CH654899A5 - Wood gas burner which can be added onto a heating boiler - Google Patents

Wood gas burner which can be added onto a heating boiler Download PDF

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Publication number
CH654899A5
CH654899A5 CH781381A CH781381A CH654899A5 CH 654899 A5 CH654899 A5 CH 654899A5 CH 781381 A CH781381 A CH 781381A CH 781381 A CH781381 A CH 781381A CH 654899 A5 CH654899 A5 CH 654899A5
Authority
CH
Switzerland
Prior art keywords
burner
air
boiler
combustion
wood gas
Prior art date
Application number
CH781381A
Other languages
German (de)
Inventor
Walter Lentzsch
Christian Gaegauf
Original Assignee
Biowatt 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 Biowatt Ag filed Critical Biowatt Ag
Priority to CH781381A priority Critical patent/CH654899A5/en
Publication of CH654899A5 publication Critical patent/CH654899A5/en

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B3/00Combustion apparatus which is portable or removable with respect to the boiler or other apparatus which is heated

Abstract

The wood gas burner is conceived as a prefiring system which can be added onto a heating boiler. The combustion space (18) can be connected to the heating boiler via a fire hole (9). The fire hole (9) is designed as a Venturi duct and has a nozzle-shaped section (10) and, following this, a diffusor (11). The burner is operated in suction operation so that the outlet of harmful gases is prevented even in the event of leaks. <IMAGE>

Description


  
 

** WARNING ** beginning of DESC field could overlap end of CLMS **.

 



   PATENT CLAIMS
1. As a pre-firing to a boiler adjustable wood gas burner, the combustion chamber (18) is intended to be connected to the boiler via a fire mouth (9), characterized in that the fire mouth (9) is designed as a venturi channel with a nozzle-shaped section (10) and an adjoining diffuser (11).



   2. Wood gas burner according to claim 1, characterized in that the free end (12) of the diffuser (11) extends over the wall of the burner and is intended to protrude into the boiler opening.



   3. Wood gas burner according to claim 1, in which the primary air in the area of the grate (8) and the secondary air is fed into the fire mouth (9), characterized in that in the area of the narrowest point (15) of the venturi channel openings (19) for the supply the secondary air are provided.



   4. Wood gas burner according to claim 1, characterized in that the fire mouth (9) is lined with refractory concrete parts (13) which are surrounded by insulation (14).



   5. Wood gas burner according to claim 1, characterized in that it has a mobile chassis (1).



   6. Wood gas burner according to claim 5, characterized in that the chassis (1) is movable on rails.



   The invention relates to a wood gas burner according to the characterizing part of patent claim 1.



   Wood pre-firing systems with vertical fuel shafts for placing on standard boilers are known.



   In such a burner, the fireclayed fuel shaft is enclosed in an insulated sheet metal jacket, and the fire mouth leads horizontally to the boiler opening at the level of the grate. The fire in the combustion chamber is fanned by primary air, which is supplied under the grate, whereby the high temperatures in the fuel shaft cause drying and pyrolysis (carbonization) of the fuel.



  The pyrolysis gases are converted to highly flammable gases due to the high temperatures in the firing zone.



  Due to the secondary air, which is fed into the boiler immediately before the flame / gas mixture enters, these gases burn almost completely.



   The output is controlled by simultaneously opening and closing the primary and secondary air flaps. The combustion air is conducted in cavities between the brick lining and the insulation.



   Pre-firings are known which work with compressed air.



  A fan pushes the secondary air into an injector, in which the flame / gas mixture from the combustion chamber is mixed with the secondary air and burned.



   The smoldering gases generated in the combustion chamber are harmful to health, so that if there are any leaks in the burner, there is a risk of injury. In addition to the health hazard, an explosion risk must also be expected in such cases.



   The invention has for its object to provide a burner of the type mentioned, in which the outflow of gases is prevented even in the event of leakages. The burner should also have a high efficiency, be inexpensive to manufacture and easy to use. This object is achieved according to the invention by a wood gas burner which has the features listed in the characterizing part of patent claim 1. As a result of the Venturi channel, the burner can be operated in suction mode so that there is always a negative pressure in the combustion chamber, which means that no gases can escape even in the event of leaks.



   An exemplary embodiment of the invention is explained in more detail below with reference to the drawing.



   Show it:
1 is a view of a wood gas burner seen from the boiler side,
Fig. 2 is a schematic horizontal section along the line II-II through the burner according to Figure 1, and
3 shows a vertical section along line 111-1 II through the burner according to FIG. 1.



   The wood gas burner is used in a manner known per se as pre-firing for a boiler, not shown.



  The burner is mounted on a chassis 1 with rollers 2 and can thus be easily switched on to any standard boiler or - pushed back for service and cleaning purposes. Rails are expediently provided in order to allow easy entry and exit of the boiler and precise positioning.



  This is particularly advantageous if the boiler is also operated with oil.



   The burner has a vetical fuel bunker 3, which is completely lined with refractory refractory bricks 5, 6 and is covered at the top by a hood 7. In the latter there is an airtight filling opening (not shown) for the firing material.



   A first incomplete combustion takes place in the combustion chamber 18 in the lower part of the bunker 3, the primary air for combustion being supplied through the grate 8, so that an ember bed forms above the grate. The high temperatures lead to the drying and smoldering of the fuel. The hot smoke and smoldering gases enter the fire mouth 9 of the burner, where secondary air is metered in to bring about complete combustion. During the combustion process, fuel constantly slips from above, with the appropriate regulation of the air supply preventing the embers from spreading upwards.



   The burner is operated in suction mode, whereby there is always a pressure in the bunker that is below atmospheric pressure. This prevents harmful gases from escaping in the event of leakage and endangering people.



   So that the burner can be operated with natural draft without any problems, the combustion chamber 18 and the fire mouth 9 are designed in such a way that the pressure loss is minimal. The fire mouth 9 is designed in the manner of a venturi channel with a narrowing, nozzle-shaped section 10, in which the flow accelerates, and a diffuser 11 with a delayed flow adjoining it. The secondary air is mixed in at the narrowest point 15 of the venturi channel through the opening 19, which as a result of the negative pressure at this point leads to thorough mixing with the flame / gas mixture and optimal combustion.



   Air regulation is given great importance, since this is a prerequisite for optimal burner operation. The primary air is mainly used to provide the basic output, while the secondary air is to be used for complete combustion and a low content of combustible components in the flue gas. The primary and secondary air is guided in the cavities 17 between the insulation 14 and the chamotte bricks 5, 6 and can already warm up before entering the combustion chamber or the fire mouth. The cavities 17



  are in communication with the grate passages and with the opening 19, the air regulating elements not being shown in detail.



   The free end 12 of the diffuser 11 protruding over the burner wall is intended to protrude into the opening of the boiler. The fire mouth 9 is lined with refractory molded concrete parts 13 which are surrounded by strong insulation 14. This ensures that the inner surface of the fire mouth becomes glowing hot and in some cases act catalytically on the combustion. The hot flame ensures practically perfect combustion with high efficiency and low pollutant emissions.



   The burner has a modular design for easy assembly, with different performance classes available depending on the size.



   The sheet metal casing 16 with the insulation 14 consists of four individual elements that can be assembled quickly. The chamotte and concrete molded parts allow simple, inexpensive production by casting.



   The use of a venturi channel with openings for the secondary air in the smallest cross-section and the extension of the diffuser into the boiler are combined with the following advantages: - Acceleration of the flame / gas mixture to generate high turbulence in the narrowest cross-section.

 

   - Vacuum in the narrowest cross section ensures the supply of secondary air.



   - High gas velocities of the intermediate gas and the radial supply of the secondary air in the narrowest cross section result in good mixing.



   - By designing the diffuser with refractory concrete and strong insulation, high wall temperatures are achieved which guarantee complete combustion.



   - Passing the diffuser into the boiler prevents the flames from coming into contact with cold boiler parts, so that clean combustion is guaranteed.



   - The design of the diffuser partially recuperates the pressure loss caused by the high gas velocities and thus reduces the total pressure loss.

Claims (6)

  1.  PATENT CLAIMS 1. As a pre-firing to a boiler adjustable wood gas burner, the combustion chamber (18) is intended to be connected to the boiler via a fire mouth (9), characterized in that the fire mouth (9) is designed as a venturi channel with a nozzle-shaped section (10) and an adjoining diffuser (11).
  2.  2. Wood gas burner according to claim 1, characterized in that the free end (12) of the diffuser (11) extends over the wall of the burner and is intended to protrude into the boiler opening.
  3.  3. Wood gas burner according to claim 1, in which the primary air in the area of the grate (8) and the secondary air is fed into the fire mouth (9), characterized in that in the area of the narrowest point (15) of the venturi channel openings (19) for the supply the secondary air are provided.
  4.  4. Wood gas burner according to claim 1, characterized in that the fire mouth (9) is lined with refractory concrete parts (13) which are surrounded by insulation (14).
  5.  5. Wood gas burner according to claim 1, characterized in that it has a mobile chassis (1).
  6.  6. Wood gas burner according to claim 5, characterized in that the chassis (1) is movable on rails.
     The invention relates to a wood gas burner according to the characterizing part of patent claim 1.
     Wood pre-firing systems with vertical fuel shafts for placing on standard boilers are known.
     In such a burner, the fireclayed fuel shaft is enclosed in an insulated sheet metal jacket, and the fire mouth leads horizontally to the boiler opening at the level of the grate. The fire in the combustion chamber is fanned by primary air, which is supplied under the grate, whereby the high temperatures in the fuel shaft cause drying and pyrolysis (carbonization) of the fuel.
    The pyrolysis gases are converted to highly flammable gases due to the high temperatures in the firing zone.
    Due to the secondary air, which is fed into the boiler immediately before the flame / gas mixture enters, these gases burn almost completely.
     The output is controlled by simultaneously opening and closing the primary and secondary air flaps. The combustion air is conducted in cavities between the brick lining and the insulation.
     Pre-firings are known which work with compressed air.
    A fan pushes the secondary air into an injector, in which the flame / gas mixture from the combustion chamber is mixed with the secondary air and burned.
     The smoldering gases generated in the combustion chamber are harmful to health, so that if there are any leaks in the burner, there is a risk of injury. In addition to the health hazard, an explosion risk must also be expected in such cases.
     The invention has for its object to provide a burner of the type mentioned, in which the outflow of gases is prevented even in the event of leakages. The burner should also have a high efficiency, be inexpensive to manufacture and easy to use. This object is achieved according to the invention by a wood gas burner which has the features listed in the characterizing part of patent claim 1. As a result of the Venturi channel, the burner can be operated in suction mode so that there is always a negative pressure in the combustion chamber, which means that no gases can escape even in the event of leaks.
     An exemplary embodiment of the invention is explained in more detail below with reference to the drawing.
     Show it: 1 is a view of a wood gas burner seen from the boiler side, Fig. 2 is a schematic horizontal section along the line II-II through the burner according to Figure 1, and 3 shows a vertical section along line 111-1 II through the burner according to FIG. 1.
     The wood gas burner is used in a manner known per se as pre-firing for a boiler, not shown.
    The burner is mounted on a chassis 1 with rollers 2 and can thus be easily switched on to any standard boiler or - pushed back for service and cleaning purposes. Rails are expediently provided in order to allow easy entry and exit of the boiler and precise positioning.
    This is particularly advantageous if the boiler is also operated with oil.
     The burner has a vetical fuel bunker 3, which is completely lined with refractory refractory bricks 5, 6 and is covered at the top by a hood 7. In the latter there is an airtight filling opening (not shown) for the firing material.
     A first incomplete combustion takes place in the combustion chamber 18 in the lower part of the bunker 3, the primary air for combustion being supplied through the grate 8, so that an ember bed forms above the grate. The high temperatures lead to the drying and smoldering of the fuel. The hot smoke and smoldering gases enter the fire mouth 9 of the burner, where secondary air is metered in to bring about complete combustion. During the combustion process, fuel constantly slips from above, with the appropriate regulation of the air supply preventing the embers from spreading upwards.
     The burner is operated in suction mode, whereby there is always a pressure in the bunker that is below atmospheric pressure. This prevents harmful gases from escaping in the event of leakage and endangering people.
     So that the burner can be operated with natural draft without any problems, the combustion chamber 18 and the fire mouth 9 are designed in such a way that the pressure loss is minimal. The fire mouth 9 is designed in the manner of a venturi channel with a narrowing, nozzle-shaped section 10, in which the flow accelerates, and a diffuser 11 with a delayed flow adjoining it. The secondary air is mixed in at the narrowest point 15 of the venturi channel through the opening 19, which as a result of the negative pressure at this point leads to thorough mixing with the flame / gas mixture and optimal combustion.  
     Air regulation is given great importance, since this is a prerequisite for optimal burner operation. The primary air is mainly used to provide the basic output, while the secondary air is to be used for complete combustion and a low content of combustible components in the flue gas. The primary and secondary air is guided in the cavities 17 between the insulation 14 and the chamotte bricks 5, 6 and can already warm up before entering the combustion chamber or the fire mouth. The cavities 17 ** WARNING ** End of CLMS field could overlap beginning of DESC **.
CH781381A 1981-12-07 1981-12-07 Wood gas burner which can be added onto a heating boiler CH654899A5 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CH781381A CH654899A5 (en) 1981-12-07 1981-12-07 Wood gas burner which can be added onto a heating boiler

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH781381A CH654899A5 (en) 1981-12-07 1981-12-07 Wood gas burner which can be added onto a heating boiler

Publications (1)

Publication Number Publication Date
CH654899A5 true CH654899A5 (en) 1986-03-14

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Family Applications (1)

Application Number Title Priority Date Filing Date
CH781381A CH654899A5 (en) 1981-12-07 1981-12-07 Wood gas burner which can be added onto a heating boiler

Country Status (1)

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CH (1) CH654899A5 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0251269A2 (en) * 1986-06-30 1988-01-07 EIGENMANN AG Werkzeug &amp; Maschinen Process and furnace for gasifying a solid fuel and for burning the gases obtained
EP2314918A2 (en) 2009-06-24 2011-04-27 Kimmo Ahola Device for gasification and combustion of solid fuel
EP3614047A1 (en) * 2018-08-22 2020-02-26 Gerd Mooshammer Combustion device for outdoor use

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0251269A2 (en) * 1986-06-30 1988-01-07 EIGENMANN AG Werkzeug &amp; Maschinen Process and furnace for gasifying a solid fuel and for burning the gases obtained
EP0251269A3 (en) * 1986-06-30 1988-11-30 EIGENMANN AG Werkzeug &amp; Maschinen Process and furnace for gasifying a solid fuel and for burning the gases obtained
EP2314918A2 (en) 2009-06-24 2011-04-27 Kimmo Ahola Device for gasification and combustion of solid fuel
US8459192B2 (en) 2009-06-24 2013-06-11 Kimmo Ahola Device for gasification and combustion of solid fuel
EP3614047A1 (en) * 2018-08-22 2020-02-26 Gerd Mooshammer Combustion device for outdoor use

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