FORM 2THE PATENT ACT 1970(39 OF 1970)&The Patent Rules, 2003COMPLETE SPECIFICATION(See Section 10 and Rule 13)
1 TITLE OF THE INVENTION :
A hot coke water quenching system adapted for moisture control in quenched coke
2 APPLICANT (S)
Name : JSW Steel Limited,
Nationality: An Indian Company
Address: Jindal Mansion, 5-A, Dr. G. Deshmukh Marg State of Maharastra. India ,Mumbai - - 400 026,
3 PREAMBLE TO THE DESCRIPTION
COMPLETE
The following specification particularly descibes the invention and the be performed. manner in which it is to

FIELD OF THE INVENTION
The invention relates to water quenching of hot coke and, in particular, to a hot coke water quenching system adapted for moisture control in quenched coke, which would enable effecting uniform and homogenous cooling of the coke bed and avoid temperature variance across the width of the coke bed. The system of hot coke quenching of the invention would also favour effective and optimal utilization of water used for cooling of the hot coke and in the process control the moisture content in the coke after quenching and avoid large variation in the moisture content of the quenched coke. The system of the invention would therefore favour achieving the required controlling of the moisture content in coke to around 4% after quenching and also favour avoiding problems of high moisture content and related adverse effects on fuel rates and productivity in iron making.
BACKGROUND ART
Conventionally the coke making process involves compaction of coke blend into a cake, baking of the cake in the coke - oven at a temperature of 1000 to 1100°C for a duration 48 to 60 hours, followed by the water quenching of the hot cake. If not quenched immediately, after ejection from coke oven (a) part of the hot coke will transform into ash and (b) transportation of coke to its destination is delayed. Therefore, the quenching process is found to have a crucial role in the determination of coke quality and the inventory management.
The existing system for hot coke quenching comprises transferring the hot coke after completion of the baking process of the coke oven to the quench tower for the purpose of water quenching. Usually, such existing quenching systems are provided with a single row of cooling headers lined longitudinally, centrally and parallel to the top surface of the hot coke to effect the quenching from the top surface only. Each header is known to be provided with one nozzle at its end. Total flow rate for such quenching is usually about 21.7 kl /min of water which is distributed through 24 nos. of nozzles of the same type located centrally along the length of the coke bed. Each nozzle is required to spray about 904 l/m»n. of water and the angle of spray is about 45°. Each quenching cycle is known to consume about 72kl of water in 200 s.
It is experienced that the above conventional system used for quenching of coke is found to have certain inherent limitations and deficiencies, which are discussed hereunder.

It would be apparent from the quenching system presently available involving the single row of cooling header lined longitudinally, centrally and parrallely to the top surface of the hot coke with the nozzles disposed at about the center of the coke bed, the same necessarily lead to cooling of the central zone of the coke bed much faster leaving red hot coke along the sides of the bed. This, therefore, leads to in-homogenous cooling of the coke bed, resulting in temperature variation of about 200°C across its width.
The coke soon after quenching is required to be transferred via belt conveyor system to the coke crusher. It is experienced that improperly quenched hot coke can damage the belt of the conveyor system resulting in possible system failure.
Moreover, in order to avoid the hot coke going on to belt conveyor, the water quenching was continued for a long time, such as about 200 s. The excess amount of water on account of long quenching cycle also resulted in large variation in moisture content of the coke say from about 4% to about as high as 13% moisture content. Importantly, such high moisture content in coke is found to adversely affect the fuel rates and the productivity in iron making.
It is thus apparent from the above discussed conventional single row header/nozzle based system used for quenching of hot coke that the same has inherent limitation of carrying out a more uniform cooling of the coke bed across its entire width and therefore necessarily lead to in-homogenous cooling of hot coke bed resulting in temperature variation across the bed. Moreover, the required quenching for a long time of about 200 s. i.e. excess amount of water on account of long quenching cycle further lead to variation in the moisture content of coke which in turn is found to adversely affect the fuel rate and productivity in iron making.
OBJECTS OF THE INVENTION
It is the thus the basic object of the present invention to provide for a system and method of quenching of hot coke which would avoid the afore discussed limitations and deficiencies of conventional quenching systems involving single row of cooling headers/nozzles disposed on top of the center of the coke bed.
Another object of the present invention is directed to control the moisture content of water quenched coke to about 4% after quenching and thereby favour avoiding the problems of high moisture in coke subject to quenching which in turn is found to adversely affect the fuel rate and productivity of iron making.

Further object of the present invention is directed to a system and method of quenching of hot coke which would enable avoiding cooling of only the center of the coke bed much faster and leaving the red hot coke along the sides of the bed to thereby achieve a more uniform and homogenous cooling of the coke bed and avoid temperature variation across the width of the coke bed.
Yet another object of the present invention is directed to a system and method for quenching of hot coke which would enable carrying out the quenching of hot cake across the width of the coke bed property and homogenously and thereby favour proper and safe transfer of the coke soon after quenching to the coke crusher without problems of hot coke damaging the conveyor belt system.
Yet further object of the present invention is directed to a system and method of water quenching of hot coke which would not require carrying out the water quenching for long duration and thereby take care of problems of excess amount of water resulting from long quenching cycle and consequential large variation in moisture content of coke.
A further object of the present invention is directed to a simple and cost effective system and method for quenching of hot coke, which would enable cost effective production of iron.
SUMMARY OF THE INVENTION
Thus according to a basic aspect of the present invention there is provided a hot coke water quenching system adapted for moisture control in quenched coke comprising:
a central first row of cooling headers with nozzles adapted for spraying water fined longitudinally and parallel to the top surface of the coke bed;
an intermediate second row of selectively spaced and centrally disposed T-shaped cooling headers each said header providing a pair of nozzles at its ends for spraying water on either sides with respect to the said central first row of cooling headers;
an end /edge region third row of headers having nozzles for spraying water disposed along the edges of the coke bed, said first ,second and third rows of cooling headers together providing for effective spraying of water over the entire coke bed for substantial homogeneous cooling.

According to another aspect of the invention there is provided a hot coke water quenching system adapted for moisture control in quenched coke comprising:
a central row of cooling headers comprising a first row of cooling headers with single nozzles for spraying water in the central zone (zone I) of the coke bed and a second row of selectively spaced and also centrally disposed T-shaped cooling headers each said T -shaped header providing a pair of nozzles at its end regions which are located on either side and parallel to the first row of headers to favour spraying water in the intermediate zone (Zone n) of the coke bed on either sides with respect to the said first row of cooling headers with single nozzles;
another third row of headers with single nozzles for spraying water disposed along the edges of the coke bed for spraying of water along the end zones of the coke bed (zone HI) to thereby achieve effective spraying of water over the entire coke bed for substantial homogeneous cooling.
In the above disclosed hot coke water quenching systems the said rows of headers are disposed dose on top of the coke bed and disposed parallel to one another with said first and third rows of headers having a single nozzle in the end regions. Preferably, the distance between the coke bed and the nozzles is maintained in the range of 1100 to 1200 mm preferably 1130 to 1180 mm
In accordance with a preferred aspect in the hot coke water quenching system of the invention, the cooling headers and the spray nozzles in said first ,second and third rows are arranged such that the sprayed water is distributed such that the central zone (Zone I) of the coke bed is sprayed with 47 to 51% preferably 49%, the intermediate zone (Zone II) is sprayed with 32 to 38% preferably 35% and the end zone (Zone III) is sprayed with 15 to 20% preferably 16% of the total water flowing for quenching.
In accordance with another preferred aspect the hot coke water quenching system adapted for homogeneous cooling of coke-bed comprises
14 to 15 preferably 14 numbers of said first row of cooling headers with single nozzle;
5 to 6 preferably 5 numbers of said second row of the T shaped cooling headers having said pair of nozzles on either sides of the first row of headers; and
18 to 22 preferably 20 numbers of said third row of headers with single nozzles.

According to another aspect of the invention there is provided a process for water quenching of hot coke adapted for moisture control in quenched coke using the system as disclosed above comprising:
distributing the water for spraying on the hot coke bed for homogeneous cooling across the width of the coke bed such that that the central zone (Zone I) of the coke bed is sprayed with 47 to 51% preferably 49%, the intermediate zone (Zone II) is sprayed with 32 to 38% preferably 35% and the end zone (Zone m) is sprayed with 15 to 20% preferably 16% of the total water flowing for quenching.
In the above disclosed process, the numbers of the first, second and third rows of the headers and its respective nozzles are selectively determined based on the coke to be cooled wherein preferably
14 to 15 more preferably 14 numbers of said first row of cooling headers with single nozzle are used ;
5 to 6 more preferably 5 numbers of said second row of the T shaped cooling headers having said pair of nozzles on either sides of the first row of headers are used; and
18 to 22 more preferably 20 numbers of said third row of headers with single nozzles are used.
The above process of water quenching of hot coke involving the system of the invention would favour controlling the moisture content in coke in the range of about 3.6 to 4.4% preferably about 4 %. The quenching time is reduced in the range of about 59 to 61s preferably about 60s.The quantity of water for quenching is reduced in the range of about 24 to 28 kl preferably about 26kl.
Importantly, the process of the invention enables achieving complete elimination of red-spots after quenching and a uniform temperature all over the bed is achieved in the range of about 60 to 80°C preferably about 70°C.
It is thus possible by way of above disclosed system of the invention to achieve a more homogenous cooling of the coke bed across the width of the hot coke bed and avoid concerns of high temperature variation across the coke bed width. As disclosed above, the system of the invention by way of the selectively provided multiple rows of headers and nozzles would take care of proper distribution of the water sprayed across the width

of the bed during the quenching cycle. In particular, the system enables proper distribution of the water on the coke bed such that the central zone (zone 1) of the bed gets about 47 to 51 % water, and intermediate zone (zone II) gets about 32 to 38% water and end zone (zone in) gets about 15 to 20 % of the total water flow through the system to effect the quenching of the hot coke.
Importantly as apparent from the above, the number of headers/nozzles located around the central zone, the intermediate zone and the end zone of the coke bed can be selectively provided depending upon the coke bed width and constitution to achieve the required target homogenous cooling of the coke bed avoiding long quenching cycle and limit the moisture content after quenching in the range of 3.6 to 4.4 % preferably about 4%.
Advantageously, the T-shaped headers used in the system of the invention favour distributing the water on either side of the Is row of centrally disposed headers with single nozzle. Moreover, such T-shaped header having nozzle on either side of the ends can be provided selectively with respect to some of the headers of the central row of headers of the quenching system. This would on one hand benefit achieving the much required uniform cooling across the width of the coke bed and avoid the unwanted much faster cooling of only the center of the coke bed leading to temperature variation as experienced in the existing systems and on the other hand enable simple and ready adaptation of the existing quenching systems with single row headers into the desired homogeneous cooling multi row header/nozzle based quenching system of the invention.
The third row of headers/nozzles are adapted and selectively disposed towards the edges of the coke bed to effect cooling of the edges of the coke bed, which was not possible by using the existing system of quenching of coke with the single row of cooling header lined longitudinally and centrally on top of the coke bed.
The system of the invention and the method of quenching of coke bed using the same would therefore favour the much desired limiting of the moisture of the quenched coke preferably to about 4% with reduced quenching time and also with optimized and less quantity of water consumption for the quenching purpose. The system of quenching further favours eliminating of red spot after quenching and serves to achieve a more uniform temperature across width of the bed preferably of about 70°C after quenching.

The details of the invention, its objects and advantages are explained hereunder in greater details in relation to non-limiting exemplary illustration as per the following accompanying figures:
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1 : illustrates a conventional quenching system having a single row headers with nozzles of the same type located centrally along the length of the coke bed;
Figure 2 : is an illustration of the quenching system in accordance with the present invention adapted for controlled moisture content in the quenched coke by way of more uniform and homogenous cooling across the width of the coke bed;
Figure 3 : is a graphical representation of the moisture content in coke after quenching using a conventional quenching system with a centrally located single row header and nozzle and that obtained using the quenching system in accordance with a present invention with multiple rows of headers; and
Figure 4 : illustrates the distribution of water as a percentage of total flow across the width of the coke bed with quenching carried out using the system in accordance with the present invention.
Reference is first invited to accompanying figure 1 which illustrates an existing quenching system and ,in particular, the arrangement of single row of headers (HD) and nozzles (NZ) in such available quenching system. As apparent from said figure such existing quenching system usually comprise of a single row of cooling headers lying longitudinally and parallel to the top surface of the hot coke so as to effect the quenching from the top surface only. Each header (HO) is provided with one nozzle (NZ) at its end. The usual total flow rate is found to be about 21.7 kl/min of water which is distributed to 24 nos. of nozzles of the same type located centrally along the length of the coke bed as further illustrated in the said figure. Each of the nozzle (NZ) in such existing system is supposed to spray about 904 l/min of water and the angle of spray is about 45°. The quenching cycle is usually known to consume about 72 kl. of water in 200s.
As would be apparent from the above illustration, such existing quenching system with nozzles located only centrally along with the length of the coke bed cause the center of tiie coke bed to cool much faster, leaving red hot coke along the sides of the bed. This leads to in-homogenous cooling of the coke bed at temperature variation of 200°C across

the width of the coke bed. Also, improperly quenched hot coke at the sides of the coke bed are found to cause damage to the belt conveyor system provided for the transfer of the quenched coke to the coke crusher. Importantly, also the quenching cycle required involving such existing system is long of about 200 s, which leads to excess amount of water and large variation of moisture content in the coke from about 4% to as high as 13%. High moisture content in coke in turn affected fuel rate and productivity in iron making.
Figure 1 also illustrates by way of sectional views the usual operative connection of the headers (HD) and nozzles (NZ) with respect to the main header (MH) in an existing spray nozzle piping arrangement of a conventional quenching system available in the art.
Reference is now invited to accompanying figure 2, which illustrates the quenching system in accordance with the present invention. As dearly illustrated in the said figure the quenching system of the invention in order to achieve more uniform and homogenous cooling of the coke bed across its width is provided with multiple rows of headers and nozzles across the width of the bed and on either side of the centrally located rows of headers and nozzles.
In particular, as illustrated in the figure 2, in accordance with an aspect of the system of the invention, the quenching system can advantageously utilize the centrally disposed single row of cooling headers to achieve a first row and the second rows of cooling header to cover not only the central region of the coke bed but also its adjacent intermediate zone. For such purpose from the existing 24 nos. of central headers (CHD) 5 of the headers are removed and 5 of the existing headers having a single nozzle are replaced with T-shaped header (THD) having nozzle (TNZ) at either of its end. Such 5 T-shaped headers provide for the said second row of water spray on either side from the center of the coke bed.
Additionally, in accordance with system of the invention, a third row of nozzle is introduced parallel to the other headers located towards the edge of the coke bed. Such header can be provided preferably with 20 nos. of nozzles (NZ).
The disposition of the T-shaped headers (THD) and the central headers (HD) alongwith the respective nozzles with respect to the main header (MH), sub-header (SH) and the pipe (PI) are illustrated in greater detail by way of the sectional illustrations also included in the figure.

The hot-coke quenching were carried out using the single row of centrally located header and nozzle of the existing quenching system and multiple row of headers and nozzles disposed along the width of the coke bed as per the quenching system of the invention and the moisture content in the coke after quenching achieved involving the existing system and the quenching systems of the invention were noted. The moisture content achieved and noted is represented further in accompanying figure 3.
As apparent from figure 3 while using the existing quenching system (Trials I to IX) the moisture content in the quenched coke was found to vary in the range of 4 to 13%. On the other hand in use of the quenching system of the invention (Trials X to XV) favouring a homogenous quenching across the width of the coke bed enabled controlling the moisture level in the quenched coke to only about 4%.
Moreover, it was confirmed by way of the above disclosed arrangement of headers and nozzles in the quenching system of the invention to advantageously and optimally distribute the water sprayed on the coke bed such that the central zone (zone 1) gets about 49% of water, the intermediate zone (zone 2) gets about 35% and the end zone (zone 3) gets about 16% of the total water flow. Such distribution of water achieved by the quenching system of the invention across the width of the coke bed is illustrated further in accompanying figure 4.
Moreover, the quenching system and the method of the invention is also found to favour reduction of the quenching time from about 200 s to 60 s and quantity of water consumed for quenching could also be reduced from 72 to 26 kl. The invention thus favours a more uniform temperature of about 70°C all over the bed after quenching with complete elimination of red spots after quenching. Importantly, the quenching system of the invention would favour controlling the moisture content of water quenched coke to about 4% after quenching and thereby favour avoiding the problems of high moisture in coke subject to quenching and favour the fuel rate and productivity of iron making.

We Claim:
1. A hot coke water quenching system adapted for moisture control in quenched coke
comprising:
a central first row of cooling headers with nozzles adapted for spraying water lined longitudinally and parallel to the top surface of the coke bed;
an intermediate second row of selectively spaced and centrally disposed T-shaped cooling headers each said header providing a pair of nozzles at its ends for spraying water on either sides with respect to the said central first row of cooling headers;
an end /edge region third row of headers having nozzles for spraying water disposed along the edges of the coke bed, said first, second and third rows of cooling headers together providing for effective spraying of water over the entire coke bed for substantial homogeneous cooling.
2. A hot coke water quenching system adapted for moisture control in quenched coke
comprising:
a central row of cooling headers comprising a first row of cooling headers with single nozzles for spraying water in the central zone (zone I) of the coke bed and a second row of selectively spaced and also centrally disposed T-shaped cooling headers each said T-shaped header providing a pair of nozzles at its end regions which are located on either side and parallel to the first row of headers to favour spraying water in the intermediate zone (Zone U) of the coke bed on either sides with respect to the said first row of cooling headers with single nozzles;
another third row of headers with single nozzles for spraying water disposed along the edges of the coke bed for spraying of water along the end zones of the coke bed (zone m) to thereby achieve effective spraying of water over the entire coke bed for substantial homogeneous cooling.
3. A hot coke water quenching system as claimed in anyone of claims 1 or 2 wherein
said rows of headers are disposed dose on top of the coke bed and disposed
parallel to one another with said first and third rows of headers having a single
nozzle in the end regions.

4. A hot coke water quenching system as claimed in caim 3 wherein the distance between the coke bed and the nozzles is maintained in the range of 1100 to 1200 mm preferably 1130 to 1180mm
5. A not coke water quenching system as claimed in anyone of claims 1 to 4 wherein the cooling headers and the spray nozzles in said first, second and third rows are arranged such that the sprayed water is distributed such that the central zone (Zone I) of the coke bed is sprayed with 47 to 51% preferably 49%, the intermediate zone (Zone H) is sprayed with 32 to 38% preferably 35% and the end zone (Zone III) is sprayed with 15 to 20% preferably 16% of the total water flowing for quenching.
6. A hot coke water quenching system adapted for homogeneous cooling of coke-bed as claimed in anyone of claims 1 to 5 comprising
14 to 15 preferably 14 numbers of said first row of cooling headers with single nozzle;
5 to 6 preferably 5 numbers of said second row of the T shaped cooling headers having said pair of nozzles on either sides of the first row of headers; and
18 to 22 preferably 20 numbers of said third row of headers with single nozzles.
7. A process for water quenching of hot coke adapted for moisture control in
quenched coke using the system as claimed in anyone of claims 1 to 6 comprising:
distributing the water for spraying on the hot coke bed for homogeneous cooling across the width of the coke bed such that that the central zone (Zone I) of the coke bed is sprayed with 47 to 51% preferably 49%, the intermediate zone (Zone n) is sprayed with 32 to 38% preferably 35% and the end zone (Zone III) is sprayed with 15 to 20% preferably 16% of the total water flowing for quenching.
8. A process for water quenching of hot coke as claimed in claim 7 wherein the
numbers of the first, second and third rows of the headers and its respective
nozzles are selectively determined based on the coke to be cooled wherein
preferably

14 to 15 more preferably 14 numbers of said first row of cooling headers with single nozzle are used ;
5 to 6 more preferably 5 numbers of said second row of the T shaped cooling headers having said pair of nozzles on either sides of the first row of headers are used; and
18 to 22 more preferably 20 numbers of said third row of headers with single nozzles are used.
9. A process as claimed in anyone of claims 7 or 8 wherein the moisture content in coke is controlled in the range of about 3.6 to 4% preferably about 4 %.
10. A process as claimed in anyone of claims 7 to 9 wherein the quenching time is reduced in the range of about 59 to 61s preferably about 60s.
11. A process as claimed in anyone of claims 7 to 10 wherein the quantity of water for quenching is reduced in the range of about 24kl to 28kl preferably about 26kl.
12. A process as claimed in anyone of claims 7 to 11 wherein there is complete elimination of red-spots after quenching.
13. A process as claimed in anyone of claims 7 to 12 wherein a uniform temperature all over the bed is achieved in the range of about 60 to 80°C preferably about 70°C.
14. A hot coke water quenching system adapted for homogeneous cooling of coke-bed and a process for water quenching of hot coke using the said system substantially as herein described and illustrated with reference to the accompanying figures.
Dated the to 12 April, 2006

Anjan Sen
Anjan Sen & Associates
Applicant's Agent

ABSTRACT
A hot coke water quenching system adapted for moisture control in quenched coke and uniform and homogenous cooling of the coke bed and thus avoid temperature variance across the width of the coke bed. Importantly, the quenching system involves provision of plurality of rows of selectively spaced cooling headers with nozzles covering the width of ttie coke bed so that the problems of in-homogenous cooling of hot coke bed resulting in temperature variation across the bed could be avoided. The system would also favour effective and optimal utilization of water used for cooling of the hot coke and in the process control the moisture content in the coke after quenching and avoid large variation in the moisture content of the quenched coke. The system favours controlling of the moisture content in coke to around 4% after quenching and also favour avoiding problems of high moisture content and related adverse effects on fuel rates and productivity in iron making. (Figure 2)