FIELD OF THE INVENTION
The present invention relates in general to production of coke in coke oven batteries for
steel making in blast furnaces, and in particular to an improved coke oven battery which is
5.0 M tall. The battery is provided with many inventive features and produces coke for use
in blast furnaces for the purpose of steel making.
This specification is being filed in pursuance of the provisional specification filed in respect of
patent application no. 1061/KOL/2015.
BACKGROUND AND PRIOR ART
Quality blast furnace operation needs high quality raw materials to yield the best quality hot
metal. Coke is one of the most important raw materials that go into the blast furnace. The
quality of coke is therefore of paramount importance in steel making.
The production of coke involves carbonization of coal at high temperatures in the absence of
air. This is done in coke oven batteries. A coke oven battery comprises of a plurality of
ovens. The coke making process generates several by-products which may be solid, liquid,
gaseous in nature. Many of these by-products are toxic and dangerous for the environment.
They have to be handled with great care and control.
Steel making, and therefore coke making is well known through centuries. So the coke
making process has been undergoing many changes for its betterment.
Steel making now takes place mostly in integrated steel plants. These plants use coke oven
batteries for the production of coke. A coke oven battery is a specially designed chamber for
heating coal in the absence of air to generate coke, and also a plurality of by-products as
stated before. In this specification, a coke oven battery is also referred simply as a battery
for brevity.
Although coke oven batteries have been in operation for several decades, the batteries of
the prior art suffer from several drawbacks. Some of them are:
- The sliding of the oven roof poses difficulties in terms of smooth sliding of fireclay
over silica.

- Tendency of fireclay brickwork at oven top of being dragged out along with
expanding silica.
- Heat loss from the battery to oven top and gas leakages from oven roof zone to
atmosphere.
- Ingress of air.
- Sagging of oven roof bricks due to supports of charging car tracks being over oven
portion.
Thus, there is a great need in the industry for a coke oven battery that can produce coke in
a more environment friendly, efficient and economic way. The present invention seeks to
overcome not only the above, but also other drawbacks of the prior art. This will become
clear from the description of the invention that follows.
OBJECTS OF THE INVENTION
The primary objective of the invention is to provide a coke oven battery which offers smooth
sliding of the oven roof brickwork during the course of heating up of battery.
Another object of the invention is to provide a coke oven battery which largely restricts
development of cracks and open joints and the overall integrity of the brick work improves
at oven roof.
Another object of the invention is to provide a coke oven battery which keeps the fireclay
bricks in loaded condition to avoid dragging with silica bricks layer in the horizontal
direction.
A further object of the invention is to provide a coke oven battery which reduces any heat
loss from battery to oven top.
Yet another object of the invention is to provide a coke oven battery which prevents any gas
leakages from oven roof zone to atmosphere.
Another object of the invention is to provide a coke oven battery which prevents ingress of
cold air inside regenerators and arrests any leakage of BF gas / waste gas.

Yet another object of the invention is to provide catenery arrangement of power lines to
avoid sagging of power line and damage of power line caused by naked flame etc.
Another object of the invention is to eliminate the sagging of oven roof bricks with the help
of solid bricks for providing necessary support for charging car track.
How the foregoing objects are achieved will be clear from the following description. In this
context it is clarified that the description provided is non-limiting and is only by way of
explanation.
SUMMARY OF THE INVENTION
An improved 5.0 m. tall coke oven battery of compound, twin flue, under jet, regenerative
type with partial recirculation of waste gases has 69 ovens in single block. It has double gas
collecting mains, one each on pusher side and coke side, its oven roofing consisting of two
layers of silica, four layers of fireclay and one layer of high CCS fireclay. The fireclay bricks
are placed over silica bricks for reducing heat transfer rate towards oven top to maintain
oven top temperature in working range. A sliding joint arrangement is provided between
59th and 60th course at the oven roofing and SS foil is provided between 11th and 12th layers
of filling bricks at oven roofing zone between 62nd and 63rd course of fireclay to further
reduce heat loss and prevent raw coke oven gas leakage from oven top.
A layer of SS foil is provided between mica and fireclay brickwork at regenerator face wall to
prevent ingress of cold air inside regenerators. The SS foil is 0.2 mm thick and conforms to
IS 316L/AISI316.
Two pairs of auxiliary springs are provided on the face of oven roof fireclay brick zone on
both pusher and coke sides to avoid dragging in the horizontal direction and prevent
opening of brick joints in the fireclay zone.
The sliding joint arrangement is made between adjacent layers of silica and fireclay by
providing graphite powder, industrial glycerin and water between the topmost layer of silica
and bottommost layer of fireclay at oven roof zone to facilitate smooth sliding of silica over

fireclay brick with the aid of a pair of auxiliary springs through auxiliary anchorage,
Buckstay and coil springs, channel and a face wall cover plate to prevent any gas leakage.
Solid bricks are provided in every heating wall across the length of heating wall of every
oven for providing necessary support for charging car track.
The catenaries for charging car power lines laid along the centre line of the battery so that
they normally do not come in contact with flames from ascension pipes. Catenary for DE
cars are not supported from individual buckstay (as normal practice without catenary). This
avoid sagging of DE car power line with expanding / deflecting buckstays during operation.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The nature and scope of the present invention will be better understood from the
accompanying drawings, which are by way of illustration of a preferred embodiment and not
by way of any sort of limitation. In the accompanying drawings:-
Figure 1 is the cross section of the coke oven battery according to the present invention in
the elevation view along with the disposition of the Power Conductors of catenary
arrangement with respect to the battery.
Figure 2 is the enlarged view of oven roofing section referred as detail “A” as marked in fig.
1 showing the disposition of the SS foil, sliding joint and the Power Conductors of catenary
arrangement near the coke oven battery.
Figure 3A is the enlarged view of detail “E” of figure 2 highlighting the SS foil at oven
roofing section.
Figure 3B is the enlarged view of detail “F” of figure 2 showing the disposition of the
composite mixture at the sliding joint in between the fire clay and silica bricks.
Figure 3C shows cross-sectional view along section P-P of figure 2 highlighting the SS foil at
oven roofing section.
Figure 3D shows cross-sectional view along section Q-Q of figure 2 highlighting the SS foil
at oven roofing section.

Figure 4 is the enlarged view of detail “C” of figure 1 showing the disposition of the Power
conductors of catenary arrangement over the coke oven battery according to the present
invention near the coal tower.
Figure 5A shows the SS Foil arrangement at the regenerator face wall.
Figure 5B shows the cross sectional view along the line ‘Z-Z’ of figure 5A.
Figure 6 is the enlarged view of detail “D” of figure 1 showing the auxiliary anchorage
system. This figure is also the cross sectional view along the line L - L of Figure 7B.
Figure 7A is the side view of the present coke oven battery along the line ‘Y-Y’ of figure 1.
Figure 7B is the enlarged view of detail “G” of figure 7A highlighting the auxiliary anchorage
system.
Figure 8A is the key plan (along the line ‘X-X’ of figure 1) of catenary supporting structures
for power conductors.
Figure 8B is the elevation view along the line ‘M-M’ of Figure 8A showing the catenary
arrangement of conductors for charging car.
Figure 8C is the elevation view along the line ‘N-N’ of Figure 8A showing the catenary
arrangement of conductors for coke guide car.
Figure 9A shows cross sectional view of charging car track of prior art.
Figure 9B shows the cross sectional view of charging car track of the present invention.
Figure 9C shows the plan of charging car track of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
Having described the main features of the invention above, a brief and non-limiting
description of a preferred embodiment will be given in the following paragraphs with
reference to the accompanying drawings.
In all the figures, like reference numerals represent like features. Further, the shape, size
and number of the devices shown are by way of example only and it is within the scope of
the present invention to change their shape, size and number without departing from the
basic principle of the invention.
Further, when in the following it is referred to “top”, “bottom”, “upward”, “downward”,
“above” or “below” , “right hand side”, “left hand side” and similar terms , this is strictly
referring to an orientation with reference to the apparatus , where the base of the
apparatus is horizontal and is at the bottom portion of the figures. The number of
components shown is exemplary and not restrictive and it is within the scope of the
invention to vary the shape and size of the apparatus as well as the number of its
components, without departing from the principle of the present invention.
All through the specification, the technical terms and abbreviations are to be interpreted in
the broadest sense of the respective terms, and include all similar items in the field known
by other terms, as may be clear to persons skilled in art. Restriction or limitation if any
referred to in the specification, is solely by way of example and understanding the present
invention.
As stated earlier, the improved coke oven battery according to the present invention has
been provided with several new and inventive features. A non-limiting list of these features
is as under:
1. Sliding joint at oven roof: This is provided between 59th and 60th course at oven
roofing.
2. Provision of 2 nos. auxiliary springs for controlling dragging of fireclay brick along
with expanding silica.

3. Provision of SS Foil at oven roof zone between 62nd and 63rd course for preventing
leakage of raw CO gas from oven roof and to reduce the heat loss from battery to
oven top.
4. Provision of SS foil between mica and fireclay brickwork at regenerator face wall for
preventing ingress of air.
5. Changing of charging car track design by providing charging car supports on both
heating walls and ovens.
6. Elimination of provision of hollow bricks above the register brick canal for
withstanding dynamic load of charging car.
7. Changing of material of construction of gas collecting main T pieces and bleeder
pipes from cast iron to mild steel and bleeder water seal to SS from cast iron. This
has been done to reduce rate of corrosion.
8. Provision of catenaries arrangement for charging car and DE car power lines.
The battery (100) according to the present invention has the following specifications.
However, the invention is equally applicable to batteries having other specifications as well.
BATTERY DESCRIPTION:
Figure 1 is the cross section of the coke oven battery (100) according to the present
invention in the elevation view along with the disposition of the power conductors of
catenary arrangement with respect to the battery and Figure 7A is the side view of the
present coke oven battery along the line ‘Y-Y’ of figure 1.
The 5m tall battery (100) is of compound, regenerative type with partial recirculation of
waste gases, twin flue, under jet type. Battery is of 69 ovens in single block. The battery
consists of double gas collecting mains one each on pusher side and coke side. There are 3
numbers of charging holes in each oven. There are two waste heat tunnels one at pusher
side and one at coke side with common tunnel leading to chimney located on pusher side in
the middle of the battery. The heating walls have 15 pairs (30 numbers) of vertical flues.
Oven pushing series is 5-2.
The oven parameters of the battery (100) are given below:


Sliding joint at oven roof:-
Figure 2 is the enlarged view of oven roofing section referred as detail “A” as marked in fig.
1 showing the disposition of the SS foil (1), sliding joint (3) and the power conductors (5) of
catenary arrangement near the coke oven battery.
Figure 3B is the enlarged view of detail “F” of figure 2 showing the disposition of the
composite mixture at the sliding joint in between the fire clay and the silica bricks.
The oven roof of a coke oven battery consists mainly of two types of refractory materials,
namely silica and fire clay bricks. The bottom block of oven roof is made of multiple layers
of silica refractories and upper block is made of multiple layers of fire clay refractories. The
oven roof consists of two layers of silica (4), four layers of fireclay (2) of category – I and
one layer of high CCS fireclay. Fireclay bricks are placed over silica bricks for reducing the
rate of heat transfer towards oven top so as to maintain oven top temperature in working
range. Coefficient of thermal expansion of silica is higher than that of fireclay. Due to large
difference in thermal expansion coefficient, cracks and open joints are developed during the
course of heating up and as a result, problem of gas leakage starts from the oven roof.
Hence to overcome this problem sliding joint is provided between the topmost layer of silica

and bottommost layer of fireclay at oven roof zone. Thus the sliding joint arrangement is
provided between 59th (topmost layer of silica) and 60th (bottom most layer of fire clay
bricks) course at oven roofing. This sliding joint facilitates smooth sliding of fire clay over
silica with the aid of a pair of auxiliary springs to prevent any gas leakage at oven roof
caused by formation of gap between silica and fireclay in that zone. The sliding joint
arrangement consist of 2 mm thick of fire clay mortar, water proof tarred paper of 1 mm
thick and a graphite paste of 1.5 to 2 mm thick. The graphite paste consists of graphite,
service water and industrial glycerin.
Auxiliary springs:-
Figure 6 is the enlarged view of detail “D” of figure 1 showing the auxiliary anchorage
system. This figure is also the cross sectional view along the line L - L of figure 7B.
Figure 7A is the side view of the present coke oven battery along the line ‘Y-Y’ of figure 1.
Figure 7B is the enlarged view of detail “G” of figure 7A highlighting the auxiliary anchorage
system.
The battery anchorage system consisting of Buckstays, flash plates, Cross and Longitudinal
tie rods, Auxiliary anchorage, springs, etc. The anchorage system maintains a positive
pressure on the refractory to avoid opening of joints or cracks due to temperature changes.
Due to differential expansion between silica and fireclay there is a tendency at the sliding
joint not to facilitate smooth sliding due to dragging. To prevent this dragging 2 (two) pairs
of auxiliary springs are provided on the face of oven roof fireclay brick zone on both the
pusher and coke sides to keep the fireclay bricks in loaded condition and avoid dragging of
fireclay zone by silica brick work in the horizontal direction. This prevents the opening of
brick joints in the fireclay zone; otherwise the same will cause leakages. In the auxiliary
anchorage (9), load is transmitted to the brick work from Buckstay (10) through coil
springs, channel and a face wall cover plate. Face wall cover plate is hanged from the top of
the brickwork. Bearing planes on the face wall cover plate for the spring assembly is
lubricated by graphite lubricants. These springs are provided to have smooth sliding of silica
bricks below fireclay brick without dragging the fireclay brick. These springs have a

tendency of getting loosened due to dragging of silica below fireclay. Hence these springs
are always kept tightened with a load of 2T to 2.5 T to arrest any sliding of brick at roof
sliding joint.
The anchorage system is provided to allow expansion of the battery in a controlled manner
during heating. This also facilitates to avoid opening of joints during course of carbonisation.
Provision of SS foil of oven roof zone between 62nd and 63rd course of fireclay:-
Figure 3A is the enlarged view of detail “E” of figure 2 highlighting the SS foil (1) at oven
roofing section. Figure 3C shows cross-sectional view along the line P-P of figure 2
highlighting the SS foil (1) at oven roofing section. Figure 3D shows cross-sectional view
along the line Q-Q of figure 2 highlighting the SS foil (1) at oven roofing section.
This SS foil (1) of 0.2 mm thickness between 11th and 12th layers of filling bricks at oven
roofing zone arrests any heat loss from battery to oven top. It also prevents any gas
leakages like raw coke oven gas from oven roof zone to atmosphere and can also be
considered as pollution control measure.
The material of SS Foil is Cold Rolled Steel, AISI 316L/AISI 316/AISI 316 TI.
In general this is provided for arresting any gas leakage, air ingress, heat loss etc.
Provision of SS foil between mica and fireclay brickwork at regenerator face wall:-
Figure 5A shows the SS Foil arrangement at the regenerator face wall. Figure 5B shows the
cross sectional view along the line ‘Z-Z’ of figure 5A.
A layer of SS foil (1) provided between mica and fireclay at regenerator face wall prevents
ingress of cold air inside regenerators. Besides that it also helps in arresting any leakage of
BF gas / waste gas. This provision can be well considered as pollution control measure as
well as measure for reducing energy consumption.

The SS foil used for the above features are with dull stain surface finish, 0.2 mm thick and
are as per IS 316L/AISI316.
Changing Of Charging Car Track With Load On Heating Wall:
Figure 9C shows the plan of charging car track of the present invention.
In prior art, supports of charging car track (6) were taken from oven portion Later on it was
observed that this causes sagging of oven roof bricks in long run and accordingly
modification was done by providing support of charging car track on both oven and heating
walls.
Charging car track consisting of rail compatible with charging car is securely fixed over oven
top. Charging car track support (wheel load of approx 16t) is such that the brick underneath
do not crumble and adjacent flue hole frames do not get disturbed. The chair plate is easily
replaceable.
Heating wall being a solid support can easily bear the load of the charging car track and
charging car.
Oven contains empty space under the oven roof bricks. Hence, the charging car support has
been shifted from oven to heating wall for uniform distribution of load on oven roof as well
as on vertical flue. For this purpose base plate has been provided. Now these plates
distribute the load of charging car track and car uniformly among the oven roofing
brickwork thereby preventing crushing of oven roofing brick.
Elimination Of Provision Of Hollow Bricks:
In prior art, a layer of hollow bricks is provided in every heating wall across the length of
heating wall (best shown in figure 9A). In the present invention, upper resistor brick
channel (the hollow bricks) are replaced with suitable solid bricks for providing necessary
support for charging car track (6) (best shown in figure 9B). Apart from this, 32 mm groove
is provided through buttress to buttress at oven top paving to accommodate under rail
plate. Quality of fireclay bricks below charging car track is changed to high CCS category.

Fabricated GC Main Tee Pipe:
Gas collecting (GC) Main Tee Pipe is located at the connection between Gas Collecting Main
and Cross Over Main.
GC Main T pieces were earlier made with cast steel is 1030:1998 Gr: 230-450W. The cast
steel made T-pieces was found to be corroded within a short period of use. Inconvenience
were being experienced in casting flanges at three side in the Tee pipe. The material of
construction of said tee pipe has been changed from cast steel to M S (mild steel) to solve
the aforesaid problem. The material of the M S flanges is IS 2062:E250A:Gr.A. Material of
construction of Bleeder water seal has been changed from cast iron to stainless steel.
Catenery arrangement for charging car and DE car power line:-
Figure 4 is the enlarged view of detail “C” of figure 1 showing the disposition of the Power
conductors of catenary arrangement for charging car over the present coke oven battery
and near the coal tower (8).
Figure 2 is the enlarged view of oven roofing section referred as detail “A” as marked in fig.
1 showing the disposition of the Power Conductors of catenary arrangement for coke guide
car near the coke oven battery.
Figure 8A is the key plan (along the line ‘X-X’ of figure 1) of Catenary Supporting Structures
(7) for Power Conductors.
Figure 8B is the elevation view along the line ‘M-M’ of Figure 8A showing the catenary
arrangement of conductors for charging car.
Figure 8C is the elevation view along the line ‘N-N’ of Figure 8A showing the catenary
arrangement of conductors for coke guide car.

Technical Specifications of Catenery arrangement:
a) Charging car power lines: In prior art batteries, supports were taken from
ascension pipe / GC main area for charging car power lines. These power lines
were prone to frequent damages due to the naked flame coming out from the
ascension pipes during pushing.
In this invention, catenary arrangement has been made to overcome this
problem. Catenaries (5) are laid along the centre line of the battery and they
normally do not come in contact with flames from ascension pipes.
b) Catenery arrangement for DE Car power line:-
Earlier, supports for DE car power line were taken from the top of buckstays. The
alignment of buckstays was frequently disturbed due to improper loading, blazing
as well as residual expansion of battery which generally varies from heating wall
to heating wall. As a result, frequent problem like sagging of power line, falling of
DE car power collectors. etc. were encountered. In the present invention
however, the problem has been resolved after introduction of the catenaries.
Catenary Power supply system for Coal Charging Car & Coke guide car consisting of
following accessories:
• Catenary wire (4 lines), 12 mm GI wire rope steel core.
• Power Conductor (4 lines), Hard drawn Cu conductor of 12 mm dia.
• Sectionalizers Assembly.
• End Termination complete Assembly.
• Dropper Wire Assembly (Considering end termination at intermediate End Bench
between to two adjacent batteries)
• Self-Tensioning of power conductor.
• Solid Joint Assembly.
• Counter weight.

Technical Specification of Catenary wire :
(i) Catenary Wire: The catenary wire will be of 12 mm diameter GI wire rope,
having tensile strength not less than 1250 Kg. individual strands will be
perfectly smooth and will be of uniform diameter all through out.
(ii) Dropper Assembly : The Power conductor wire will be connected with the
dropper assembly by means of brass clamps. The clamp will have and eye
bolt for fastening the dropper wire of charging car. Guide car dropper
assembly will have one insulator having eye-bolts at top for fastening the
dropper wire. Other side of the insulator will have M16 bolt for fixing to brass
clamps. At the point of fixing with catenary dropper clip power conductor
clamp and insulator the dropper wire will be clamped using clamps made of
G.I. The dropper wire will be of variable length to be adjusted at site.
(iii) Sectionaliser: The sectionaliser will be independently supported type at
suitable interval consisting of ISMC 100 x 500 plates. Rail, turn buckles,
shackle insulators, supporting insulators, feeding terminals etc. The
sectionaliser will be straight and rails perfectly leveled.
(iv) End Terminations: End termination for both catenary wire and power
conductor will be at suitable locations with turn buckles and shackle insulators
of adequate strength complete with end clamp, hook, bolt etc.
(v) Self Tensioning of Power Conductor : Self tensioning of power conductor of
charging car will be provided at the sectionaliser assembly under load lifting
device/Portal structure at end bench to maintain a tension of 1250 kg by
means of counter weights.
The present invention has been described with reference to some drawings and a preferred
embodiment purely for the sake of understanding and not by way of any limitation and the
present invention includes all legitimate developments within the scope of what has been
described herein before and claimed in the appended claims.

We claim:
1. An improved 5.0 m. tall coke oven battery (A) of compound, twin flue, under jet,
regenerative type with partial recirculation of waste gases and having 69 ovens in
single block has double gas collecting mains, one each on pusher side and coke side,
its oven roofing consisting of two layers of silica (4), four layers of fireclay (2) and
one layer of high CCS fireclay, the fireclay bricks being placed over silica bricks for
reducing heat transfer rate towards oven top to maintain oven top temperature in
working range, a sliding joint (3) arrangement being provided between 59th and 60th
course at said oven roofing and SS foil (1) being provided between 11th and 12th
layers of filling bricks at oven roofing zone between 62nd and 63th course of fireclay
to arrest any heat loss from battery to oven top.
2. The coke oven battery (A) as claimed in claim 1, wherein a layer of SS foil (1) is
provided between mica and fireclay brickwork at regenerator face wall to prevent
ingress of cold air inside regenerators and helps in arresting any leakage of blast
furnace gas / waste gas, in case of regenerator choking.
3. The coke oven battery (A) as claimed in claims 1 and 2, wherein said SS foil (1) is
0.2 mm thick and conforms to IS 316L/AISI316.
4. The coke oven battery (A) as claimed in claim 1, wherein two pairs of auxiliary
springs are provided on the face of oven roof fireclay brick zone on both pusher and
coke sides to avoid dragging in the horizontal direction and prevent opening of brick
joints in the fireclay zone.
5. The coke oven battery (A) as claimed in claim 1, wherein said sliding joint (3)
arrangement is made between adjacent layers of silica and fireclay by providing
graphite powder, industrial glycerin and water between the topmost layer of silica
and bottommost layer of fireclay at oven roof zone to facilitate smooth sliding of
silica over fireclay brick with the aid of a pair of auxiliary springs through auxiliary
anchorage (9), Buckstay (10) and coil springs, channel and a face wall cover plate to
prevent any gas leakage.

6. The coke oven battery (A) as claimed in claims 1-5, wherein solid bricks are provided
in every heating wall across the length of heating wall of every oven for providing
necessary support for charging car track (6).
7. The coke oven battery (A) as claimed in claims 1-5, wherein catenaries (5) for
charging car power lines and DE car power line are laid along the centre line of the
battery so that they normally do not come in contact with flames from ascension
pipes.