US3570471A - Radiant tube having uniform high-temperature distribution - Google Patents

Radiant tube having uniform high-temperature distribution Download PDF

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Publication number
US3570471A
US3570471A US799249A US3570471DA US3570471A US 3570471 A US3570471 A US 3570471A US 799249 A US799249 A US 799249A US 3570471D A US3570471D A US 3570471DA US 3570471 A US3570471 A US 3570471A
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United States
Prior art keywords
radiant tube
burner
channels
air
tube
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Expired - Lifetime
Application number
US799249A
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English (en)
Inventor
Lazaros J Lazaridis
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Thermo Fisher Scientific Inc
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Thermo Electron Corp
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Publication date
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Publication of US3570471A publication Critical patent/US3570471A/en
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    • 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 
    • F23C3/00—Combustion apparatus characterised by the shape of the combustion chamber
    • F23C3/002—Combustion apparatus characterised by the shape of the combustion chamber the chamber having an elongated tubular form, e.g. for a radiant tube

Definitions

  • the rotation is initiated by helical channels formed in the peripheral surface of the burner head. Air is forced through those channels at high velocity and fuel is fed through the interior of the head and into the channels at right angles through a series of spaced orifices.
  • the resultant complete mixing followed by nearadiabatic combustion create extremely high flame tempera tures resulting in high radiant tube temperatures and high heat fluxes and heat release rates.
  • the present invention although having the same general objectives of increasing the use and broadening the fields of use of radiant tube furnaces is more related to improving the radiant tube per se by raising its operating temperature and heat flux density well beyond what can be achieved with presently available combustion units of this type.
  • the improved radiant tube apparatus is eminently suitable for use not only in the furnace disclosed in my cited application but also generally with radiant and immersiontype systems.
  • the radiant tube is cylindrical in shape as is the burner. At the peripheral surface of the burner, helical channels are formed. It is fitted snugly either directly into the radiant tube or into an enclosing sleeve which, with the channels forms a group of helical passages through which air or other combustion gas is forced. These passages serve the primary purpose of creating rotary motion of the fuel-mix which, after ignition, persists as a helical flue gas stream down the length of the radiant tube to enhance heat transfer and provide uniform temperature distribution along the radiant tube. Secondly, the passages in conjunction with fuel orifices normal to the channels aid in thorough mixing which increases efficiency and permit the achievement of high flame temperatures within the entire mass of the mixture.
  • the air or other combustion-supporting gas forced through the sleeve and formed by the channels into high velocity helical air streams is preferably delivered through a relatively large sleeve to the member enclosing the burner and the gas is delivered through a smaller sleeve communicating with the interior of the burner to reach the radial orifices.
  • the gas, emerging as it does, through the radial orifices at right angles to the turbulent airstream creates a vortex contributing to thorough mixing.
  • the mixture as it leaves the burner head is rotating helically and is there ignited. Because of the thorough mixing, it burns almost adiabatically and products of combustion continue as flue gas streams down the radiant tube with the same generally helical motion imparted to the mixture.
  • the rotation of the flue gas stream and the pressure against the interior wall of the radiant tube caused by the centrifugal force of the rotating stream scavenges away boundary layers to enhance heat transfer from the stream to the tube. Most important, transfer of heat from the stream to the tube is such that a uniform distribution of temperature along a tube of considerable length is achieved.
  • a peep sight tube having a transparent seal at its end remote from the burner and terminating at the end wall of the burner head permits combustion to be observed and monitored.
  • An electrode extending to a point external to that end wall to form a spark gap may be used for ignition.
  • the electrode may pass through the burner head and out through the outer enclosing sleeve in, for example, a spark plug body to which conventional arrangements for electrical excitation may be made outside the enclosing sleeve.
  • FIG. I is a view, partly in section, of a burner head suitable to be incorporated in my radiant tube burner system
  • FIG. 2 is a fragmentary sectional view providing detail on the configuration of the burner head of FIG. 1;
  • FIG. 3 is an enlargement of the burner head of FIG. 1, and
  • FIG. 4 is a view, partly in section, illustrating the action of the flue gases in the radiant tube.
  • FIG. 1 I show the introduction of air at the lower right through what may conveniently be a conventional pipe nipple 12.
  • the pipe nipple may be, in turn, connected to a larger pipe or sleeve 14 through a wall of which a spark plug 16 is threaded.
  • An electrode 13 of the spark plug is extended to pass parallel to the axis of the sleeve as is explained in greater detail below.
  • An opening is formed in the elbow of the pipe nipple 12 to accommodate a smaller pipe nipple 20 which may be welded or otherwise suitably sealed into the pipe nipple 12.
  • a source of gas not shown, is connected to the pipe nipple 20.
  • the pipe nipple 20 also has an opening formed in its elbow to accommodate a tube 22 which may be of steel or other inexpensive metal.
  • the tube 22, is also, of course, sealed into the opening in the nipple 20.
  • a cap 24 is threaded upon the tube 22 and its end is sealed by an element of a quartz or other transparent material to permit observation of combustion through the tube 22.
  • a burner head 28 may be fitted axially into the radiant tube 22, but where it is desired to limit the length of the radiant tube, it may be fitted into a bridging ceramic adapter sleeve 26.
  • the sleeve 26 is made of Mulfrax or other suitable hightemperature resistant material and has shoulders formed at its ends. The internal shoulder at the right end of the adapter 26 is fitted into the sleeve 14 and the external shoulder at the left end of the adapter 26 is fitted over a radiant tube 30. Onlya portion of the radiant tube 30 is visible, but it will be noted that the inside diameters of the adapter 26 and the radiant tube 30 are substantially the same and no discontinuity exists between the two.
  • burner head 28 is snugly fitted into the adapter 26 and air coming through the adapter 26 at high velocity is forced into the desired rotation by the vanes 32 formed upon the outer surfaces of the burner head 28.
  • the helical configuration of the vanes is made more obvious in FIG. 3.
  • the peep sight 22 is brazed or otherwise sealed in place in the end wall of the burner head 28 remote from the input side.
  • the gasline 20, which may be formed with a suitable shoulder adjacent its end is fitted into an opening formed in the near wall of the burner head and it, too, is preferably brazed or welded in place.
  • a tube 36 within which is disposed a sleeve 38 of ceramic insulating material such as alundum.
  • the electrode extension 18 passes to a point beyond the far end wall where it is bent to form a spark gap.
  • Radial openings 40 are formed through the cylindrical wall of the burner head 28 and, as is plain in FIG. 3. these orifices are spaced along the helical channels formed by the vanes 32.
  • FIG. 4 I show in a somewhat idealized manner the effects obtained in my invention as a result of the thorough mixing, near-adiabatic combustion and, especially, the rotation of the products of combustion or flue gases, as they pass down the radiant tube 30.
  • the burner head is recessed in its ceramic sleeve from the near end of the radiant tube.
  • the sleeve 26 surrounding and snugly fitted over the burner head 28 has an internal diameter closely matched to that of the radiant tube 30.
  • Complete mixing and combustion are achieved before the'flue gasses reach the radiant tube and no discontinuities are present to interfere with the continued rotation of the flue gases.
  • the larger the angle made by the helical channels with the axis of the cylindrical structure the shorter the length over which uniform temperature distribution will be had.
  • Uniform temperature distribution over widely varying lengths of radiant tube can be achieved by proper selection of the vane angle so that rotation of flue gas continues to the end of the radiant tube and boundary layer scavenging is more or less uniform over that entire length and not concentrated at the entry to the radiant tube.
  • the velocities of the air and the gas as well as other parameters including the number of orifices 40, and the diameters of the various components are interrelated in such a fashion that various changes and adjustments are feasible to optimum performance.
  • an air velocity of approximately 320 f.p.s. and a gas velocity at the injection orifices of approximately 185 f.p.s. have given excellent results.
  • a total of 24 such orifices each having a diameter of approximately 0.093 inches provided optimum performance.
  • changes of air velocity not only the size but the number of fuel injection orifices could be varied.
  • the various lines have been shown to be concentric, that is, the air input line, the gas input line, and the peep sight being constructed one within the other these need not be so arranged. It is desirable, however, to maintain the air input line as the outer enclosure, not only to form the desired helical passages with the burner head but also to provide a cooling effect.
  • the cooling effect is so pronounced that the temperatures even at points just behind the burner head are several orders of magnitude lower than the temperatures at the radiant tube. Therefore, it is possible to use available, cheap materials such as conventional piping bringing the cost of the system to a point where the radiant tube burner unit and the furnace using it are competitive with other types of radiant tube combustors and furnaces.
  • preheated combustion air may be fed to the burner at temperatures approaching that of fuel ignition.
  • the helical channels may be formed in the sleeve surrounding the burner head rather than in the burner head per se, the important point being the helical openings at the interface for mixing and rotating the fuel mix.
  • the design of the burner is such that all conventional safety equipment may be incorporated with a minimum of complication.
  • a burner disposed axially of said tube for the combustion of a fuel mix, a sleeve closely surrounding said burner, helical channels being formed at the interface of said sleeve and said burner, means for forcing air through said helical channels and means for introducing fuel at right angles into said channels whereby products of combustion are formed into streams of flue gases proceeding helically through said radiant tube.
  • saidburner being hollow, and disposed adjacent an end of said radiant tube, said burner having a first plurality of helical channels formed on the outer surface thereof and a second plurality of radial openings formed therethrough, said openings being disposed at spaced points in said channels, means for forcing air from said source thereof through said helical channels and means for forcing gas from said source thereof through said radial openings to obtain a mixture of said air and gas in said channels and to impart rotation to said mixture, and means disposed adjacent said burner for igniting said mixture to form said rotating mixture into said stream of flue gases proceeding helically through said radiant tube.
  • said burner is generally cylindrical in cross section and which further includes a sleeve having substantially the same internal diameter as said radiant tube surrounding said burner and aligned with said radiant tube.
  • the combination which includes means connecting the interior of said burner head to said source of fuel and means connecting the interior of said sleeve to said source of air, the fiow of said air providing a cooling effect to said connecting means.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Gas Burners (AREA)
  • Combustion Of Fluid Fuel (AREA)
US799249A 1969-02-14 1969-02-14 Radiant tube having uniform high-temperature distribution Expired - Lifetime US3570471A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US79924969A 1969-02-14 1969-02-14

Publications (1)

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US3570471A true US3570471A (en) 1971-03-16

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Application Number Title Priority Date Filing Date
US799249A Expired - Lifetime US3570471A (en) 1969-02-14 1969-02-14 Radiant tube having uniform high-temperature distribution

Country Status (5)

Country Link
US (1) US3570471A (fr)
JP (1) JPS507286B1 (fr)
DE (1) DE1950077B2 (fr)
FR (1) FR2031416A1 (fr)
GB (1) GB1275599A (fr)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4673350A (en) * 1986-08-26 1987-06-16 Eclipse, Inc. Burner assembly for radiant tube heating system
US4673348A (en) * 1983-10-21 1987-06-16 Air Products And Chemicals, Inc. Heating apparatus
WO1999005453A1 (fr) * 1997-07-25 1999-02-04 Maxon Corporation Bruleur
US6443728B1 (en) * 2001-03-19 2002-09-03 Alstom (Schweiz) Ag Gas pipe ignitor
US6461148B1 (en) * 2000-09-28 2002-10-08 Mcdermott Technology, Inc. Compact, high-temperature, low-flow rate, liquid fuel-fired burner
US20030235798A1 (en) * 2001-05-10 2003-12-25 Moore Edward E. U-tube diffusion flame burner assembly having unique flame stabilization
US20080131824A1 (en) * 2006-10-26 2008-06-05 Deutsches Zentrum Fuer Luft- Und Raumfahrt E.V. Burner device and method for injecting a mixture of fuel and oxidant into a combustion space
WO2009078899A1 (fr) * 2007-12-14 2009-06-25 Dow Technology Investments Llc Mélengeur de gaz rapide (à cisaillement élevé) d'oxygène/hydrocarbure
US20100204495A1 (en) * 2007-12-14 2010-08-12 Dow Technology Investments Llc Hydrocarbon/oxygen industrial gas mixer with water mist
US20100204496A1 (en) * 2007-12-14 2010-08-12 Dow Technology Investments Llc Hydrocarbon/oxygen industrial gas mixer with coarse water droplet environment to reduce ignition potential
US20100263535A1 (en) * 2007-12-14 2010-10-21 Dow Technology Investments Llc Wet scrubbing for removing particulate solids from oxygen supply line
US20100307337A1 (en) * 2007-12-14 2010-12-09 Dow Technology Investments Llc Low shear gas mixer
ITGE20090043A1 (it) * 2009-06-26 2010-12-27 Ergo Design S R L Bruciatore
US20110283598A1 (en) * 2010-05-20 2011-11-24 Cruz Robert T Vented propane combustion chamber for insect attractant engine
ITUD20130167A1 (it) * 2013-12-06 2015-06-07 Univ Degli Studi Trieste Bruciatore ad irraggiamento
USD910830S1 (en) 2019-04-12 2021-02-16 Saint-Gobain Ceramics & Plastics, Inc. Flame diffuser insert for immersion tube furnace
USD910829S1 (en) 2019-04-12 2021-02-16 Saint-Gobain Ceramics & Plastics, Inc. Flame diffuser insert for immersion tube furnace

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
HU175769B (hu) * 1977-02-17 1980-10-28 Koennyueipari Szereloe Es Epit Smesitel' gazoobraznoj toplivnoj sredy
JPS5714106A (en) * 1980-06-27 1982-01-25 Kawasaki Steel Corp Method and apparatus for combustion with low nox in radiant tube burner
DE3230853A1 (de) * 1982-08-19 1984-02-23 Stünkel, Klaus-Erich, 3000 Hannover Geschlossene vorbaubrennkammer mit druckluft-gasbrenner fuer erdoel-erdgas erwaermungs-und erdoel erwaermungs- und trennungsvorrichtungen
FR2533670B1 (fr) * 1982-09-24 1985-01-18 Inst Ispolzovania Gaza Narod Tube radiant
GB8301274D0 (en) * 1983-01-18 1983-02-16 Wb Combustion Ltd Single-ended recouperative radiant tube
FR2555296B1 (fr) * 1983-11-18 1986-03-14 Stein Heurtey Perfectionnements apportes aux tubes radiants
GB8511352D0 (en) * 1985-05-03 1985-06-12 Allday & Co Ltd William Forge hearth
DE19619873A1 (de) * 1996-05-17 1997-11-20 Abb Research Ltd Brenner
CN102588974B (zh) * 2011-01-18 2014-09-10 爱烙达股份有限公司 可提高火焰高度的装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB846237A (en) * 1958-02-13 1960-08-31 Nassheuer Jean Improvements in or relating to jet type burners
US3137486A (en) * 1962-11-28 1964-06-16 Multifastener Company Burner construction
US3195609A (en) * 1960-11-28 1965-07-20 Midland Ross Corp Self stabilizing radiant tube burner
US3267927A (en) * 1964-08-20 1966-08-23 Eclipse Fuel Eng Co Nozzle mixing burner assembly

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB846237A (en) * 1958-02-13 1960-08-31 Nassheuer Jean Improvements in or relating to jet type burners
US3195609A (en) * 1960-11-28 1965-07-20 Midland Ross Corp Self stabilizing radiant tube burner
US3137486A (en) * 1962-11-28 1964-06-16 Multifastener Company Burner construction
US3267927A (en) * 1964-08-20 1966-08-23 Eclipse Fuel Eng Co Nozzle mixing burner assembly

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4673348A (en) * 1983-10-21 1987-06-16 Air Products And Chemicals, Inc. Heating apparatus
US4673350A (en) * 1986-08-26 1987-06-16 Eclipse, Inc. Burner assembly for radiant tube heating system
WO1999005453A1 (fr) * 1997-07-25 1999-02-04 Maxon Corporation Bruleur
US6059566A (en) * 1997-07-25 2000-05-09 Maxon Corporation Burner apparatus
US6461148B1 (en) * 2000-09-28 2002-10-08 Mcdermott Technology, Inc. Compact, high-temperature, low-flow rate, liquid fuel-fired burner
US6443728B1 (en) * 2001-03-19 2002-09-03 Alstom (Schweiz) Ag Gas pipe ignitor
US20030235798A1 (en) * 2001-05-10 2003-12-25 Moore Edward E. U-tube diffusion flame burner assembly having unique flame stabilization
US6872070B2 (en) 2001-05-10 2005-03-29 Hauck Manufacturing Company U-tube diffusion flame burner assembly having unique flame stabilization
EP1422473A1 (fr) * 2002-11-21 2004-05-26 Hauck Manufacturing Company Ensamble brûleur à tube en "U" à flamme de diffusion ayant une stabilisation unique de la flamme
US20080131824A1 (en) * 2006-10-26 2008-06-05 Deutsches Zentrum Fuer Luft- Und Raumfahrt E.V. Burner device and method for injecting a mixture of fuel and oxidant into a combustion space
US20100263535A1 (en) * 2007-12-14 2010-10-21 Dow Technology Investments Llc Wet scrubbing for removing particulate solids from oxygen supply line
US8334395B2 (en) 2007-12-14 2012-12-18 Dow Technology Investments Llc Hydrocarbon/oxygen industrial gas mixer with coarse water droplet environment to reduce ignition potential
US20100204495A1 (en) * 2007-12-14 2010-08-12 Dow Technology Investments Llc Hydrocarbon/oxygen industrial gas mixer with water mist
US20100204496A1 (en) * 2007-12-14 2010-08-12 Dow Technology Investments Llc Hydrocarbon/oxygen industrial gas mixer with coarse water droplet environment to reduce ignition potential
WO2009078899A1 (fr) * 2007-12-14 2009-06-25 Dow Technology Investments Llc Mélengeur de gaz rapide (à cisaillement élevé) d'oxygène/hydrocarbure
US20100307337A1 (en) * 2007-12-14 2010-12-09 Dow Technology Investments Llc Low shear gas mixer
US8500320B2 (en) 2007-12-14 2013-08-06 Dow Technology Investments Llc Low shear gas mixer
US8500894B2 (en) 2007-12-14 2013-08-06 Dow Technology Investments Llc Wet scrubbing for removing particulate solids from oxygen supply line
US8404190B2 (en) 2007-12-14 2013-03-26 Dow Technology Investments Llc Hydrocarbon/oxygen industrial gas mixer with water mist
US20100191005A1 (en) * 2007-12-14 2010-07-29 Dow Technology Investments Llc Oxygen/hydrocarbon rapid (high shear) gas mixer, particularly for the production of ethylene oxide
US8404189B2 (en) 2007-12-14 2013-03-26 Dow Technology Investments Llc Oxygen/hydrocarbon rapid (high shear) gas mixer, particularly for the production of ethylene oxide
WO2010150228A3 (fr) * 2009-06-26 2011-03-17 Ergo Design S.R.L. Brûleur
ITGE20090043A1 (it) * 2009-06-26 2010-12-27 Ergo Design S R L Bruciatore
US20110283598A1 (en) * 2010-05-20 2011-11-24 Cruz Robert T Vented propane combustion chamber for insect attractant engine
US8753110B2 (en) * 2010-05-20 2014-06-17 Woodstream Corporation Vented propane combustion chamber for insect attractant engine
US9949471B2 (en) 2010-05-20 2018-04-24 Woodstream Corporation Vented propane combustion chamber for insect attractant engine
ITUD20130167A1 (it) * 2013-12-06 2015-06-07 Univ Degli Studi Trieste Bruciatore ad irraggiamento
USD910830S1 (en) 2019-04-12 2021-02-16 Saint-Gobain Ceramics & Plastics, Inc. Flame diffuser insert for immersion tube furnace
USD910829S1 (en) 2019-04-12 2021-02-16 Saint-Gobain Ceramics & Plastics, Inc. Flame diffuser insert for immersion tube furnace

Also Published As

Publication number Publication date
JPS507286B1 (fr) 1975-03-24
GB1275599A (en) 1972-05-24
DE1950077B2 (de) 1974-08-15
DE1950077C3 (fr) 1975-04-03
FR2031416A1 (fr) 1970-11-20
DE1950077A1 (de) 1970-08-27

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