Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C6/00—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion
  • F23C6/04—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
  • C21C5/52—Manufacture of steel in electric furnaces
  • C21C5/5211—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace
  • C21C5/5217—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace equipped with burners or devices for injecting gas, i.e. oxygen, or pulverulent materials into the furnace
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C2205/00—Pulsating combustion
  • F23C2205/20—Pulsating combustion with pulsating oxidant supply
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C2900/00—Special features of, or arrangements for combustion apparatus using fluid fuels or solid fuels suspended in air; Combustion processes therefor
  • F23C2900/03005—Burners with an internal combustion chamber, e.g. for obtaining an increased heat release, a high speed jet flame or being used for starting the combustion
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D99/00—Subject matter not provided for in other groups of this subclass
  • F27D99/0001—Heating elements or systems
  • F27D99/0033—Heating elements or systems using burners
  • F27D2099/0043—Impulse burner
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D99/00—Subject matter not provided for in other groups of this subclass
  • F27D99/0001—Heating elements or systems
  • F27D99/0033—Heating elements or systems using burners
  • F27D2099/0046—Heating elements or systems using burners with incomplete combustion, e.g. reducing atmosphere
  • F27D2099/0048—Post- combustion
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling

Definitions

• the invention relates to a method and a pulse flow controlled fuel / oxygen lance for the afterburning of products from incomplete combustion.
• a thermal nozzle combustion process is known from DE 693 14 903 T2.
• an oxidizing agent with an oxygen concentration of at least 30% at an initial speed of 15.2 to 61 m / s and separately from that is introduced into the thermal nozzle designed as a lance
• Oxidizing agent Fuel is introduced into an oxidizing agent feed channel at a speed of more than 61 m / s and burns up to about 20% of the oxygen with fuel therein.
• the combustion reaction products generated during the combustion of the fuel are mixed with the remaining oxygen of the oxidizing agent within the oxidizing agent supply channel and the oxygen stream heated up to 1650 ° C. is injected into the combustion zone at 152 to 610 m / s through an outlet nozzle.
• This known thermal nozzle combustion process is limited to oxygen supply systems with low source pressure. It is disadvantageous that the oxidant supply channel must be dimensioned very large due to the existing impulse flow ratios between natural gas and oxygen. This results in very high investment costs. In addition, the durability of the oxidant supply channel is low, which can result in high operating costs for maintenance. The availability of the furnace system is reduced and there is a loss of production.
• No. 5,823,762 describes a system for generating gas jets of different designs.
• nitrogen, argon or carbon dioxide as the main gas and propane, natural gas and other hydrocarbons as well as a gaseous fuel as well as an oxidizing agent containing oxygen or only consisting of oxygen are introduced into the nozzle in different flow rates / flow rates through channels arranged separately from one another, so that the one generated in the nozzle Gas jet flows out of the nozzle at the speed of sound. Due to the high impulse currents that are generated by the speed of sound of the gas jet, deflections and reflections can occur in certain phases of the production process, which affect the refractory delivery or the can destroy the water-cooled elements of the oven. This results in high operating costs for the repair of the furnace and additional production costs.
• the object of the invention is therefore to provide a generic
• Combustion process which allows a more economical and flexible process compared to the prior art by means of an oxidant feed that is flexibly adapted to the requirements. Furthermore, the invention is based on the object of specifying a generic fuel / oxygen lance which is suitable for such a method.
• the fuel / oxygen lance is fed a fossil fuel, for example natural gas, through the axial fuel channel via the fuel nozzle arranged with a concentric sleeve at 15-50 m / s into the mixing chamber.
• a fossil fuel for example natural gas
• the oxygen flows into the mixing chamber via the oxygen supply through an oxygen channel surrounding the axial fuel channel via the primary cross section connected to the oxygen channel and the mixing chamber.
• oxygen is introduced into the mixing chamber of the fuel / oxygen lance via the oxygen supply through the oxygen channel surrounding an axial fuel channel via a secondary cross section connected to the oxygen channel and the mixing chamber.
• the fuel in the mixing chamber is completely burned with the oxygen introduced through the primary cross section.
• the combustion reaction products generated during the combustion of the fuel heat the oxidizing agent introduced into the mixing chamber to at least 560 ° C.
• the stoichiometric amount of oxygen required for the combustion of the fuel which corresponds to 8-24 vol.% Of the total oxygen, is introduced into the primary cross section and as the oxidizing agent
• Oxygen to be introduced into the combustion zone is introduced into the mixing chamber through the secondary cross section at flow velocities of 70 to 200 m / s or 95 to 225 m / s.
• the secondary cross section has a value that is at least 5.5 times larger than the primary cross section.
• the oxidizing agent heated to at least 560 ° C. in the mixing chamber of the fuel / oxygen lance by means of the combustion reaction products is passed through the outlet nozzle out of the copper mixing chamber with a Speed of at least Mach 0.8 injected into the combustion zone.
• the length L of the mixing chamber corresponds to at least 2.5 times the diameter D of the outlet nozzle.
• the fuel / oxygen lance with water cooling is made of copper in the mixing chamber area, the fuel channel and the oxygen channel are made of stainless steel pipes.
• the thermal nozzle combustion process used for the afterburning of products from incomplete combustion ensures a substantial improvement in the heat transfer conditions in the combustion zone by means of the oxygen input into the combustion zone which is adapted to the respective process conditions by means of the fuel / oxygen lance according to the invention.
• a fuel for example natural gas
• a fuel nozzle 2 concentrically enclosed by a sleeve 5 at 20 to 80 m 3 / h and with a Velocity in the range of 15-50 m / s is introduced into a mixing chamber 8 equipped with an outlet nozzle 9 arranged at the end.
• the stoichiometric oxygen required to burn the fuel introduced into the mixing chamber 8 is fed to the mixing chamber 8 via an oxygen supply 3 through an oxygen channel 4 surrounding the axial fuel channel 1 via a primary cross section 6 connected to the oxygen channel 4 and the mixing chamber 8.
• the one in the Mixing chamber 8 as an oxidizing agent for the combustion zone is heated to at least 560 ° C. by the combustion reaction products formed during the combustion of the fuel with the oxygen supplied through the primary cross section 6 and flows through the front-side outlet nozzle 9 of the mixing chamber 8 at a speed of at least 0.8 Get into the combustion zone.
• the secondary cross section 7 is at least 5.5 times larger than the primary cross section 6.
• the length L of the copper mixing chamber 8 is at least 2.5 times larger than the diameter D of its outlet nozzle 9.
• the fuel / oxygen consisting of copper and stainless steel pipes
• the lance is further equipped with a cooling water tract 10 surrounding the mixing chamber 8 and the oxygen channel 4 with the primary and secondary cross sections 6, 7 and a cooling water supply and cooling water discharge 11, 12.
• the fuel / oxygen lance according to the invention was successfully tested in an electric arc furnace in a process for the afterburning of products from incomplete combustion.
• two fuel / oxygen lances were arranged in the area of the hot gas manifold in the furnace wall with an angle of inclination of 30 ° to the horizontal downwards and tangentially into the space between the electrode and the furnace wall, so that the main exhaust gas flow is recorded with a superimposed oxygen flow cover.
• the fuel / oxygen lances were operated as fuel / oxygen burners in the initial phase of melting down.
• the combustion output per device was specified in accordance with the scrap ratios between 1.0 and 1.5 MW.
• the combustion ratio was set between 0.9 and 2.0 depending on the oxygen content in the furnace.
• the natural gas supply was reduced and oxygen injection rates adjusted to match the oxygen content in the exhaust gas between 5 to 20 m 3 / min, this corresponds to a specific oxygen consumption of 2 to 8 m 3 / tfl.
• no oxygen was passed through the fuel / oxygen lances.
• approximately 30 m 3 of natural gas and 60 m 3 of oxygen per hour and fuel / oxygen lance were applied to the fuel / oxygen lances to keep the outlet nozzles 9 free.
• degrees of afterburning of at least 75% are achieved, with a saving potential of electrical energy per cubic meter of oxygen of at least 4.5 KWh being achieved.
• the kinetic energy of the oxygen jet can be adapted to the process sequence by varying the proportion of fuel

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Fluidized-Bed Combustion And Resonant Combustion (AREA)
• Furnace Charging Or Discharging (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7665232

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Family Cites Families (16)

• 2000
  • 2000-11-30 DE DE10059440A patent/DE10059440A1/de not_active Ceased
• 2001
  • 2001-11-27 PL PL01366032A patent/PL366032A1/xx not_active Application Discontinuation
  • 2001-11-27 CZ CZ20031468A patent/CZ20031468A3/cs unknown
  • 2001-11-27 WO PCT/EP2001/013805 patent/WO2002044617A1/de not_active Ceased
  • 2001-11-27 EP EP01989520A patent/EP1340018A1/de not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events