FI127741B - Bio oil burner - Google Patents

Abstract

The bio-oil burner comprises an oil lance (13) with an oil nozzle (1) at its apex having spray openings (12) for supplying atomized oil to the boiler furnace. The bio-oil burner further comprises a first cylinder (19) which, together with the oil lance (13) defines an annular primary air flow passage (3); a second cylinder (20) defining together with the first cylinder (19) an annular secondary air flow passage (4) and a third cylinder (23) defining an annular tertiary air flow conduit (9) together with the second cylinder (20). The bio-oil burner further comprises a primary air vortex (6) which annularly surrounds the oil nozzle (1) and covers at least a portion of the outlet (21) of the primary air flow passage (3). The oil nozzle (1) has from 10 to 50 atomizing apertures (12) distributed on an inclined peripheral surface (17) of the oil nozzle (1) such that said atomizing apertures (12) form at least two groups of atomizing apertures (B1, B2) at regular intervals (S1) from each other, and that there are intermediate spaces (16) without spray apertures (12) between said groups of spray openings (B1, B2). Connected to the free end (25) of the first cylinder (19) is a flame stabilizer ring (7) that surrounds the outlet (21) of the primary air flow passage (3) and covers part of the outlet (22) of the secondary air flow passage (4). The outer diameter Di of the primary air vortex (6) is calculated by the formula Di = a ∙ D1ry, where a is 0.45-0.6 and D1ry is the inside diameter of the first cylinder (19).

Description

BIOÖLJYPOLTIN

FIELD OF THE INVENTION

The invention relates to a bio-oil burner which so5 burns bio-based pyrolysis oil in heat only boilers. The invention also relates to an oil nozzle for an oil burner.

BACKGROUND OF THE INVENTION

Combustion of heavy fuel oil and natural gas is currently well known and there are many commercial solutions. However, the ever-tightening emission limits for nitrogen oxides (NO _X ) are creating pressures for change, and technical improvements to the equipment15 are constantly needed. In addition to NO _x emissions, carbon dioxide (CO2) emission limits will be tightened in the future. One way to reduce CO 2 emissions is to replace heavy fuel oil with bio-oil produced from bio-based material.

For the combustion of gaseous, liquid and solid fuels, there are separate burners that are optimized for the particular type of fuel. In addition, there are hybrid burners that are suitable for burning two or more different fuels.

Typically, the largest heavy-duty oil burners currently manufactured have a thermal output of 40 to 60 MW, resulting in an oil flow rate of 4 to 6 t / h (one thousand kilograms per hour). A typical oil burner 30 comprises an oil lance surrounded by a primary air supply channel, a secondary air supply channel, and a tertiary air supply channel. The oil can be broken down into droplets by steam or compressed air. The fuel is atomized by means of an oil nozzle at the end of the oil lance 35 into a hot furnace where it is immediately ignited, creating a flame at the burner mouth. The combustion is enhanced by the airflow supplied around the flame

20146099 prh 13 -08-2018 with air control devices located in the air supply ducts.

Requirements for the oil burner change as fuel characteristics change. Bio - oil produced by pyrolysis of biomass may contain 20

- 40% by weight of water. When the calorific value of heavy fuel oil is about 40 MJ / kg, the calorific value of bio-oil is only about 10 15 MJ / kg. In order to achieve the same thermal output, the amount of bio-oil must be fed to the boiler in a larger amount than heavy fuel oil. When the fuel mass flow rate for a 40-60 MW heavy fuel oil burner is about 4-6 t / h, for a bio-oil burner of the same size, the cash flow of the fuel should be about 10-12 t / h. This type of feed stream cannot be produced by the heavy fuel oil burners currently in use. The high water content of bio-oil lowers the temperature of the flame and reduces its stability. The nitrogen content of the bio-oil can be high, for example 0.5% by weight, which increases NO _x emissions.

In addition, pyrolysis of biomass usually produces acids, which is why bio-oil is mostly acidic. For example, bio-oil produced from wood has a pH of about 2-3. In order to prevent the boiler from corroding, it is important that the flame of the oil burner on the roof of the furnace or on the wall does not under any circumstances hit the surfaces of the boiler's cooking pipes.

OBJECT OF THE INVENTION

The object of the invention is to provide an oil burner and an oil nozzle suitable for burning bio-oil. Thus, the object is a burner capable of atomizing and burning liquid fuel of low calorific value and low pH.

In particular, the object is a bio-oil burner which can simultaneously achieve or at least achieve the following objectives: [1] the carbon monoxide (CO) content of the flue gas is less than 100 ppm;

20146099 prh 13 -08-2018 [2] the proportion of non-combustible carbon in fly ash contained in the flue gas is less than 5% by weight; [3] NO _x less than 400 mg / Nm ^{3 in the} flue gas; and [4] the flame does not extend to the walls of the furnace where it could cause hot corrosion.

As the possible means of achieving the stated objectives are partly contradictory, the simultaneous achievement of all the objectives requires careful optimization of the structural characteristics of the oil burner.

SUMMARY

A bio-oil burner has now been disclosed, comprising:

- an oil lance at the tip of which is an oil nozzle with spray holes for supplying atomized oil to the boiler furnace,

- a first cylinder which coaxially surrounds the oil lance and defines, together with the oil lance, an annular primary air flow channel terminating at the outlet of the primary air flow channel,

- a second cylinder coaxially surrounding the first cylinder and defining, together with the first cylinder, an annular secondary air flow channel terminating at the outlet of the secondary air flow channel,

- a third cylinder coaxially surrounding the second cylinder and defining together with the second cylinder an annular tertiary air flow passage terminating at the outlet of the tertiary air flow passage, and

- a primary air vortex, which annularly surrounds the oil nozzle and covers at least a portion of the outlet of the primary air flow passage, and which is characterized by a bio-oil burner that:

- the oil nozzle has an oblique circumferential surface and 10 50 atomizing apertures spaced along the oblique circumferential surface of the oil nozzle such that said atomizing apertures

20146099 prh 13 -08-2018 form at least two groups of nebulization apertures at regular intervals between the nebulization apertures, with spacers having no orifice apertures between said nebulization aperture groups and having a circumferential length of said intermediate apertures greater than said peripheral apertures between said atomizing apertures a first cylinder having a free end at the outlet of the primary air flow passage, and a free flame stabilizer ring connected to the free end of the first cylinder surrounding the outlet of the primary air flow passage and covering a portion of the secondary air flow channel outlet;

- the outer diameter 15 Di of the primary air vortex is calculated by the formula D ± = a · Di _ry , where a is 0,45 0,6 and D _lry is the inside diameter of the first cylinder.

Also disclosed is an oil nozzle for an oil burner, the oil nozzle having an oblique circumferential surface having atomizing apertures, and having an oil nozzle having 20 to 50 atomizing apertures spaced along the inclined peripheral surface of the oil nozzle such that said atomizing apertures form at least two groups of atomizing apertures and that there is a space between the groups of said spray apertures which does not have a spray aperture and and the circumferential length of the intermediate spaces is greater than the circumferential distance between the atomization apertures within the group.

The large number of spray openings in the oil nozzle causes a greater mass flow of fuel through the oil nozzle than a nozzle having a smaller number of spray openings. In addition, the nebulization apertures are arranged in two or more groups in the oil nozzle such that spaces are provided between the atomization aperture groups. In one embodiment, said spray openings form two, three or four groups of spray openings. Intermediate spaces provide access to primary air to the center of the oil nozzle. Air flowing into the central region improves the flame ignition in two ways. The air flowing into the center region of the droplets blends into the fuel region, improving the air with each other, which is more stable.

and oil earnings

In addition, ignition of the central portion of the air pushes the formed oil particles outward, which contributes to the ignition of the flame.

In one embodiment, the spray apertures have a diameter of 6 mm. In one embodiment, the spray apertures have a diameter of 7.5 mm. With a spray aperture diameter of 7.5 mm, computer calculations provide sufficient oil supply.

A flame stabilizer ring attached to the free end of the first cylinder is disposed so that primary air flows on one side and secondary air on the other. The stabilizer ring covers a portion of the secondary airflow outlet outlet so that a portion of the secondary air flow collides with the stabilizer ring, thereby changing the airflow field. Behind the stabilizer ring is secondary air

20146099 prh 13 -08-2018 the flow channel creates a vacuum field which causes flame stabilization or at least improves the stability of the flame. The stabilizer ring also gives the flame a better ignition than the air stabilizer ring. In addition, the flame stabilizer ring alters the flame flow field so that the flame remains narrow, whereby the flame does not extend to the boiler walls and thus does not cause heat corrosion of the walls or at least reduce heat corrosion.

The primary air vortex covers at least a portion of the primary air flow duct outlet so that at least a portion of the primary air flow collides with the vortex 35, thereby changing the air flow field.

The primary air vortex according to the invention causes the primary air to flow out of the flow duct.

20146099 prh 13 -08-2018 The air flow is more straightforward towards the center of the boiler than in a burner with a larger outer diameter of the vortex. The flame thus remains narrow and does not essentially extend to the boiler wall.

The design of the oil nozzle, the outer diameter of the vortex and the stabilizer ring can influence the flow field throughout the boiler and thereby the burner. The flow field 10 of the burner in turn regulates the local oxygen concentration and thus the formation of nitrogen oxide emissions.

Bio-oil refers to liquid fuel produced by the pyrolysis of biomass. In one embodiment, the bio-oil is produced by pyrolysis of wood pulp. In one embodiment, the bio-oil is a pyrolysis oil.

Atomization means the breaking up of oil into small droplets. In one embodiment, the oil is decomposed by means of a pressure medium. In one embodiment20, the pressure medium is vapor. In one embodiment, the pressure medium is compressed air. In one embodiment, the oil is decomposed by controlling the oil pressure without the use of a pressure medium.

The first cylinder is coaxially surrounded by 25 oil lances. The space between the inner surface of the first cylinder and the outer surface of the oil lance forms the primary air flow channel. The primary air flow passage has an annular cross-section.

The second cylinder coaxially surrounds the en30 first cylinder. The space between the inner surface of the second cylinder and the outer surface of the first cylinder forms a secondary air flow channel. The secondary air flow duct has an annular cross-section.

A third cylinder surrounds 35 second cylinders coaxially. The space between the inner surface of the third cylinder and the outer surface of the second cylinder is formed

20146099 prh 13 -08-2018 provides a tertiary air flow channel. The third cylinder has an annular cross-section.

In one embodiment, the oil nozzle has 15 to 40 atomization apertures. In one embodiment, the oil jet nozzle has 20 to 25 spray apertures.

In one embodiment, the circumferential length of the intermediate spaces is 2 to 4 times greater than the circumferential distance between the spray apertures within the array. In one embodiment, the circumferential length of the intermediate spaces 10 is 3 times greater than the circumferential distance between the spray apertures within the array.

In one embodiment, the atomization apertures are divided into two ke15 tail lines in the inclined peripheral surface of the oil nozzle. In another embodiment, the spray apertures are divided into two circumferential rows on two different inclined peripheral surfaces.

In one embodiment, the stabilizing ring comprises an annular portion extending away from the outlet 20 of the primary air flow passage. The stabilizing ring may also comprise a plurality of toothed projections extending radially into the primary air flow passage. In one embodiment, the wall 25 of the expanding annular portion of the stabilizer ring is uniformly reduced toward the free edge of the stabilizer ring. In one embodiment, the free end of the first cylinder is thinned and the stabilizer ring comprises a flat annular portion that can be fitted around the thinned end of the first cylinder and secured by a locking ring. In one embodiment, the stabilizer ring is made of heat-resistant steel. The stabilizing ring may consist of one or more parts. Said tooth-like projections can be made of heat-resistant steel or heat-resistant ceramic material.

In one embodiment, a is 0.5. In one embodiment, the outer diameter of the vortex is 120

20146099 prh 13 -08- 2018

180 mm. In another embodiment, the outer diameter of the vortex is 150 mm.

When the number of atomization apertures in the oil nozzle is 20 and the circumferential length of the intermediate spaces is three times the circumferential distance between the atomization apertures within the group and a is 0.5 when calculating the outer diameter of the primary air turbulator, a stable and narrow flame . Similarly, the above values achieve, according to computer calculations, a carbon monoxide concentration of less than 100 ppm and a NO _x concentration of less than 400 mg / Nm ^{3 in the} flue gas. In addition, the non-combustible carbon content of the fly ash contained in the flue gas is, according to computer calculations, below 5% by weight.

In one embodiment, the bio-oil burner is provided with gas lances located in the primary air flow passage that allow the combustion of gaseous fuel. In another embodiment, the bio-oil burner is not provided with gas lances.

In one embodiment, the bio-oil burner has a thermal output of 5 to 60 MW. In one embodiment, the bio-oil burner has a thermal output of 10 to 55 MW. In one embodiment, the thermal power of the bio-oil burner is from 20 to 50 MW. In one embodiment, the bio-oil burner is used to burn bio-oil in heat only boilers which produce only heat or heat and steam but no electricity. The bio-oil burner can also be used in another type of boiler. There may be several bio-oil burners in the same boiler.

In one embodiment, the oil nozzle is for a bio-oil burner.

The bio-oil burner disclosed herein provides significant advantages over the prior art. At least some of the embodiments disclosed herein provide a suitable oil for combustion of bio-oil

20146099 prh 13 -08-2018 jet burner capable of feeding the boiler a sufficient amount of fuel per time unit and providing a sufficiently stable and narrow flame, according to computer calculations, which does not subject the surfaces of the boiler 5 to heat corrosion (either at all or at least significantly). The flame ignition also improves. A bio-oil burner according to at least some embodiments has been found to have low nitrogen oxide concentrations according to computer calculations, so that they comply with 10 Industrial Emission Directive (IED) regulations coming into force in the EU in 2016. Similarly, at least in some embodiments, the bio-oil burner has, according to computer calculations, achieved a carbon monoxide content of less than 100 ppm in the flue gas and less than 5% by weight of unburned carbon in the fly ash.

LIST OF FIGURES

The invention will now be illustrated by means of the accompanying drawings, which show exemplary embodiments. The invention is not limited to the embodiments of the figures.

Figure 1 is a schematic front view of a heavy oil burner, Figure 2 is a cross-sectional view AA of the heavy oil burner of Figure 1, Figure 3 is a cross-sectional view of a heavy oil burner, Figure 4 is a front view of Figure 7 shows an enlarged detail of the opening of a bio-oil burner,

20146099 prh 13 -08-2018 Figure 8 is a cross-sectional view of a bio-oil nozzle according to one embodiment, and Figure 9 is a front view of a bio-oil nozzle according to an embodiment.

Figures 1 and 2 show a heavy fuel oil burner whose structure as such is not suitable for burning bio-oil. The heavy oil burner is intended to be placed in the roof or wall structures of the boiler so that the burner outlet opens towards the furnace. A boiler can usually have 1-5 oil burners depending on the boiler output.

The heavy oil burner according to Figures 1 and 2 comprises an oil lance 13 surrounded by an annular 15 primary air flow passage 3, a secondary air flow passage 4 (indicated by oblique lines) and a tertiary air flow passage 9 (indicated by horizontal lines). By means of the oil lance 13, the fuel is fed atomically to the furnace of the boiler, where it ignites 20 to form a flame in front of the burner orifice. Through the air flow passages 3, 4 and 9, the combustion air is supplied around the flame to provide a stable flame. The heavy oil burner further comprises a plurality of gas lances 2 arranged in the primary air air flow passage 3. The gas lances 2 can, if necessary, supply natural gas or other gaseous fuel to the boiler furnace. The oil burner is further provided, in a manner known per se, with an igniter (not shown) for igniting the fuel at start-up of the burner, and with a flame monitor (not shown).

Figures 1 and 2 show a first cylinder 19, a second cylinder 20, and a third cylinder 23 disposed coaxially around an oil lance 13. 35 The first, second, and third cylinders 19,20,23 terminate in primary air, secondary air, and tertiary air.

20146099 prh 13 -08- 2018 air outlet 21,22,24. Figure 2 further shows the free end 25 of the first cylinder 19.

In Figures 1 and 2, the oil lance 13 comprises a pressure medium supply channel 14, one or more fuel supply channels 15, and an oil nozzle IA in which the fuel is atomized by means of a pressure medium before being fed to the furnace. For atomization, for example, steam or compressed air may be used as the pressure medium. Atomization can also be accomplished by controlling the oil pressure without the use of a pressure medium. The oil nozzle IA, shown in more detail in Figures 4 and 6, comprises a plurality of atomization openings 12 through which fuel is fed into the boiler furnace in droplets. The fuel discharged from the oil nozzle IA ignites when it encounters an air stream discharged from the primary air stream 15.

1 and 2, the oil nozzle IA is circumferentially surrounded by a primary air vortex 6A. The vortexer 6A is disposed at the outlet 21 of the primary air flow duct 3 so that the vortexer 6A obscures at least a portion of the outlet 21. The vortexer 6A is mounted around the oil nozzle IA. The vortexer 6A may be either inside or outside the flow passage 3 so that it is inside or outside the free end 25 of the first cylinder 19. The rotating nozzle 6A may comprise flaps, blades, or the like, which rotates the air stream discharged from the primary air flow passage 3 before it collides with the fuel jet or flame discharged from the oil nozzle IA.

In the heavy oil burner of Figures 1 and 2, the secondary air flow passage 4 and the tertiary air flow passage 9 may also be provided with means (not shown) for tangential movement of said air flow prior to passing the tertiary air flow around the flame.

Figures 3 and 4 show, in principle, the structure of a heavy oil nozzle IA. The heavy oil nozzle typically has an external diameter of 30 to 50 mm. The heavy oil nozzle typically has a spray aperture diameter of about 5 to about 3-5 mm. This nozzle is not suitable as such

20146099 prh 13 -08-2018 for use in bio oil burner. The heavy oil nozzle IA shown in Figures 3 and 4 comprises six spray apertures 12 evenly spaced across the inclined peripheral surface 17 of the oil nozzle IA.

In the following, the structure and operation of the oil nozzle will be discussed in principle. Oil Nozzle

Inside IA there is a cavity 14a which is in fluid communication with the pressure medium flow conduit 14. A plurality of atomizing channels 12a open into the cavity 14a, each terminating in the nebulization opening 12 and through it to the spray holes 12.

The pressure medium (steam or compressed air) is passed through the pressure medium flow passage 14 through the oil nozzle

IA into the inner cavity 14a from which the pressure medium discharges through the spray channels 12a into the spray openings

12. The fuel is introduced into the oil nozzle IA via the fuel supply channels 15 which terminate in the oil channels 15a in the oil nozzle IA which are in fluid communication with the spray channels 12a. As the pressure medium discharges from the cavity 14a into the spray channels 12a, it at the same time draws from the oil channels 15a fuel 30 which mixes with the pressure medium into small droplets.

By means of the flow channels 12a and 15a, such a nozzle arrangement is used as a nozzle.

The angles of the flow channels 12a and the structure, denoted Y15a, and of the bevelled peripheral surface 17 relative to the central axis of the nozzle may be varied according to the embodiment.

Figures 5 and 6 show a bio-oil burner according to the invention. The bio oil burner is different

20146099 prh 13 -08-2018 Oil Nozzle 1 as in Figures 1-4 Heavy Oil Burner. The outside diameter of the bio-oil burner 6 is smaller than the outside diameter of the heavy-oil burner IA. In addition, a stabilizer ring 7 is connected to the left end 25 of the first cylinder 19.

The bio-oil burner comprises an oil lance 13 which is annularly surrounded by a primary air flow passage 3, a secondary air flow passage 4 (indicated by oblique lines), and a tertiary air flow passage 9 (indicated by horizontal lines). By means of the oil lance 13, the fuel is fed atomically to the furnace of the boiler, where it ignites, creating a flame in front of the burner orifice. Through the air flow channels 3, 4 and 9, the ground needed for combustion is fed around the flame to provide a stable flame. The bio-oil burner of Figures 5 and 6 further comprises a plurality of gas lances 2 arranged in the primary air flow passage 3. The gas lances 2 can, if necessary, supply natural gas or other gaseous fuel 20 to the boiler furnace. In addition, the oil burner is equipped, as is known per se, with an igniter (not shown), which is used to ignite the fuel when the burner is started, and with a flame monitor (not shown).

Figures 5 and 6 show a first cylinder 19, a second cylinder 20 and a third cylinder 23, coaxially disposed on the oil lance 13 and around the first, second, and third cylinders 19, 20, 23 terminating at the primary, secondary, and tertiary air outlet 21,22, 24. Figure 6 shows the free end 25 of the en30 first cylinder 19 to which the flame stabilizer ring 7 is attached.

In Figures 5 and 6, the oil lance 13 comprises a pressure medium supply channel 14, one or more fuel supply channels 15, and an oil nozzle 1 in which the fuel 35 is atomized by means of a pressure medium before being fed to the furnace. For example, steam or compressed air may be used as the pressure medium. The atomizing

20146099 prh 13 -08-2018 can also be done by regulating oil pressure without pressure medium. The oil nozzle 1, shown in more detail in Figures 8 and 9, comprises a plurality of atomization openings 12 through which fuel is fed into droplets into the boiler fire chamber. The fuel discharged from the oil nozzle 1 lights up when it encounters an air stream discharged from the primary air flow passage 3. The diameter of the bio-oil nozzle 1 is larger than the diameter of the heavy oil nozzle IA of Figures 1-4. Also, the structure of the bio-oil nozzle 1 is different from that of the heavy oil nozzle of Figures 1-4.

The structure of the bio-oil nozzle 1 is described in more detail below with reference to Figures 8 and 9. The diameters of the air supply channels 3, 4, 9 surrounding the oil nozzle 1 need not necessarily be changed when the heavy oil burner 15 is replaced by a bio oil burner.

5 and 6, the oil nozzle 1 is circumferentially surrounded by the primary air vortex 6. The vortex 6 is disposed at the outlet 21 of the primary air flow conduit 3 such that the vortex 6 covers at least 20 portions of the outlet 21. The vortex 6 is secured around the oil nozzle 1. The vortex core 6 may be either inside or outside the flow channel 3 so that it is inside or outside the free end 25 of the first cylinder 19. The vortex 6 may comprise flaps, blades or the like which causes the air stream discharged from the primary air flow channel 3 to circulate before it collides with the fuel jet or flame discharged from the oil nozzle 1.

5 and 6, the primary air turbulator 6 has a smaller outer diameter than the heavy oil burner of Figures 1 and 2. As the outer diameter of the primary air vortex 6 is reduced, the air flow discharged from the primary air flow passage 3 35 is more linearly directed toward the center of the boiler than in a burner with a rotor 15.

20146099 prh 13 -08-2018 The outer diameter of the dispenser is larger. As a result, the flame will not spread as wide as in a burner with a larger outer diameter of the vortex. While in the 50 MW heavy oil burners, the diameter of the vortex 6A? 5 is typically about 300 to 310 mm, in the burner according to one embodiment, the outer diameter of the vortex 6 is about half that. In one embodiment, the vortex 6 has an outer diameter of about 120 to 180 mm. In another embodiment, the bio-oil burner has a heat output of about 50 MW and a vortex diameter of about 150 mm.

Also, the secondary air flow passage 4 and the tertiary air flow passage 9 may be provided with means (not shown) for directing said air stream 15 through tangential movement prior to passing the secondary air stream and the tertiary air stream around the flame.

5 and 6, a flame stabilizer ring 7 is attached to the free end 25 of the primary cylinder 19 at the free end 25 of the first cylinder 19 so that the primary air flowing from the primary air flow channel 3 flows on one side and the secondary air flow channel 4 flows on the other side. air. The stabilizer ring 7 covers part of the outlet 22 of the secondary air flow channel 4 so that part of the secondary air flow collides with the stabilizer ring. The function of the flame stabilizer ring 7 is to modify the flame flow field so that it remains sufficiently narrow so that the flame 30 cannot reach the walls of the furnace. At the same time, the function of the flame stabilizer ring 7 is to ignite the bio-oil flame well and to stabilize its combustion.

The stabilizer ring 7 extends outwardly and forwardly from the first cylinder 19, i.e. toward the center of the boiler 35 and the edges of the boiler. The shape of the stabilizer ring 7 may be staggered so that the stabilizer ring 16

20146099 prh 13 -08-2018 the end attached to the first cylinder 19 is parallel to the cross-section of the first cylinder 19 and the stabilizing ring 7 pivots at a distance from its attachment point to the center and edges of the boiler. The Stabi5 winding ring 7 may be substantially frustoconical, opening towards the center and the edges of the boiler. The stabilizer ring 7 may also be of other shapes as long as it changes the flow field of the flame in the desired direction.

Fig. 7 is an enlarged view of a portion of the structure of a bio-oil burner according to one embodiment. At the end of the oil lance 13 is a new type of oil nozzle 1 surrounded by a primary air vortex 6. The oil lance 13 is surrounded by a primary air flow channel 3, a second 15 aero air flow channel 4 and a tertiary air flow channel 9. In this solution, the oil nozzle 1 has a The outer diameter 6 is smaller than that of the heavy oil burner of Figures 1-4 and furthermore the oil burner is provided with a flame sta20 balancing ring 7. The stabilizing ring 7 comprises an annular portion 26 extending away from the outlet 21 of the primary air flow channel.

Figures 8 and 9 show, in principle, the structure of a bio-oil nozzle 1 ra25 according to an embodiment. The operation of the bio-oil nozzle 1 is similar to that of the heavy oil nozzle IA of Figures 3 and 4. The operation is described above with reference to Figures 3 and 4. Also, the structure of the bio-oil nozzle 1 is similar to that of the heavy oil nozzle IA shown in connection with the description of Figures 3 and 4, except for the outer diameter of the nozzle 1 and the number and position of the spray holes 12, spray channels 12a and oil channels 15a. The diameter of the bio-oil nozzle 1 shown in Figures 8 and 9 is larger than that of the heavy-oil nozzle IA 35 because a larger mass flow rate must be passed through the bio-oil nozzle 1 than with conventional fuels.

20146099 prh 13 -08- 2018 neilla. When 6-8 oil spray holes 12 are provided in the heavy oil nozzle IA, the number of spray holes 12 in the bio-oil nozzle 1 may be 10 to 50. In addition, these spray openings 12 are disposed in a different manner from the heavy oil nozzle IA.

8 and 9 comprise a total of 20 spray openings 12 disposed in two groups of spray openings B1, B2 on the oblique circumferential surface 17 of an oil nozzle 10. Each spray openings group B1, B2 comprises ten spray openings 12 equally spaced so that two successive spray openings The distance between the 12 centers is SI. Between two groups of nebulization openings B1, B2 there is a spacer 16 having a length S2 greater than the distance S1 between two successive nebulization openings 12 within a group B1, B2. The length S2 of the space 16 refers to the distance between the centers of the outermost spray openings 12 of groups B1, B2 of adjacent spray openings. It is also possible to divide the spray apertures in groups B1, B2 into two circumferential rows.

Through the intermediate spaces 16, air can flow into the region 18 of the central portion 18 of the oil nozzle 1 where the air improves the flame ignition in two ways. The air inlet 25 in the middle of the oil droplets discharged from the spray holes 12 enhances the mixing of the air with the oil droplets, which is important for the stable ignition of the fuel. In addition, the air flowing into the region 18 of the central part of the oil nozzle 1 spreads the already formed oil particles 30 outwardly while spreading the flame, which is also advantageous for the flame to ignite. In a split oil nozzle IA, the flame tends to enter the suppository and the air is poorly mixed, resulting in the formation of harmful non-combustible soot and carbon monoxide.

The new design of the oil nozzle 1 allows large quantities of oil to be burned with a bio-oil burner according to the invention. Splitting the spray openings 12 into two groups B1, B2, with intermediate spaces 16, enhances ignition and stabilizes combustion.

The invention is not limited to the examples provided herein, but is convertible within the scope of the appended claims.

Claims (8)

20146099 prh 13 -08- 2018 A bio-oil burner comprising: an oil lance (13) with an oil nozzle (1) at its apex having spray openings (12) for supplying atomized oil 5 to the furnace of the boiler, - a first cylinder (19) coaxially surrounding the oil lance (13) and defining, together with the oil lance (13), an annular primary air flow passage (3) terminating in the primary air flow channel (3); To the outlet (21) of the 10 channels (3), - a second cylinder (20) coaxially surrounding the first cylinder (19) and defining, together with the first cylinder (19), an annular secondary air flow passage (4) terminating in a 15, the third cylinder (23) coaxially surrounding the second cylinder (20) and defining, together with the second cylinder (20), an annular tertiary air flow channel (9) terminating at the tertiary air outlet (24). ), and - a primary air vortex (6) which annularly surrounds the oil nozzle (1) and covers at least a portion of the outlet (21) of the primary air flow channel (3), Characterized in that the oil nozzle (1) has an oblique circumferential surface (17) and 10 to 50 atomizing apertures (12) distributed along the oblique circumferential surface (17) of the oil nozzle (1) such that said atomizing apertures (12) form at least 30 groups of atomizing apertures (B1, B2), wherein the spray openings (12) are spaced at a regular distance (SI), and that between said groups of spray openings (B1, B2) are intermediate spaces (16) without spray openings (12) and intermediate spaces (16) the circumference35 (S2) is greater than that of the group (B1, B2) circumferential spacing (SI) between the interior spray holes (12), 20146099 prh 13 -08-2018 the first cylinder (19) has a free end (25) at the outlet (21) of the primary air flow passage (3), and a flame stabilizer ring 5 (7) is connected to the free end (25) of the first cylinder (19). which surrounds the outlet (21) of the primary air flow passage (3) and covers part of the outlet (22) of the secondary air flow passage (4), and - the outer diameter D ± of the primary air vortex (6) is calculated by the formula D ± = a · Di _ry , where a is 0.45 to 0.6 and Di _ry is the inside diameter of the first cylinder (19). Bio oil burner according to Claim 1, characterized in that the oil nozzle (1) has 15 to 40 atomization apertures (12). 15 Bio oil burner according to Claim 1 or 2, characterized in that the circumferential length (S2) of the intermediate spaces (16) is 2 - 4 times the circumferential distance (SI) between the spray apertures (12) within the group (B1, B2). Bio oil burner according to one of the preceding claims, characterized in that the spray openings (12) are divided into two circumferential rows on the oblique circumferential surface (17) of the oil nozzle (1). 5. A method according to any one of the preceding claims. 25, characterized in that the stabilizing ring (7) comprises an annular portion (26) extending away from the outlet (21) of the primary air flow passage. A process according to any one of the preceding claims, 30 oil burner, characterized in that a is 0.5. Bio oil burner according to one of the preceding claims, characterized in that it is provided with gas lances (2) located in the primary air flow passage (3), which enable 35 incinerating fuel. A bio-oil burner according to any one of the preceding claims, characterized in that it has a thermal power of 5 to 60 MW.