CA1270460A

CA1270460A - Door plugs for coke oven doors

Info

Publication number: CA1270460A
Application number: CA000498235A
Authority: CA
Inventors: Wilhelm Holz; Felix Schonmuth; Lothar Metzler
Original assignee: Ruhrkohle AG
Current assignee: RAG AG
Priority date: 1984-12-22
Filing date: 1985-12-20
Publication date: 1990-06-19
Anticipated expiration: 2007-06-19
Also published as: BR8506418A; DE3447187A1; EP0186774A2; JP2641094B2; JPS61155489A; EP0186774B1; AU579911B2; EP0186774A3; DE3565853D1; AU5134685A; SU1616521A3

Abstract

ABSTRACT
The present invention is directed to provide ceramic door plugs on coke oven doors, consisting of a 50 to 100 mm thick plate which is held at a distance from the coke oven door.

Description

~ 7~ 26982-27 The invention relates to door pluys for coke oven doors which are made from ceramic material and are held at a distance from the coke oven door. In the operating condition -the plugs protrude into the oven chamber and hold the oven charge at a specific distance Erom the door body, whereby the door body is pressed against the door frame of the oven during the coking pro-cess by means oE a locking device.
At the beginning of this cen-tury there were both metallic and ceramic door plugs. The door plug known from the German patent 23 83 63 is an example of a metallic door plug.
This door plug is formed by an adjustable protective shield attached to the back wall of the coke oven door, said protective shield being connected to the back of the door through articulated interrnediate members and being moveable relative to the door.
However, metallic door plugs could not gain acceptance.
~his was also the case with ceramic door plugs. Only at the end of the 1920's was an attempt made to use steel in door plugs, namely in the form of a jacket. It was the object of the jacket, among other things, to prevent the build-up of heat at the door ~0 plugs and to form a large gas channel. The large gas channel was advantageous for relieving stress on the door seals, in that the gas was carried off to the gas collecting chamber. This type of door plug is disclosed in German patent 48 92 49.
At the end of the 1970's the idea of using steel for door plugs was again taken up in the Federal Republic oE Germany and the United States. Examples of this are steel plugs known from German Offenlegungsschrift 29 45 017 and a protective shield . ~ - 1 - ~

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made of steel known from U.S. patent ~,086,145. I'hese first attempts to use steel plugs again did not prove successFul during operation, but did encourage further development that was useful under certain conditions. Door plugs in the form of metallic protective shields which were constructed of one piece or of a plurality of parts resulted within the framework of this develop-ment. Thus, the protective shields either extend over the entire length of the coke oven door in one piece or they are made up of several panels.
1~) A substantial problem of metallic protective shields is heat expansion. The heat expansion of metal as compared with ceramic material, makes it necessary that the door plugs have relatively large play in the oven chamber. They would otherwise become fixed in the oven after cooling during ejection of the coke, as a result of the increase in volume caused by the heat expansion. When filling the coke oven, the temperature o-f the protective shields is still relatively low. With the typified large play, this results in fine-grained, and in particular dry, charging material penetrating past the protective shield into the ~0 crude gas channel between the protective shield and the doorO
This leads to blockage of the channel, preventing an adequate drawing off of the resulting crude gas into the gas collecting main situated above in the oven cha~ber, as well as to leakage.
The leaks are caused by unfavourable temperature conditions and the release of gases or precipitation of gases on the sealing surfaces of the coke oven door. After lifting out the oven door, the gas channels must then be laboriously cleaned by hand.

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A further problem of the rnetallic plugs is deformation.
Depending on the design oE the metallic plugs, a sharp inward or outward bulging results. In addition, with the extreme alternating heat load, all types oE steel show permanent deEormations Only high heat-resistant steel can be used, its special alloying constituents making the processiny very difficult.
An advantage of metallic door plugs is the increase in the oven chamber, already described in the German Offenlegungs-schrift 29 45 017. In addition, a greatly expanded gas channel, as can be seen for example, from the German patent 23 83 63, exhibits operating advantages by relieving stress on the sealing surfaces.
The present invention is based on the object of avoidingthe operating difficulties of current metallic door plugs. For this purpose, the invention provides door plugs for coke oven doors, whlch are of ceramic material and are held at a distance from the coke oven door, the door plug, in the operating condition, penetrating into the oven chamber and keeping the oven charge at a certain distance from the door body and the door body being pressed, during the coking operation, by a locking device against the door frame of the oven, characterized by the use of ceramic plates of hydraulically setting refractory concrete,~-the essential constituents of which are aluminium oxide (Al2O3) in a proportion of 40-55~, silicon dioxide (SiO2) in a proportion between 40 and 50% and iron oxide (Fe2O3) in a proportion between 0.5 and 1.5~, the plates having a thickness from 35 to 120 mm.

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4 ~5g~2-27 Depending on the type of ceramic material used, a thick-ness to plate width ratio of 1:3 to 1:20 can result.
In a further embodiment of the invention the ceramic plate consists of exchangeable elements. The exchangeable elements are optionally arranged one above the other and are respectively held in meta] frames. The metal frames are fastened individually, for example with welded girder irons. This permits a simple and easy exchange of the ceramic elements in the event of damage.
1~ Preferably the metal supporting frames are adjustably Eastened to the doors. This occurs by means of suitable girder irons or counter girder irons which are screwed together or fastened together by wedges. If screwed together, elongated holes are provided for adjustment.
The wing of the coke oven door is provided with an insulting layer which prevents the door from heating up and also prevents the high radiation of heat, i.e. heat loss and heat load on the operating personnel.
The ceramic plate may optionally protrude so far into ~0 the oven chamber that the oven charge is held back just as far as with conventional ceramic plugs. However, the adjustability also makes it possible to move back the ceramic plates and thus increase the oven chamber. The respective position of the ceramic plates can also be dependent upon an optimum arrangement with respect to the last heating flue in the coke oven walls.
By using the ceramic plates according to the invention the desired large gas collecting chamber forms behind the metallic . . .
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4a 26982-27 supporting frame, i.e. between the ceramic plate and the insulating layer.
By way of illustration but not limitation embodiments o:E
this invention will be hereinaEter described, with reference to the drawings, in which:

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Figure 1 shows a cross-sectional view through a door plug and a coke oven door.
Figure 2 shows a sectional view of ~che door plug of Figure 1 with several front panels arranged one above the other.
Figure 3 shows fastening points for girder irons for each front panel of the door plug according to Fiyure 1.
Figure 4 shows a section through a fastening point of a front panel of the door plug of Figure 1.
Figure 5 shows a partly sectlonal view of a girder iron 111 held on a panel of a door plug and held on a counter girder iron which is screwed to a coke oven door.
Figures 6 and 7 show the construction of ceramic shields.
The ceramic plate, numbered 1, is adjustably held in a heat-resistant steel frame 2 with three welded girder irons 3.
Retaining anchors 4 are thereby moulded as connecting elements to the metal frame 2 in the ceramic front panel. The retaining anchors 4 are illustrated by the dot-dash lines. In the exemplary embodiment either one of the following are provided as ceramic ~0 material:
1. material group:
hydraulic binding refractory concrete with high strength and processing-ready for the addition of water

2. thermal values:
maximum application temperature 1480C
thermal conductivity 500C~M 1.54 W/mK
800C~ M 1.55 W/mK
1100C~ M 1.63 W/mk - . ... : .
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Seger cone point of fall SK 31 1695C
reversible heat expansion at 1000C 0.63%

3. analysis:
A123 SiO2 Fe23 50.0% 43.0% 0.8%

4. physical values:
consump-tion of material 2~30 t/m3 bulk density following burning at 1100C 2.26 g/cm3 shrinkage following burning at 1100C 0.55%
cold compressive strength following burning at 1100C 90 ~/mm2 granulation 0 - 7 mm or:
1. material group:
hydraulic binding refractory concrete, low in iron, high in alumina, processing-ready for the addition of water 2. thermal values:
maximum application temperature 1320C
thermal conductivity 500C ~M 0.40 W/mK
reversible heat expansion at 1000C 0.65 3~ analysis:
A123 SiO2 Fe23 46.0% 4700% 1.1%
4. physical values:
consumption of material 1.47 t/m3 bulk density following burning at 1100C 1.45 g/cm3 , . .. ..

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shrinkage followiny burning at 1100C 0.6 cold compressive strength following burning at 1100C 16 N/mm2 granulation 0 - 8 mm The girder irons are held on the counter girder irons 5 which are screwed to the coke oven door. The counter girder irons 5 have elongated holes 9 Eor adjustment of the ceramic front panel 1. Girder irons 3 are fastened to counter girder irons 5 by means of screws or wedges.
As can be seen from Figure 1 and 2, coke oven door 8 is protected from excessive heat load by an insùlating layer 7. The insulating layer 7 again optionally comprises ceramic ma~erial.
When using ceramic material, it is moulded and preferably secured by retaining anchors 10. Retaining anchors 10 are again illustrated by dot-dash lines.
Between ceramic front panel 1 and insulating layer 7 there is a gas channel through which the gases released during the coking process, and which pass between the coke oven wall not illustrated and the ceramic front panel 1, are drawn off into the ?O gas collecting chamber.
According to Figure 2 and 3, a door plug is made up of several front panels 1 arranged one above the other. Girder irons 3 and counter girder irons 5 are respectively located above and ~elow on the metal frame belonging to ceramic front panel 1.
This advantageously permits the use of a counter girder iron 5 simultaneously with two girder irons 3 lying opposite one another.
Furthermore, it is advantageous to provide three fastening points with girder irons 3 and counter girder irons 5 for each front ,, ~ , . .

panel 1 with steel frame 2. As a result, statically deterrnined systems with particularly favourable behaviour under heat load result~ of the three fastening points, one is arranged on the centre line of the coke oven door, and the two other points each lie on either side of the centre line, as is illustrated in Figure 3.
However, four fastening points can also be selected.
They are then located at the four corners of the plates. Each girder iron and counter girder iron can thereby form the fixing device for two adjacent corners of two adjoining ceramic places.
Figure ~ shows a section through a fastening point with two girder irons 3 lying opposite one another and one counter girder iron 5.
To heat a door plug, the gas channel between the plug and the door is closed with mineral wool or the like. Following adequate heating of the plug, this wool is removed from the mould.
According to Figure 6 and 7, the ceramic shields are provided with plates 20 which are each fastened at the four ~0 corners. Girder irons 21 and counter girder irons 22, which are adjustable, again serve as the fixing device. Each girder iron simultaneously forms a fixing device for one plate 20 disposed above it and one plate 20 disposed below it. While the fastening at the upper plate corners takes place non-positively and positively, the fastening at the lower plate corners permits dis-placement in the longitudinal slots in accordance with heat expan-sion. The associated fastening screws are loose. A complete loosening i5 prevented by lock nuts.

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To protect the lower fastening of the plates from the coking coal, the bottom of the plates is pulled in at 23 and the fastening points are covered by edge stones 24. The edge stones 24 are likewise held by the girder irons 21.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

l. Door plugs for coke oven doors, which are of ceramic material and are held at a distance from the coke oven door, the door plug, in the operating condition, penetrating into the oven chamber and keeping the oven charge at a certain distance from the door body and the door body being pressed, during the coking operation, by a locking device against the door frame of the oven, characterized by the use of ceramic plates of hydraulically setting refractory concrete, the essential constituents of which are aluminium oxide (A12O3) in a proportion of 40-55%, silicon dioxide (SiO2) in a proportion between 40 and 50% and iron oxide (Fe2O3) in a proportion between 0.5 and 1.5%, the plates having a thickness from 35 to 120 mm.
2. Door plugs according to claim l wherein the ceramic plates are exchangeable.
3. Door plugs according to claim l wherein the plates are held in steel frames.
4. Door plugs according to claim l, 2 or 3 wherein each door plug is made up of a plurality of plates disposed one above the other.
5. Door plugs according to claim 3 wherein each steel frame is connected to the coke oven door at three points.
6. Door plugs according to claim 1, 2 or 3 wherein girder irons and counter girder irons fasten the plates to the coke oven door.
7. Door plugs according to claim 1, 2 or 3 wherein girder irons and counter girder irons fasten the plates to the coke oven door, and the girder irons are respectively arranged above and below on steel frames and that one counter girder iron is respectively provided for two girder irons lying opposite one another.
8. Door plugs according to claim 1, 2 or 3 wherein an insulating layer made of ceramic material is on the coke oven door.
9. Door plugs according to claim 1, 2 or 3 wherein the thickness to width ratio of the ceramic plates is 1:3 to 1:20.
10. Door plugs according to claim 1, 2 or 3 wherein the ceramic plates are pulled in laterally at the lower end, are fastened at the two upper corners and the two lower corners and that the lower fastening points are covered by edge stones.