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FIELD OF THE INVENTION:
001. The present invention relates to a novel chemical composition for arresting gas leakage from hot and pressurized industrial vessels or Blast furnace and also relates to a methodology of checking gas leakage by applying the novel composition in Blast furnace.
BACKGROUND OF THE INVENTION:
002. In blast furnaces (BF), hot metal (liquid iron) is produced from iron ore lump,
sinter and/or pellet, coke and injected fuel. This objective is achieved by passing
a hot enriched air flow (hot blast air) through the ore and coke burden which goes
down in the internal column of the BF. The hot blast air and auxiliary fuel are
injected into the blast furnace through Tuyeres located around the perimeter of
the BF. Tuyere is very important part of Blast Furnace. The Tuyere is the hole
through which the wind is introduced to the furnace. The number of Tuyeres per
furnace depends upon the size of the furnace. Any fuel and oxygen injection will
also be added here and with the peep-sights one can see the blast furnace process
at work.
003. Tuyeres stocks connect bustle pipe to the Tuyeres. The purpose of Tuyere stocks
is to supply hot blast air into blast furnace. These are normally manufactured
from boiler-quality /alloy steel plate and are lined with refractory material usually
a castable. Each Tuyeres stock is an assembly of gooseneck, expansion bellow,
connecting pipe, elbow, peep hole, blow pipe, fixing arrangement and tensioning
device. The Tuyere stocks adapts to the relative movements between the hot blast
delivery system and the blast furnace. All the components of Tuyere stock are
usually flange connected. The blowpipe, which connects the hot blast system to
the Tuyere, normally fits into a machined spherical seat at the base of the Tuyere.
The main components of the Tuyere stock are tightly connected with the polished
tapered surfaces by means of the consequent close arrangement of the next part
in the previous one. Thus the closed-fitted tapered surfaces provide the leak-tight
integrity of the joint. A disturbance of operating heating cycle as well as any

leakage of the one of the joints in the Tuyere stock results in the burning of the construction elements and eventual failures.
004. The gas leakage in the Tuyere is observed mainly due to the following reasons:
a. At the time of the installation slip-up happens during the alignment of the
Tuyere cooler and Tuyere holder.
b. At the time of fixing Tuyere cooler with Tuyere holder a gap may be created at
lower side of the Tuyere cooler, if fitting is not properly done. There is a seal (Viton
Silicon ‘O’ Ring Cord) between the seating but the seal may not last longer
because of the gap.
c. Due to the continuous slip of burden inside the furnace due to which high
pressure generates at the bosh area.
During the operations and maintenance of Blast Furnaces, gas leakage through the gap of Tuyere cooler area and furnace shell is often observed (figure 1 & 2).
005. The gas leakage takes place 4.5 bar and at a temperature of 250-350 Deg C. Major constituents of the leaking gas (by volume) is given below:
Carbon dioxide- 12 to 30%
Carbon monoxide – 22 to 25%
Oxygen- 0.2 to 0.5%
Methane- 1–4 %
Hydrogen- 4-5 %
Nitrogen- 55–58%
006. Gas leakage results in creation of very hazardous environment at Tuyere platform. A person working in the affected area can be affected by the gas which is extremely poisonous due to presence of high amount of CO. Possibility of furnace getting fire also exists.

7. During normal course of blast furnace operation, leakage is monitored every day. In case it goes to a dangerous level, the furnace is shut down and whole Tuyere cooler assembly needs replacement.
8. A new Tuyere cooler cost around Rs. 12 lacs and a shutdown of furnace is also required. For replacing one Tuyere cooler, it takes around 14 hours and needs around 10 skilled labors. This directly impacts the production volume of the blast furnace.
9. Hence, there is always a need to find an alternative solution for checking such leakage of poisonous gas in Blast Furnace in a simple and economic way.
010. The present invention meets the long felt need.
SUMMARY OF THE INVENTION:
011. A novel composition for arresting gas leakage at high temperature and pressure
condition in Blast furnace comprises Mud Gun Mass, Refractory Dust, two parts
epoxy based adhesive, graphite rope , Hydraulic Oil, Glass wool and soap solution.
OBJECTS OF THE INVENTION:
12. It is therefore, the primary object of the present invention is to provide a composition for arresting gas leakage at high temperature and pressure condition at the tuyere area of Blast furnace.
13. Another object of the present invention is to provide a composition, which can be applied in paste or putty form at the affected area for prevention of gas leakage in Blast Furnace.
14. Yet another object of the present invention is to provide a process, which save cost of repeated exchange of tuyere spare and extra labours.
15. Further object of the present invention is to provide a process, where plant shut down is avoided and hence the blast furnace productivity has increased substantially.

16. Another object of the present invention is to provide a process, which can provide safe working condition in Blast furnace.
17. Yet another object of the present invention is to provide a process, which is easy, rapid, economic and environment friendly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
018. It is to be noted, however, that the appended drawings illustrate only typical
embodiments of the present subject matter and are therefore not to be
considered for limiting of its scope, for the invention may admit to other equally
effective embodiments. The detailed description is described with reference to
the accompanying figures. Some embodiments of system or methods in
accordance with embodiments of the present subject matter are now described,
by way of example, and with reference to the accompanying figures, in which:
Figure 1 illustrates gap measurement.
Figure 2 illustrates proper cleaning of the affected area.
Figure 3 illustrates making of the paste (putty).
Figure 4 illustrates application of putty.
Figure 5 illustrates curing.
Figure 6 illustrates visual inspection.
Figure 7 illustrates blast furnace tuyere area.
Figure 8 illustrates gap between furnace shell and tuyere cooler.
Figure 9 illustrates the Putty application in Tuyere area.
DETAILED DESCRIPTION OF THE INVENTION:
019. The present invention relates to a development of a novel composition in putty or paste form which can be applied for prevention of gas leakage in the Tuyere area of the Blast Furnace.

020. Tuyere is one of the important part of the blast furnace. The main
components of the Tuyere stock are tightly connected with the polished tapered
surfaces by means of the consequent close arrangement of the next part in the
previous one. Thus the closed-fitted tapered surfaces provide the leak-tight
integrity of the joint.
021. But any type of disturbance of operating heating cycle as well as any leakage
of any joints in the Tuyere stock sometimes result in deviation of the
construction elements and eventually failure of the whole system.
022. To withstand this type of gas leakage a novel composition has been developed
which can be applied at leakage area i.e, in the gap between Tuyere cooler and
furnace shell. Ingredient of composition is in Table 1.

Table 1
23. In the current invention, Mud Gun mass is silica based composition having chemical composition Silicon carbide and carbon more than 60%. The remaining constituents can be varied from silica, alumina (bauxite), and binder.
24. Soap solution is a state of art salt of a fatty acid used for surface finish or more particularly a sodium or potassium salts of long fatty acids.

25. The present invention uses Araldite as epoxy based adhesive which comprises epoxy, acrylic and polyurethane adhesives.
26. The hardener is selected from polyfunctional amines, acids or/and acid anhydride, phenols, alcohols and thiols.
27. All the ingredients are cold mixed and converted to a pasty consistency which is called TQ – putty.
28. In the Blast furnace operation, the composition has been used to close the hole of the tap hole at high pressure, so that molten metal flow stops.
29. This mix is applied at affected area and subjected to curing for about 2 hours.
030. After this time, the mix solidifies and completely arrests the leakage. Furnace
can be put into operation after curing time.
031. The chemical mix, after solidification, has the chemicals given in Table 2.

32. Water is also used in a very small quantity in the above-mentioned table.
33. In accordance with another embodiment of the present invention, the pasty composition is applied after identifying the area of gas leakage and then the paste is applied on them and cured.
34. The temperature withstanding value of the solidified paste is 1515°C.

35. The composition is tested in a place where gap was around 10 mm and length was around 250 mm. The task was to arrest the leakage of BF gas coming out of the Tuyere as quickly as possible.
36. In accordance with another embodiment, the present invention also provides a method for checking gas leakage in Blast furnace while comprises the steps of:
i. Identification of leakage
ii. Gap measurement
iii. Proper cleaning the gap
iv. Making of putty
v. Applying putty
vi. Curing
vii. Visual inspection
viii. Preparation of Putty application data sheet
037. i) IDENTIFICATION OF LEAKAGE
Gas mapping of the place indicates area of gas leakage. A typical gas mapping report is given below:


38. The area of gas leakage is identified by gas mapping. The detailed report is given in table 3.
39. ii) GAP MEASUREMENT
40. A feeler gauge is used the measure the gap (as shown in Fig 1).

041. iii. PROPER CLEANING OF THE AFFECTED AREA
42. The affected area is first clean by using high pressure air and water and CRC is used for removal of the rust. Abrasive paper such as emery paper or sand paper (as shown in Fig 2) is used for the edge preparation.
43. iv. MAKING OF THE PASTE (PUTTY)
044. All the ingredients such as Mud Gun Mass, Refractory Dust, Resin ,
Hardener, Hydraulic Oil, Graphite rope and Glass wool are cool mixed in a pre¬
determined ratio and converted to a paste commonly called a putty. Fig 3
discloses this process steps.
045. v. APPLICATION OF PUTTY
046. Fig 4 discloses the gap is first filled with the prepared putty and seam plate
made up of copper is used to fill the gap with the putty and last finishing is
done by hand.
047. vi. CURING
48. After application of the putty in the gap, curing is preferred by using compressed air at a pressure maximum of 1 Bar, gas cutting torch can also be used for quick curing after sprinkling of the refractory dust (as shown in Figure 5). The curing is occurred for 2 hours.
49. vii. VISUAL INSPECTION
50. After finishing, the repaired area is visually inspected to find presence of any hair gaps. If gap is found, putty is further applied after roughing the edge by using sand paper (as shown in Fig 6).
51. Table 4 and Figure 9 provide a complete data sheet for putty application.

052. Table 4 provides a data sheet for putty application.


053. Table 5 provides different characteristics features and value of the process:



054. The non-limiting advantages of the present invention are given below:
a. Cost saving as replacement of costly spare (Tuyere) is eliminated by
arresting the leakage by applying the chemical mix.
b. Need of plant shut-down is avoided resulting in increased Blast Furnace
productivity.
c. Safe working conditions in Blast Furnace area are ensured.
055. Although embodiments for the present subject matter have been described in
language specific to structural features, it is to be understood that the present
subject matter is not necessarily limited to the specific features described.
Rather, the specific features are disclosed as embodiments for the present
subject matter. Numerous modifications and adaptations of the method of the
present invention will be apparent to those skilled in the art, and thus it is

intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

WE CLAIM:
1. A novel composition for arresting gas leakage at high temperature and
pressure condition in Blast furnace comprises Mud Gun Mass, Refractory Dust,
two parts epoxy based adhesive, graphite rope , Hydraulic Oil, Glass wool and
soap solution.
2. The composition as claimed in claim 1, wherein the weight percentages of the
ingredients are given below:
Mud gun mass – 25%
Refractory dust – 25%
Two part epoxy based adhesive – 25%
Graphite rope – 3%
Glass wool – 3%
Polyamide hardener – 15%
Hydraulic oil – 2%
Soap solution – 2%
3. The composition as claimed in claim 1, wherein epoxy based adhesive is comprised of epoxy, acrylic and polyurethane adhesives (Araldite).
4. The composition as claimed in claim 1, wherein the soap solution is sodium or potassium salts of long fatty acids.
5. The composition as claimed in claim 1, which is in pasty consistency and applied in form of putty.
6. The composition as claimed in claim 1, has the following chemical constituents after solidification:
Fe -1.43 to 2.77
CaO - 0.5 to 1.04

SiO2 - 74.48 to 79.75 P2O5 - 0.22 to 0.36 MgO - 2.67 to 8.06 Al2O3 - 12.58 to 21.42 TiO2 - 0.26 to 0.69 Cr2O3- 0.12 to 0.39
7. The process for checking gas leakage in blast furnace comprises the steps of:
i. Identification of leakage
ii. Gap measurement
iii. Proper cleaning the gap
iv. Making of putty
v. Application of putty
vi. Curing
vii. Visual inspection
viii. Putty application data sheet
8. The process as claimed in claim 7, wherein the gas leakage is identified by gas mapping with the help of a feeler gauge.
9. The process as claimed in claim 7, wherein the affected area is cleaned with high pressure air and then with CRC for removal of rust.

10. The process as claimed in claim 7, wherein the putty is applied with the help of a seam plate made up of copper.
11. The process as claimed in claim 7, wherein the curing is performed by using compressed air at pressure of 1 bar.

12. The process as claimed in claim 7, wherein curing can be performed by gas cutting torch, which provides outlet curing after sprinkling of the refractory dust.
13. The process as claimed in claim 7, wherein curing can be done for 2 hour and the temperature value of the resultant solidified paste is 1515°C.