DE4231788A1 - Burners for liquid or gaseous fuels - Google Patents

Burners for liquid or gaseous fuels

Info

Publication number
DE4231788A1
DE4231788A1 DE19924231788 DE4231788A DE4231788A1 DE 4231788 A1 DE4231788 A1 DE 4231788A1 DE 19924231788 DE19924231788 DE 19924231788 DE 4231788 A DE4231788 A DE 4231788A DE 4231788 A1 DE4231788 A1 DE 4231788A1
Authority
DE
Germany
Prior art keywords
mixing tube
air
characterized
baffle plate
burner according
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.)
Withdrawn
Application number
DE19924231788
Other languages
German (de)
Inventor
Uwe Dr Ing Wiedmann
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.)
KOERTING AG
Original Assignee
KOERTING AG
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 KOERTING AG filed Critical KOERTING AG
Priority to DE19924231788 priority Critical patent/DE4231788A1/en
Priority claimed from DE1993505583 external-priority patent/DE59305583D1/en
Publication of DE4231788A1 publication Critical patent/DE4231788A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23DBURNERS
    • F23D11/00Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
    • F23D11/36Details, e.g. burner cooling means, noise reduction means
    • F23D11/40Mixing tubes or chambers; Burner heads
    • F23D11/402Mixing chambers downstream of the nozzle

Description

The invention relates to a low-NO x burner for liquid or gaseous fuels, with a mixing tube as a passage for the combustion air and with a baffle arranged in the front loading area of the mixing tube, which is perpendicular to the axis of the mixing tube and is axially displaceable in the mixing tube , wherein the baffle plate with a central opening for the introduction of part or all of the fuel and a first part of the combustion air (core air) into the combustion chamber and with radial oblique slots for the tangential introduction of a second part of the combustion air (swirl air) into the combustion chamber is provided and has a collar on its outer circumference, between which and the inner wall of the mixing tube, a third part of the combustion air (axial air) can be introduced into the combustion chamber.

Most fans today have such a structure sebrenner on. The baffle plate is inside the mixing tube res arranged so that the combustion air from behind to the Baffle plate hits and partly through the central opening, partly through the radial oblique slots and partly through the intermediate space between the collar on the outer circumference of the baffle plate and the mixing tube enters the combustion chamber. In the area of Collar of the baffle plate, the mixing tube tapers inwards, so that by axial displacement of the baffle plate within the  Mixing tube the distance between the baffle plate collar and the conically tapered front end of the mixing tube, and thus the amount of air supplied can be varied.

The arrangement of the baffle plate in the combustion air space has the purpose of stabilizing the flame and a good through ensure a mixture of fuel and air and thus a the most perfect possible combustion of the fuel with stable To reach flame shape. This mixing is on the one hand through the tangential through the radial oblique slots th combustion air content and on the other hand by a ter of the baffle plate forming backflow through which Combustion gases are returned to the flame root.

These mixing devices have been in practice lasts, but has been shown that with the conventional design the baffle plate and the mixing tube are getting sharper Requirements with regard to the emission limit of the exhaust gases hardly can still be fulfilled.

The invention has for its object to provide a mixing device of the type described above so that the pollutants in the exhaust gas, in particular the NO x content, are significantly reduced.

The object is achieved according to the invention solved that between the collar of the baffle plate and the inner wall the conical tapered ring body of the mixing tube net is that of the third part of the combustion air in two parts divides currents, and that by way of between the ring body and the partial flow of the mixing tube several nozzles in one End face of the mixing tube are arranged.  

The inner partial flow is fed as axial air between the baffle plate collar and the inner surface of the ring body of the primary combustion zone, in addition, part of the remaining combustion air passes through the radial annular gap between the end face of the ring body and the inner surface of the mixing tube end face as radial air also into the primary zone . Due to the radial air accelerated radially in the annular gap, the swirl flow formed from core, swirl and axial air is constricted, whereby the recirculation of hot, largely burned-out exhaust gases is intensified. This causes a faster heating of the fuel and a reduction in the oxygen content in the fuel-rich primary zone and thereby a reduction in fuel and thermal NO x .

The rest of the combustion air is used as step air the nozzles in the mixing tube end face axially or slightly in NEN inclined to the secondary zone. Due to the high Axialim In the pulse of the individual jets, exhaust gas is drawn in from the combustion chamber and mixed into the air jet so that air and exhaust gas already are largely mixed before entering the secondary zone.

By axially displacing the ring body, the division between the axial and radial air can be adjusted, where the inflow angle of the mixture of axial and radial air can be adjusted. A higher proportion of radial air increases the constriction and lowers the NO x emissions via the stronger internal backflow. It may be appropriate that the annular gap between the ring body and the inner edge of the mixing tube face is inclined obliquely forward.

There are preferably approximately in the mixing tube end face five to ten nozzles arranged, which run axially or slightly are inclined inward so that the air flowing out of them in Direction is directed to the center line of the mixing device.  

The arrangement of the ring body makes it possible to Face of the mixing tube over the diameter of the baffle plate pull inward without the inside of the forehead is hit by oil droplets in an oil burner.

Preferably, in a manner known per se, before Mixing pipe an additional pipe for targeted exhaust gas recirculation intended.

It is also expedient on the upstream side of the Baffle plate a throttle chamber with adjustable entry area must be provided in order to reduce the pressure before the jam at higher fan pressures reduce disk. It is also beneficial to choose between the To provide a throttling device and the ring body, to increase the speed of the axial air at high fan pressures to reduce.

The invention is based on one in the Drawing shown embodiment of an oil burner explained in more detail.

The drawing shows a mixing tube 1 , which tapers slightly conically at the front end 2 and opens into an end face 15 , and in which centrally, for. B. with liquid fuel, a fuel lance 3 with a fuel nozzle 4 is arranged. On the fuel lance 3 with struts 5 a baffle plate 6 BEFE Stigt, which is axially slidable ver with the fuel lance in the mixing tube 1 , and which is provided on its circumference in a known manner with a collar 7 . The baffle plate 6 has a central opening 8 in a usual manner as a passage for part or all of the fuel and a first part 9 of the combustion air, which is also referred to as core air. In the core air z. B. also the ignition. Furthermore, radial slots are provided in the usual way between the central opening 8 and the outer edge of the disc, which are formed by wing-like projections 10 before, and which are attached by a pressing operation in the disc 6 . As a result, a second part of the combustion air flow is directed into the combustion chamber in the tangential direction as swirl air 11 .

This swirl air ensures in connection with the blockage through the baffle plate for stabilizing the flame immediately bar in front of the baffle plate by returning hot combustion gases.

The invention now provides between the collar 7 of the jam disk and the inner surface of the mixing tube 1, an annular body 13 which divides the third part 12 of the combustion air into two streams. One partial flow runs as an axial air 14 between the baffle plate collar 7 and the conically tapering inner surface of the body 13 into the primary combustion chamber, where the baffle plate 6 is axially displaceable in order to meter the axial air 14 and to adapt it to the burner output required in each case. The other partial flow 17 runs outside the ring body 13 .

The end face of the ring body 13 forms with the inner side of the mixing tube end face 15 a radial annular gap 18 through which a part 17 a of the air flow is accelerated radially.

The remaining combustion air, about 30 to 70%, preferably before 50% of the stoichiometric amount of air, occurs in individual jets 17 b through the nozzles 16 in the secondary combustion zone.

The ring body 13 is axially displaceable in a Füh tion in the mixing tube 1 , so that for a certain jam disk position, the division between the axial air 14 and radial air 17 a, and thus the inflow angle, the total flow 14 and 17 a can be adjusted. In extreme cases, the axial or radial clearance can be completely reduced.

The inner edge of the end face 15 is sufficiently far outside with respect to the central opening 8 of the baffle plate, so that, for. B. with liquid fuels, there is no risk of droplets hitting the inside of the end face.

The inner edge of the end face 15 can therefore also be pulled in further than shown.

It is also possible to weaken the constrictions tion of the radial annular gap by inclining the end faces of Design the ring body and mixing tube at an angle.

As previously mentioned, the radial air flow 17 a increases the internal recirculation, while the air jets 17 b reach the secondary zone at high speed as step air, with the exhaust gases sucked in from the combustion chamber being mixed into the air jets before they reach the flame chen. The two air streams 17 a and 17 b thus ensure a reduction in the oxygen content in the primary zone and a large drop in temperature in the secondary zone by increasing the internal backflow in the primary zone and the external backflow of exhaust gas. NO x and thermal NO x can be greatly reduced.

To improve the external exhaust gas recirculation, a recirculation tube 19 can be provided in a known manner outside the mixing tube 1 , which reduces the oxygen content of the exhaust gases and increases the pulse exchange, resulting in high efficiency because the amount of exhaust gas penetrates into the flame early. Furthermore, a throttle chamber 20 can be arranged in the flow direction in front of the baffle plate, with which the pressure on the baffle plate is reduced and thus the ignition and the flame stability are improved at high blower pressures. The pressure can be made adjustable by changing the entry surface into the chamber.

Furthermore, a throttle 21 can be provided on the baffle plate collar 7 in order to reduce the speed of the axial air at high blower pressures.

Finally, it should be mentioned that the nozzles 16 do not have to be inclined upwards, but that their axes can also run parallel to the central axis of the mixing tube 1 . In addition, it is possible to align only a part of the nozzles axially parallel and to arrange the remaining nozzles at an incline.

The invention is not limited to oil burners, son also applicable to burners for gaseous fuels.

Claims (9)

1. Burner for liquid or gaseous fuels, with a mixing tube as a passage for the combustion air and with a baffle arranged in the front region of the mixing tube, which is perpendicular to the axis of the mixing tube and is axially displaceable in the mixing tube, the baffle plate having a center Opening for introducing part or all of the fuel and a first part of the combustion air (core air) into the combustion chamber and with radial oblique slots for tangentially introducing a second part of the combustion air (swirl air) into the combustion chamber, and a collar on its outer circumference has, between which and the inner wall of the mixing tube a third part of the combustion air (axial air) can be introduced into the combustion chamber, characterized in that between the collar ( 7 ) of the baffle plate ( 6 ) and the inner wall of the mixing tube ( 1 ) a conical tapered gender ring body ( 13 ) is arranged, the the third part of the combustion air (12) into two partial streams (14, 17) divides, and that in the way of extending between the annular body (13) and the mixing tube (1) part-stream (17) a plurality of nozzles (16) in an end face (15 ) of the mixing tube ( 1 ) are arranged.
2. Burner according to claim 1, characterized in that the annular body ( 13 ) is axially displaceably mounted in the mixing tube ( 1 ).
3. Burner according to claim 1 or 2, characterized in that the annular gap ( 18 ) between the ring body ( 13 ) and the inner edge of the mixing tube face ( 15 ) is inclined obliquely forward.
4. Burner according to one of claims 1 to 3, characterized in that the end face ( 15 ) of the mixing tube contains about five to ten nozzles ( 16 ) and the nozzles are dimensioned such that 30 to 70%, preferably 50% of the stoichiometric Combustion air that flows through nozzles.
5. Burner according to claim 4, characterized in that the nozzles ( 16 ) extend axially or are inclined slightly inwards at the same angle.
6. Burner according to one of the preceding claims, characterized in that the end face ( 15 ) of the mixing tube ( 1 ) is pulled inward beyond the diameter of the baffle plate.
7. Burner according to one of the preceding claims, characterized in that an attachment tube ( 19 ) is provided for a targeted exhaust gas recirculation in a conventional manner outside in front of the mixing tube ( 1 ).
8. Burner according to one of the preceding claims, characterized in that on the upstream side of the baffle plate ( 6 , 7 ) a throttle chamber ( 20 ) is provided with an adjustable entry surface.
9. Burner according to one of the preceding claims, characterized in that a throttle device ( 21 ) is provided between the baffle plate ( 6 , 7 ) and the ring body ( 15 ) in order to reduce the speed of the axial air ( 14 ) at high fan pressures.
DE19924231788 1992-09-23 1992-09-23 Burners for liquid or gaseous fuels Withdrawn DE4231788A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19924231788 DE4231788A1 (en) 1992-09-23 1992-09-23 Burners for liquid or gaseous fuels

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE19924231788 DE4231788A1 (en) 1992-09-23 1992-09-23 Burners for liquid or gaseous fuels
DE1993505583 DE59305583D1 (en) 1992-09-23 1993-08-25 Burners for liquid or gaseous fuels
EP19930113542 EP0589226B1 (en) 1992-09-23 1993-08-25 Burner for liquid ot gaseous fuels
AT93113542T AT149661T (en) 1992-09-23 1993-08-25 Burners for liquid or gaseous fuels

Publications (1)

Publication Number Publication Date
DE4231788A1 true DE4231788A1 (en) 1994-03-24

Family

ID=6468595

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19924231788 Withdrawn DE4231788A1 (en) 1992-09-23 1992-09-23 Burners for liquid or gaseous fuels

Country Status (3)

Country Link
EP (1) EP0589226B1 (en)
AT (1) AT149661T (en)
DE (1) DE4231788A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19509854A1 (en) * 1994-09-28 1996-07-04 Abig Werke Carry Gross Gmbh Use for a device for igniting or burning fuels, in particular a heating device, and device for igniting or burning fuels
EP0754908A2 (en) 1995-07-20 1997-01-22 DVGW Deutscher Verein des Gas- und Wasserfaches e.V. Method and apparatus for suspressing flame and pressure vibrations in a furnace
WO1997040315A1 (en) 1996-04-20 1997-10-30 Joh. Vaillant Gmbh U. Co. COMBUSTION DEVICE AND METHOD FOR OPERATING A COMBUSTION DEVICE FOR LOW-NOx AND LOW-CO COMBUSTION
DE29912362U1 (en) * 1999-07-15 2001-01-11 Viessmann Werke Kg Blue burner for boilers

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT400259B (en) * 1993-11-29 1995-11-27 Schwarz A & Co Mixing device for oil or gas burners

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2809933A1 (en) * 1978-03-08 1979-09-20 Hermann Dipl Ing Kopp Burner for liq. or gaseous fuel - has cup shielding primary flame from radially inwards flowing air and contg. interchangeable nozzles
CH670297A5 (en) * 1986-02-13 1989-05-31 Schilling Siegfried W

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19509854A1 (en) * 1994-09-28 1996-07-04 Abig Werke Carry Gross Gmbh Use for a device for igniting or burning fuels, in particular a heating device, and device for igniting or burning fuels
DE19509854C2 (en) * 1994-09-28 2001-01-04 Abig Werke Carry Gross Gmbh Heating device for burning supplied fuel
EP0754908A2 (en) 1995-07-20 1997-01-22 DVGW Deutscher Verein des Gas- und Wasserfaches e.V. Method and apparatus for suspressing flame and pressure vibrations in a furnace
EP0754908B2 (en) 1995-07-20 2001-04-18 Horst Dr.-Ing. Büchner Method and apparatus for suspressing flame and pressure vibrations in a furnace
WO1997040315A1 (en) 1996-04-20 1997-10-30 Joh. Vaillant Gmbh U. Co. COMBUSTION DEVICE AND METHOD FOR OPERATING A COMBUSTION DEVICE FOR LOW-NOx AND LOW-CO COMBUSTION
DE29912362U1 (en) * 1999-07-15 2001-01-11 Viessmann Werke Kg Blue burner for boilers

Also Published As

Publication number Publication date
EP0589226B1 (en) 1997-03-05
EP0589226A1 (en) 1994-03-30
AT149661T (en) 1997-03-15

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Legal Events

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8139 Disposal/non-payment of the annual fee