| Title of Invention | A METHOD FOR PRODUCING FERROCHROME USING A CLOSED SUBMERGED ARC FURNACE (SAF) |
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| Abstract | A method for producing ferrochrome using a closed submerged arc furnace (SAF), comprising the steps of: injecting air into the closed submerged arc furnace (1) (SAF) for combustion of carbon monoxide gas generated from the reduction reactions in the SAF, utilizing the heat generated from said combustion of carbon monoxide by transferring the heat to the ferrochrome charge in the submerged arc furnace, thereby resulting in reduction in electric power consumption of said arc furnace. |
| Full Text | FIELD OF APPLICATION The present invention relates to a method for producing ferrochrome using a closed submerged arc furnace. In particular it relates to reduction in electric power consumption in a submerged arc furnace (SAF) used for producing ferrochrome by utilizing the heat generated from combustion of carbon monoxide in the furnace. The invention also provides a closed submerged arc furnace for carrying out the method. BACKGROUND OF THE INVENTION Ferrochrome production process is power intensive. The process consumes 3300-3400 KWH of energy per tonne of ferrochrome metal produced. This amounts to about 34% of the total production cost. Also electric power cost in India is almost four times higher than that in leading ferrochrome producing countries like South Africa. There is therefore, a need to look for alternative sources of energy either within or outside the submerged arc furnace (SAF). SUMMARY OF THE INVENTION A large quantity of carbon monoxide gas (~ 850 kg / ton of FeCr) is generated in the reduction reactions within the SAF itself, which represents a high potential combustion energy source. Use of this energy inside submerged arc furnace (SAF) can result in electrical power consumption reduction of 15-20 % even at a low efficiency of 40 % heat transfer to the charge. The main object of the present invention therefore, is to use the energy generated from the post-combustion of carbon monoxide gas generated within the submerged arc furnace (SAF) by supplying combustion air. The oxidation of carbon monoxide gas takes place due to oxygen supplied by combustion air. The oxidation of carbon monoxide gas is a highly exothermic reaction which releases 281 KJ of energy for every mole of carbon monoxide gas oxidized at standard temperature of 298 ° K. The oxidation of carbon monoxide gas takes place via following reaction. 2CO + O2->2CO2; ΔH0 = -281 KJ / mole In ferrochrome smelting huge gas volumes (14000-14500 m3 / hr) of carbon monoxide gases at temperatures of 550-650 ° C are generated. This represents potential source of chemical energy which can replace the costly electric energy consumption in ferrochrome making. Thus the present invention provides a method for producing ferrochrome using a closed submerged arc furnace, comprising the steps of: injecting air into the closed submerged arc furnace for combustion of carbon monoxide gas generated therein; and utilizing the heat generated form said combustion of carbon monoxide by transferring to the ferrochrome charge in the submerged arc furnace, thereby resulting in reduction in electric power consumption of said arc furnace. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The invention can now be explained with reference to the accompanying drawing where Figure 1 shows a closed submerged arc furnace (SAF) for smelting ferrochrome, where the present invention is applied. DETAILED DESCRIPTION A schematic arrangement of the closed submerged arc furnace (SAF) of the present invention is shown in Figure 1. A closed (submerged arc furnace 1 is provided with injectors 2 at the top for injecting combustion air into the furnace. The objective of introducing air is to achieve 50% combustion of the carbon monoxide gas generated in the furnace. The injection of air from the top of the furnace is such that maximum heat generated due to combustion of carbon monoxide will be transferred to the surface of the ferrochrome charge 3, charge 3 thus will get heated. At a realistic heat transfer efficiency of 40 %, this process can result in reduction in electric power consumption equivalent to 15-20 % of the present consumption in ferrochrome making with closed submerged arc furnace (SAF). WE CLAIM; 1. A method for producing ferrochrome using a closed submerged arc furnace (SAF), comprising the steps of: - injecting air into the closed submerged arc furnace (1) (SAF) for combustion of carbon monoxide gas generated from the reduction reactions in the SAF, - utilizing the heat generated from said combustion of carbon monoxide by transferring the heat to the ferrochrome charge in the submerged arc furnace, thereby resulting in reduction in electric power consumption of said arc furnace. 2. The method for producing ferrochrome as claimed in claim 1, wherein the step of injecting air into said closed arc furnace is carried out such that maximum amount of heat generated by oxidation of carbon monoxide is allowed to be transferred to the ferrochrome charge in the furnace. 3. A closed submerged arc furnace (1) for producing ferrochrome comprising injectors (2) arranged at the top of the furnace for injecting air for combustion of carbon monoxide generated in the furnace so as to utilize the chemical energy for reduction in consumption of electro power. 4. A method for producing ferrochrome using a closed submerged arc furnace, substantially as herein described and illustrated in the accompanying drawing. Abstract Title: "A Method for reduction in power consumption in closed SAF used for producing ferrochrome". A method for producing ferrochrome using a closed submerged arc furnace (SAF), comprising the steps of: injecting air into the closed submerged arc furnace (1) (SAF) for combustion of carbon monoxide gas generated from the reduction reactions in the SAF, utilizing the heat generated from said combustion of carbon monoxide by transferring the heat to the ferrochrome charge in the submerged arc furnace, thereby resulting in reduction in electric power consumption of said arc furnace. |
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00233-kol-2006-description provisional.pdf
233-KOL-2006-(16-12-2011)-ABSTRACT.pdf
233-KOL-2006-(16-12-2011)-AMANDED CLAIMS.pdf
233-KOL-2006-(16-12-2011)-CORRESPONDENCE.pdf
233-KOL-2006-(16-12-2011)-DESCRIPTION (COMPLETE).pdf
233-KOL-2006-(16-12-2011)-DRAWINGS.pdf
233-KOL-2006-(16-12-2011)-FORM-1.pdf
233-KOL-2006-(16-12-2011)-FORM-2.pdf
233-KOL-2006-(16-12-2011)-OTHERS.pdf
233-KOL-2006-(30-12-2011)-CORRESPONDENCE.pdf
233-KOL-2006-(30-12-2011)-OTHER PATENT DOCUMENT.pdf
233-KOL-2006-CORRESPONDENCE-1.1.pdf
233-KOL-2006-CORRESPONDENCE-1.2.pdf
233-kol-2006-correspondence.pdf
233-kol-2006-description (complete).pdf
233-KOL-2006-EXAMINATION REPORT.pdf
233-KOL-2006-GRANTED-ABSTRACT.pdf
233-KOL-2006-GRANTED-CLAIMS.pdf
233-KOL-2006-GRANTED-DESCRIPTION (COMPLETE).pdf
233-KOL-2006-GRANTED-DRAWINGS.pdf
233-KOL-2006-GRANTED-FORM 1.pdf
233-KOL-2006-GRANTED-FORM 2.pdf
233-KOL-2006-GRANTED-FORM 3.pdf
233-KOL-2006-GRANTED-FORM 5.pdf
233-KOL-2006-GRANTED-SPECIFICATION-COMPLETE.pdf
233-KOL-2006-PETITION UNDER RULE 137.pdf
233-KOL-2006-REPLY TO EXAMINATION REPORT-1.1.pdf
233-KOL-2006-REPLY TO EXAMINATION REPORT.pdf
233-kol-2006-specification.pdf
| Patent Number | 260825 | ||||||||||||
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| Indian Patent Application Number | 233/KOL/2006 | ||||||||||||
| PG Journal Number | 22/2014 | ||||||||||||
| Publication Date | 30-May-2014 | ||||||||||||
| Grant Date | 23-May-2014 | ||||||||||||
| Date of Filing | 20-Mar-2006 | ||||||||||||
| Name of Patentee | TATA STEEL LIMITED | ||||||||||||
| Applicant Address | RESEARCH AND DEVELOPMENT DIVISION JAMSHEDPUR | ||||||||||||
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| PCT International Classification Number | C21C 5/52 | ||||||||||||
| PCT International Application Number | N/A | ||||||||||||
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