US20090214990A1 - Flame burner and method for flame burning a metallic surface - Google Patents

Flame burner and method for flame burning a metallic surface Download PDF

Info

Publication number
US20090214990A1
US20090214990A1 US12/305,236 US30523607A US2009214990A1 US 20090214990 A1 US20090214990 A1 US 20090214990A1 US 30523607 A US30523607 A US 30523607A US 2009214990 A1 US2009214990 A1 US 2009214990A1
Authority
US
United States
Prior art keywords
nozzle
gas
region
flame burner
oxygen
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/305,236
Inventor
Egon Evertz
Ralf Evertz
Stefan Evertz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Egon Evertz KG GmbH and Co
Original Assignee
Egon Evertz KG GmbH and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Egon Evertz KG GmbH and Co filed Critical Egon Evertz KG GmbH and Co
Assigned to EGON EVERTZ KG (GMBH & CO) reassignment EGON EVERTZ KG (GMBH & CO) ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: EVERTZ, EGON, EVERTZ, RALF, EVERTZ, STEFAN
Assigned to EGON EVERTZ KG (GMBH & CO) reassignment EGON EVERTZ KG (GMBH & CO) CORRECTIVE ASSIGNMENT TO CORRECT THE ZIP CODE OF THE ASSIGNEE'S ADDRESS. PREVIOUSLY RECORDED ON REEL 021992 FRAME 0021. ASSIGNOR(S) HEREBY CONFIRMS THE THE CORRECT ZIP CODE IS 42651. Assignors: EVERTZ, EGON, EVERTZ, RALF, EVERTZ, STEFAN
Publication of US20090214990A1 publication Critical patent/US20090214990A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/20—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone
    • F23D14/22—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/38—Torches, e.g. for brazing or heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/48—Nozzles
    • F23D14/56—Nozzles for spreading the flame over an area, e.g. for desurfacing of solid material, for surface hardening, or for heating workpieces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/48—Nozzles
    • F23D14/58—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration
    • 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
    • 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
    • F23D—BURNERS
    • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
    • F23D2900/00012—Liquid or gas fuel burners with flames spread over a flat surface, either premix or non-premix type, e.g. "Flächenbrenner"
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
    • F23D2900/14—Special features of gas burners
    • F23D2900/14642—Special features of gas burners with jet mixers with more than one gas injection nozzles or orifices for a single mixing tube
    • 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 flame burner having a nozzle disposed in a head, wherein in addition to annularly disposed gas-supply passages the nozzle has a central gas-supply duct.
  • the invention further relates to a method for flame scarfing of a metallic surface by means of the stated flame burner.
  • flame burners In the known flame burners combustion gas is guided to a nozzle head via annularly disposed gas-supply passages and is mixed with the oxygen transported via the central gas supply, and forms the combustion flame. Flame burners are utilized for various application purposes. For example, during the cooling of slabs produced by means of casting, undesired tears often occur, which have to be removed by means of a surface treatment. The same is also true for ridges and burrs, which occur, for example, during cutting in the processing of the slabs. The flame burners are guided along the affected surfaces for removing the surface blemishes, which may be accomplished with a manually manipulated burner or an automatically guided burner where a flame burner is attached to a controllable robot arm.
  • the processing costs for surface treatment are substantially determined by the processing time and the gas consumption, an adequate surface quality being absolutely required.
  • the object of the present invention is to provide a flame burner and a method for flame scarfing, in which an optimum surface quality of the workpiece to be treated is attainable with an oxygen consumption and processing time that is as low as possible.
  • the invention provides the flame burner described in claim 1 and the method described in claim 9 .
  • the flame burner according to the invention has a nozzle comprising multiple gas-supply passages annularly disposed around a central gas-supply duct.
  • the central gas-supply duct has at least three successive regions, as viewed in the flow direction, that is a first region tapering in to a minimal inner diameter, a second region whose inner surface flares out to a larger diameter than the minimal inner diameter, and a third region of uniform cross-sectional profile, preferably a uniform cylindrical inner diameter.
  • the important factor is the cross-sectional constriction of the inner diameter up to a critical measurement of the diameter, which is followed by flaring.
  • the last third region having a uniform cross-sectional profile serves to maintain the produced gas flow profile.
  • a pulsating gas flow can be created by means of this design, which has the speed of sound, or supersonic speed, at the nozzle outlet mouth.
  • the ratio of the oxygen pressure upstream of the nozzle and the ambient pressure on one hand, and the ratio of the oxygen pressure at the nozzle outlet surface and the ambient pressure, determine the gas profile. If the pressure at the nozzle outlet surface is below ambient pressure, the exiting gas flow has a narrowing shape in the initial section downstream of the nozzle, whereas with reversed conditions the shape expands in a barrel-shaped manner. If the oxygen pressure upstream of the nozzle and at the exit from the nozzle is equal to the ambient pressure, a straight line envelope of the initial section of the exiting gas is created.
  • the pulse frequency achievable using the nozzle and the amplitude individually depend on the initial pressure, the degree of tapering, and the degree of expansion.
  • the non-isobaric turbulent supersonic flow created is characterized by strong spatial inhomogeneities of the velocity and pressure fields, which lead to the creation of volatile state changes, that is the pulse-like shocks and layer displacements at high velocity gradients.
  • This flow velocity and pressure pulsation leads to a pulsation spectrum. Starting with a certain value, the gas velocity locally reaches supersonic speed in the described nozzle at the smallest critical nozzle cross-section, upon exceeding of which pulse-like compressed and thinned regions occur as pulses.
  • pulse waves can form a barrel-shaped flow, the strung compressions of which depend on the ratio of the oxygen pressure in the nozzle to the ambient pressure, and on the so-called critical velocity ratio, which is the ratio of the gas velocity at the nozzle outlet surface to the speed of sound.
  • the flame burner has a nozzle configured in the type of a Laval nozzle, which together with the third region as the “stabilizing ring” forms an oscillating resonator.
  • the present invention generally provides within its scope that the first and the second regions are disposed in succession, however, short partial parts may be contained in them where the minimal diameter does not change. The flow velocity is maintained in such a short partial part.
  • the central gas-supply duct also ends slightly upstream of the level defined by the openings, in which the annularly disposed gas-supply passages end. Solutions within the scope of the present inventions are also incorporated, whereby multiple rings of coaxially extending gas-supply passages that end at different levels downstream of the outlet opening of the central pipe in a graduated manner.
  • the length of the first region is preferably smaller than the length of the second region, and is preferably also smaller than the length of the third region.
  • the third region may, depending on the desired pulse characteristics, be selected longer, of the same length, or even shorter than the total length of the first and second regions.
  • the diameter of the third region is smaller than the maximum outlet diameter of the central gas-supply duct at an upstream end of the first region.
  • the diameter and the lengths of these three regions are coordinated such that gas exits at the nozzle outlet mouth in the form of pulses, preferably having a pulse frequency of between 100 and 650 Hz.
  • a maximum gas flow velocity of 2 Ma should be present in the central gas-supply duct at predetermined values of the oxygen and combustion gas pressure.
  • the nozzle may have a round or concentric cross-section, wherein particularly the central gas-supply duct has an annular cross-section in order to elongate the at least one ring, or possibly two rings, on which additional gas-supply ducts are positioned for the combustion gas.
  • the nozzle head is preferably cooled, water in particular being suited as the coolant.
  • the method according to the invention for flame burning of a metallic surface, such as a slab is characterized in that oxygen guided via a central nozzle of a flame burner is incited to oscillate such that a pulsating oxygen flow exits the nozzle outlet mouth at the speed of sound, or at supersonic speed.
  • the pulsating oxygen flow consists of longitudinal waves, i.e. a periodic succession of pressure increases and decreases of the gaseous oxygen. Not only is the central oxygen flow made to pulsate by means of this measure, but the peripherally inflowing combustion gas is also made to oscillate. The result is a substantial savings of oxygen consumption and a smooth surface of the metal piece to be processed via flame scarfing.
  • the process parameters are selected as a function of the nozzle shape such that the oxygen flow is distributed into a central flow and peripheral flows.
  • FIG. 1 is a combined side view and a longitudinal section through the nozzle of the flame burner according to the invention
  • FIG. 2 is a top view of the nozzle
  • FIGS. 3 a to d are cross-sections through the central gas-supply duct having different gas flow shapes.
  • the core of the flame burner according to FIGS. 1 and 2 is a nozzle 10 disposed in a head, wherein in addition to an annular array of gas-supply passages 11 the nozzle has a central gas-supply duct 12 .
  • annular arrays of gas inlet openings 111 and 112 on rings are concentric to the gas-supply duct 12 .
  • Their angular spacing a is determined by their number n so it equals 360/n.
  • the gas-supply passages 111 and 112 open into an annular gas-supply passage 11 , as shown in FIG. 1 .
  • the passages 112 , 111 , and 11 carry a combustion gas or a mixture of oxygen and a combustion gas, whereas the central gas-supply passage 12 is provided for feeding oxygen.
  • the central gas-supply duct 12 is subdivided into sections L 1 , L 2 , L 4 , L 3 , and L K , or L 1 , L c , and L K , along its length L, the latter regions being of particular meaning.
  • the gas-inlet region L 1 corresponds to the inlet region used in nozzles known from the prior art.
  • a Laval nozzle-like shape of the central first supply passage 12 extending along the length L c , is novel. This nozzle shape is formed by a region in which the nozzle inner diameter tapers up to a minimum critical diameter d min that is maintained along a length L 4 (also see FIG. 3 ).
  • L 1 43 mm
  • L 2 10 mm
  • L 3 25 mm
  • L 4 2 mm
  • L K 72 mm. While L 1 , L 2 , L 3 , and L 4 remain unchanged at given oxygen and combustion gas pressures, the length of L K may be changed to 65 mm or 25 mm.
  • FIG. 3 merely illustrates the cross-sectional views of the central gas-supply duct in the Laval nozzle-like equipped region and in the stabilization region.
  • the gaseous oxygen flowing into the Laval-like region has a pressure P 0 and a Temperature T 0 .
  • the pressure is P A at the end of this Laval-like region, i.e. at the mouth of the upstream region L c .
  • the first region where the nozzle is frustoconically tapered is shown at 121
  • the adjoining region of the frustoconical nozzle expansion is shown at 122
  • the region of constant diameter is shown at 123 , and has the shape shown in FIG. 3 .
  • a to d illustrate different gas pulsations depending on the initial pressure P o , which appear as longitudinal waves, in which higher and lower pressures alternate. It is also obvious that depending on the initial pressure P o selected, the central gaseous oxygen flow surrounded by a peripheral combustion gas flow is constricted in a narrower or broader manner.
  • the length L K is the decisive factor as to the degree in which the pulsating oxygen flow can be stabilized.
  • the flame burner according to the invention may be configured either as a manual or an automatic device.
  • the pressures utilized, by means of which the gaseous oxygen is pulled into the central opening, are between 5 and 20 bars.
  • the natural gas utilized as the combustion gas is substantially comprised of methane, and is at a pressure of 1 to 5 bars.
  • Methane is added via the nozzle inlets 111 and mixes with the oxygen entering via the nozzle inlets 112 such that an oxygen/methane mixture flows peripherally to the nozzle outlet mouth via the annular opening 11 .
  • the velocity aspired in the central line 112 at the stated application pressure of the oxygen flow should be within a range of supersonic speed, and should be up to 2 Mach at the predetermined values of the oxygen and combustion gas pressure.
  • a first flame burner having a common nozzle according to the prior art for flaming a slab was used.
  • Oxygen was introduced via the central nozzle at a pressure of approximately 12 ⁇ 10 5 Pa
  • combustion gas was introduced via the peripherally disposed nozzles at a pressure of 2 ⁇ 10 5 Pa.
  • oxygen was in the first case during flaming work at amounts between 370 to 290 m 3 .
  • 90 to 100 m 3 was required by the nozzle according to the invention, which illustrates that an enormous gaseous oxygen savings can be achieved.

Abstract

The invention relates to a flame burner having a nozzle (10) disposed in a head, wherein in addition to annularly disposed gas supply channels (11) the nozzle has a central gas supply opening (12), which has a laval nozzle-like region and a stabilizing region having a consistent diameter connected thereto in the flow direction. In order to flame burn a metallic surface the oxygen gas guided through a central nozzle of a flame burner is incited to oscillate in such a manner, such that a pulsating oxygen flow exiting the nozzle mouth is formed at the speed of sound, or at supersonic speed.

Description

  • The invention relates to a flame burner having a nozzle disposed in a head, wherein in addition to annularly disposed gas-supply passages the nozzle has a central gas-supply duct.
  • The invention further relates to a method for flame scarfing of a metallic surface by means of the stated flame burner.
  • In the known flame burners combustion gas is guided to a nozzle head via annularly disposed gas-supply passages and is mixed with the oxygen transported via the central gas supply, and forms the combustion flame. Flame burners are utilized for various application purposes. For example, during the cooling of slabs produced by means of casting, undesired tears often occur, which have to be removed by means of a surface treatment. The same is also true for ridges and burrs, which occur, for example, during cutting in the processing of the slabs. The flame burners are guided along the affected surfaces for removing the surface blemishes, which may be accomplished with a manually manipulated burner or an automatically guided burner where a flame burner is attached to a controllable robot arm.
  • The processing costs for surface treatment are substantially determined by the processing time and the gas consumption, an adequate surface quality being absolutely required.
  • The object of the present invention is to provide a flame burner and a method for flame scarfing, in which an optimum surface quality of the workpiece to be treated is attainable with an oxygen consumption and processing time that is as low as possible.
  • In order to attain this object, the invention provides the flame burner described in claim 1 and the method described in claim 9.
  • Further improvements of the invention are described in the sub-claims.
  • The flame burner according to the invention has a nozzle comprising multiple gas-supply passages annularly disposed around a central gas-supply duct. The central gas-supply duct has at least three successive regions, as viewed in the flow direction, that is a first region tapering in to a minimal inner diameter, a second region whose inner surface flares out to a larger diameter than the minimal inner diameter, and a third region of uniform cross-sectional profile, preferably a uniform cylindrical inner diameter. The important factor is the cross-sectional constriction of the inner diameter up to a critical measurement of the diameter, which is followed by flaring. As a stabilizing ring, the last third region having a uniform cross-sectional profile serves to maintain the produced gas flow profile. A pulsating gas flow can be created by means of this design, which has the speed of sound, or supersonic speed, at the nozzle outlet mouth. The ratio of the oxygen pressure upstream of the nozzle and the ambient pressure on one hand, and the ratio of the oxygen pressure at the nozzle outlet surface and the ambient pressure, determine the gas profile. If the pressure at the nozzle outlet surface is below ambient pressure, the exiting gas flow has a narrowing shape in the initial section downstream of the nozzle, whereas with reversed conditions the shape expands in a barrel-shaped manner. If the oxygen pressure upstream of the nozzle and at the exit from the nozzle is equal to the ambient pressure, a straight line envelope of the initial section of the exiting gas is created.
  • The pulse frequency achievable using the nozzle and the amplitude individually depend on the initial pressure, the degree of tapering, and the degree of expansion. The non-isobaric turbulent supersonic flow created is characterized by strong spatial inhomogeneities of the velocity and pressure fields, which lead to the creation of volatile state changes, that is the pulse-like shocks and layer displacements at high velocity gradients. This flow velocity and pressure pulsation leads to a pulsation spectrum. Starting with a certain value, the gas velocity locally reaches supersonic speed in the described nozzle at the smallest critical nozzle cross-section, upon exceeding of which pulse-like compressed and thinned regions occur as pulses. These types of pulse waves can form a barrel-shaped flow, the strung compressions of which depend on the ratio of the oxygen pressure in the nozzle to the ambient pressure, and on the so-called critical velocity ratio, which is the ratio of the gas velocity at the nozzle outlet surface to the speed of sound. In principle, the flame burner has a nozzle configured in the type of a Laval nozzle, which together with the third region as the “stabilizing ring” forms an oscillating resonator.
  • The present invention generally provides within its scope that the first and the second regions are disposed in succession, however, short partial parts may be contained in them where the minimal diameter does not change. The flow velocity is maintained in such a short partial part.
  • In the present invention the central gas-supply duct also ends slightly upstream of the level defined by the openings, in which the annularly disposed gas-supply passages end. Solutions within the scope of the present inventions are also incorporated, whereby multiple rings of coaxially extending gas-supply passages that end at different levels downstream of the outlet opening of the central pipe in a graduated manner.
  • For technical flow reasons, the length of the first region is preferably smaller than the length of the second region, and is preferably also smaller than the length of the third region. The third region may, depending on the desired pulse characteristics, be selected longer, of the same length, or even shorter than the total length of the first and second regions.
  • According to a further improvement of the invention the diameter of the third region is smaller than the maximum outlet diameter of the central gas-supply duct at an upstream end of the first region. In order to optimize the effect, the diameter and the lengths of these three regions are coordinated such that gas exits at the nozzle outlet mouth in the form of pulses, preferably having a pulse frequency of between 100 and 650 Hz. Preferably, a maximum gas flow velocity of 2 Ma should be present in the central gas-supply duct at predetermined values of the oxygen and combustion gas pressure.
  • The nozzle may have a round or concentric cross-section, wherein particularly the central gas-supply duct has an annular cross-section in order to elongate the at least one ring, or possibly two rings, on which additional gas-supply ducts are positioned for the combustion gas.
  • As generally known according to prior art, the nozzle head is preferably cooled, water in particular being suited as the coolant.
  • The method according to the invention for flame burning of a metallic surface, such as a slab, is characterized in that oxygen guided via a central nozzle of a flame burner is incited to oscillate such that a pulsating oxygen flow exits the nozzle outlet mouth at the speed of sound, or at supersonic speed. The pulsating oxygen flow consists of longitudinal waves, i.e. a periodic succession of pressure increases and decreases of the gaseous oxygen. Not only is the central oxygen flow made to pulsate by means of this measure, but the peripherally inflowing combustion gas is also made to oscillate. The result is a substantial savings of oxygen consumption and a smooth surface of the metal piece to be processed via flame scarfing. Preferably, the process parameters, particularly the oxygen application pressure by means of which the oxygen flow is entered into the nozzle, are selected as a function of the nozzle shape such that the oxygen flow is distributed into a central flow and peripheral flows. The ratio of the oxygen pressure upstream of the central nozzle to the ambient pressure N=po/pu is preferably between 1 and 200, whereas the ratio of the oxygen pressure pa at the nozzle outlet surface to the ambient pressure pu is between 0.1 to 100.
  • Further embodiment variants and details of the invention are illustrated in the drawings and described below. Therein:
  • FIG. 1 is a combined side view and a longitudinal section through the nozzle of the flame burner according to the invention,
  • FIG. 2 is a top view of the nozzle, and
  • FIGS. 3 a to d are cross-sections through the central gas-supply duct having different gas flow shapes.
    •
  • The core of the flame burner according to FIGS. 1 and 2 is a nozzle 10 disposed in a head, wherein in addition to an annular array of gas-supply passages 11 the nozzle has a central gas-supply duct 12. Here and as detailed in FIG. 2, annular arrays of gas inlet openings 111 and 112 on rings are concentric to the gas-supply duct 12. Their angular spacing a is determined by their number n so it equals 360/n. In the present case the gas- supply passages 111 and 112 open into an annular gas-supply passage 11, as shown in FIG. 1. The passages 112, 111, and 11 carry a combustion gas or a mixture of oxygen and a combustion gas, whereas the central gas-supply passage 12 is provided for feeding oxygen.
  • The central gas-supply duct 12 is subdivided into sections L1, L2, L4, L3, and LK, or L1, Lc, and LK, along its length L, the latter regions being of particular meaning. The gas-inlet region L1 corresponds to the inlet region used in nozzles known from the prior art. However, a Laval nozzle-like shape of the central first supply passage 12, extending along the length Lc, is novel. This nozzle shape is formed by a region in which the nozzle inner diameter tapers up to a minimum critical diameter dmin that is maintained along a length L4 (also see FIG. 3). In the region immediately downstream in a gas flow direction 13, the inner surface of the gas-supply duct 12 flares smoothly to a larger diameter dK (see FIG. 3) that is maintained up to the nozzle outlet mouth along the remaining length Lk. The following dimensions were selected in the specific illustrated embodiments: L1=43 mm, L2=10 mm, L3=25 mm, L4=2 mm, and LK=72 mm. While L1, L2, L3, and L4 remain unchanged at given oxygen and combustion gas pressures, the length of LK may be changed to 65 mm or 25 mm.
  • FIG. 3 merely illustrates the cross-sectional views of the central gas-supply duct in the Laval nozzle-like equipped region and in the stabilization region. The gaseous oxygen flowing into the Laval-like region has a pressure P0 and a Temperature T0. The pressure is PA at the end of this Laval-like region, i.e. at the mouth of the upstream region Lc. The first region where the nozzle is frustoconically tapered is shown at 121, the adjoining region of the frustoconical nozzle expansion is shown at 122, whereas finally the region of constant diameter is shown at 123, and has the shape shown in FIG. 3. FIGS. a to d illustrate different gas pulsations depending on the initial pressure Po, which appear as longitudinal waves, in which higher and lower pressures alternate. It is also obvious that depending on the initial pressure Po selected, the central gaseous oxygen flow surrounded by a peripheral combustion gas flow is constricted in a narrower or broader manner. The length LK is the decisive factor as to the degree in which the pulsating oxygen flow can be stabilized.
  • The flame burner according to the invention may be configured either as a manual or an automatic device. The pressures utilized, by means of which the gaseous oxygen is pulled into the central opening, are between 5 and 20 bars. The natural gas utilized as the combustion gas is substantially comprised of methane, and is at a pressure of 1 to 5 bars. Methane is added via the nozzle inlets 111 and mixes with the oxygen entering via the nozzle inlets 112 such that an oxygen/methane mixture flows peripherally to the nozzle outlet mouth via the annular opening 11. The velocity aspired in the central line 112 at the stated application pressure of the oxygen flow should be within a range of supersonic speed, and should be up to 2 Mach at the predetermined values of the oxygen and combustion gas pressure.
  • The following results have been achieved in tests using flame burners:
  • Initially, a first flame burner having a common nozzle according to the prior art for flaming a slab was used. Oxygen was introduced via the central nozzle at a pressure of approximately 12×105 Pa, and combustion gas was introduced via the peripherally disposed nozzles at a pressure of 2×105 Pa.
  • Subsequently, a flame burner having a nozzle according to the invention was used. Due to the resultant pressure pulses, blowback was so great that manual flaming at an oxygen pressure of 12×105 Pa could not be performed. For this reason, the oxygen pressure was reduced to 8×105 Pa, whereas the combustion gas pressure remained unchanged.
  • Surprisingly, oxygen was in the first case during flaming work at amounts between 370 to 290 m3. For the same flaming work only 90 to 100 m3 was required by the nozzle according to the invention, which illustrates that an enormous gaseous oxygen savings can be achieved.

Claims (11)

1. A flame burner having a nozzle disposed in a head, wherein in addition to annularly disposed gas-supply passages the nozzle has a central gas-supply duct wherein the central gas-supply duct has directly succeeding regions in the flow direction, namely
a first region tapering in to a minimal inner diameter,
a second region whose inner surface flares to a larger diameter than the minimal diameter, and
a third region extending up to the nozzle outlet mouth and having a uniform cross-sectional profile, preferably a uniform cylindrical inner diameter.
2. The flame burner according to claim 1 wherein a length of the first region is smaller than a length of the second region.
3. The flame burner according to claims 1 wherein a diameter of the third region is smaller than a maximum initial diameter at an upstream end of the first region.
4. The flame burner according to claim 1 wherein diameters of the three regions and their lengths are adjusted to one another such that gas exits as pulses at the nozzle outlet mouth.
5. The flame burner according to claim 4 wherein the pulse frequency at the nozzle outlet mouth is 100 to 650 Hz.
6. The flame burner according to claims 4 wherein the maximum gas flow velocity is 2 Ma at predetermined values of the oxygen and the combustion gas pressure.
7. The flame burner according to claim 1 wherein the central gas-supply duct has an annular cross-section.
8. The flame burner according to claim 1 wherein the nozzle head is liquid-cooled, particularly water-cooled.
9. A method for flame burning a metallic surface, the method comprising the steps of:
feeding gaseous oxygen guided through a central nozzle of a flame burner; and
controlling flow of the gaseous oxygen in the burner such that the gaseous oxygen is made to oscillate such that and a pulsating oxygen flow exiting the nozzle outlet mouth is formed at the speed of sound or at supersonic speed.
10. The method for flame burning according to claim 9, further comprising the step of
subdividing the gaseous oxygen flow into a central flow and peripheral flows.
11. The method according to claims 9 further comprising the step of
maintaining the ratio of the oxygen pressure upstream of the central nozzle to the ambient pressure is to between 1 and 200 such that the ratio of the oxygen pressure at the nozzle outlet surface to the ambient pressure is between 0.1 to 100.
US12/305,236 2006-07-22 2007-05-18 Flame burner and method for flame burning a metallic surface Abandoned US20090214990A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102006034014A DE102006034014A1 (en) 2006-02-23 2006-07-22 Flame deseaming burner has nozzle arranged in head and circularly arranged gas supply channels has central gas supply opening
DE102006034014.0 2006-07-22
PCT/DE2007/000901 WO2008011851A1 (en) 2006-07-22 2007-05-18 Flame burner and method for flame burning a metallic surface

Publications (1)

Publication Number Publication Date
US20090214990A1 true US20090214990A1 (en) 2009-08-27

Family

ID=38475981

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/305,236 Abandoned US20090214990A1 (en) 2006-07-22 2007-05-18 Flame burner and method for flame burning a metallic surface

Country Status (10)

Country Link
US (1) US20090214990A1 (en)
EP (1) EP2044366A1 (en)
JP (1) JP2009544925A (en)
KR (1) KR20090037894A (en)
CN (1) CN101460780A (en)
BR (1) BRPI0715425A2 (en)
DE (1) DE102006034014A1 (en)
EA (1) EA012772B1 (en)
MX (1) MX2009000447A (en)
WO (1) WO2008011851A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108204590A (en) * 2016-12-16 2018-06-26 中国石油化工股份有限公司 A kind of gas well open flow test burner
US11446770B2 (en) * 2019-05-03 2022-09-20 Thierry Rozot Systems, apparatuses, and methods for reducing the size of a material

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140291900A1 (en) * 2011-11-25 2014-10-02 Alexander Deica Nozzle System for a Cutting Torch for Autogenous Torch-Cutting with a Sleeve-Like Pipe Jacket for Drawing in Outside Air
US10188344B2 (en) 2012-12-27 2019-01-29 Ihi Corporation Optimum administration form providing system for magnetic drug
DE102013101184A1 (en) * 2013-02-07 2014-08-07 Gega Lotz Gmbh Flämmblockbaugruppe
JP7455653B2 (en) * 2016-06-15 2024-03-26 リケンテクノス株式会社 Antibacterial hard coat and its manufacturing method
JP7270577B2 (en) * 2020-05-12 2023-05-10 リケンテクノス株式会社 ANTIBACTERIAL HARD COAT AND METHOD FOR MANUFACTURING SAME
JP7032473B2 (en) * 2020-05-12 2022-03-08 リケンテクノス株式会社 Antibacterial hard coat and its manufacturing method
JP7270578B2 (en) * 2020-05-12 2023-05-10 リケンテクノス株式会社 ANTIBACTERIAL HARD COAT AND METHOD FOR MANUFACTURING SAME
CN113757660B (en) * 2021-09-29 2023-08-29 广东美的白色家电技术创新中心有限公司 Burner and gas stove

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2825202A (en) * 1950-06-19 1958-03-04 Snecma Pipes traversed by pulsating flow gases
US3230924A (en) * 1962-12-26 1966-01-25 Sonic Dev Corp Sonic pressure wave generator
US5931985A (en) * 1994-11-18 1999-08-03 Mannesmann Aktiengesellschaft Process and device for blowing oxygen-containing gas with and without solid material on a metal melt in a metallurgical vessel
US7258831B2 (en) * 2002-07-11 2007-08-21 Danieli & C. Officine Meccaniche S.P.A. Injector-burner for metal melting furnaces

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2823037C2 (en) * 1976-04-30 1980-06-26 E. Schlueter Fachhandel Fuer Schweisstechnik, 3014 Laatzen Welding, cutting, heating or scarfing torches
US5304256A (en) * 1991-12-09 1994-04-19 Esab Welding Products, Inc. Scarfing method
US5714113A (en) * 1994-08-29 1998-02-03 American Combustion, Inc. Apparatus for electric steelmaking
GB2342610B (en) * 1998-10-14 2003-01-15 Heckett Multiserv Plc Surface treatment of metal articles
IT1302798B1 (en) * 1998-11-10 2000-09-29 Danieli & C Ohg Sp INTEGRATED DEVICE FOR THE INJECTION OF OXYGEN AND GASTECNOLOGICS AND FOR THE INSUFFLATION OF SOLID MATERIAL IN
EP1179602A1 (en) * 2000-08-07 2002-02-13 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Method for injection of a gas with an injection nozzle
FR2823290B1 (en) * 2001-04-06 2006-08-18 Air Liquide COMBUSTION PROCESS INCLUDING SEPARATE INJECTIONS OF FUEL AND OXIDIZING AND BURNER ASSEMBLY FOR IMPLEMENTATION OF THIS PROCESS

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2825202A (en) * 1950-06-19 1958-03-04 Snecma Pipes traversed by pulsating flow gases
US3230924A (en) * 1962-12-26 1966-01-25 Sonic Dev Corp Sonic pressure wave generator
US5931985A (en) * 1994-11-18 1999-08-03 Mannesmann Aktiengesellschaft Process and device for blowing oxygen-containing gas with and without solid material on a metal melt in a metallurgical vessel
US7258831B2 (en) * 2002-07-11 2007-08-21 Danieli & C. Officine Meccaniche S.P.A. Injector-burner for metal melting furnaces

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108204590A (en) * 2016-12-16 2018-06-26 中国石油化工股份有限公司 A kind of gas well open flow test burner
US11446770B2 (en) * 2019-05-03 2022-09-20 Thierry Rozot Systems, apparatuses, and methods for reducing the size of a material

Also Published As

Publication number Publication date
KR20090037894A (en) 2009-04-16
MX2009000447A (en) 2009-03-03
CN101460780A (en) 2009-06-17
DE102006034014A1 (en) 2007-10-31
WO2008011851A1 (en) 2008-01-31
EP2044366A1 (en) 2009-04-08
EA012772B1 (en) 2009-12-30
EA200802429A1 (en) 2009-06-30
BRPI0715425A2 (en) 2013-01-01
JP2009544925A (en) 2009-12-17

Similar Documents

Publication Publication Date Title
US20090214990A1 (en) Flame burner and method for flame burning a metallic surface
JP4204867B2 (en) Combustion method with separate injection for fuel and oxidant and burner assembly for performing the method
US5823762A (en) Coherent gas jet
US6342086B1 (en) Method and apparatus for improved EAF steelmaking
JP2651969B2 (en) Fluid burner
JP2000193215A (en) Combustion method for manufacturing glass and metal and use thereof
JPS62207815A (en) Oxygen blowing lance
US5165602A (en) Process and device for cutting by liquid jet
DE50302463D1 (en) Device for controlling the gas / air ratio for a premixing combustion device
JPH0248500B2 (en)
KR20040057995A (en) Method of Processing Preform for Optical Fiber and Apparatus Therefor
US6709630B2 (en) Metallurgical lance and apparatus
KR20090023593A (en) Gas burner nozzle
US20070057417A1 (en) Metallurgical lance with annular gas flow control
AU2007278611A1 (en) Flame burner and method for flame burning a metallic surface
US4022383A (en) Nozzle for welding, heating, cutting and/or flame cleaning
US3938743A (en) Adjustably positionable supersonic nozzle means
US4795138A (en) Metallurgical tuyere and method of calibrating same
RU2338638C2 (en) Method of thermo abrasive treatment and machine "castor" for its implementation
JP3156731B2 (en) Quartz glass burner
JP2019190695A (en) Burner and heating method using burner
JPH0379606B2 (en)
SU1201050A1 (en) Apparatus for secondary cooling of continuously cast billet
SU963692A1 (en) Apparatus for cooling continuously cast ingots
RU2223164C2 (en) Gas - oxygen cutter

Legal Events

Date Code Title Description
AS Assignment

Owner name: EGON EVERTZ KG (GMBH & CO), GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:EVERTZ, EGON;EVERTZ, RALF;EVERTZ, STEFAN;REEL/FRAME:021992/0021

Effective date: 20081020

AS Assignment

Owner name: EGON EVERTZ KG (GMBH & CO), GERMANY

Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE ZIP CODE OF THE ASSIGNEE'S ADDRESS. PREVIOUSLY RECORDED ON REEL 021992 FRAME 0021;ASSIGNORS:EVERTZ, EGON;EVERTZ, RALF;EVERTZ, STEFAN;REEL/FRAME:022282/0378

Effective date: 20081020

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION