Note: Descriptions are shown in the official language in which they were submitted.
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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
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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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3 26982-27
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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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
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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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