COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION AND RAPID FUEL MIXING METHOD

Abstract

This relates to a combustion system (10) using rapid mixing fuel gas method with combustion air to obtain intense mixture of air flow with strong rotational components with a plurality of gas jets being discharged for this flow. The assembly of the combustion system (10) includes an external body provided with an air inlet and mounting flanges. The external body (12) is connected to the conical outlet element (18) and further to the combustor with cylindrical shape (20). The combustion system (10) further includes the fuel set comprised by two coaxial tubes (24) and (26) with curved swirl fins (42) and gas injectors (48). This assembly is placed inside the external body (12) along the burner axis with the fins (42) being positioned close to the conical element inlet (18). The combustion system operates using a rapid mixing method, with the fuel gas jets injected and regularly distributed in the combustion air flow with high intensity rotational components.

Description

TECHNICAL FIELD OF THE INVENTION

The present patent of invention relates to a combustion system with ultralow NOx emission and rapid fuel mixing method. It refers, specifically, to a combustion mechanism and operating method which enables the reduction of the NOx (Nitrogen Oxides) formation in the industrial combustion systems. Said method allows the rapid mixing of fuel gas, for example natural gas and combustion air, so as to make up an intense air flow mixture (swirl) with a plurality of fuel gas jets discharged into this flow.

The design of the combustion system and respective operating method combine advantageous operating characteristics for the rapid mixing at the injection nozzle, which allows achieving extremely low emissions of NOx, CO, and hydrocarbons.

HISTORY OF THE INVENTION

Nitrogen oxides NO and NO₂ (NOx) are typically formed by the reaction of N₂ and O₂ at high temperatures during the combustion process. The highest temperatures, where there is greater formation of thermal NOx, are observed around the stoichiometric zones of the flame and can be as high as 1925° C./3500° F. for flames originating from the combustion of natural gas with air. Reducing the formation of temperature peaks in the flames, or even eliminating them, is the goal of many manufacturers and suppliers of burners with ultralow NOx emissions.

U.S. Pat. No. 5,667,376, US2009/0029302A1, US2013/0203003A1 and U.S. Pat. No. 8,662,887 and several models of industrial burners by the company ‘North American’, present burner models of fuel gas with combustion air, in a ‘lean” premix configuration, before the injection nozzle, obtained through a set of long tubes. In these models, the mixer is comprised of two concentric tubes: inner tube, through which the high pressure fuel gas is injected; and external tube, through which the combustion air flows. Fuel and air mix together along the interior of the annular section of the mixer creating a “lean” mixture, with up to 70% excess air above the amount of stoichiometric air required for the complete combustion. Being ignited, the lean mixture forms a flame with low adiabatic flame temperature, of around 1000° C./1850° F., with reduced formation of thermal NOx.

The models with long tubes mentioned present several inconveniences, such as, the need for relatively long burners to accommodate this configuration, since this requires mixing tubes with high length/diameter ratio, so that the adequate mixture of air with fuel gas is achieved, and the need for flame stabilizer devices at the tube exit. In the case of operating the burner with reduced thermal load, due to process requirements, the speed of the mixture of fuel air inside the mixing tubes can become excessively low, that can cause a flashback flame inside the tubes, which is not acceptable for the stable operating of the burner.

Another model and method of rapid mixture of fuel gas and air before ignition and combustion reaction is based on fuel jets distributed in straight air flow, which can be mixed with combustion gases by means of the recirculation of furnace gases, presented in documents U.S. Pat. Nos. 5,460,512; 8,118,588 B2; 8,794,960 B2. This burner model has high constructive complexity, presents high manufacturing cost, and requires high-cost control systems.

Models of burners manufactured by “Coen Company, Inc” and by “Eclipse Inc.’ foresee intense use of rotational air to promote the mixture of fuel gas with combustion air before ignition thereof, with additional stabilization of the flame.

In the model conceived by ‘Coen’, the rotational air fins (swirl) are manufactured of metallic blades that form a hollow structure. The fuel gas flows inside this structure and is injected into the air flow by means of a plurality of orifices located in the fins. The injection orifices are located on the edge of each fin downstream of same. There is no fuel flow between the fins, only combustion air flow, which is in the process of transforming from a strictly axial flow to an outflow with axial and rotational components (swirl). The fuel gas is injected in parallel to the air flow which can extend the mixture time and, thus, lengthen the zone for total mixture. That is, this model does not present the advantages of the rapid mixture burners.

Another disadvantage is that the type of hollow fin described above is relatively complex to manufacture and therefore, more costly.

The rapid mixture burner model manufactured by ‘Eclipse Inc.’ employs a turbulator constituted by deflector fins, thick walls, manufactured in molten material (iron or carbon/stainless steel). Each fin is conceived with a “step” downstream in the same direction as the air flow, wherein fuel gas injection orifices are located. During discharge thereof, the fuel gas jets are protected by the step of the fin, from instantaneous contact with the combustion air flow. The gas jets are discharged in radial direction away from the central line of the burner. The burner rapidly mixes the air and gas, it provides a compact flame with rotational components (swirl) in operation with high excess air, producing at the exit NOx emissions of 10-20 ppm to 3% O₂.

The greatest disadvantage of the above cited model consists in the fact that the turbulator is made from cast metal, being therefore extremely heavy, for which reason the maximum capacity of the burner does not exceed 10 MMBtu/h (3.3 MW).

Another disadvantage is that, having thick and hollow fins, the number of fins of the turbulator, for a given burner diameter, is less than that of the turbulator with solid fins, manufactured with metal plates. The configuration with smaller number of fins brings additional disadvantages for obtaining high swirl numbers, such as, for example, the need of the use of more combustion air, less stability of the flame, less uniform angular thermal profile of the flame, among others.

OBJECTIVES OF THE INVENTION

It is an objective of the invention to present a combustion system (10) with ultralow NOx emission and rapid mixture fuel method, which allows overcoming the disadvantages of the prior art. At the same time, the conical outlet part (18) or the diametral funneling of the combustion system (10) is advantageous for the additional reduction of the NOx emissions by the extremely rapid mixture of fuel gas with combustion air before ignition and stabilization of the flame in the combustor.

It is an objective of the invention to present a new combustion system (10) with ultralow NOx emission which set consists in an external body (12) with an air inlet and mounting flanges (14)/(14′) on both sides. The body (12) is connected with a conical outlet element (18) and further with the cylindrical combustor (20). A second set of concentric tubes (24) and (26) provided with fins (42) and gas injectors (48) is inserted inside the external body (12).

The combustion air is supplied to the combustion system (10) by means of fan or air blower and flows through the annular channel formed by the external body (12) and the tube (26) and in sequence flows through the open passages between the fins (42) of the turbulator, thus forming a current with intense rotational component. The fuel gas flows through the annular channel formed by the concentric tubes (24) and (26). The external tube (26) has perforations (50) over which the gas injectors (48) are installed. The number of injectors (48), mounted between two adjacent fins (42), can vary from one to ten; in this specific case we present a model with three injectors (48) arranged between two adjacent fins (42). Each injector has perforated orifices (52) through which the fuel gas (FG) is injected in the combustion air current, which flows between two adjacent fins (42). In this way, the fuel gas (FG) is evenly distributed in the rotational air flow and in all the circumference of the combustion system (10).

To start the operation of the combustion system (10), you must start by providing air to the system, for example, 30-40% of the nominal flow of combustion air. Next, activate the electric igniter (62), and then open the fuel gas valve gradually until there occurs the ignition of the flame. Observe the flame through the observation port; the UV sensor must capture a strong sign of the presence of the flame. As a result, the flame is stabilized in the conical element (18) of the combustion system (10), which, together with the turbulator fins and the gas injectors, can be denominated as a RAPID mixture zone. Then, adjust the gas and air flows to the thermal power and air excess required by the process.

The flame, with intense rotational component (swirl), exits by the conical part (18) in the direction of the cylindrical combustor (20), which has a diameter significantly larger than the RAPID mixture zone. The main flame is established in the combustor. The diameter and length of the combustor (20) are determined so that the combustion reaction occurs completely within the combustor volume, with the excess air required to reduce the adiabatic temperature of the flame and, thus, reduce the NOx formation.

Due to the nature of the rotational flames (or, in general, rotational flows), the negative pressure area is developed both along the combustor axis (20) as the RAPID mixture zone. As a result, an important recirculation (return) of the hot combustion product moves along the combustion system axis (65), in the direction of the turbulator and penetrates the RAPID mixture zone. This recirculation constantly promotes the ignition of the mixture of fuel/air stemming from the turbulator. Then, the flame stabilization mechanism in this model of combustion system (10) occurs by the recirculation of the hot combustion products. A few minutes after the start of the operation, the combustor wall (20) and the insulating material plate (40) can begin to glow. These glowing elements can help in the flame stabilization by means of the heat transfer by radiation mechanism. The intensity of the glowing surfaces is strongly dependent on the temperature thereof, that is, the greater the excess air used, the smaller the effect of the radiation in the flame stabilization mechanism.

In process combustion systems, the burner can operate with less excess air (10%-30%), however the combustor wall (20) and the front plate (38) can overheat. In this case, cooling means are necessary for these elements.

The level of excess air is an important element in the control of combustion systems. The greater the excess air, the lower the adiabatic temperature of the flame and lower formation of thermal NOx. However, the fuel gas must ideally be mixed with combustion air before ignition and with excess air close to 60-70% to obtain low levels of NOx, which can be in the range of 10-20 ppm corrected to 3% O₂. This is valid only for burners with “lean” rapid mixture nozzle or with a design for “lean” pre-mixture. For example, if we operate a standard burner with 60-70% excess air, the NOx can be 100 ppm or even higher.

The combustor can be manufactured from refractory material. The use of excess air over 70% can lead to instability of the combustion system (10), however, if the flame is still stable, it can lead to the excessive formation of CO (carbon monoxide).

Advantages

The main advantages of the combustion system reside in the fact that the innovative constructiveness, particularly by the provision of gas injectors by the air flow arrangement allows a more even and rapid mixture of the gas and air flow, which leads to a more simple and compact design resulting in low NOx emission.

DESCRIPTION OF THE FIGURES

In order to complement the present description so as to obtain a better understanding of the characteristics of the present invention and in accordance with a preferred practical embodiment of same a set of drawings is provided together with a description, in an exemplified manner, although not limitative, the operation thereof is represented:

FIG. 1 shows an exploded perspective view of the elements that comprise the combustion system in question;

FIG. 2 represents a perspective view of the assembled system;

FIG. 3 discloses a longitudinal sectional A.A. view of the combustion system;

FIG. 4 illustrates an assembly of the gas supply tube with gas inlet, turbulator fins and fuel gas injectors;

FIG. 5 shows a perspective view of the turbulator, including the positioning of the fins and the gas injectors relative to each other;

FIG. 6 illustrates the discharge ports of the gas injector positioned with different air flow discharge angles;

FIG. 7 represents a transversal sectional B.B. view on a plane through the middle of the fins to illustrate the gas injectors positioned relative to each fin; and

FIG. 8 discloses a longitudinal sectional C.C. view of the injectors to illustrate the distances and dimensions.

DESCRIPTION OF THE INVENTION

The present patent of invention refers to a COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION AND RAPID FUEL MIXING METHOD, more precisely it relates to combustion system (10) for industrial combustion of the type applied in hot gas generators, steam boilers, single burner installations, furnaces, and other processes. Said combustion system (10) has an external body (12) preferably in cylindrical shape with the mounting flanges (14)/(14′) positioned in the inlet and outlet openings (see FIGS. 1 and 2). Said external body (12) is equipped with an air inlet (16) having rectangular or cylindrical shape or any other appropriate shape for supplying combustion air to the external body (12).

According to the present invention, the external body (12) is attached by the flange (14′) to the conical element (18) (see FIG. 3) which, in its turn, is mounted within the combustor (20), which can be manufactured in stainless steel or refractory material, preferably in a cylindrical shape. Said external body (12), conical element (18) and combustor (20), when assembled, compose the main body of the combustion system (10).

The fuel gas is provided to the combustion system (10) by means of a fuel gas set (22) (see FIG. 4) provided with concentric tubes (24) and (26) making an annular channel (28). The inlet (30) of the fuel gas (FG) is assembled orthogonally to the external tube (26). The flange (34) attached to the inlet (32) can be removed for the installation, for example, of an oil lance as second fuel. The outlet side (36) is blocked by the plate (38) which is covered with an insulating layer (40).

The outlet end of the fuel gas set (22) (36) is equipped with a plurality of fins (42) having curved shape (see FIG. 5), which together with the external surface of the tube (26) make up the passages (46) for the air flow to be deflected for creating the rotational movement (swirl). Between each pair of fins (42), there is a set of three gas injectors (48), which can be fixed by means of welding to the external tube (26) or other form of fixation such as thread (not illustrated), which foresees a plurality of orifices (50) aligned under each injector (48), enabling the fuel gas flow (FG) from the annular space (28) into the injector (48).

Each injector (48) has a plurality of openings (52) which inject fuel gas (FG) with the pre-arranged (α), (β), (γ) angles, in the combustion air flow. The height of the gas injectors (48) can vary in the direction of the flow, such as for example, the first injector (48) comprises three injection orifices (52), while the second injector (48) has four orifices (52) and the third injector has five orifices (52). The number of orifices (52) of fuel gas (FG) in each injector (48) can vary, however, the ratio of the discharge area between the injectors (48) is maintained the same, whereby the longer the injector (48) the greater the number of discharge openings (52). Each gas injector (48) is assembled inclined so as to have the longitudinal axis thereof as parallel as possible to the fin surface (42).

Said discharge openings (52) are distributed along the injectors (48) so that the gas jets (GJ) are discharged in the air flow in an even manner from the bottom to the top of the passage (46). This arrangement guarantees that each and all the passages (46) receive an evenly distributed fuel gas (FG) flow, and thus, there occurs the rapid mixture between air and fuel gas (FG).

The fuel gas set (22) is arranged inside the external body (12) of the combustion system (10) and fixed thereto by the flange (54). The set can have a provision for the insertion of an additional alternative fuel lance, such as oil, aligned to the central axis (65) of the combustion system (10). The flange (34) covers the opening (32) for this provision (see FIG. 4).

Said fuel gas injectors (48) are positioned inside the air passages (46) and supported on the curvature surface of the fins (42) (see FIGS. 3 and 6). Therefore, the fuel discharge orifices (52) are located in a low-pressure aerodynamic cavity, formed by the curvature of the fins (42), thus resulting in a better dissipation of the fuel gas jets in the air current, and, in this manner, providing a quicker mixture with air.

Said injectors (48), are further arranged in a row along the movement direction of the air current, one after the other, whereby there may be three, as in the model presented, or in smaller or greater number. The distance (L) between the injectors (48) can vary from 1 to 2 diameters (D) of the injector. The first injector (48) installed is the shortest with height (H1). The third injector (48) which extremity (66) presents greater height (H3). The second injector (48) arranged between the first and second injector has intermediary height (H2).

The number of openings (52) and diameter (d) can vary depending on the thermal capacity and physical size of the combustion system (10), whereby, in this embodiment, the first injector (48) is equipped with three openings (52), the second with four openings (52) and the third with five opening (52). For a given combustion system, all the openings have the same diameter (d), however, this can vary in dimension depending on the size and thermal capacity of the combustion system. The openings (52) are aligned in a row as from the upper wall (66) of the injector (48), being equally distributed with a distance (X) (see FIG. 8) of about 2 to 3 diameters (d). The fuel gas is injected through the openings (52) in an even manner covering the distance from the bottom (68) to the upper part (66) of an air passage (46).

The arrangement of the discharge openings (52) is made so that more fuel is injected on the upper part of the air passage (46), since the mass air flow is also highest in this part due to the exponential increase of the transversal section area along the radius, starting from the burner axis (65) of the combustion system (10) in radial direction along the central line (56) of the combustion system (10) (see FIG. 7). Thus, the lowest injector, with height H1 has only three injection orifices, since less fuel is required in the lower section, while the height injectors (H2) and (H3) have more orifices since a more fuel is necessary on the upper sections.

FIG. 6 represents a top view of the gas injectors (48) to illustrate the angles (α, β, γ) wherein the gas jets are discharged in the air current between the fins (42). The discharge openings (52) of fuel gas direct the gas jets from the tallest injector (H2) with angle (y) relative to the burner axis (65) so that the predominant direction is parallel to the tangential line to the external curve of the fin (42). The discharge openings (52) of fuel gas direct the gas jets of the injector with height (H2) with angle (β) relative to the burner axis (65) so that the predominant direction is parallel to the axis (65) of the combustion system (10), that is (equal to zero). The fuel gas discharge openings (52) direct the gas jets of the injector with height (H1) predominantly in angle (α), which can be between 0-90 degrees to the axis (65) of the fuel system (10). This arrangement and the combination of discharge angles allows a uniform and quicker mixture than in the prior art designs.

Said combustion system (10) is operated through the method of rapid mixing of fuel gas with high air excess to produce flames with ultralow NOx emission which presents the phases:

• • Phase 1—The combustion air (60) (see FIG. 3) is provided to the external body (12) by the air blower or fan (not illustrated) and then, through the passages (46) between the fins (42) of the turbulator, is deflected and acquires rotational components, continuing to the conical outlet (18) and obtaining a rotating movement inside the cone (18). The intensity of the rotation movement depends on the shape and number of fins (42) installed on the turbulator;
  • Phase 2—The fuel gas (FG) for example natural gas (see FIG. 4) is provided to the channel (28), continues to the gas injectors (48) from which it is discharged in the passages (46) through the injection openings (52) to be rapidly mixed with the rotating air current. After ignition, for example, through an electric igniter (62) (see FIG. 3), the flame is stabilized in the conical element (18) of the combustion system (10) which together with the fins (42) and injectors (48) comprises the rapid mixture zone (Z1);
  • Phase 3—The flame, with intense rotational components, continues from the conical outlet (18) to the cylindrical combustor (20), which has a larger diameter than the external body (12). The flame continues the rotation movement in the combustor. The diameter and length of the combustor (20) are determined so that the combustion reaction is complete within the combustor volume (20). The complete reaction guarantees minimal emissions of CO and unburned hydrocarbons out of the combustor tube (20), as well as minimal emissions of NOx in the operation with elevated air excess.

In a general manner, flows and flames with intense rotational components create low pressure zones, which in turn induce the formation of recirculation. In this combustion system, the negative pressure area is developed along the axis (65) of the combustor (20) and conical element (18). As a result, the intense reflux of hot combustion products moves along the axis (65) and penetrates in the rapid mixture zone. This reflux constantly promotes the ignition of the air/fuel mixture which originates from the passages (46) of the turbulator. Then, the rotational flame stabilization mechanism (10) is carried out by reflux of the hot combustion products.

The combustion system (10) can operate in variable levels of combustion air, however, within the inflammability limits. The amount of excess air is an important parameter for the control of the burner emissions. The use of high excess air allows obtaining flames with lower average adiabatic temperature and, in this manner, the formation of thermal NOx is inhibited. However, the fuel gas must ideally be mixed with air (typically with excess air close to 60-70%) before ignition, to eliminate temperature peaks in the flame and, thus, reduce the NOx formation which can reach emissions as low as 10-12 ppm corrected to 3% O₂. This occurs only for combustion systems (10) with rapid “lean” mixture nozzle, or in “lean” pre-mixture burners. For example, when operating a standard burner with air in excess of 60-70%, the NOx can be 100 ppm and even higher, due to the temperature peaks in the regions of stoichiometric concentration and close to stoichiometric inside the flame.

All the new and exclusive elements described above of the new design for rapid mixture combustion system (10) allow the mixing of the gas jets and air flow in a more even and quicker manner. This will guide the simpler and more compact design of the mixer of the combustion system. The NOx outlet emission will also be reduced, when compared with the prior art.

It is certain that when the present invention is put in practice modifications of certain construction and shape details can be introduced, without this implying a departure from the fundamental principles which are clearly substantiated in the set of claims, being therefore understood that the terminology used does not have the purpose of limitation.

Claims

1. A COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION comprising an external body with cylindrical shape with the mounting flanges arranged on the inlet and outlet openings; said external body being equipped with an air entry having rectangular or cylindrical or any other appropriate shape to deliver the combustion air to the external body; which includes a plurality of fins distributed on the external face of the external tube, which comprises a plurality of orifices; wherein each fin comprises at least three fuel gas (FG) injectors, which are mounted on the corresponding orifices communicant with the annular space; each injector having a plurality of openings which discharge the fuel gas (FG) in the combustion air flow under the pre-arranged angles; said fuel gas injectors being positioned inside the air passages and supported in the direction of the curvature surface of the fins; the fuel discharge openings being positioned in an aerodynamic cavity with lower pressure due to the curvature of the fins; said discharge openings of the injectors being duly distributed so that the gas jets (GJ) are evenly discharged, from the bottom to the top of the passage, in the air current that flows through the passage between the fins.

2. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION according to claim 1, wherein the height of the gas injectors can vary in the direction of the flow, such as, gradually, whereby the first injector three discharge openings while the second injector comprises four openings and the third injector comprises five discharge openings.

3. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION, according to claim 1, wherein the number of fuel (FG) discharge openings in each injector can vary wherein the ratio of the discharge area among the injectors remains the same, whereby the taller the injector, the greater the number of discharge openings.

4. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION, according to claim 1, wherein said injectors are arranged in a row along the air current movement direction, one after the other, whereby there may be three or less in number.

5. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION according to claim 1, wherein distance (L) between the injectors can vary from 1 to 2 of a diameter (D) of an injector.

6. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION, according to claim 1, wherein the first injector is shorter in height (H1); the third injector which end presents greater height (H3); the second injector arranged between the first and third injectors having intermediary height (H2).

7. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION according to claim 1, wherein the number of openings and diameter (d) can vary depending on the capacity and physical size of the combustion system, wherein the first injector is equipped with three openings, the second with four openings and the third with five openings; all the ports having the same diameter (d), depending on the size and thermal capacity of the burner; the openings being positioned in a row from the upper wall of the injector while being regularly distributed with a distance (X) between the adjacent ones, which is around 2 to 3 of the diameter (d) of each opening; the fuel gas is discharged through the openings evenly covering the distance from the bottom to the upper part of an air passage.

8. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION according to claim 1, wherein the discharge openings of the gas fuel jets direct from the injector with height (H1) at angle (α), and capable of being within 0° to 90° to the axis of the combustion system; the fuel gas discharge openings direct the gas jets from the tallest injector (H3) with angle (γ) relative to the burner axis parallel to the tangential line to the external curve of the fin; the fuel gas discharge openings direct the gas jets of the injector with height (H2) with angle (β) relative to the axis of the burner predominantly parallel the axis of the combustion system equal to zero.

9. The COMBUSTION SYSTEM WITH ULTRALOW NOX EMISSION, according to claim 1, wherein the main body of the combustion system is formed by an external body attached by the flange to the conical element which, in turn, is mounted on the combustor which can be manufactured from stainless steel or refractory material in cylindrical shape; the fuel gas being delivered to the fuel gas set provided with coaxial tubes and comprising a channel; the fuel gas (FG) inlet being orthogonally assembled to the external tube; a flange blocks the inlet capable of receiving an oil lance as second fuel; the outlet side being blocked with the plate, which is covered with an insulating layer; the fuel gas set on the discharge side being equipped with a plurality of fins in curved shape, which together with the outer surface of the tube comprise the passages.

10. A RAPID FUEL MIXING METHOD, comprising a rapid mixing method with elevated excess air to produce ultralow NOx emission which comprises: phase 1—supply of combustion air to the external body which flows through the passages of the fins forming an air current with intense rotational components; fuel gas being provided through the annular channel which is formed by two coaxial tubes; the external tube having perforations, and over these perforations gas injectors are installed; each injector having orifices which discharge the gas in the combustion air current;phase 2—the fuel gas flows through the openings of the injectors and is discharged in the passages of the fins of a turbulator to be evenly distributed around the circumference and within the rotational air flow, and further to mix rapidly and completely thereto;phase 3—the completely mixed mixture is subsequently inflamed and stabilized in the conical element and next in a combustor; the stabilization mechanism is by means of the recirculation of hot combustion products moving in the opposite direction of the flame from the combustor into the conical element; said hot combustion products will constantly relight the mixture of fuel gas/air originating from the passages of the fins;phase 4—the nature of the flame stabilization is a reignition aerodynamic effect.

11. The RAPID FUEL MIXING METHOD, according to claim 10, wherein the method further comprises the discharge and mixture of fuel gas with air in a lower pressure zone created along the external curve of the fin.

12. The RAPID FUEL MIXING METHOD, according to claim 10, wherein the gas injectors have different heights (H1), (H2) and (H3) and number of discharge openings arranged so that the fuel gas is gradually discharged from the bottom to the top of the passage between the fins.

13. The RAPID FUEL MIXING METHOD, according to claim 12, wherein each gas injector is surrounded by fresh air currents, without interposition between the gas jets of each injector.

14. The RAPID FUEL MIXING METHOD, according to claim 10, wherein the discharge openings of the gas injectors discharge the gas jets in the air current under specially arranged angles.

15. The RAPID FUEL MIXING METHOD, according to claim 14, wherein the gas jets from the short injector are discharged within 0° to 90 degrees to the combustion system axis, from the average height (H2) injector parallel the axis of the burner the tallest injector (H3) predominantly parallel to the tangential line to the external curve of the fin.