[0001] The invention relates to a method of repair of a coke-oven battery during operation
in which at least one coking chamber is taken out of operation and emptied, is repaired
and reintroduced into operation. The invention also relates to a panel for use in
the method.
[0002] A coke oven battery of a type conventional in practice consists of a structure made
of refractory material with coking chambers arranged within it. A plurality of combustion
chambers are arranged between each adjacent pair of coking chambers. The coking chambers
generally each measure approximately 45cm wide, 4 to 6 m high and about 10 m long.
The side walls of the coking chambers are generally made of silica bricks. The overall
coefficient of expansion of the silica material is such that the material has about
1% expansion from room temperature to 500°C, and a further expansion of around 0.1%
from 500°C to the operating temperature, which is around 1200°C.
[0003] Silica's expansion characteristic makes it an ideal material when the battery is
in operation, because when the coke is pushed out at the end of the coking period
and the coking chamber is subsequently refilled with coking coal, the temperature
of the refractory material undergoes a temporary reduction without falling. below
500°C, which means that the refractory material only contracts and expands to a slight
degree. This means that cracks do not readily form.
[0004] These temporary reductions in temperature do however cause hairline cracks which,
in the case of the side walls of the coking chamber, expand in the course of time
to form larger and deeper cracks. These cracks are a cause of gas leakage between
the combustion chambers and the coking chambers.
[0005] When repairing a coking chamber, for instance the cracks in the side walls thereof,
it is necessary to work inside the coking chamber. For this purpose, the temperature
of the coking chamber needs to be greatly reduced, which means entering the temperature
range below 500°C in which the silica material undergoes substantial contraction.
This causes fresh and larger cracks in the side walls. Through these cracks, there
will be further gas leakages between the combustion chambers and the coking chamber,
when the chamber is brought back into operation, and in extreme cases the stability
of the side walls may be endangered.
[0006] It has been proposed to line the walls of a coking chamber, which is to be repaired,
with insulation, in order that a person may enter it while the battery remains in
operation. See US 2 179 635, DE 2 274 552 and DE 2 112 729. This practice is not wholly
satisfactory, because the temperature of the working space remains uncomfortably high.
The worker has to wear insulating clothes, which is very inconvenient in the confined
space. Intensive ventilation of the space is needed, in order to reduce the temperature
of the air which the worker breathes. Furthermore, in practice, it is found that reduction
of the firing in adjacent combustion chambers is needed. The insulation layer may
be rather thick (e.g. 7.5cm as disclosed in US 2 179 635, reducing the room available
for working.
[0007] The invention has as its object to provide a method of repair of a coke-oven battery
during operation in which the conditions for the worker in the insulated coking chamber
are improved, and particularly in which the temperature of the air in which he works
approaches room temperature.
[0008] According to the present invention, the insulation material includes at least one
panel which comprises a layer of thermally insulating material and ducts through which
cooling fluid is passed during the repair operation. The panel is located against
a side-wall of a coking chamber, with the insulating layer adjacent the wall and the
ducts on the inside with respect to the working space.
[0009] The combination of an insulating layer and cooling by means of a fluid is a considerable
improvement over the prior art proposals. In this way it is possible to reduce the
temperature in the working space to for example 20°C, while the side-wall temperature
remains above 500°C, and yet leave sufficient room within the chamber for the worker
to carry out the necessary repairs. Working conditions are improved because insulating
clothing and forced air ventilation are not required. It is also not necessary to
reduce the degree of firing in neighbouring combustion chambers, so that thermal disturbance
of the coke-oven battery is reduced.
[0010] Fluid cooling is known in a screen providing protection for workmen (see US 3 550
679). However it is the combination of an insulating layer and fluid cooling which
is surprisingly effective in the present invention, and can achieve about room temperature
in the working space even with a relatively thin panel (e.g. 5cm).
[0011] There are various possible ways of using the panels to create the screened-off space.
For example, several panels may be positioned alongside one side wall. It is also
possible for one panel only to be positioned alongside one side wall. One or more
panels may be used to create a screened-off space without being positioned alongside
a side wall. Insofar as the working space is not screened off from the hot coking
chamber walls by means of panels, this may for example by effected with blankets of
insulating material or the like.
[0012] In many cases, the repair affects one coking chamber only. It is then preferable
to create a screened-off space inside the chamber using panels positioned alongside
both hot walls of the chamber. When it is necessary to repair the side walls between
more than one coking chamber however, the screened-off space should preferably be
created in two or more adjacent coking chambers and the panels positioned alongside
the two outermost side walls of the group of adjacent coking chambers.
[0013] Where the refractory material of the side walls is silica, it is preferable for the
temperature of each side wall alongside which a panel is located to be maintained
at a minimum of 500°C.
[0014] One possible way in which the method may be executed consists of moving the screened-off
space within the coking chamber during the repair operation. For this purpose it is
proposed more specifically that the screened-off area is movable longitudinally in
the coking chamber.
[0015] The panel used in the method of the invention is preferably provided with at least
one working opening through which work on the wall behind can be performed. Preferably
each opening of this type is capable of being closed individually.
[0016] In view of the relatively small width of a coking chamber, the area in which the
repair is effected may be narrow. In order to have as much space available as possible,
the preferred choice for the cooling fluid is water, which will serve to minimise
the thickness of the screen. The use of the insulating layer, outside the water carrying
ducts, minimises the risk of contact of the water with the hot walls of the chamber.
[0017] Preferably the panel ducts comprise a number of parallel pipes, which may be rigidly
linked together by connecting elements. In order to keep the panel as thin as possible,
the pipes are preferably rectangular in cross-section. The connecting elements may
also be rectangular in cross-section and these elements may be connected to the ducts
by means of welding.
[0018] One useful form of panel has a U-shape, such that one face of the panel has mutually
opposed regions.
[0019] Preferred embodiments of the invention will now be described by way of non-limitative
example and with reference to the accompanying drawings, in which:-
Fig. 1 is a graph showing the relation between expansion and temperature for the material
silica.
Fig. 2 shows a coke-oven battery in the course of repair by a method embodying the
invention, in horizontal cross-section on line II-II in Fig. 3.
Fig. 3 is a vertical cross section on line III-III in Fig. 2.
Fig. 4 shows a battery in the course of repair by a second method embodying the invention,
in horizontal cross-section on line IV-IV in Fig. 5.
Fig. 5 is a vertical cross-section on line V-V in Fig. 4.
Fig. 6 shows a battery in the course of repair by yet another method of the invention,
in a horizontal cross-section on line VI-VI in Fig. 7.
Fig. 7 is a vertical cross-section on line VII-VII in Fig. 6.
Fig. 8 illustrates a panel of the invention for use in the repair of a coke-oven battery.
Fig. 9 is. a side view of the panel of Fig. 8, as indicated by arrow IX in Fig. 8.
Fig. 10 is a cross-section of the panel of Fig. 8 on line X-X in Fig. 8.
Fig. 11 shows a panel of the invention for use in the repair of a coke-oven battery
by the method shown in Fig. 6.
Fig. 12 illustrates the drop in temperature from a side wall to a coking chamber when
using a panel of the invention.
[0020] The graph of Fig. 1 shows a typical expansion of the material silica as a percentage
along the vertical axis, and the temperature in C along the horizontal axis. Once
the material is brought up to a temperature of 500°C, the expansion does not exceed
0.1% over an extensive temperature range above 500°C. When the temperature drops below
500°C, substantial contraction of the material occurs, which has proved capable of
producing cracks in the side walls of the coking chambers of a coke-oven battery made
of thin material.
[0021] The repair of a coke-oven battery by the invention may involve a variety of different
arrangements, a number of which are presented in the following examples. The same
reference numerals are used throughout for corresponding parts.
[0022] Figs. 2 and 3 illustrate an extensive repair to a coke-oven battery. The coking chambers
1 of a part of a coke-oven battery 2 are in a refractory material structure which
also comprises the combustion chambers 3. The coking chambers are bounded by their
side walls 4, and are closed during charging of the coking coal and coking period
by means of doors 5. In the course of time, predominantly vertical cracks develop
in the side walls, above all in the vicinity of the doors. These cracks may give rise
to leakage of gas between one or more combustion chambers and a coking chamber. Fig.
2 illustrates a situation where the side walls of two adjacent coking chambers are
so severely cracked that a part 6 of the refractory-material structure between them
needs to be demolished and replaced by a new structure.
[0023] Figs. 4 and 5 illustrate a different repair operation, in which the cracks or other
faults which have occurred in the side walls 4 of a coking chamber 1 may be repaired
by injecting refractory material.
[0024] Finally, Figs. 6 and 7 illustrate a special repair. The combustion chambers 3 are
supplied with air and gas through the floor 7 via supply ducts 8. These ducts may
be blocked by fallen parts of the refractory structure in which the combustion chambers
are arranged, so that combustion cannot take place in the combustion chambers, which
means that no heat is supplied to the adjacent coking chambers, and hence coking does
not take place at the point where the combustion chamber is located.
[0025] In each of these repairs, a space screened-off from the hot coke-oven walls is created,
in accordance with the invention, using one or several panels 10.
[0026] Figs. 8,9 and 10 illustrate a suitable panel design. The area available for repair
purposes in a coking chamber is greatly restricted by its minimal width. The flat
panel of the invention has ducts 11 for the passage of a cooling fluid and is provided
with a layer of insulation material on one side 12. The pipes 13 used for the ducts
11 in this embodiment are rectangular with a cross-section of, for example 25 x 50
mm, welded together in a parallel arrangement using cross-connecting elements in the
form of pipes 14 which are likewise rectangular in cross section, measuring, for example
20 x 20 mm.
[0027] The preferred coolant is water. Although its choice as cooling fluid is not obvious
in view of the risk of it leaking into the coking chamber which is still hot, water
is preferred because of its high specific heat and high coefficient of heat, which
enables the cross-section of the ducts to be minimised.
[0028] The preferred material for the insulation layer is a blanket of ceramic fibre with
a high insulating value, such as for example Triton (trade mark) Kao-Wool, mainly
consisting of A1
20
3 and Si0
2 measuring 25 mm thick.
[0029] These measures enable a thin panel to be produced.
[0030] In the panel illustrated, the cooling fluid is supplied through supply pipe 15 to
a supply duct 16 and, after passing through the ducts 11, is discharged via an outlet
duct 18 and an outlet pipe 19. The supply duct 16 and outlet duct 18 are separated
from one another by a partition 20. The pipes 13 are connected to the ducts 16 and
18 and the casing 17 by welding. For design reasons, the connecting pipes 14 do not,
however, run right through to the ducts 16 and 18 and the casing 17 at the point 20a.
[0031] Figs. 2 to 7 show the repairs being effected by a person 27 in a space 26 screened
off from the hot coke oven walls which has been created by using at least one panel
10 of the type illustrated in Fig. 8.
[0032] In the repair shown in Figs. 2 and 3, two panels 10 are positioned alongside the
respective outermost side-walls 4 with the layer 12 of insulating material on the
side of the panel 10 which faces towards the side walls. These panels extend the full
height of the side walls. The parts of the two coking chambers which are not being
repaired are partitioned off by temporary walls 22 covered with insulation material
25. Much thicker and therefore less vulnerable walls are formed by the oven roof 23
and generator roof 24. This serves to create a screened-off space 26 in which the
worker 27 can demolish and relace the part 6 of the refractory material. structure.
[0033] In the repair shown in Figs. 4 and 5, a similar screened-off space 26 is created
in a single coking chamber. In this case, however, one panel 28 has a working opening
29 which may be closed by a door 31 which pivots on an axis 30. A person 27 in the
screened-off space 36 may thus carry out repair through the opening 29, e.g. using
injection techniques. The panel or panels may contain several of these working openings
which as desired may or may not be capable of being closed. Provision is made for
the screened-off space to be moved within the coking chamber. In this instance it
is proposed more specifically that the screened-off area be moved in a horizontal
direction longitudinally of the chamber as indicated by arrows 32.
[0034] In the repair shown in Figs. 6 and 7, the side walls 4 are covered for part of their
height by a panel 10 and a panel 28 with a working opening 29. The top and bottom
boundaries of the working space 26 are constituted by a panel 33 of the design shown
in Fig. 11, which contains pipes 13 and 14 as shown in Fig. 8 but these are bent in
this case into a U shape to form a U-shaped panel 33, which is provided with a layer
12 of insulation material on the outside.
[0035] The screened-off space 26 (see Figs. 6 and 7) formed by the panels 10,28 and 22 may
easily be moved within the coking chamber in the direction indicated by the arrows
32 for instance using rollers or rails as shown at 34. In order to keep the side walls
above the screened-off space 26 at a sufficiently high temperature, an insulation
partition is temporarily fitted in the door opening to the coking chamber above the
screened-off space. During the repair operation, a person 27 in the space 26 takes
a part of the refractory structure, e.g. a brick, out of the side wall through the
working opening 29, thus enabling the combustion chamber to be cleaned, after which
the repair opening 35 made in the side wall is closed again. After this, it is possible
to clean another combustion chamber by moving the screened-off space within the coking
chamber until the working opening reaches the point where the next combustion chamber
is located. It should be noted that in this case, the panels 10,28 and 33 used to
form the screened-off area 26 lend themselves to being joined together outside the
coke-oven battery in advance to form a screen 9 which may be installed inside the
coking chamber in its entirety following emptying of the chamber. This enables the
time required for the repair operation to be kept to a minimum. A screen 9 of this
type may be kept permanently available for repairs.
[0036] Fig. 12 illustrates the drop in temperature 36 from a side wall 4, through a panel
10 positioned alongside this side wall, to a coking chamber. The dimensions of the
panel and the extent of the cooling action of the fluid in the cooling duct system
11 are such that the conditions created on the side of the panel facing away from
the side wall 4 in the working space 26 are suitable for personnel to carry out repair
operations therein. If additionally necessary, the area is ventilated. The major part
of the temperature drop occurs in the layer of insulation material 12. The surface
temperature of side wall 4 is at least 500°C. This protects the side wall from the
adverse effects of the excessive cooling.
1. A method of repair, during operation, of a coke-oven battery having coking chambers
(1) with refractory side walls (4), wherein a screened-off working space (26), which
extends over at least part of at least one coking chamber is created in the battery
by means of thermal insulation material (10,12) applied against side-walls of the
coking chamber or chambers so as to maintain those side-walls at a high temperature
while the temperature in the working space is reduced sufficiently to allow the repair
work to be performed,
characterised in that:
the said insulation material includes at least one panel (10) which comprises a layer
of thermally insulating material (12) and ducts (13) through which cooling fluid is
passed during the repair operation.
2. A method according to claim 1 wherein the cooling fluid passed through the panel
(10) is water.
3. A method according to claim 1 or claim 2 wherein the said insulating layer (12)
of the panel is applied against the side-wall (4) of the coking chamber and the said
ducts (13) are located on the inside of the insulating layer (12) (with respect to
the working space (26)).
4. A method according to any one of claims 1 to 3 wherein said working space (26)
is within a single coking chamber, respective said panels being applied to the opposed
side-walls (4) thereof.
5. A method according to any one of claims 1 to 3 wherein the said working space (26)
extends over a plurality of neighbouring coking chambers, said panels (10) being applied
to the respective outermost side-walls of those chambers.
6. A method according to any one of claims 1 to 3 wherein the refractory material
of the side-walls (4) is silica, the temperature of the side-walls bounding said working
space (26) being maintained at at least 500oC..
7. A method according to any one of the preceding claims wherein, during the repair
operation, the working space (26) is displaced within a coking chamber, by movement
of the insulation material (10,12).
8. An insulating panel for use in a method according to any one of the preceding claims
characterised by a system of ducts (13) for passage of cooling fluid through the panel
(10) and a layer of insulating material (12) arranged on one side of said system of
ducts (13).
9. A panel according to claim 8 having at least one working aperture (29) through
the panel (10), through which a repair operation can be effected.
10. A panel according to claim 9 having means.for closing the or each working opening
(29).
11. A panel according to any one of claims 8 to 10 wherein the ducts (13) are of rectangular
cross-section.
12. A panel according to any one of claims 8 to 11 which is U-shaped, so that one
face thereof has mutually opposed portions (Fig. 11).