzschilden.
• Figur 6 zeigt ausschnittweise die Schutzschilde mit Dichtblechen im angehobenen und gesenkten Zustand in der Koksofenkammer.
• Figur 7 zeigt wie Figur 1 einen waagerechten Schnitt durch ein anderes Ausführungsbeispiel der erfindungsgemäßen Koksofentür.

Finally, it is advantageous to arrange the sealing plates close to the protective shield on the body side. This allows the raw gas to flow unhindered through the gap between the protective shield on the coke side and the chamber walls into the inner raw gas channel. The inflow into the outer gas discharge duct is opposed, however, so that the seal between the door body and the chamber frame is additionally relieved. The invention is explained in more detail in exemplary embodiments with reference to the attached FIGS. 1 to 7.

• Figure 1 shows a horizontal section through the door inserted according to the invention in a chamber opening.
• Figure 2 shows a vertical section through part of the door according to the invention.
• Figure 3 shows a number of protective shields usable according to the invention in cross section.
• Figures 4 and 5 show in vertical section the coke oven door with different distances between the protective shields.
• Figure 5a shows a door according to the invention with multi-part protective shields.
• FIG. 6 shows sections of the protective shields with sealing plates in the raised and lowered state in the coke oven chamber.
• Figure 7 shows like Figure 1 a horizontal section through another embodiment of the coke oven door according to the invention.

In the figures, the furnace chamber with the associated heating or chamber walls is indicated by 1. The door frame 7, against which the sealing element 6 of an inserted coke oven door rests, runs around the vertical opening of the furnace chamber 1. As described for example in DE-A-3 327 337.5, the coke oven door consists of a door body, with a power transmission unit and a sealing unit. The power transmission unit runs as a hollow profile along the door frame and is connected to the door frame at least via a locking device. The locking device is designed as a spring lock. These include locking hooks on the door frame 7 and pivotable locking bars on the door body, which act on the door body 7 via springs or power pistons. The sealing unit has a sealing plate 5. which is pressed against the door frame at the periphery of the door frame by means of many evenly distributed and spring-mounted screws 4. 5a denotes a cover that serves for insulation. To improve the thermal insulation towards the outside, the sealing plate 5 can be designed as a hollow profile, the hollow profile being filled with insulating compound 5b. The sealing plate can be provided with a one-sided bulge according to Figures 1 and 7 to the outside. On the inside of the sealing plate 5, angle irons are attached distributed over the height, of which angle irons 15 are screwed with screws 16 to further angle irons 14, which in turn are connected to a shaped profile 9 as an external protective shield. The connection between the shaped profile 9 and the angle iron 14 is made by hanging the shaped profile 9 with suitable hooks 9 a on the angle iron 14.

Instead of the angle iron 15, flanges or other profiles or screws can also be used. Another shape profile is attached to the shape profile 9 in mirror image as a protective shield by means of bolts 13 with spacers. In FIGS. 1 and 2, the positions of the shaped profiles are shown at a greater distance from one another at 18, 19 in dashed form. In Figures 4 and 5, the difference between the smaller and larger distance between the shaped profiles from each other is made clear.

Except for the explanations in FIGS. 4 and 5, the explanations also apply analogously to protective shields which are composed of several shots.

According to FIG. 5a, several shots are arranged one above the other in a protective shield.

The shaped profiles of the inner protective shield 8 forming the wefts overlap, while the shaped profiles of the outer protective shield 9 abut one another with sufficient play for thermal expansion.

In the exemplary embodiment, the distance between the inner protective shield 8 and the sealing surface between the door body and the door frame 7 is 400 mm. The distance between the two protective shields is 120 mm. This corresponds to the usual stone plug depth. In practice, depending on the mode of operation of the coke oven, the ratio of the distance between the two protective shields 8 and 9 to the distance between the outer protective shield 9 and the sealing surface between the door body and the door frame 7 is between 1: 1 and 1:10, preferably between 1: 3 and 1 : 5.

A number of possible cross sections for the shaped profiles are shown in the figure. The shaped profiles can be rolled in one piece and / or folded and / or bent, or can be composed of several parts. The parts can be screwed or welded. In the simplest case, the shaped profiles are designed as smooth sheets. The cross sections according to FIG. 3 are advantageous. While, according to FIG. 1, the shaped profiles are laterally connected to one another in cross section and have bulges in the middle between the connection points. it is reversed according to Figure 3.1. The shaped profiles according to FIG. 3.1 have a small distance in the middle and the shaped profiles are ver there with each other via the bolts 13 bound, while they are at a greater distance from the outside of the chamber walls. The protective shields then again run parallel to each other on the outside. The protective shields can also be curved in the form of a circular arc towards the chamber walls or angularly bent outwards according to FIG. 3.6.

According to FIG. 3.7, the ends are first curved outwards in the form of a circular arc and then again inwards in a semi-circular manner, so that the ends are directed towards one another. Figures 3.1 to 3.4 also contain various middle bulges, which are triangular, semicircular or trapezoid-like on the outside.

3 can be used together. I.e. it can be z. B. Combine the shape profile 8 of Figure 3.1 with the shape profile 9 of Figure 3.2. This preferably serves to increase the section modulus of the shield construction. Finally, FIGS. 6 and 7 show additional sealing plates 24 which are provided with elongated holes 25. In the exemplary embodiments, only one row of sealing plates is provided between the two shaped profiles 8 and 9. Instead of the one row, however, several rows of sealing plates can also be arranged one behind the other between the shaped profiles 8 and 9, or can be distributed over a plurality of shaped profiles arranged one behind the other. The sealing plates 24 are as close as possible to the outer molded profile 9 in order to hinder the gas entry into the outer raw gas channel between the molded profile 9 and the door body and to relieve the sealing member 6.

FIG. 6 shows the raised state of the shaped profiles in the left half. The sealing plate 24 has moved away from the chamber wall 2 in the raised state or has been pressed inwards and downwards by a plunger 26. It protrudes below the shape profile.

In the right, lowered state of the shaped profiles, the protective shields and sealing plates 24 stand on the furnace sole and the sealing plate 24 has leaned against the chamber wall 2. The sealing plate movement is up to 60 mm compared to the shaped profiles 8 and 9. The gap between the shaped profiles 8 and 9 and the chamber wall 2 is up to 20 mm in the exemplary embodiment, depending on the width of the coke oven chamber. e.g. B. 15 mm gap are provided with an average chamber width of 45 cm.

7 shows the S-shaped shape of the sealing plate 24, the sealing plates resting against the inside of the outer molded profile 9 and outside a vertical gap for the gas passage remaining between the molded profile 8 and the sealing plates.

The various sealing plates 24 of the three shots of multi-part protective shields shown in FIG. 5 a are optionally connected to one another via joints which, when the door is placed in the furnace chamber, transmit the upward movement of the lowest sealing plates 24 to the sealing plates arranged above them. The same applies to the downward movement. I.e. Should a sealing strip hesitate to detach itself from the chamber wall by moving downwards when lifting the door, this resistance is overcome by the weight of the other sealing strips. Hinges with two hinge joints can serve as joints, which secure a power transmission in the vertical direction and leave freedom of movement horizontally in the longitudinal direction of the furnace chamber.

Claims (21)

1. Door for a coke oven with horizontal chambers, having an integral or multiple-part protecting shield combined with the body of the door, extending into the oven chamber, which also serves as a heat shield, above which the oven filling is maintained at a given spacing from the body of the door, whereby the body of the door, during the coking process, is pressed against the door frame of the oven with a bolting device, characterised in that at least one further integral or multiple-part shield is positioned between the protective shield and the body of the door.

2. Coke oven door according to claim 1, characterised in that an open gas channel runs, between the protective shield and the further shield, at the sides of the shields.

3. Coke oven door according to claim 1 or 2, characterised in that the protective shield and/or the further shield comprises sections (8, 9) extending along the length of the door.

4. Coke oven door according to claim 3, characterised in that the sections (8, 9) are the same and/or are compatible with other sections.

5. Coke oven door according to one or more of claims 1 to 4, characterised in that the sections are of the same form and, on parallel orientation, are symmetrically arranged about a plane therebetween.

6. Coke oven door according to one or more of claims 1 to 5, characterised in that the sections (8, 9) have the profile of steel walls or simple profiles or table profiles of steel construction for underground construction.

7. Coke oven door according to one or more of claims 1 to 6, characterised in that the sections (8, 9) run parallel to one another over the whole height of the protective shield or are inclined towards one another in an upward direction, whereby the coke side of the shield is again perpendicular in the inclined orientation.

8. Coke oven door according to one or more of claims 1 to 7, characterised in that the spacing between the sections (8, 9) is variable.

9. Coke oven door according to claim 8, characterised in that the sections (8, 9) are provided with interchangable spacing means (12) uniformly distributed over the height of the sections (8, 9).

10. Coke oven door according to one or more of claims 1 to 9, characterised in that the spacings, between the body of the door and the intermediate section (9) on the one hand, and the intermediate section (9) and the section (8) on the coke oven side on the other hand, are independently variable.

11. Coke oven door according to claim 10. characterised in that the ratio of the spacing of the coke-side section (8) to the intermediate section (9) on the one hand to the spacing of the intermediate section (8) to the surface of the chamber frame with the body of the door on the other hand is between 1 : 1 to 1 : 10, preferably 1 : and 1 : 5.

12. Coke oven door according to one or more of claims 1 to 11, characterised in that sheets (24) are movably secured between the sections (8, 9) and the chamber walls (2) bounding the sides of the sections (8, 9), in which the plates lie on the chamber walls (2) on lowering of the sections (8, 9) and, on the coke side, leave the gas channel open.

13. Coke oven door according to claim 12, characterised in that a plurality of sheets (24) are arranged behind one another.

14. Coke oven door according to claim 13, characterised in that the sheets (24) are provided with diagonal elongate holes through which bolts (13) and/or spacing means (12) for the two sections (8, 9) are passed.

15. Coke oven door according to claim 14, characterised in that the sheets (24) include open slits lateral to the middle of the chamber.

16. Coke oven door according to one or more of claims 14 or 15, characterised in that the sheets (24) in the raised state project over the sections (8, 9) on their under edge and are displaced on lowering the sections (8, 9) upwardly against them and laterally against the chamber walls (2).

17. Coke oven door according to one or more of claims 13 to 16, characterised in that orthogonally-acting tappets (26) are positioned at the upper edge of the protective shield, and against which the sheets (24) are pressed on raising the sections (8, 9) from the chamber walls (2) away towards the centre of the chamber.

18. Coke oven door according to one or more of claims 13 to 17, characterised in that the sheets (24) are shaped, preferably as a doubling-back, along their orthogonal longitudinal edges.

19. Coke oven door according to claim 18, characterised in that the sheets (24) are S-shaped.

20. Coke oven door according to claim 19, characterised in that the sheets (24) are adjacent to the intermediate section (9).

21. Coke oven door according to one or more of claims 13 to 20, characterised in that the sheets (24) comprise a plurality of sections, in the vertical direction.

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