US3838652A - Furnace installation for burning liquid or gaseous fuel, in particular for a boiler - Google Patents

Furnace installation for burning liquid or gaseous fuel, in particular for a boiler Download PDF

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Publication number
US3838652A
US3838652A US00285856A US28585672A US3838652A US 3838652 A US3838652 A US 3838652A US 00285856 A US00285856 A US 00285856A US 28585672 A US28585672 A US 28585672A US 3838652 A US3838652 A US 3838652A
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United States
Prior art keywords
flue gas
box
flame hole
burner
installation
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Expired - Lifetime
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US00285856A
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English (en)
Inventor
R Schol
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Ingenieursbureau Rodenhuis & Verloop Nv nl
Rodenhuis & Verloop Bv
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Rodenhuis & Verloop Bv
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D17/00—Burners for combustion conjointly or alternatively of gaseous or liquid or pulverulent fuel

Definitions

  • the invention relates to a furnace installation for burning liquid or gaseous fuel with recycling of the flue gases, in particular for boilers. More in particular, the invention relates to such a furnace installation having a furnace wall enclosing a combustion chamber and provided with at least one flame hole, a burner being mounted .in line with this flame hole for directing fuel through the hole to be burned in the combustion chamher, which flame hole is in communication with a pressure source for secondary combustion air whereby this air flows past the burner and through the flame hole into the combustion chamber while mixing with the fuel injected by the burner.
  • the invention has for its main object to provide a furnace installation of the kine above referred t which obviates the above-discussed disadvantage of the known arrangements and which allows to keep the flame temperature below the limit which is critical to the development of nitrogen oxides while maintaining a stable flame and a good control both at full load and at reduced load.
  • the recycled flue gas is supplied to each one of the flame holes by conducting means which open circumferentially of the flow of secondary combustion air adjacent the periphery of the flame hole whereby the flue gas flowing together with this combustion air through the flame hole forms a mantle of flue gas enveloping and thereby cooling the flame of the burning fuel injected by the burner.
  • the flame is thus cooled in the desired manner directly it is formed by means of the flue gas mantle enveloping it without the necessity of first mixing the flue gases with the combustion air.
  • This way of flame cooling also offers a further considerable advantage in terms of control technique.
  • an increase in the amount of flue gas supplied has the effect of causing the neck of the burner assembly to be-.
  • FIG. 1 is an axial section through one of the burner locations of the installation
  • FIG. 2 is a view of the flue gas box of the installation in a section along theline IIII of FIG. 1;
  • FIG. 3 is an axial section through the burner head on an enlarged scale.
  • the drawings show one burner location of a boiler fitted, in a known manner, with a plurality of burners.
  • the boiler has a combustion chamber 1 within a furnace wall 2 on which are mounted boiler tubes 3 and a boiler wall insulation 4, as is shown diagrammatically in FIG. 1.
  • the furnace wall has a number of flame holes such as 5 each with a similar burner 6 mounted there behind, only one of which can be seen in the drawings.
  • the burner 6 can be of any suitable type for burning liquid and/or gaseous fuels.
  • the burner illustrated here is of the kind as described in my British Pat. No. 1,080,528, being a burner for fuel oil as well as for natural gas.
  • the burner has a double-walled cylindrical casing with an outer wall 7 and an inner wall 8 which enclose a ring-shaped gas channel 9 into which natural gas or another suitable gaseous fuel can be supplied by means of a gas supply conduit 10 which is attached to the rear end of the outer wall 7 and extends rearwards.
  • Both walls 7 and 8 run conically inwards at the front end and meet up with a conical front wall 11 which seals off the space 9 and in which is provided an annular row of outlet bores 12 for the fuel gas.
  • a coneshaped flame funnel 13 which extends forward isattached to this front wall 11.
  • a crown of outlet tubes 14 for the fuel gas are screwed into the in-turned end of the outer wall 7, their axes lying on a conical surface and running parallel to the generatrices of the funnel 13.
  • annular air channel 16 which has a contracted throat at the middle, is thus formed, so that mixing air is conducted, in a way which will be described below, along the outflow tubes 14 for the gas.
  • An oil burner 17 is fitted into the gas burner casing 7, 8 and can again be of any suitable type, but in the example shown it is designed in accordance with my Dutch Pat. Application 270,257 and provides twostage atomization of the oil by means of primary com bustion air or atomizing air under higher pressure than the secondary combustion air.
  • the oil is supplied through an oil feed conduit 18 which runs centrally through the casing 7, 8 and is attached at its rear end to a flexible feed pipe 21 via a coupling member 12 which is fitted with an oil pressure gauge 19.
  • the atomizing air is led in within the inner casing wall 8 which has at its rear end a lateral connecting member 22 for connecting with a source of compressed air which supplies air under constant pressure.
  • the combined gas and oil burner 6 lies with its burner mouth in the centre directly behind the circular flame hole 55 and extends rearwards through a wind box 23 which is common to the various burners.
  • This wind box 23 lies enclosed between an inner wall 24 and an outer wall 25 and by means of natural draught or by means of a forced draught fan supplies the secondary combustion air.
  • the outer wall 25 of the wind box has an aperture 26 which is sealed off by a burner front plate 27. which is removably attached.
  • This front plate 27 supports the outer casing wall 7 of the burner by means of a bushing 28 and reinforcing plates 29.
  • the gas feed conduit 10, the oil feed conduit 18, and the inner casing wall 8 with the connecting member 22 for the atomizing air extend sealingly through this front plate 27 and a dome-shaped member 30 attached to it.
  • the flaps 32 are adjustable by means of an operating rod 33, which extends through the wall 25 of the wind box, and an operating mechanism 34 attached to this wall, so as to control the supply of secondary combustion air to the burner in a known manner.
  • a flue-gas box 35 is built against the furnace wall 2 of the boiler and around the flame hole 5 in this wall.
  • the box 35 has an approximately elliptical peripheral shape (FIG. 2) with circumferential side wall 36, extending between the inner wall 24 of the wind box 23 and the furnace wall 2, and with a back wall 37 which fits into a corresponding aperture in the wall 24 of the wind box.
  • a tubular sleeve 38 coaxial with the burner, encloses the head of the burner and is housed in the flue-gas box 35, which sleeve has a smaller diameter than the flame hole 5 and is connected on the one hand by a funnel-shaped wall portion 39 to the inner edge of the flame hole 5 and on the other hand by a funnel-shaped wall portion 40 to the edge of an aperture 41 in the back wall 37 of the fluegas box, said aperture 41 having approximately the same diameter as the flame hole 5.
  • a throughflow duct or channel for the secondary combustion air which encloses the foremost part of the burner 6, and has a constriction 42 around the head of the burner.
  • the forward part of the sleeve 38 has a large number of outflow apertures 43 for the flue gas which are distributed in series circumferentially of the sleeve and run obliquely inwards and forwards as shown in FIG. 3.
  • a circular aperture 44 in the back wall 37 of the flue gas box 35 next to the aperture 41, receives a tube 45 connected by means of an expansible member 46 to a tubular conduit 47 which extends through the wall 25 of the wind box 23 and housesa butterfly valve 48.
  • the tube 45 and conduit 47 form a flue-gas duct fed by a flue-gas collecting channel (not shown) from which the flue-gas ducts of the various burner locations branch off and to which the part of the boiler flue gas which is to be recycled is supplied by known means.
  • a flue-gas collecting channel not shown
  • Gas also enters the space within the flame funnel through the narrow gas outflow bores 12, and is thoroughly mixed with the primary air emerging with pronounced turbulence from the mouth of the coil burner 17, the result being a constant stable fan-shaped flame at the mouth of the burner 17 which serves as a supporting flame for the ring-shaped main flame.
  • the burner 6 is used as an oil burner the gas supply is closed and oil is supplied under pressure to the oil feed conduit 18.
  • the oil which emerges is atomized in two stages, in the manner as described in the above mentioned Dutch Pat. Application 270,257, by means of the emergent atomizing air which has been subjected to pronounced turbulence, and is then mixed with the secondary combustion air flowing through the constriction 42. In specific cases it is also possible to burn gas and oil simultaneously in the burner 6.
  • the pressure of the flue gas in the flue-gas box 35 is somewhat higher than that of the air in the wind box 23.
  • the flue gas which flows through the apertures 43 into the constriction 42 forms a mantle 49 of flue gas whose boundary lines 49 are shown diagrammatically in FIG. 1 and which gradually spreads over some distance in the form of a funnel in the combustion chamber 1 from the perforated part of the sleeve 38 and the funnel-shaped wall portion 39.
  • This mantle 49 of flue gas thus forms an evelope for the burning air/fuel mixture which emerges from the burner 6, its outline being'shown diagrammatically by 50.
  • This flame 50 is consequently cooled in its hottest part by the flue-gas mantle 49 enveloping it whereby the flame temperature can be brought below the above-mentioned critical boundary temperature of l,300 C.
  • the emerging mantle of flue gas initially bends inwards from the outflow apertures 43 and has its smallest internal diameter (smaller than the diameter of the constriction 42) at the point indicated by the broken line 5] just in front of the mouth of the flame hole 5.
  • the minimum diameter of this mantle throat 51 depends upon the amount of flue gas which is flowing out, and this can be adjusted by means of the valve 48. When the boiler is under full load, in which case, for instance, -20 percent flue gas is added relative to the total volume of out-flowing gas, this minimum diameter will be only slightly smaller than that of the constriction,42.
  • the flue gas control valves 48 can be individually adjusted for the different burners so that one burner group can work in a superstoichiometric state and one burner group in a substoichiometric state, which provides the abovementioned favourable additional possibilities for lowering the flame temperature.
  • a furnace installation for burning liquid or gaseous fuel with recycling of the flue gases, in particular for a boiler, comprising a combustion chamber; a furnace wall enclosing said combustion chamber and having at least one flame hole; a burner mounted in line with said flame hole for directing fuel through said hole to be burned in said combustion chamber; a source of secondary combustion air; duct means for conducting said secondary combustion air to said flame hole; means for conducting recycled flue gas to said flame hole.
  • said means opening circumferentially into said duct means adjacent to said flame hole whereby said flue gas-flowing through said flame hole forms a mantle of flue gas enveloping the flame of said burning fuel; a flue gas box mounted on the outside of said furnace wall around the flame hole, said box having a back wall opposite said furnace wall and provided with an aperture in line with said flame hole; a flue gas conduit opening into said box; sleeve means extending through said box and coaxially enclosing said burner, said sleeve means having a forward end joining the periphery of said flame hole and having a rear end attached to the edge of the aperture in said box rear wall whereby a ring-shaped duct for said secondary combustion air is formed between said sleeve and said burner and passing through said flue gas box and communicating with said source of secondary combustion air, said sleeve having outflow apertures for the flue gas uniformally distributed around its circumference and opening into said duct.
  • said sleeve means comprises a cylindrical sleeve section of smaller diameter than said flame hole and said aperture in said flue gas box back wall, a first conical sleeve part connecting said cylindrical sleeve section to the periphery of said flame hole, and a second conical sleeve part connecting said cylindrical sleeve section to said aperture in said flue box back wall.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion Of Fluid Fuel (AREA)
  • Gas Burners (AREA)
  • Nozzles For Spraying Of Liquid Fuel (AREA)
US00285856A 1972-01-06 1972-09-01 Furnace installation for burning liquid or gaseous fuel, in particular for a boiler Expired - Lifetime US3838652A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7200207A NL7200207A (sv) 1972-01-06 1972-01-06

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US3838652A true US3838652A (en) 1974-10-01

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US (1) US3838652A (sv)
JP (1) JPS5244453B2 (sv)
AU (1) AU465859B2 (sv)
BE (1) BE783481A (sv)
CA (1) CA959347A (sv)
DE (1) DE2210319A1 (sv)
GB (1) GB1367997A (sv)
NL (1) NL7200207A (sv)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3940234A (en) * 1974-05-28 1976-02-24 John Zink Company Noiseless pms burner
US3965829A (en) * 1974-02-25 1976-06-29 The British Petroleum Company Limited Boiler
US4181491A (en) * 1976-09-22 1980-01-01 Bloom Engineering Company, Inc. Method and apparatus for heating a furnace chamber
US4237858A (en) * 1978-01-16 1980-12-09 John Zink Company Thin and flat flame burner
US4253403A (en) * 1979-10-02 1981-03-03 Joel Vatsky Air flow regulator
US4708637A (en) * 1986-04-22 1987-11-24 Dutescu Cornel J Gaseous fuel reactor
US4708638A (en) * 1985-02-21 1987-11-24 Tauranca Limited Fluid fuel fired burner
US4846679A (en) * 1985-07-08 1989-07-11 Institute Of Gas Technology Flueless, low NOx, low CO space heater
US4958619A (en) * 1985-07-08 1990-09-25 Institute Of Gas Technology Portable, flueless, low nox, low co space heater
US5083917A (en) * 1990-05-15 1992-01-28 Cat Eye Co., Ltd. Single port inshot target burner
US5573391A (en) * 1994-10-13 1996-11-12 Gas Research Institute Method for reducing nitrogen oxides
US5636977A (en) * 1994-10-13 1997-06-10 Gas Research Institute Burner apparatus for reducing nitrogen oxides
US6289851B1 (en) 2000-10-18 2001-09-18 Institute Of Gas Technology Compact low-nox high-efficiency heating apparatus
US20050244764A1 (en) * 2002-07-19 2005-11-03 Frank Haase Process for combustion of a liquid hydrocarbon
US20110179797A1 (en) * 2008-10-01 2011-07-28 Bernd Prade Burner and method for operating a burner

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE795261A (fr) * 1972-02-10 1973-05-29 Bailey Frank W Bruleurs canon a retention de flamme bleue et systemes d'echangeur de chaleur
JPS5094533A (sv) * 1973-12-25 1975-07-28
US3868211A (en) * 1974-01-11 1975-02-25 Aqua Chem Inc Pollutant reduction with selective gas stack recirculation
JPS50115330A (sv) * 1974-02-25 1975-09-09
AU5639780A (en) * 1979-03-23 1980-09-25 Kintyre Enterprises Ltd. Fuel burner
GB2133516A (en) * 1983-01-10 1984-07-25 Cameron Iron Works Inc Recirculating flue gases to a furnace
GB9425691D0 (en) * 1994-12-20 1995-02-22 Boc Group Plc A combustion apparatus
GB2338055A (en) * 1998-06-02 1999-12-08 Padley G W Holdings Ltd Gas burner

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1729763A (en) * 1925-11-02 1929-10-01 Texas Co Apparatus and method of fuel burning
US2224544A (en) * 1940-12-10 Temperature control foe tubular
US2701608A (en) * 1951-02-03 1955-02-08 Thermal Res And Engineering Co Burner
US2993479A (en) * 1958-05-14 1961-07-25 Gibbons Heaters Ltd Fluid heaters

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2224544A (en) * 1940-12-10 Temperature control foe tubular
US1729763A (en) * 1925-11-02 1929-10-01 Texas Co Apparatus and method of fuel burning
US2701608A (en) * 1951-02-03 1955-02-08 Thermal Res And Engineering Co Burner
US2993479A (en) * 1958-05-14 1961-07-25 Gibbons Heaters Ltd Fluid heaters

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3965829A (en) * 1974-02-25 1976-06-29 The British Petroleum Company Limited Boiler
US3940234A (en) * 1974-05-28 1976-02-24 John Zink Company Noiseless pms burner
US4181491A (en) * 1976-09-22 1980-01-01 Bloom Engineering Company, Inc. Method and apparatus for heating a furnace chamber
US4237858A (en) * 1978-01-16 1980-12-09 John Zink Company Thin and flat flame burner
US4253403A (en) * 1979-10-02 1981-03-03 Joel Vatsky Air flow regulator
US4708638A (en) * 1985-02-21 1987-11-24 Tauranca Limited Fluid fuel fired burner
US4958619A (en) * 1985-07-08 1990-09-25 Institute Of Gas Technology Portable, flueless, low nox, low co space heater
US4846679A (en) * 1985-07-08 1989-07-11 Institute Of Gas Technology Flueless, low NOx, low CO space heater
US4708637A (en) * 1986-04-22 1987-11-24 Dutescu Cornel J Gaseous fuel reactor
US5083917A (en) * 1990-05-15 1992-01-28 Cat Eye Co., Ltd. Single port inshot target burner
US5573391A (en) * 1994-10-13 1996-11-12 Gas Research Institute Method for reducing nitrogen oxides
US5636977A (en) * 1994-10-13 1997-06-10 Gas Research Institute Burner apparatus for reducing nitrogen oxides
US6289851B1 (en) 2000-10-18 2001-09-18 Institute Of Gas Technology Compact low-nox high-efficiency heating apparatus
US20050244764A1 (en) * 2002-07-19 2005-11-03 Frank Haase Process for combustion of a liquid hydrocarbon
US20110179797A1 (en) * 2008-10-01 2011-07-28 Bernd Prade Burner and method for operating a burner
US9217569B2 (en) * 2008-10-01 2015-12-22 Siemens Aktiengesellschaft Burner and method for operating a burner

Also Published As

Publication number Publication date
AU5083973A (en) 1974-07-11
AU465859B2 (en) 1975-10-09
JPS5244453B2 (sv) 1977-11-08
NL7200207A (sv) 1973-07-10
BE783481A (nl) 1972-09-01
CA959347A (en) 1974-12-17
DE2210319A1 (de) 1973-07-12
JPS4881135A (sv) 1973-10-30
GB1367997A (en) 1974-09-25

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