CLIAMS:We Claim:

1. A system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace, comprising

atleast one lance adapted for desired reciprocating downward and upward motion for
introducing and retracting the lance in and from said furnace having a releasably closable opening;

said lance operatively connected to oxygen blowing source and substantially vertically disposed in relation to said furnace opening and supported from top of said furnace by a lance supporting arm;

said lance supporting arm operatively connected to height regulating mechanism whereby the height of the said lance supporting arm can be regulated to in the process bring down or retract upwards the said lance into and from said furnace;

said height regulating mechanism supported with respect to a rotatable member whereby the lance supporting arm and the lance can be swiveled and rotated in any desired position for facilitating the location of the lance for desired lance disposition and/or furnace operation.

2. A system as claimed in claim 1 wherein said height regulating mechanism operatively connected to said lance arm and supported with respect to said rotatable member comprises said lance arm connected to a guide column which in turn is connected to a guide frame including a bottom guide frame portion supported with respect to said rotatable member with cooperative hydraulic means for height adjustment of said lance arm;

said rotable member comprising of a guide frame supporting platform and operatively connected to a slew bearing for said rotary motion, said slew bearing rotatable supported with respect to a stationary column; and

power means for selectively operating said slew bearing for said desired rotary motion of said rotary member and in turn said lance with respect to the furnace.

3. A system as claimed in anyone of claims 1 or 2 comprising drive mechanism for controlled lifting or closing of said releasably closable furnace opening involving a water cooled delta.

4. A system as claimed in claim 3 comprising a structural outrigger to hold to hold a water cooled releasably closable furnace opening /water cooled delta and also to carry said drive mechanism comprising of a drive arrangement having drive with chain & sprocket arrangement.

5. A system for controlled introduction of lance from furnace top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace, comprising

three lances adapted for desired reciprocating downward and upward motion for
introducing and retracting the lance in and from said furnace having a releasably closable opening, said lances spatially arranged preferably at an angular distance of 120 deg ;

each said lance operatively connected to oxygen blowing source and substantially vertically disposed in relation to said furnace top having corresspondinh opening and supported from top of said furnace by respective lance supporting arm;

each said lance supporting arm operatively connected to respective height regulating mechanism whereby the height of each said lance supporting arm can be regulated to in the process bring down or retract upwards the respective lance into and from said furnace top openings;

said height regulating mechanism supported with respect to a rotatable member whereby the lance supporting arm and the lance can be swiveled and rotated in any desired position for facilitating the location of the lances for desired lance disposition and/or furnace operation;

said respective height regulating mechanism operatively connected to said respective lance arm and supported with respect to said rotatable member comprises each said lance arm connected to a corresponding guide column which in turn is connected to a corresponding guide frame including a corresponding bottom guide frame portion supported with respect to said rotatable member with cooperative respective hydraulic means for height adjustment of each said lance arm;

said rotable member comprising of a guide frame supporting platform and operatively connected to a slew bearing for said rotary motion, said slew bearing rotatable supported with respect to a stationary column and maintained at a height of above 9 meters ; and

power means for selectively operating said slew bearing for said desired rotary motion of said rotary member and in turn said lance with respect to the furnace.

6. A system as claimed in anyone of claims 1 to 5 wherein said stationary column internally houses a drive CPL, oxygen piping with rotary and bellow, Nitrogen piping with rotary and bellow and water piping including inlet and outlet headers with rotary and bellow.

a bottom column with bottom flange fixed with foundation bolts and a slew bearing mounted on top with outer race bolted with super bolt arrangement with the top flange;

a guide frame platform is mounted on inner race of said slew bearing with super bolt arrangement adapted to be provided with controlled swiveling motion;

a drive CPL to drive the bearing for rotational movement;

a Displacement Guide Roller assembly is welded at top of said guide frame platform comprising a Bottom Guide frame just above said guide frame platform, a Guide Frame with roller arrangement positioned above said bottom guide frame, providing support for vertical up and down movement of three Guide Columns disposed therein;

three said structural Guide Columns used to hold corresponding three Lance Arms and are operated by respective Regulating cylinders(hydraulic) mounted on said Guide frame Platform, and those are guided by guide frame with guide rollers to avoid deflection during operation;

three said lance arms comprising left hand, right hand and a middle arm, bolted on the top of three said guide columns are used to hold the Oxygen lances for oxygen blowing disposed through three openings in water cooled delta;
a structural outrigger mounted on said guide frame is used to hold said Water cooled Delta and also carrying a Delta Drive used to drive Water Cooled delta during operation;
means for nitrogen cooling of oxygen lances through nitrogen ring fitted on the water cooled delta;
WinCC HMI screen provided for triple lance visualization and operation, having means for lance position control and PLC based controlled flow rate of oxygen and cooling water.

7. A system as claimed in anyone of claims 1 to 6 comprising

a bottom column with bottom flange fixed with foundation bolts and a slew bearing mounted on top with outer race bolted with super bolt arrangement with the top flange;

a guide frame platform is mounted on inner race of said slew bearing with super bolt arrangement adapted to be provided with controlled swiveling motion;

a drive CPL to drive the bearing for rotational movement;

a Displacement Guide Roller assembly is welded at top of said guide frame platform comprising a Bottom Guide frame just above said guide frame platform, a Guide Frame with roller arrangement positioned above said bottom guide frame, providing support for vertical up and down movement of three Guide Columns disposed therein;

three said structural Guide Columns used to hold three Lance Arms and are operated by respective Regulating cylinders(hydraulic) mounted on said Guide frame Platform, and those are guided by guide frame with guide rollers to avoid deflection during operation;

three said lance arms comprising left hand, right hand and a middle arm, bolted on the top of three said guide columns are used to hold the Oxygen lances for oxygen blowing disposed through three openings in water cooled delta;
a structural outrigger mounted on said guide frame is used to hold said Water cooled Delta and also carrying a Delta Drive used to drive Water Cooled delta during operation;
means for nitrogen cooling of oxygen lances through nitrogen ring fitted on the water cooled delta;
WinCC HMI screen provided for triple lance visualization and operation, having means for lance position control and PLC based controlled flow rate of oxygen and cooling water.

8. A system as claimed in anyone of claims 1 to 7 wherein three lances are spatially arranged at an angular distance of 120 deg and use of three lances facilitate blowing oxygen with a flow rate of preferably 300 Nm3/min, such that the approach area of metal bath surface that is in direct contact with the oxygen jets increases, leading to higher rate of reaction between the metal droplets and the slag layer resulting in improved yield with reduced cycle time.

9. A system as claimed in anyone of claims 1 to 8, wherein said regulating cylinders (hydraulic), mounted on Guide plate platform at bottom and fixed to arms at the top are used to operate said three lance arms.

10. A system as claimed in claims 1 to 9, wherein said water cooled delta attached to outrigger is provided to cover the shell during operation, having three openings for three lances with the arrangement of nitrogen cooling.

11.A system as claimed in claims 1 to 10 , wherein independent operated Hydraulic Regulating cylinder with support of Guide rollers provide for operation individually of the said three lances.

12.A system as claimed in claims 1 to 11, wherein Hydraulic lines are placed adjacent to the Guide Frame Platform with hose and rotary arrangement.

13. A system as claimed in claims 1 to 12, wherein oxygen piping is inserted form bottom side and through the Bottom Column and Guide frame platform.

14. A system as claimed in claims 1 to 13, wherein water piping is inserted form middle and through the Bottom Column and Guide frame platform.

15. A system as claimed in claims 1 to 14, wherein Nitrogen piping is inserted form bottom side and through the Bottom Column and Guide frame platform.

16. A system as claimed in claims 1 to 15 wherein Delta lifting drive arrangement is placed under the outrigger on Drive mounting and maintenance platform and pulley with brackets are mounted on the outrigger to transfer the water cooled delta on the outrigger arms.

17. A system as claimed in claims 1 to 16 comprising encoders for 3 lances to know the lance position.

18. A system as claimed in claims 1 to 17, wherein electrically-operated piston valves are provided on said lance O2 pipelines to adjust the O2 flow rate and are PLC controlled.

19. A system as claimed in claims 1 to 18, comprising Flow meters installed in water lines to check water flow rate and signals connected to PLC, which in turn is visible on HMI screen for use by operation crew.

20. A system as claimed in claims 1 to 19, wherein slip ring with all electrical connections are placed on the guide frame platform for enabling rotary motion of the said rotatable member.

21. A system as claimed in claims 1 to 20, wherein said bottom guide frame is used to increase the height of outrigger to avoid the interference between Outrigger and Fume Elbow.

Dated this the 25th day of January, 2014
Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)
,TagSPECI:FIELD OF THE INVENTION

The present invention relates to a system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace. More particularly, the present invention is directed to provide three top lance operation system for Conarc Furnace with provision for controlled lance positioning including lifting and lowering as per need and controlled oxygen blowing arrangement and water cooled delta with three openings for lance with the arrangement of nitrogen cooling, suitably supported on guided column and frame structures with bearing mounted swiveling operation of support column. Advantageously, the three lance operation system for Conarc furnace according to the present invention is equipped with WinCC HMI screen for triple lance visualization and operation, alongwith signals from flow meters connected to PLC, which in turn is visible on HMI screen for use by operation crew. Importantly, the three lance operation system is capable to support desired oxygen blowing for refining of steel in such refining vessels such as CONARC furnace which would achieve higher efficiency and productivity in spite of the limitations of vessels constructions with lower height-to-diameter ratio (typically 1:1).

BACKGROUND OF THE INVENTION

In recent years attempts are being made to improve operational efficiency and flexibility of charge in EAF and oxygen steelmaking in relation to the use of energy and raw materials. The objective was to develop a technology utilizing benefits of both EAF and top blown steelmaking. CONARC is the resultant of such experiments that combines the benefits of Converter and Arc furnace.

The SMS Demag CONARC process was developed for using any kind and mix of raw materials like hot metal (HM), DRI and scrap to ensure highest quality requirements for the production of all steel grades covering a wide range from carbon to stainless steel. The first twin-shell conarc furnace was commissioned at Saldanha Steel in South Africa, a part of Mittal Steel South Africa which in turn is part of global steel company Arcelor-Mittal. Worldwide there are around 12 units in operation.

The charge mix of an Electric Arc Furnace is mainly determined by the steel quality or grade to be produced. As the quality demands are steadily increasing, highest flexibility in terms of charging scrap, DRI and hot metal, the use of different energy sources and the production of a wide range of steel qualities is of extreme importance for the producer. The SMS Demag CONARC process was developed for using any kind and mix of raw materials like hot metal (HM), DRI and scrap to ensure highest quality requirements for the production of all steel grades covering a wide range from carbon to stainless steel.

As already stated, the first twin-shell conarc furnace was commissioned at Saldanha Steel in South Africa, a part of Mittal Steel South Africa. Applicants’ steel production facility proved as a flagship company in the introduction of Conarc process in India, with the first in Asia having CSP (Compact Strip production) setup.

The Conarc set-up of the applicants extends a number of advantages, primarily in terms of the flexibility in use of charge-mix – Hot metal (HM) and solid charge (DRI/Scrap) can be fed in any proportion ranging 0 to 100%.However, when using Hot metal as the major portion of charge-mix, some of the important benefits and operational efficiency of LD Converters, like less tap-to-tap time and higher %Yield are desired. High cycle time with use in EAF / CONARC is a bottleneck for determining the productivity of a steel plant. Various improvement have been done in the steel-making technology in past decades to decrease the cycle time as well as increase the flexibility of using various combination of raw material i.e. Hot metal or pig iron, Direct reduced iron (DRI), scrap, iron ore.

More specifically, the existing CONARC furnace involves a single top lance along the central vertical axis which is used for injecting Oxygen through multiple orifices, as required for the refinement of hot metal. It is a standard practice worldwide to use similar position of the lance and all commercially available steel refining vessels use single lance design. As per the conventional oxygen blowing practice, this oxygen injection into the bath is usually done using a single Top Lance with a max flow rate of 210 Nm3/min. Operational limitation on the oxygen flow rate from top lance of maximum 210 Nm3/min due to splash leads to jamming, while higher flow rate leads to high refractory wear & other operational difficulties. High skull formation needs arcing heat or physical removal in between. It also causes shell damage/ water leakage.

Thus because of the above such limitations while using 100% hot metal, higher operational efficiency of converter was desired, that could not be achieved with the existing limitations of CONARC furnace.

In the co-pending application no. 308/MUM/2013 dated 4th February, 2013, there is disclosed a system and method for oxygen blowing in CONARC furnace for steel making involving three top lances wherein higher volumetric oxygen flow rate can be achieved for desired faster processing time without increasing the flow rate through individual lance and thus avoiding churning at furnace bottom, ensure protection of refractory lining on furnace wall and bottom with increased service life and reduced refractory consumption, reducing occurrence of Jamming in EAF operation.

There has been thus a need in the art to developing a system for the operation of the three top lance for Conarc furnace which would provide means for desired controlled movement and positioning of the three lances in relation to the furnace walls, furnace delta and liquid metal inside alongwith controlled flow of oxygen commensurate with process requirements as well as water flow control and nitrogen flow control for cooling of delta and the oxygen blowing lances, in a reliable and operator friendly manner.

OBJECTS OF THE INVENTION

The basic object of the present invention is thus directed to a system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace for precise and selective positioning of the lances in relation to furnace delta and ensures desired controlled oxygen blowing in an operator friendly manner.

A still further object of the present invention is directed to providing a system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace wherein said system incorporates three lances selectively disposed spatially arranged at an angular distance of 120 deg.

A still further object of the present invention is directed to providing a system for three top lance operation in Conarc Furnace wherein the three lances are moved up and down as per need in relation to liquid metal in furnace by controlled operation of hydraulic regulating cylinders.

A still further object of the present invention is directed to providing a system for three top lance operation in Conarc Furnace wherein support column for lances are provided with means for controlled swiveling motion for fast and accurate positioning of lances in relation to the lance openings in furnace delta.

A still further object of the present invention is directed to providing a system for three top lance operation in Conarc Furnace wherein PLC based control is implemented for valves and flow meters for controlled flow of oxygen through individual lance or water flow for cooling of delta/lances.
A still further object of the present invention is directed to providing a system for three top lance operation in Conarc Furnace wherein WinCC HMI screen for triple lance visualization and operation including operation of flow meters and valves for use and convenience of operation crew.
A still further object of the present invention is directed to providing a system for three top lance operation in Conarc Furnace which can be installed separately for any electric arc furnace as per need and can also be retrofitted with required modifications to the system based on arc furnace design/make.

SUMMARY OF THE INVENTION

The basic aspect of the present invention is thus directed to a system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace, comprising

atleast one lance adapted for desired reciprocating downward and upward motion for
introducing and retracting the lance in and from said furnace having a releasably closable opening;

said lance operatively connected to oxygen blowing source and substantially vertically disposed in relation to said furnace opening and supported from top of said furnace by a lance supporting arm;

said lance supporting arm operatively connected to height regulating mechanism whereby the height of the said lance supporting arm can be regulated to in the process bring down or retract upwards the said lance into and from said furnace;

said height regulating mechanism supported with respect to a rotatable member whereby the lance supporting arm and the lance can be swiveled and rotated in any desired position for facilitating the location of the lance for desired lance disposition and/or furnace operation.

A further aspect of the present invention is directed to said system wherein said height regulating mechanism operatively connected to said lance arm and supported with respect to said rotatable member comprises said lance arm connected to a guide column which in turn is connected to a guide frame including a bottom guide frame portion supported with respect to said rotatable member with cooperative hydraulic means for height adjustment of said lance arm;

said rotable member comprising of a guide frame supporting platform and operatively connected to a slew bearing for said rotary motion, said slew bearing rotatable supported with respect to a stationary column; and

power means for selectively operating said slew bearing for said desired rotary motion of said rotary member and in turn said lance with respect to the furnace.

A still further aspect of the present invention is directed to said system comprising drive mechanism for controlled lifting or closing of said releasably closable furnace opening involving a water cooled delta.

A still further aspect of the present invention is directed to said system comprising a structural outrigger to hold to hold a water cooled releasably closable furnace opening /water cooled delta and also to carry said drive mechanism comprising of a drive arrangement having drive with chain & sprocket arrangement.

A still further aspect of the present invention is directed to said system for controlled introduction of lance from furnace top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace, comprising

three lances adapted for desired reciprocating downward and upward motion for introducing and retracting the lance in and from said furnace having a releasably closable opening, said lances spatially arranged preferably at an angular distance of 120 deg ;

each said lance operatively connected to oxygen blowing source and substantially vertically disposed in relation to said furnace top having corresspondinh opening and supported from top of said furnace by respective lance supporting arm;

each said lance supporting arm operatively connected to respective height regulating mechanism whereby the height of each said lance supporting arm can be regulated to in the process bring down or retract upwards the respective lance into and from said furnace top openings;

said height regulating mechanism supported with respect to a rotatable member whereby the lance supporting arm and the lance can be swiveled and rotated in any desired position for facilitating the location of the lances for desired lance disposition and/or furnace operation;

said respective height regulating mechanism operatively connected to said respective lance arm and supported with respect to said rotatable member comprises each said lance arm connected to a corresponding guide column which in turn is connected to a corresponding guide frame including a corresponding bottom guide frame portion supported with respect to said rotatable member with cooperative respective hydraulic means for height adjustment of each said lance arm;

said rotable member comprising of a guide frame supporting platform and operatively connected to a slew bearing for said rotary motion, said slew bearing rotatable supported with respect to a stationary column and maintained at a height of above 9 meters ; and

power means for selectively operating said slew bearing for said desired rotary motion of said rotary member and in turn said lance with respect to the furnace.

A still further aspect of the present invention is directed to said system wherein said stationary column internally houses a drive CPL,oxygen piping with rotary and bellow, Nitrogen piping with rotary and bellow and water piping including inlet and outlet headers with rotary and bellow;

a bottom column with bottom flange fixed with foundation bolts and a slew bearing mounted on top with outer race bolted with super bolt arrangement with the top flange;

a guide frame platform is mounted on inner race of said slew bearing with super bolt arrangement adapted to be provided with controlled swiveling motion;

a drive CPL to drive the bearing for rotational movement;

a Displacement Guide Roller assembly is welded at top of said guide frame platform comprising a Bottom Guide frame just above said guide frame platform, a Guide Frame with roller arrangement positioned above said bottom guide frame, providing support for vertical up and down movement of three Guide Columns disposed therein;

three said structural Guide Columns used to hold corresponding three Lance Arms and are operated by respective Regulating cylinders(hydraulic) mounted on said Guide frame Platform, and those are guided by guide frame with guide rollers to avoid deflection during operation;

three said lance arms comprising left hand, right hand and a middle arm, bolted on the top of three said guide columns are used to hold the Oxygen lances for oxygen blowing disposed through three openings in water cooled delta;
a structural outrigger mounted on said guide frame is used to hold said Water cooled Delta and also carrying a Delta Drive used to drive Water Cooled delta during operation;
means for nitrogen cooling of oxygen lances through nitrogen ring fitted on the water cooled delta;
WinCC HMI screen provided for triple lance visualization and operation, having means for lance position control and PLC based controlled flow rate of oxygen and cooling water.

Yet another aspect of the present invention is directed to said system comprising

a bottom column with bottom flange fixed with foundation bolts and a slew bearing mounted on top with outer race bolted with super bolt arrangement with the top flange;

a guide frame platform is mounted on inner race of said slew bearing with super bolt arrangement adapted to be provided with controlled swiveling motion;

a drive CPL to drive the bearing for rotational movement;

a Displacement Guide Roller assembly is welded at top of said guide frame platform comprising a Bottom Guide frame just above said guide frame platform, a Guide Frame with roller arrangement positioned above said bottom guide frame, providing support for vertical up and down movement of three Guide Columns disposed therein;

three said structural Guide Columns used to hold three Lance Arms and are operated by respective Regulating cylinders(hydraulic) mounted on said Guide frame Platform, and those are guided by guide frame with guide rollers to avoid deflection during operation;

three said lance arms comprising left hand, right hand and a middle arm, bolted on the top of three said guide columns are used to hold the Oxygen lances for oxygen blowing disposed through three openings in water cooled delta;
a structural outrigger mounted on said guide frame is used to hold said Water cooled Delta and also carrying a Delta Drive used to drive Water Cooled delta during operation;
means for nitrogen cooling of oxygen lances through nitrogen ring fitted on the water cooled delta;
WinCC HMI screen provided for triple lance visualization and operation, having means for lance position control and PLC based controlled flow rate of oxygen and cooling water.

A still further aspect of the present invention is directed to said system wherein three lances are spatially arranged at an angular distance of 120 deg and use of three lances facilitate blowing oxygen with a flow rate of --- to --- preferably 300 Nm3/min, such that the approach area of metal bath surface that is in direct contact with the oxygen jets increases, leading to higher rate of reaction between the metal droplets and the slag layer resulting in improved yield with reduced cycle time.

A still further aspect of the present invention is directed to said system, wherein said regulating cylinders (hydraulic), mounted on Guide plate platform at bottom and fixed to arms at the top are used to operate said three lance arms.

A still further aspect of the present invention is directed to said system, wherein said water cooled delta attached to outrigger is provided to cover the shell during operation, having three openings for three lances with the arrangement of nitrogen cooling.

A still further aspect of the present invention is directed to said system, wherein independent operated Hydraulic Regulating cylinder with support of Guide rollers provide for operation individually of the said three lances.

A still further aspect of the present invention is directed to said system, wherein Hydraulic lines are placed adjacent to the Guide Frame Platform with hose and rotary arrangement.

A still further aspect of the present invention is directed to said system, wherein oxygen piping is inserted form bottom side and through the Bottom Column and Guide frame platform.
A still further aspect of the present invention is directed to said system, wherein water piping is inserted form middle and through the Bottom Column and Guide frame platform.
Yet another aspect of the present inventionis directed to said system, wherein Nitrogen piping is inserted form bottom side and through the Bottom Column and Guide frame platform.
A further aspect of the present invention is directed to said system wherein Delta lifting drive arrangement is placed under the outrigger on Drive mounting and maintenance platform and pulley with brackets are mounted on the outrigger to transfer the water cooled delta on the outrigger arms.
A still further aspect of the present invention is directed to said system comprising encoders for 3 lances to know the lance position.
A still further aspect of the present invention is directed to said system, wherein electrically-operated piston valves are provided on said lance O2 pipelines to adjust the O2 flow rate and are PLC controlled .
A still further aspect of the present invention is directed to said system, comprising Flow meters installed in water lines to check water flow rate and signals connected to PLC, which in turn is visible on HMI screen for use by operation crew.
A still further aspect of the present invention is directed to said system, wherein slip ring with all electrical connections are placed on the guide frame platform for enabling rotary motion of the said rotatable member.
A still further aspect of the present invention is directed to said system, wherein said bottom guide frame is used to increase the height of outrigger to avoid the interference between Outrigger and Fume Elbow.
The objects and advantages of the present invention are described hereunder in greater details with reference to the following accompanying non limiting illustrative drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1(a) is the schematic front view of the complete arrangement without the fume elbow of the three lance operation system for Conarc furnace according to the present invention.

Figure 1(b): is the schematic isometric view of the complete assembly of the three lance operation system for conarc furnace showing its disposition in relation to the furnace shell and delta and the different components of the system including the outrigger and fume elbow.

Figure 2: show the schematic front view and the top view of Bottom Column of the three lance operation system for Conarc furnace according to the present invention which rotatably support the guide frame platform through slew bearing mounted on its top flange and bottom flange is fixed with the foundation bolt.
Figure 3: show the schematic top view and isometric view of the Guide Frame Platform for supporting at its top the Bottom Guide frame, Guide Frame with roller arrangement for Guide Column movement.
Figure 4: show the schematic isometric view and the sectional front view of the Bottom Guide Frame for mounting on the guide frame platform.
Figure 5: show the schematic isometric view and the front view of the Guide Frame equipped with Front, Rear & Side Guide rollers used to guide the Guide frame during its vertical movement, for mounting on Bottom Guide Frame.
Figure 6: shows the schematic isometric view and the front view of the Guide Rollers for use as front, rear and side guide rollers in Guide frame to Guide the Guide Column to avoid the defalcation during operation.
Figure 7: shows the schematic isometric view and the front view of the Outrigger structure that is mounted on Guide Frame and used to hold the Water cooled Delta and also carrying the Delta Drive used to drive the Water Cooled delta during operation.
Figure 8: shows the schematic isometric view and the front view of the Guide Columns, three in number, are used to hold the Lance Arms and are operated by Regulating cylinders mounted on Guide frame Platform, and those are guided by guide frame with guide rollers to avoid the deflection during vertical up & down movement.
Figure 9: shows the schematic isometric view and top view of the Lance Arms (LH, RH & Middle) bolted on the top of 3 guide columns and are used to hold the Oxygen lances for oxygen blowing.
Figure 10: shows the schematic top view of the water cooled delta attached to outrigger through belt pulley connection of delta drive arrangement, is used to cover the shell during operation, having 3 openings for 3 lances as shown.
Figure 11: shows the schematic isometric view and top view of the belt pulley assembly of delta drive arrangement fitted to the lower side of Outrigger to avoid interference with lance arm, to operate the water cooled delta.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURES

The present invention is thus directed to a system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace for precise and selective positioning of the lances in relation to furnace delta and ensures desired controlled oxygen blowing in an operator friendly manner. The system also provide means for cooling of delta and the lances.

The three top Lance design is a new innovation of the applicants. The application of Triple lance is basically aimed at achieving benefits of an LD Converter. The blowing strength and the penetration depth of the oxygen jet in Conarc is low as compared to LD converters mainly on account of the lower height to diameter ratio. In applicants, manufacturing facility this ratio is 1, whereas it is generally in the range of 1.5-1.7 for LD converters. This restricts the oxygen top lance flow rate in 100% Hot Metal (HM) heats (Conarc) to 180 Nm3/min, whereas it is in the range of 350 - 400 Nm3/min in LD converters. By using a triple lance system in Conarc furnace, the blowing rate of 300 to 360 Nm3/min is achieved as approach area of metal bath surface that is in direct contact with the oxygen jets will increase, leading to higher rate of reaction between the metal droplets and the slag layer, as achieved in LD converters. As a result, this will improve %Yield, reduce cycle time, reduce Nitrogen, reduce jamming of roof and elbow, and increase refractory life.

The new system incorporates three lances in place of one, spatially arranged at an angular distance of 120 deg. Oxygen and water-cooling arrangements for each lance have been provided, along with necessary visualization on the WinCC HMI screen for its operation by the pulpit engineers. The use of three lances has facilitated blowing oxygen with a flow rate of 300 Nm3/min, which was earlier restricted to 210 Nm3/min in case of a Single lance due to operational difficulties.

The present invention thus provides a system for three top lance operation in Electric Arc Furnace including Conarc Furnace for precise positioning, placement and withdrawal of the three top lances inside the Conarc furnace through the openings in delta for oxygen blowing operation at desired flow rate for desired duration.

Accompanying Figure 1(a) shows the schematic front view of the complete arrangement without the fume elbow of the three lance operation system for Conarc furnace according to the present invention and accompanying Figure 1(b) shows the schematic isometric view of the complete assembly of the three lance operation system for Conarc furnace showing its disposition in relation to the furnace shell and delta and the different components of the system including the outrigger and fume elbow. The list of different components/subsystems as marked with reference number shown in the assembly is as follows:
1) Bottom Column
2) Guide Frame Platform
3) Slew Bearing
4) Drive CPL
5) Bottom Guide Frame
6) Guide Frame
7) Front, Rear & Side Guide Rollers
8) Outrigger
9) Guide Column - 3 no's
10) Lance Arm LH, RH & Middle
11) Oxygen Lance - 3 no's
12) Delta Drive Arrangement
13) Regulating Cylinders - 3 no's
14) Water Cooled Delta
15) Oxygen Piping
16) Water Piping
17) Nitrogen Piping Details
18) Hydraulic Piping - For Regulating Cylinders
19) Cylinder Mounting Arrangement.
20) Drive Mounting & Maintenance Platform
21) Pulley with Bracket

It can be seen that the lance operation system in Figure 1(b) comprises a bottom column(1) secured on foundation at bottom flange and holding a guide frame platform(2) rotatably mounted on its top flange with a slew bearing(3) mounted in between the top flange of bottom column and the bottom face of guide frame platform. Accompanying Figure 2 show the schematic front view and the top view of Bottom Column. Slew bearing of Diameter 3306mm is used for swiveling the top portion. A Drive CPL(4) is used to drive the bearing for rotational movement. The guide frame platform(2) is a structural platform mounted on inner race of slew bearing with super bolt arrangement. And at top, the Displacement Guide Roller assembly comprising Bottom Guide frame, Guide Frame with roller arrangement for Guide Column movement is welded.
Accompanying Figure 3 shows the schematic top view and isometric view of the Guide Frame Platform(2) for supporting at its top the Bottom Guide frame, Guide Frame with roller arrangement for Guide Column movement. Accompanying Figure 4 shows the schematic isometric view and the sectional front view of the Bottom Guide Frame(5) for mounting on the guide frame platform(2). Bottom guide frame(5)is a structural platform used to increase the height of outrigger(8) that holds water cooled delta(14) to avoid the interference between Outrigger and Fume Elbow.
Accompanying Figure 5 show the schematic isometric view and the front view of the Guide Frame(6) for mounting on top face of Bottom Guide Frame(5) equipped with Front, Rear & Side Guide rollers used to guide the Guide Columns during its vertical movement. The guide frame is a structural frame equipped with Front, Rear & Side Guide rollers used to guide the Guide columns during its vertical movement. The guide frame platform(2), the bottom guide frame(5) and the guide frame(6) have openings and internal hollow spaces to accommodate the three vertivcally disposed guide columns(9) that holds the three oxygen blowing lances through extended arms, and to allow for unobstructed vertical up and down motion of the said guide columns. Accompanying Figure 6 shows the schematic isometric view and the front view of the Guide Rollers(7) for use as front, rear and side guide rollers in Guide frame(6) to Guide the Guide Columns(9) to avoid the deflection during operation.
Accompanying Figure 8 shows the schematic isometric view and the front view of the Guide Columns(9), three in number-left hand right hand and middle, are used to hold the Lance Arms(10) and are operated by three corresponding Regulating Cylinders(13) mounted on Guide Frame Platform(2), and those are guided by Guide Frame(6) with guide rollers(7) to avoid the deflection during vertical up & down movement. The three Regulating cylinders (hydraulic)(13), mounted on Guide plate platform at bottom & fixed to arms at the top are used to operate 3 guide columns(9) with lance arms(10) to provide desired up or down motion for lance operation. Cylinder Mounting arrangement(19) is attached to guide frame platform(2) bolted with mounting bracket, on which cylinder's(13) are mounted.
Accompanying Figure 9 shows the schematic isometric view and top view of the Lance Arms (LH, RH & Middle)(10) bolted on the top of 3 guide columns(9) at one end and are used to hold the three Oxygen lances(11) for oxygen blowing at the other end of three arms extending over the furnace delta. Three Oxygen lances(11) fitted with lance arms(10) are used for oxygen blowing. Lance Holding Arrangement – Lance Holding drum and clamps fabricated and fixed in each holder of arm.

Accompanying Figure 7 shows the schematic isometric view and the front view of the Outrigger structure(8) that is mounted on Guide Frame(6) and used to hold the Water cooled Delta(14) and also carrying the Delta Drive arrangement(12) used to drive the Water Cooled delta during operation and also support the drive mounting and maintenance platform(20). Drive mounting & maintenance platform(20) is welded under the outrigger(8).
Accompanying Figure 10 shows the schematic top view of the water cooled delta(14) attached to outrigger(8) through belt pulley connection of delta drive arrangement(12), is used to cover the shell during operation, having 3 openings for 3 lances as shown.
Accompanying Figure 11 shows the schematic isometric view and top view of the belt pulley assembly(21) of delta drive arrangement(12) fitted to the lower side of Outrigger(8) to avoid interference with lance arm, to operate the water cooled delta. Pulley with brackets are mounted on the Outrigger to transfer the water cooled delta on the outrigger arms.
There are 3 Oxygen pipes(15) of 125mm NB with individual rotary and bellow arrangement used for oxygen supply to the three lances. These pipes are inserted from bottom side and through the Bottom Column (1) and Guide frame platform(2). 3 electrically-operated Gabler valves fixed on 3 lance O2 pipelines to adjust the O2 flowrate.

Water piping(16) Inlet & Outlet headers of 300mm NB is inserted from middle and through the Bottom Column(1) and Guide frame platform(2) having Rotary and bellow arrangement to provide water supply to three individual 100mm NB pipes for lance cooling and one 150mm NB piping for delta cooling. Flowmeters are installed to check the water flow-rate. 3 Inlets and 3 Outlets tappings taken from Inlet & Outlet Header of DM water for lance cooling. For each of these 3 arms, water line along with manual valve and necessary accessories are fixed.

A nitrogen pipe(17) of 65mm NB with Rotary arrangement is inserted from bottom side and through the Bottom Column (1) and Guide frame platform (2) which is used to cool O2 lance through nitrogen ring fitted on the water cooled delta.
Hydraulic pipings(18) provided at 9 meter height and are placed adjacent to the Guide Frame Platform (2) with hose and rotary arrangement used to operate 3 hydraulic cylinders. Slip ring(22) with all electrical connections are placed on the guide frame platform(2).

For triple lance visualization and operation, WinCC HMI screen has been designed. 3 nos. encoders fixed for 3 lances to know the lance position. Twin-piston Gabler valves fixed on oxygen pipe line for lances and their programming done in PLC. Flow meters installed in water lines and signals connected to PLC, which in turn is visible on HMI screen for use by operation crew.

It is thus possible by way of the present invention to provide a system for three top lance operation in Electric Arc Furnace including Conarc Furnace to precisely positioning and placement and withdrawing of the three lance for oxygen blowing operation, ensure controlled oxygen blowing at desired flow rate, required cooling of delta and the oxygen lances by controlled flow of cooling water as well as nitrogen cooling of lances through nitrogen ring fitted on the water cooled delta. Advantageously, the system provides WinCC HMI screen for triple lance visualization and operation involving PLC based control of oxygen/water flow rates, in an operator friendly manner.

We Claim:

1. A system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace, comprising

atleast one lance adapted for desired reciprocating downward and upward motion for
introducing and retracting the lance in and from said furnace having a releasably closable opening;

said lance operatively connected to oxygen blowing source and substantially vertically disposed in relation to said furnace opening and supported from top of said furnace by a lance supporting arm;

said lance supporting arm operatively connected to height regulating mechanism whereby the height of the said lance supporting arm can be regulated to in the process bring down or retract upwards the said lance into and from said furnace;

said height regulating mechanism supported with respect to a rotatable member whereby the lance supporting arm and the lance can be swiveled and rotated in any desired position for facilitating the location of the lance for desired lance disposition and/or furnace operation.

2. A system as claimed in claim 1 wherein said height regulating mechanism operatively connected to said lance arm and supported with respect to said rotatable member comprises said lance arm connected to a guide column which in turn is connected to a guide frame including a bottom guide frame portion supported with respect to said rotatable member with cooperative hydraulic means for height adjustment of said lance arm;

said rotable member comprising of a guide frame supporting platform and operatively connected to a slew bearing for said rotary motion, said slew bearing rotatable supported with respect to a stationary column; and

power means for selectively operating said slew bearing for said desired rotary motion of said rotary member and in turn said lance with respect to the furnace.

3. A system as claimed in anyone of claims 1 or 2 comprising drive mechanism for controlled lifting or closing of said releasably closable furnace opening involving a water cooled delta.

4. A system as claimed in claim 3 comprising a structural outrigger to hold to hold a water cooled releasably closable furnace opening /water cooled delta and also to carry said drive mechanism comprising of a drive arrangement having drive with chain & sprocket arrangement.

5. A system for controlled introduction of lance from furnace top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace, comprising

three lances adapted for desired reciprocating downward and upward motion for
introducing and retracting the lance in and from said furnace having a releasably closable opening, said lances spatially arranged preferably at an angular distance of 120 deg ;

each said lance operatively connected to oxygen blowing source and substantially vertically disposed in relation to said furnace top having corresspondinh opening and supported from top of said furnace by respective lance supporting arm;

each said lance supporting arm operatively connected to respective height regulating mechanism whereby the height of each said lance supporting arm can be regulated to in the process bring down or retract upwards the respective lance into and from said furnace top openings;

said height regulating mechanism supported with respect to a rotatable member whereby the lance supporting arm and the lance can be swiveled and rotated in any desired position for facilitating the location of the lances for desired lance disposition and/or furnace operation;

said respective height regulating mechanism operatively connected to said respective lance arm and supported with respect to said rotatable member comprises each said lance arm connected to a corresponding guide column which in turn is connected to a corresponding guide frame including a corresponding bottom guide frame portion supported with respect to said rotatable member with cooperative respective hydraulic means for height adjustment of each said lance arm;

said rotable member comprising of a guide frame supporting platform and operatively connected to a slew bearing for said rotary motion, said slew bearing rotatable supported with respect to a stationary column and maintained at a height of above 9 meters ; and

power means for selectively operating said slew bearing for said desired rotary motion of said rotary member and in turn said lance with respect to the furnace.

6. A system as claimed in anyone of claims 1 to 5 wherein said stationary column internally houses a drive CPL, oxygen piping with rotary and bellow, Nitrogen piping with rotary and bellow and water piping including inlet and outlet headers with rotary and bellow.

a bottom column with bottom flange fixed with foundation bolts and a slew bearing mounted on top with outer race bolted with super bolt arrangement with the top flange;

a guide frame platform is mounted on inner race of said slew bearing with super bolt arrangement adapted to be provided with controlled swiveling motion;

a drive CPL to drive the bearing for rotational movement;

a Displacement Guide Roller assembly is welded at top of said guide frame platform comprising a Bottom Guide frame just above said guide frame platform, a Guide Frame with roller arrangement positioned above said bottom guide frame, providing support for vertical up and down movement of three Guide Columns disposed therein;

three said structural Guide Columns used to hold corresponding three Lance Arms and are operated by respective Regulating cylinders(hydraulic) mounted on said Guide frame Platform, and those are guided by guide frame with guide rollers to avoid deflection during operation;

three said lance arms comprising left hand, right hand and a middle arm, bolted on the top of three said guide columns are used to hold the Oxygen lances for oxygen blowing disposed through three openings in water cooled delta;
a structural outrigger mounted on said guide frame is used to hold said Water cooled Delta and also carrying a Delta Drive used to drive Water Cooled delta during operation;
means for nitrogen cooling of oxygen lances through nitrogen ring fitted on the water cooled delta;
WinCC HMI screen provided for triple lance visualization and operation, having means for lance position control and PLC based controlled flow rate of oxygen and cooling water.

7. A system as claimed in anyone of claims 1 to 6 comprising

a bottom column with bottom flange fixed with foundation bolts and a slew bearing mounted on top with outer race bolted with super bolt arrangement with the top flange;

a guide frame platform is mounted on inner race of said slew bearing with super bolt arrangement adapted to be provided with controlled swiveling motion;

a drive CPL to drive the bearing for rotational movement;

a Displacement Guide Roller assembly is welded at top of said guide frame platform comprising a Bottom Guide frame just above said guide frame platform, a Guide Frame with roller arrangement positioned above said bottom guide frame, providing support for vertical up and down movement of three Guide Columns disposed therein;

three said structural Guide Columns used to hold three Lance Arms and are operated by respective Regulating cylinders(hydraulic) mounted on said Guide frame Platform, and those are guided by guide frame with guide rollers to avoid deflection during operation;

three said lance arms comprising left hand, right hand and a middle arm, bolted on the top of three said guide columns are used to hold the Oxygen lances for oxygen blowing disposed through three openings in water cooled delta;
a structural outrigger mounted on said guide frame is used to hold said Water cooled Delta and also carrying a Delta Drive used to drive Water Cooled delta during operation;
means for nitrogen cooling of oxygen lances through nitrogen ring fitted on the water cooled delta;
WinCC HMI screen provided for triple lance visualization and operation, having means for lance position control and PLC based controlled flow rate of oxygen and cooling water.

8. A system as claimed in anyone of claims 1 to 7 wherein three lances are spatially arranged at an angular distance of 120 deg and use of three lances facilitate blowing oxygen with a flow rate of preferably 300 Nm3/min, such that the approach area of metal bath surface that is in direct contact with the oxygen jets increases, leading to higher rate of reaction between the metal droplets and the slag layer resulting in improved yield with reduced cycle time.

9. A system as claimed in anyone of claims 1 to 8, wherein said regulating cylinders (hydraulic), mounted on Guide plate platform at bottom and fixed to arms at the top are used to operate said three lance arms.

10. A system as claimed in claims 1 to 9, wherein said water cooled delta attached to outrigger is provided to cover the shell during operation, having three openings for three lances with the arrangement of nitrogen cooling.

11.A system as claimed in claims 1 to 10 , wherein independent operated Hydraulic Regulating cylinder with support of Guide rollers provide for operation individually of the said three lances.

12.A system as claimed in claims 1 to 11, wherein Hydraulic lines are placed adjacent to the Guide Frame Platform with hose and rotary arrangement.

13. A system as claimed in claims 1 to 12, wherein oxygen piping is inserted form bottom side and through the Bottom Column and Guide frame platform.

14. A system as claimed in claims 1 to 13, wherein water piping is inserted form middle and through the Bottom Column and Guide frame platform.

15. A system as claimed in claims 1 to 14, wherein Nitrogen piping is inserted form bottom side and through the Bottom Column and Guide frame platform.

16. A system as claimed in claims 1 to 15 wherein Delta lifting drive arrangement is placed under the outrigger on Drive mounting and maintenance platform and pulley with brackets are mounted on the outrigger to transfer the water cooled delta on the outrigger arms.

17. A system as claimed in claims 1 to 16 comprising encoders for 3 lances to know the lance position.

18. A system as claimed in claims 1 to 17, wherein electrically-operated piston valves are provided on said lance O2 pipelines to adjust the O2 flow rate and are PLC controlled.

19. A system as claimed in claims 1 to 18, comprising Flow meters installed in water lines to check water flow rate and signals connected to PLC, which in turn is visible on HMI screen for use by operation crew.

20. A system as claimed in claims 1 to 19, wherein slip ring with all electrical connections are placed on the guide frame platform for enabling rotary motion of the said rotatable member.

21. A system as claimed in claims 1 to 20, wherein said bottom guide frame is used to increase the height of outrigger to avoid the interference between Outrigger and Fume Elbow.

Dated this the 25th day of January, 2014
Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)

ABSTRACT
TITLE: A SYSTEM FOR CONTROLLED INTRODUCTION OF LANCE FROM TOP FOR CONTROLLED OXYGEN BLOWING IN FURNACES SUCH AS ELECTRIC ARC FURNACE INCLUDING CONARC FURNACE.
The present invention relates to a system for controlled introduction of lance from top for controlled oxygen blowing in furnaces such as Electric Arc Furnace including Conarc Furnace with provision for controlled lance positioning including lifting and lowering as per need and controlled oxygen blowing arrangement and water cooled delta with three openings for lance with the arrangement of nitrogen cooling, suitably supported on guided column and frame structures with bearing mounted swiveling operation of support column. Advantageously, the three lance operation system for Conarc furnace according to the present invention is equipped with WinCC HMI screen for triple lance visualization and operation, alongwith signals from flow meters connected to PLC, which in turn is visible on HMI screen for use by operation crew. Importantly, the three lance operation system is capable to support desired oxygen blowing for refining of steel in such refining vessels such as CONARC furnace which would achieve higher efficiency and productivity.