The present invention relates to a system-for injection of powder/granular material in industrial processes and in particular to a system for injection of ilmenite sand in blast furnace for protection of hearth of blast furnace.
It is desirable that blast furnace campaign life (blast furnace operation time between two major repairs for relining) should be high for keeping the hot metal (product of blast furnace) production cost low. Blast furnace hearth refractories are subject to regular wear and many times uneven wear i.e., more wear of refractory at some particular position. Such uneven wear causes increased temperature of furnace shell and leads to stoppage of furnace operation.
It is known to protect against such wear of hearth of blast furnaces such as by charging of Titanium in blast furnaces. Titanium is charged in blast furnace through various means for protection of hearth. It is charged either in form of pellets/cubes which are prepared from mixture mainly of ilmenite sand and cement (binder). Titanium is also charged in blast furnace as pellets which are prepared from coke breeze powder mixed with ilmenite sand. Titanium is also charged in blast furnace through titani ferrous ore i.e. the iron ore which contains high percentage of Titanium oxide (TiO2). Injection of reagents/fuels in blast furnace tuyeres is prior art. Solid fuels like coal dust, oil and thick highly viscous flufd like coal tar have been injected in the blast furnace since quite sometime and still in practice.
Above injections are known to be done through the modification of blow pipe (a cylindrical taper component) placed just before the copper tuyeres. In case of fuel injection, inclined lance (inclined to the axis of tuyeres) does not cause any problem as the fuels ignite immediately after coming in contact with hot blast (hot air temp. 800-1000° C. or even more). In case of sand if injection is done through inclined lance, the same will impinge over the wall of the blow pipe and erode the same.
Thus such known systems require spacious locations for installation and being heavy also require permanent foundations. Accordingly it is experienced that such known injection systems suffer from problems in injection due to erosion in

bends or necessitate use of high pressure compressed air if placed at far off distance from the point of injection.
It is thus the basic object of the present invention to provide a system of injection of any powder/granular material for industrial applications which would be simple to manufacture, assemble and use.
Another object of the present invention is to provide a system for injection of powder/granular reagents for industrial applications such as desulphurisation, dephosphorisation, desiliconisation of hot metal and liquid steel.
Yet another object of the present invention is to provide a system for injection of powder/granular material in process industry which would be simple and cost -effective.
Yet further object of the present invention is to provide a system for injection of power/granular material which would be light weight and portable, simple and convenient to assembly and use without requiring spacious locations and avoid problems in injection due to erosion in bends or requiring distanced location from the place of injection and consequent requirement of high pressure compressed air for effective injection from such distanced location. •
Yet further object of the present invention is to provide for a system for injection of ilmenite sand in blast furnaces to protect the hearth of the furnace which is adapted for location very close to the blast furnace tuyere stock i.e. the point of injection.
Thus according to the present invention there is provided a system for injection of powder/granular material in industrial processes comprising :
a dispenser assembly having a fluidising cone which is operatively connected to a converging/diverging nozzle means;
a compressed air source operatively connected to dispenser assembly through valve means adapted for supply of compressed air to different regions of said
dispenser assembly to facilitate the dispensing of said particulate/povder material through said dispenser;
said converging/diverging nozzle operatively connected to an injectng means for supply of said particulate/powder material from said dispenser to -he place of injection.
The above disclosed system of injection of powder/granular rrmerial of the invention can be used for various industrial applications and/or in industrial processes including desulphurisation, dephosphorisation, desiliconsation of hot metal, liquid steel and the like.
In accordance with one aspect the system for injection of povtter/granular material for injection of ilmenite sand in blast furnaces for protectiot of hearth of the furnace comprise:
said dispenser assembly having an inlet for ilmenite sand at the toj. a fluidising cone which is operatively connected to a converging/diverging nozzs means at the bottom;
said compressed air source operatively connected to said disperser assembly through valve means adapted for supply of compressed air to drfferwt regions of said dispenser assembly to facilitate the dispensing of the ilmenite sand through said dispenser;
said converging/diverging nozzle further operatively connected to a lance assembly for supply of said ilmenite sand into said furnace throupi said lance assembly.
The above system of injection of ilmenite sand in blast furnaces of tru invention is light weight, portable and does not require permanent foundations forinstallations and also does not require spacious locations for installation. In tie proposed system the lance assembly is through peep hole and system R handy and
portable. It can be brought very close to the blast furnace tuyere stock i.e. the point of injection.
More details of the system of the invention, its objects and advantages will be apparent from the ensuring description made in relation to the accompanying figure 1 which schematically illustrates the system of ilmenite sand injection in blast furnace of the present invention.
As shown schematically in Fig-1 the system of the invention comprises the dispenser assembly (DA) comprising a cylindrical vessel (1) having an ilmenite sand charging funnel (7) at the top and a conical bottom portion fitted with a fuidising cone (2). A converging/diverging nozzle (3) is fitted below the conical portion. A set of valves and pipeline known as valve stand (4) is incorporated for supply of compressed air. A specially developed lance assembly (5) is incorporated for interfacing with the furnace.
As further illustrated the valve stand consists of means for supply of conveying media (compressed air) to the different portions of the dispenser comprising (i) pressurisation means (ii) fluidisation means and (iii) transportation means. Each said "means consists of valves, pressure gauges for control and indication of pressure. Type of valves and control depend on the accuracy of the flow rate desired. The apparatus / system is provided with safety valve (6) to prevent any accident / damage to the equipment.
Optionally the system is provided with flow rate indicator/recorder for gaseous media and powder level indicators for the powder media.
The lance assembly comprises a pipe of 12-15 mm bore and 1000 - 1500 mm length. This pipe is made of heat resistant steel. A stainless steel ball valve/check valve is used for interfacing with the furnace. Lance assembly is such that 12-15 mm bore pipe passes through the ball/check valve. One additional valve is provided before ball/check valve, so that engagement/disengagement of powder/granule conveying hose may be done without disrupting the furnace operation. Bore of the injection pipe is decided as per quality of sand to be

injected length of the injection pipe is dependent on the tuyere shape and configuration.
The method of operation of the system for injection of ilmenite sand in blast furnace is as follows :
System is brought closer to the tuyere in which ilmenite sand is to be injected. Compressed air connection is done to the valve stand. Ilmenite sand is charged to the dispenser through charging funnel. Charging funnel is preferably provided with a screen (2 mm opening) which prevents ingress of any contamination in the sand to be injected. Peep hole assembly cover is removed and lance assembly is inserted either keeping the furnace at full blast (in case of low blast pressure) or often reducing the blast (in case of high blast pressure). Injection is started after adjustment of pressure in different lines.
The injection system of the invention is light weight, portable and doesn't require foundation for installation and also does not require spacious locations for installation. In the proposed system lance assembly is through peep hole and system is handy and portable. It can be brought very close to the blast furnace tuyere stock i.e. point of injection.
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The above disclosed system for injection of ilmenite sand/particulate material of the invention is found to be much superior to the known prior arts of titania addition/charging in blast furnace. The main advantages of the system of the invention include:
i) it is adapted for injection in the blast furnace where it is required most;
ii) preparation of cubes/pellets of powder/granular material for injection is not required.
iii) in use for injection of sand in blast furnace, the blast furnace permeability and furnace behaviour is not affected.

iv) much economical and effective means for the hearth protection of blast furnaces i.e. increasing the refractory lining life of blast furnace hearth, increasing its campaign life and achieving economy in hot metal production.
It is thus possible by way of the present invention to provide for a system of injection of powder / granular material in industrial processes which would be light weight, portable, simple and convenient to operate. Also the system of the invention does not require expensive foundations or installation and/or spacious locations for its installation which make it a simple and cost-effective device for injection of powder/granular material.

WE CLAIM
1. A device for injection of powder/granular material in industrial processes
comprising :
a dispenser assembly having a fluidising cone which is operatively connected to a converging/diverging nozzle means ;
a compressed air source operatively connected to dispenser assembly through valve means adapted for supply of compressed air to different regions of said dispenser assembly to facilitate the dispensing of said particulate/powder material through said dispenser;
said converging/diverging nozzle operatively connected to an injecting means for supply of said particulate/powder material from said dispenser to the place of injection.
2. A device for injection of powder/granular material in industrial processes
as claimed in claim 1 for injection of ilmenite sand in blast furnaces for
protection of hearth of the furnace comprise :
said dispenser assembly having an inlet for ilmenite sand at the top, a fluidising cone which is operatively connected to a converging/diverging nozzle means at the bottom ;
said compressed air source operatively connected to said dispenser assembly through valve means adapted for supply of compressed air to different regions of said dispenser assembly to facilitate the dispensing of the ilmenite sand through said dispenser;
said converging/diverging nozzle further operatively connected to a lance assembly for supply of said ilmenite sand into said furnace through said lance assembly.

3. A device as claimed in anyone of claims 1 or 2 wherein said dispenser
assembly comprise a cylindrical shaped main body portion having means
for charging of powder/particulate material at the top and a conical shaped
bottom thereof having a fluidising cone, said fluidising cone operatively
connected to a converging/diverging nozzle means.
4. A device as claimed in anyone of claims 1 to 3 wherein said means for
charging of powder/particulate material comprise :
a hopper and/or a funnel at the top of said dispenser means.
/
5. A device as claimed in anyone of claims 1 to 4 wherein said dispenser is
provided with a safety valve.
6. A device as claimed in any one' of claims 1 to 5 wherein said means for
supplying compressed air to different regions of said dispenser assembling
comprise means for supplying compressed air at the top of said dispenser,
valve means for supplying compressed air at said fluidising cone of said
dispenser assembly and valve means for supplying compressed air into
said connecting pipe line therebetween said converging/diverging nozzle
of said dispenser assembly and said lance assembly.
7. A device as claimed in claim 6 wherein said valve means for supplying
compressed air to said dispenser assembly at the top comprise
pressurisation line valve means, said valve means for supplying
compressed air at said fluidising cone comprise fluidisation line valve
means and said valve means for supplying compressed air at said pipe
line connecting said nozzle of said dispenser assembly to said injecting
means/lance assembly comprise transportation line valve means.
8. A device as claimed in anyone of claims 1 to 7 wherein said
converging/diverging nozzle is connected to said lance assembly through
a connecting hose/conduit.

9. A device as claimed in anyone of claims 1 to 8 wherein said lance
assembly comprises :
a pipe preferably of 12-15 mm bore and 1000 -1500 mm length.
10. A device as claimed in anyone of claims 1 to 9 comprising a valve means
for interfacing said lance assembly with said furnace.
11. A device as claimed in claim 10 wherein said valve means comprise a
ball/check valve.
12. A device as claimed in anyone of claims 10 or 11 wherein additional valve
means is provided to facilitate engagement/disengagement of said
powder/granular material conveying means without affecting the furnace
operation.
13. A device as claimed in anyone of claims 1 to 12 wherein the bore of said
injecting means is selected based upon the quality of the particles to be
injected and said length of said injection means is dependent on the tuyere
shape and configuration.
14. A device as claimed in anyone of claims 7 to 13 wherein each said
pressurising line valve means, fluidising line valve means and said
transportation line valve means comprise valve means selected from
pressure regulating valve, on-off valve, needle valve, non-return valve.
15. A device as claimed in anyone of claims 7 to 14 wherein said
pressurisation line valve means, said fluidisation line valve means and
said transportation line valve means are mounted on a valve stand.
16. A device as claimed in claim 15 wherein said compressed air from said
compressed air source is connected to a common inlet of said valve stand
from where it is further distributed to said pressurisation line valve means,
fluidisation line valve means and said transportation line valve means.
17. A device as claimed in claims 16 wherein in said connecting pipeline
operatively connected to said compressed air source to said common inlet
of said valve stand there is provided a needle valve and a flow meter.
18. A device as claimed in anyone of claims 6 to 17 wherein the type of valve
is selected based upon the control and accuracy of the injection of the
powder/granular material desired.
19. A device as claimed in anyone of claims 1 to 18 wherein the charge inlet of
said dispenser assembly is adapted to be closed by threaded plug and/or
valves.
20. A device as claimed in anyone of claims 1 to 19 wherein said charge inlet
opening is operatively connected to remote control means for opening and
closing said charge inlet.
21. A device as claimed in anyone of claims 1 to 20 which is portable and
handy.
22. A device as claimed in anyone of claims 1 to 21 wherein said
pressurisation line valve means, said fluidisation line valve means and
said transportation line valve means comprise :
manually operative valves with pressure indicator or pneumatic/electro-pneumatic valves with flow indicator and controllers.
23. A device as claimed in anyone of claims 1 to 22 wherein said inlet means
of said dispenser assembly for entry of powder/particulate material
comprise screening means for selectively allowing only powder/particulate
material of desired size into said dispenser assembly.
24. A device as claimed in claim 23 wherein said screening means have
opening of 2 mm.
25. A method of injecting powder/particulate material in industrial processes
using a device as claimed in anyone of claims 1 to 24 comprising :
providing said device closer to the unit in which sand is to be injected ;
charging powder/particulate material into said dispenser;
inserting the injecting means/lance assembly outlet into said unit ; and finally,
injecting the said powder/particulate material after proper adjustment of pressure in said pressurising line, fluidising line and transportation line.
26.A method as claimed in claim 25 wherein the said lance assembly is inserted into said peep hole maintaining the furnace at full blast in case of low blast pressure.
27. A method as claimed in claim 25 wherein the said lance assembly is inserted into said peep hole reducing the blast of said furnace in case of high blast pressure.
28.A method as claimed in claim 25 carried out for desulphurisation, desiliconnisation of hot metal and/or liquid steel.
29. A device for injection of powder/granular material for use in industrial process and a method for injection of powder/granular material in industrial processes substantially as herein described and illustrated with reference to the accompanying figures.