JPH01500049A - Annular nozzle burner and method of using the annular nozzle burner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Annular nozzle burner and its annular How to use nozzle burner [Technical field] The present invention relates to an annular nozzle burner. More specifically, the present invention includes: At a given fuel/air ratio and at a given speed to obtain high peak temperatures from a dense flame. , relates to a method and apparatus for introducing a mixture of fuel and air into a fuel chamber.

[Conventional background] In many conventional drying equipment and burner systems.

Solid fuel is mixed with a carrier of primary air and injected into the combustion chamber. The primary air is completely combusted. A portion of the total air required for baking, less than 10% It ranges from very little to 100%. complete combustion Supplemental air needed to maintain combustion is added to the combustion chamber as secondary air. one Generally, the secondary air is preheated to a temperature of around 815°C (1500''F). Enters the combustion chamber and is mixed with the primary air and fuel mixture to completely burn the fuel . On the other hand, to prevent premature combustion or explosion of coal dust, mixing of primary air and fuel is The compound must be kept at a temperature below 204°C (400°F). The temperature is normally maintained at 82°C (180″F) or lower.

Patent granted to Deusner et al. (U.S. Pat. No. 4,428°727) and nickel No. 4,373,900, currently in use. The burner 9 system, which is The assumption is that it is limited by the mixing ratio of air, secondary air, and fuel. Ru. The current theory in this regard is that the fuel burns quickly and completely. Requires that the secondary air be well mixed with the fuel and air streams to There is. Therefore, in burners currently used, the primary air and fuel are mixed into the secondary air. The majority of methods employ a rapid convection type that mixes with water.

Modern burner systems also use powdered fuel to make the burner structure wear-resistant. It is recognized that it is worn out. This causes the fuel to flow at a relatively low speed. controlled. In addition, in the case of the current furnace, the length of the combustion chamber is 49 m (160 f set) to only about 61m (200fset), The flames hit the side walls and ends of the furnace, significantly shortening the life of the furnace's refractories. On the other hand, Configuring the furnace long enough to accept a longer flame than necessary will reduce the furnace manufacturing cost. Strikes will increase significantly. Therefore, in order to prevent the flame from hitting the walls of the furnace, 7 Comparison from 62m (2500feet) to 1830m (6000fset) A lower air velocity is used.

Recent burner development efforts have focused on creating spiral movements to improve the flow of fuel and air. Emphasis is placed on the use of flexible vanes that mix quickly and turbulently with the secondary air. It has been placed.

Therefore, high velocity air jets are involved to promote such mixing conditions. A turbulence device is used instead.

According to the method described above, the primary air and fuel flow can be well mixed with the secondary air. However, it is not possible to obtain the high temperature necessary to make a satisfactory product in a furnace etc. not present.

To reduce the amount of harmful nitrogen oxides (No) emitted from coal-burning equipment, , a great deal of effort has been made.

The traditional way to control Not emissions is by recirculating the combustion gases. The goal is to lower the oxygen concentration and flame temperature. However, this method does not recycle the circulating gas. Energy consumed increases when circulating and reheating to flame temperature. There are drawbacks.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the drawbacks associated with the conventional burners mentioned above. is to provide an improved method and an improved burner system for burning .

Another object of the present invention is to allow the flame to ignite without damaging the structure of the burner or the walls of the refractory. Efficient annular nozzle fist burner that can provide high peak temperatures of It is to provide.

Another object of the invention is to recirculate and reheat exhaust gas consuming energy. Annular nozzle with reduced process and acceptable NOx levels is to provide a burner.

The features of the present invention are that the combustion chamber is made smaller and the nozzle is designed to reduce the amount of flame hitting the refractory wall. Another feature of the present invention is that it provides a small, short flame that is close to the flame. There is an improvement in the products heated by the burner and method of the present invention.

Another feature of the present invention is that even though the present invention provides for a high peak temperature of the flame, This is because we were able to extend the lifespan of the annular body to an unexpected extent.

Yet another feature of the invention is that it provides a more stable flame than currently used burners; The pulverized particle fuel that allowed the flame to “stick” to the burner When using.

It is controlled until the granular fuel is heated enough to sustain combustion during switching. It is common to use a gas or oil flame to heat the refractory wall at a That's the way to do it. However, the present invention easily stabilizes the combustion of granular fuel in the burner. It is possible to convert from relatively expensive starting fuel to the required granular fuel. This provides a flame core that can be switched more quickly. to this point Therefore, the detailed description of the present invention is referred to as fuel "particles." However, this The use of “particles” is limited to finely pulverized particle fuels. gas molecules and liquids, as is clear from examples related to various fuels. The present invention uses an annular nozzle with a cylindrical cross section containing small particles of fuel. Although burners are described, such burners may have a cross section other than cylindrical. It may be something you have.

As a result of many tests by the inventor, the pairing of the mixture of primary air and fuel with the secondary air It is unfavorable in terms of productivity to use fluid mixing as conventional mixing, and Contrary to concept, it does not provide the most favorable temperature and flame profile. It became clear. A mixture of primary air and fuel is used to disperse the fuel particles. It is customary practice to mix the air with secondary air intensively. However, the inventor found that increasing the average distance between particles is undesirable. .

[Disclosure of invention] The method of the present invention suppresses the dispersion of fuel particles and concentrates them in the primary combustion region of the flame. Create a dense flame by letting it flow inside.

An annular nozzle configured to maintain high velocity radiant heat transfer between fuel particles. Use a burner. Of course, this does not apply to traditional annular nozzle Q-burners. Although contrary to the applied theory, as noted below, The condition of use has been greatly improved. In this regard, the heat of the high-temperature flame is mainly due to radiation. The temperature rise when the fuel leaves the burner is primarily due to the high temperature It has long been found that this is a function of the transfer of radiant heat from the fuel particles to the cooler fuel particles. ing. Therefore, the temperature of a given particle is a function of its distance from adjacent combustion particles. The present invention employs these principles to obtain improved results.

According to another aspect of the present invention, NOx in the exhaust gas transforms the primary combustion region into a reducing atmosphere. It can be significantly reduced by keeping it in the This means that excess oxygen can be achieved by preventing burning particles from reaching the It turned out that.

The rate at which solid fuel particles burn is a function of the oxygen available at the surface of the particles. It has been known for a long time. However, from the flow of fuel and air to a certain amount of fuel particles The movement of oxygen is through the boundary layer surrounding one particle to the surface where the particle is burning. Depends on gaseous dispersion.

A method to improve the rate of oxygen transfer to the surface where the particles are burning is The above explanation also shows that the next thing to do is to increase the relative velocity difference between air and air. It has since become clear. This is thought to reduce the thickness of the boundary layer.

For example, in one embodiment of the present invention, pulverized solid fuel is The fuel is transported at high velocity through an annular nozzle to the combustion chamber, where it is relatively stopped. Passes through secondary air. This interaction has been shown to significantly improve combustion. ing.

According to another aspect of the invention, the annular nozzle has an inner core region and an outer fuel inlet ring. It has a shape. Relatively high speed of at least 2135 m/min (7000 fpm) Using a relatively small amount of primary air to force the granular fuel through the annulus at high velocity With this, the resulting fuel and air flow is nearly straight, and even closer to the core. It has been shown to create a low-velocity vortex effect in the region. This area of low pressure is a flame It provides a core of flame length along the axis of the flame. Additionally, this low pressure, low speed in the core at fuel and air velocities greater than 6100 meters per minute (20,000 fpm). It also works by attaching the flame to the tip of the burner to prevent it from blowing out.

Furthermore, maintaining a high ratio between the outer dimension and area of the fuel inlet annulus, from which The above effects can be further enhanced by increasing the volume of the flame core area. can.

Note that the term 'straight' should not be confused with 'laminar flow'.

“Straight” here means that a certain particle is almost It is used in the sense of moving almost only in the axial direction without falling.

As a result of the characteristics of the annular nozzle burner constructed and used according to the principles described above, Produces a very dense and powerful flame, allowing the use of smaller and more efficient furnaces becomes. Additionally, in certain embodiments, conventional annular burner m-systems may be used. A much larger furnace would produce better quality product in larger quantities. difference Additionally, the method and apparatus of the present invention provide controlled formation of a protective coating on the furnace walls. can significantly delay the need for costly repairs in some cases. It has the additional feature of being able to

Other objects, features and advantages of the invention are illustrated in the accompanying drawings. The same reference numbers throughout the accompanying drawings will be apparent from the following detailed description of the embodiments. are showing the same parts. The attached drawings are not necessarily to scale; the attached drawings are , were created solely to illustrate the principles of the invention.

[Brief explanation of the drawing] Figure 1 schematically shows the structure of the annular nozzle/burner used when carrying out the method of the present invention. A conceptually illustrated cross-sectional view, Figure 2, shows the annular nozzle O-burner shown in Figure 1. A partially enlarged cross-sectional view, Figure 3 shows the annular nozzle burner shown in Figure 1. FIG. 2 is a partially enlarged cross-sectional view showing supplementary elements used in other embodiments of the present invention; FIG. 4 shows an annular nozzle bar used in one embodiment of the invention. Figure 5 is a cross-section of the annular nozzle and burner taken along line 5-5 in Figure 4. Top view, Figure 6 is an end view of another annular nozzle burner used in one embodiment of the invention. 7 is a sectional view taken along line 7-7 in FIG. 6, and FIG. 8 is an example of the present invention. Figure 9 is an end view of another annular nozzle burner used in FIG. 10 shows yet another annular nozzle used in another embodiment of the invention. End view of the Zull burner, Figure 11 is a sectional view taken along line 11-11 in Figure 10. It is.

[Best mode for carrying out the invention] FIG. 1 shows the structure of an annular nozzle burner 11 installed in a furnace with a refractory wall 13. This is a conceptual illustration of the structure. The annular part 15 through which the primary air and fuel flow is located on the outside. It is formed between the pipe 17 and the inner pipe 19. in the center of burner 11 The core 21 may be open or closed with a refractory plug. The secondary air may enter the combustion chamber through conventional means and form a flame 27 within region 25. surround.

Primary air and fuel are blown through the annulus 15 into the combustion chamber by a fan device 26. The flame is ignited in the combustion chamber, forming a powerful and dense flame 27. Burning point 2 9 is located at a distance greater than a predetermined distance from the nozzle, and at the combustion point 29, approximately 95% is burned. The line 31 connecting the points where the flame temperature is at its peak is the inner line. In the preferred embodiment, this inner line extends from the outer surface of the flame. It is located at approximately 0.4c layer.

The annular nozzle burner 11 also has a low speed and low pressure in the inner core 33 of the flame 27. As shown, this inner core 33 of the flame 27 promotes combustion in the region of It creates a vortex effect and is very close to the tip of burner 11 or The tip of No. 11 creates an ignition point for the fuel. In addition, when using fireproof plug 23 , the fireproof plug 23 functions as an ignition device.

FIG. 2 is an enlarged illustration of the annular burner 11, and shows the annular burner 11. The inner 11 has a machined cylindrical insert 35. The root 35 has a length approximately 4 to 12 times the radius 37 of the annular portion 15, and extends backward from the tip. It extends to The surface of the insert 35 is machined smoothly so that there are no protrusions. Since the primary fuel and air are mixed from the annular part of the annular nozzle burner 11, Can create a straight flow of things.

FIG. 2 also shows the pilot port 39, which Burning gas can be injected from 39 to ignite the flame 27 during startup. difference If not, extend the ignition system from the pilot boat 39 and perform the same function. You may also force them to do so.

FIG. 3 shows an inner annular portion 41 formed between the pipe 19 and the outer annular portion 15. FIG. 2 is a cross-sectional view conceptually illustrating the configuration of another burner 11. This inner ring The part 41 is for inserting an annular insert 43 between the pipe 19 and the annular part 15. a passageway formed by a fuel cell and through which another fuel or starting fuel, such as gas or oil, passes is provided. The inner annular part 41 is also a machined insert of the primary annular part. A machined insert 46 corresponding to the insert 35 is provided. As shown in Figure 3 A radial air passage 45 is provided circumferentially around the insert 43 as shown in FIG. However, the inner annular portion 41 may be connected to the primary air and fuel annular portion 15. Good, as mentioned above, when it is possible to have a controlled deposit layer on the refractory wall. is sometimes desirable, but it also selectively disrupts straight flow and creates dense and strong flames. Selectively change the outline to an elongated flame.

Injection is used to remove excess deposits on the refractory lining.

The diameter of the outer annulus 15 is selected to provide the required high velocity straight flow and to provide the required It can be varied in a certain cross-sectional area to create the essential dense and powerful flame 27.

To explain the operation of an annular nozzle burner, primary air and fuel such as powdered coal are The fuel is blown through the annulus 15 using a fan. Volume of primary air is limited to at least approximately 213 m/min (213 m/min) to convey fuel to the furnace combustion chamber It is injected at a high speed of 7,000 fpm).

Since the primary air and combustion particles are in an almost straight flow, the fuel particles are very are in close proximity. As the primary air and fuel particles pass through the combustion chamber, the fuel particles and the primary air move at high velocity into the combustion chamber through the secondary air, so that the boundary The layer thickness decreases. Therefore, oxygen quickly passes through the boundary layer to the combustion surface of the fuel particles. As it diffuses, fuel particles are ignited by the radiant heat of already ignited fuel particles. It turns out. Thus, the high velocity primary air and fuel mixture completes combustion.

Thanks to the vortex effect of the core 33 inside the flame 27, the fuel and air flow velocity is the highest. to keep the fuel ignition point very close to the top of the burner, even when Can be done. Due to the high velocity of the fuel and air flow, the annulus 15 entering the combustion chamber is The life of the annular part can be extended by the cooling effect produced at the inlet.

Tests were successfully conducted using an annular nozzle at the volumes described above. using powdered charcoal A strong and very thick apical flame was produced even when using It was short, only 50 meters (20 feet) long. In addition, the results of the test As a result, the method and burner of the present invention are significantly more effective than convective mixing type burners. It was shown that Furthermore, the annular nozzle concept used as mentioned above is suitable for liquid fuel can also be applied with similar results.

Related to this, limiting the amount of primary air in straight flow conditions increases the velocity of the fuel particles. If it increases, is it expected that the burning rate will increase and the peak temperature of the flame will become higher? This results in a significant reduction in fuel usage per ton of product. Others, use In some cases, higher temperatures have clear advantages in producing better products. It is very advantageous. For example, in the cement kiln example (with conventional equipment) The product made by the method of the present invention has a crystal size of was small, strength was high, and alkali content was low.

At the same time, measurable N made from the above method using an annular nozzle O burner ow is significantly reduced without resorting to energy-consuming recirculation of combustion gases. Ru. Therefore, the present invention can be widely used and can be applied to boilers used for commercial purposes. It can also be applied to other types of burners used in savings and reduce the amount of combustion air that is recirculated. and nitrogen oxides can be effectively controlled.

Example 1 Figures 4 and 5 are of the type described in U.S. Pat. No. 4,428,728. The furnace in which this example was used is an "indirect" type furnace, showing an example of a burner modification. The finely pulverized dry coal is collected in a cyclone and filter collector, Primary air at ambient temperature was carried through the annulus 15'.

The inside of the outer pipe 50 is 305cm (12inch), and the width of the annular part 15' is was 19 mm (0.75 inch) T'. pulverized coal at a rate of 5 to 7 tons per hour and Primary air at a rate of approximately 1019 m' (3600 cfpm) per minute is approximately 642 m' per minute. It passed through the annular portion 15' at a maximum speed of (19557 fpm). In connection with this, The peak temperature of the flame increases as the velocity through the 15° annulus increases; By reducing excess air to a minimum, NOx was significantly reduced. In addition, the air Carbon monoxide monitor to control inlet equipment to reduce excess oxygen to below 1.5% - was used, and the Nor in the exhaust guy was reduced to below 400 ppm. .

At maximum combustion capacity, primary air accounts for approximately 10% of the total combustion, with the remainder being secondary air. Ta.

During normal operation, no flow occurred through the inner core 52. inner core The flow used had a negative effect on the peak temperature of the flame. However, refractory to significantly increase the cross-sectional area until undesirable deposits are removed from the walls of the for a short period of time (less than 1 hour) to change the shape of the flame. A small amount of primary air was diverted to the inner core 52 by a device not shown.

Example 2 The furnace in this example is a direct feed type, which means that after drying and pulverizing the coal, Powdered coal was blown directly into the burner.

In direct combustion furnaces, the primary air usually makes up a high percentage of the combustion air. The primary air is directly sent from the coal pulverizer, so it is already is heated to a high temperature. In this illustrative embodiment, the coal pulverizer sends The primary air temperature is approximately 65@C (150°F) and 82°C (180°F). At maximum combustion capacity, the primary air accounts for approximately 33 to 40 percent of the total combustion air. The rest was secondary air.

This particular example furnace was used in conjunction with a rotary cement kiln. Immediately after starting the device using the invented method, a noticeable improvement in the shape of the flame was observed. It was done. Furthermore, a significant increase in the quality and thermal energy efficiency of the tallincar was observed. It was. In addition, the kiln can generate up to 7% per unit time without additional fuel input. produced many products. Capacity of kiln without converting calcium chloride The required low alkali cement was obtained without reducing the

The annular burner shown in Figures 6 and 7 has a rate of approximately 10 tons per primary space. Powdered coal and powdered coke, 4440m (14560 feet) and 5711m per minute (18,725 feet) and about 392 m” (14,000 feet per minute) fpm) and 504 rrf (18,000 cf pm). It was used to supply air. The inner diameter of the outer pipe 54 is 39.4 cm (15.5i nch), and the outer diameter of the inner pipe 56 is 20.3 cm (8 inches). Therefore, the width of the annular portion 15" (7) was 9.5 cm (3,75 inch). The inner pipe 56 is approximately 30.5c+5( 12 inches) extending to the reduced bottom portion 60.

Actual example 3 The embodiments shown in Figures 8 and 9 relate to a burner burning acetylene. was used. From 2235 m/min (7330 fpm) to 8947 m (29335 m/min) fpm) with a volume in the range of 0.14 rn' (5 cfpm) and 0.2 0 to 0.2 per minute with acetylene between 8 m” (10 cfpm) A volume of primary air of 8 m'' (10 cfpm) was used.

The inner diameter of the outer vibro 2 is 2.54 cm (finch), and the inner diameter of the inner vibro 2 is 2.54 cm (finch). 4 has an outer diameter of 2.38 cm (0,9375 inch), so the annular part 15'' The width of the plug 66 was 0.8 cm (0°03125 inch). It is fixed inside the blower 4 and has a diameter of 0.86 cm (0.34 inch). Fis 64 was prepared. In addition, as indicated by the reference number 66, A suitable inner pipe support is also used in the embodiments shown up to FIG. There is.

Acetylene filled in a cylinder forms a ring with various amounts of compressed air. 15". Even at low velocities, the flame was relatively short (approximately 25.4 cm (1 0i nch) or 930.4 cm (12 inch)), and the diameter at the maximum point is The velocity of the air and fuel was about 3.8 cm (about 1.5 inch), which was different from what was expected. As the ignition point increased, the ignition point moved closer and closer to the burner tip. parable For example, the ignition point is from 1.3 cm (0.5 f nch) to 1.9 cm (0.5 f nch) from the tip. , 75 inches), but at maximum speed the ignition point was at the tip. It appears to be stationary, and the length of the flame ranges from 17.8 cm (7 inches) to 20 inches. It was shortened to about 3 cm (8 inches). As the speed increases, the flame It became brighter and brighter. Maximum flow of air and fuel available from the equipment used Try to "blow out" the flame or move the ignition point away from the tip of the burner. It was impossible.

During normal operation, orifice 68 was plugged. However, I removed the stopper. and remove very small amounts of air (less than 0.028 m2 (1 cubic foot) per minute). The flame will be slightly stronger if fed through orifice 68 at a constant low velocity. However, it seemed to take a little longer. some air through the orifice 68 If more than 100% was supplied, the flame would spread and become turbulent, producing black smoke.

In the comparative study, the annular part 15'' was closed so that it had the same cross-sectional area as the annular part 15''. An orifice corresponding to that shown at reference numeral 68 was fabricated. above Except for this point, other parameters were the same. In addition, approximately 2135 m/min (700 m/min) At a fuel and air velocity of 0 fpm, the burner flame length is approximately 61 ci + (2 fpm). e　e　t), and the ignition point is about 1.3 cm (0.5 inch) from the tip of the burner. The diameter of the flame at a distance of 1.9 cm (0.751 nch) from h) is 1.9 cm (0.751 nch). It was 90■ (0.75 inch). However, the flame was quite yellow, A considerable amount of black smoke was generated. Is the speed from 305m/min (1000fpm)? When the diameter increases from 457 m (15,000 f pm) to The ignition point moved further from the tip. As the speed increases further, the flame will reach the tip The flames moved approximately 7.6 cm from the ground, and the flames were extinguished. Maximum flame obtained before flame is blown out The length was approximately 91 cm (36 inches).

Example 4 In this example, the outer pipe 72 has an inner diameter of 4 inches; The outer diameter of the plug 74 is 5.1 cm (2 inches), and the width is 2, . 5cm (1i An annular portion 15"" of nch) was prepared.

The fuel is natural gas, and the flow rate ranges from 0.7 m' (25 cfpm) to 1.4 m' (5 cfpm). The primary air capacity was approximately 70 m' (250 cf pm). ) and 14 m' (500 cfpm), with an estimated speed of approximately 1281 m/min ( It was between 420 of pm) and 2562 m (8400 fpm).

The embodiment described above was used in conjunction with a vertical combustion chamber. Shown in Figures 10 and 11. The burner was tested with and without the inner core 74. tested. If the inner core is not used, the ignition point of the burner flame is 61° from the tip. cm (2 feet) apart and the flame was unstable even at relatively low velocities. speed When the temperature was relatively high, the flame was irregular and quickly blown out. inner core 74 When installed, the ignition point is approximately 0.6 cm from the tip of the burner even at relatively low speeds. m (0,25i nch), and the flame was very stable. burner A blue flame could be seen in the center of the tip. After the test is finished, the inside The color disappeared in the center of the core plug 74, but this did not occur at or near the tip. This shows that the ignition point actually occurred.

Based on the data collected in this way, the maximum ratio of the outer diameter to the inner diameter of the annular portion 15 is It appears to be about 2.0. The numerical ratio of the outer diameter to the area of the annular portion is less than 0.1. In most embodiments, the entrance from the annulus 15 into the combustion chamber must be large. The minimum effective operating speed at the exit is approximately 2135 meters per minute (7000 fpm). The minimum length of the smooth annular surface represented by insert 35 in FIG. A suitable annular surface with a smooth annular surface equal to the width of the annular portion 15 but corresponding to the insert 35 The length is between approximately 4 and 12 times the width of the annular portion 15.

Having illustrated and described the invention with respect to preferred embodiments thereof, the spirit and scope of the invention are The exhibitor is free to make appropriate changes to the present invention as long as they do not deviate from the above. I hope you can understand it easily.

[Industrial applicability] According to the present invention, a high temperature flame can be provided, and this nozzle burner can be used to You can use it to make better products. Moreover, since the temperature of the flame is high, the fuel It is possible to significantly reduce the usage amount and reduce costs. Moreover, the temperature of the flame The life of the nozzle and burner is long even at high temperatures, and the wall of the refractory is not damaged. There is no.

Also, since the flame is brought close to the nozzle, the combustion chamber can be made smaller. .

Additionally, exhaust gases are recirculated to reduce the amount of combustion air and allow for nitrogen resistant materials. It can be brought to an acceptable level.

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Claims (1)

[Claims] (1) A method of burning fuel with a burner having an annular nozzle, By suppressing the dispersion of fuel particles, a dense flame is generated and the primary combustion area of the flame is concentrating the fuel particles in a region; Maintain sufficient velocity of the fuel particles to avoid high velocity convergence between particles of the fuel. a step of transferring radiation heat; A method characterized by comprising: (2) The method according to claim 1, wherein the reduction is performed in the primary combustion region. A method characterized by comprising a step of maintaining a sexual atmosphere. (3) the annular nozzle burner has an inner region and an outer fuel inlet annulus; A method according to claim 1, which is of the type , injecting the fuel approximately through the fuel inlet annulus. A method characterized by: (4) the annular nozzle burner has an inner core having inner dimensions and outer dimensions; claim 1, which is of the type comprising a region and an outer fuel inlet annulus. 3. The method according to paragraph 1, wherein the method setting the numerical ratio of the area between the A method characterized by: (5) said annular nozzle burner has an inner region having an inner dimension and an outer dimension; Claim 1, which is of the type with a region and an outer fuel inlet annulus. The method of claim 1, wherein the method reduces the ratio of the outer dimension to the inner dimension to about A method characterized by comprising the step of setting the value to be smaller than 2. (6) The flame extends from the burner along the axis of the burner. The method according to scope 1, wherein the method comprises: near the annular nozzle; A method characterized by comprising a step of creating a low-pressure core/flame region along the axis. Law. (7) The method according to claim 1, wherein the particles are formed in the annular nozzle. a step for maintaining a substantially straight flow of said particles after leaving the flow chamber; How to characterize it. (8) The method according to claim 1, wherein secondary air surrounds the flame. and that the oxygen from the secondary air is mainly dispersed into the fuel particles. A method characterized by combining with. (9) Scope of the patent The method according to item 8, wherein the fuel particles and the secondary air maintaining a sufficiently high relative velocity between the A method characterized by comprising: (10) Claim 1, wherein a portion of the fuel particles are surrounded by a boundary layer. The method according to paragraph 1, wherein the method is characterized in that the method It is characterized by comprising a step of controlling the combustion rate by controlling the combustion rate. How to do it. (11) The annular nozzle burner has an inner core region and an outer fuel inflow. The method according to claim 1, which is of a type comprising an annular body. Therefore, the method includes an air flow which is caused to pass through the annular body together with the fuel. controlling the rate at which the fuel particles burn by limiting the amount of air. A method characterized by: (12) The method according to claim 1, which reduces NOx in exhaust gas. The process of monitoring the combustion air and adjusting the amount of combustion air to reduce NOx levels. A method characterized by comprising: (13) The method according to claim 1, wherein the dispersion of the fuel particles A method for selectively lowering the rate of suppression of the flame and selectively increasing the cross-sectional area of the flame. A method characterized by having a certain degree of (14) The method according to claim 1, in which the burner is passed through the center of the burner. It is characterized by having a step of selectively and temporarily introducing a small amount of air. How to do it. (15) The method according to claim 1, wherein secondary air surrounds the flame. and the method includes a sufficiently high relative velocity between the fuel particles and the secondary air. and a step of creating a core of flame in the primary combustion region. how to. (18) A type of annular nozzle with an inner core region and an outer fuel inlet annulus. An improved burner comprising: combustion air passing through the inner core region; A burner characterized in that said inner core region is provided with means for limiting the amount of -. (17) The burner according to claim 16, wherein the burner The fuel inflow annular body is kept in a straight state so that the fuel flowing in the fuel flows in a substantially straight state. A burner characterized in that it is provided with a means for (18) The burner according to claim 18, wherein the annular nozzle The degree of extension of said straightening means along the axis is at least as large as that of said annular body. Burner characterized by equal width. (19) The burner according to claim 18, wherein the burner is in the straight state. characterized in that the degree of extension of the means for Burner. (20) The burner according to claim 17, wherein from the burner of the straight stream to selectively and temporarily increase the outer dimensions of the extended flame. characterized by comprising means for selectively and temporarily reducing the straight state; burner. (21) The burner according to claim 16, wherein the fuel inflow annular The body has an inner dimension and an outer dimension, and said outer dimension versus said inner dimension. A burner characterized in that the ratio of dimensions is about 2.0 or less. (22) The burner according to claim 21, wherein the outer dimension A bar characterized in that the numerical ratio of the areas of the annular body is at least 0.1. Nah. (23) The burner according to claim 16, wherein the fuel inlet annular A hand that expels fuel from the body at a rate of at least 700 feet (2135 meters per minute) A burner characterized by having stages. (24) The burner according to claim 16, wherein the annular body is on the inner side. and an outer dimension, and the outer dimension versus the area of the annular body. A burner characterized in that the numerical ratio is at least about 0.1. (25) The burner according to claim 16, wherein the annular nozzle a burner producing a flame having a primary combustion zone; a bar characterized in that it comprises means for maintaining a substantially reducing atmosphere in the area; Nah. (26) The burner according to claim 25, wherein a flame is located at the center of the flame. A burner characterized by comprising means for creating a core area. (27) A burner according to claim 16, in which the resulting Supplementary fuel entry into the annulus in a non-axial flow direction to selectively modify the flame shape A burner characterized in that it is equipped with a means for selectively introducing air.