CN106931437A - A kind of low NOx gas burners with air conducting cover - Google Patents

Abstract

The invention discloses a low-NOx gas burner with an air guide cover, which mainly includes an air guide cover, an air nozzle and its bottom plate, a central main gas gun, a group of auxiliary gas guns, an annular gas drum tube, an ever-burning lamp, a connecting Hose, air adjustment mechanism and fuel adjustment ball valve, etc. The air guide cover is arranged on the upper part of the burner barrel and connected with the burner barrel. The bottom plate of the air nozzle is arranged below the central main gas gun, and the air nozzles are evenly distributed on the bottom plate. The annular fuel drum tube is arranged around the periphery of the burner body, on which a central main gas gun and a group of auxiliary gas guns are arranged. The invention makes full use of the Venturi effect to make fuel and air staged combustion and sets the main and auxiliary gas ratio adjustment mechanism to make the air and fuel evenly mixed, and enhances the automatic circulation of the flue gas inside the furnace, so that the temperature distribution in the furnace is even, Local high temperature is avoided, and the generation of NOx at the furnace outlet is reduced.

Description

A low NOx gas burner with air guide cover

technical field

The patent of the invention belongs to the field of petrochemical technology, and mainly relates to a gas combustion equipment, in particular to a low NOx gas burner with an air guide cover.

Background technique

The "Petroleum Refining Industry Pollutant Discharge Standard" (GB 31570-2015) issued by the National Environmental Protection Agency stipulates that since July 1, 2015, the nitrogen oxide emission concentration of the process heating furnace shall not exceed 180mg/m ³ , and in some In areas with weak environmental carrying capacity, the concentration is limited below 100 mg/m ³ . However, the domestic petrochemical heating furnace burners generally can only guarantee the nitrogen oxide emission concentration of 80-120 mg/m ³ , so the design and development of new low NO _x burners has great practical significance. At present, domestic burners generally use technologies such as fuel staged combustion, air staged combustion, and concentration deviation combustion. The disadvantages are that when some burners are running, the flue gas recirculation structure is complicated and the effect is not obvious enough, and the air delivery is concentrated and the speed is limited. The formed recirculation zone is small, resulting in weak mixing ability of air and fuel, local high temperature and excessive emission of nitrogen oxides will occur during operation.

Invention patent content

The technical problem to be solved by the present invention is to provide a kind of fuel for the problems of the above-mentioned existing burners, such as complex flue gas recirculation structure, insufficient effect, concentrated air delivery, weak mixing ability with fuel, and insufficient combustion. It is a low NOx gas burner that can effectively reduce the formation of _NOx by adjusting the grades in proportion, with a simple automatic flue gas recirculation structure and uniform mixing of the air distribution channel and the gas.

The technical scheme adopted by the present invention to solve its technical problems is that a low NOx gas burner with an air guide cover is fixed on the bottom of the heating furnace, and it includes an air guide cover, an air nozzle and its base plate, a burner cylinder, Central main gas gun, a group of auxiliary gas guns, annular gas drum tube, pilot lamp, fire viewing hole, ignition hole, fuel intake hose, pilot lamp intake hose, connecting hose, air regulating mechanism, fuel regulating ball valve and other components .

The above-mentioned low NOx gas burner with an air guide cover, the air guide cover is arranged on the upper part of the burner cylinder, the diameter is equal to the annular fuel drum tube, and the air guide cover is not directly connected to the burner cylinder Instead, a ring-shaped hollow layer with a width of 30mm is provided at the junction of the two.

The above-mentioned low NOx gas burner with an air guide cover, the bottom plate of the air nozzle is arranged under the central main combustion nozzle with a spray hole, and two layers of the air nozzle and the long light are arranged on it. Hole, fire viewing hole, lighting hole.

In the aforementioned low NOx gas burner with an air guide hood, the set of auxiliary gas guns includes four auxiliary gas guns evenly arranged on the annular gas drum tube.

The above-mentioned low NOx gas burner with an air guide cover, the top of each auxiliary gas nozzle with nozzle holes has three nozzle holes near the inner side of the burner barrel, and the diameter of the first nozzle hole is 1.4mm , the angle with the vertical direction is 90°; the diameter of the second nozzle hole is 1.5mm, the angle with the vertical direction is 68°; the diameter of the third nozzle hole is 4.9mm, the angle with the vertical direction is 29°.

The above-mentioned low NOx gas burner with an air guide hood can control the amount of gas entering the entire flue gas self-circulation ultra-low _NOx gas burner by adjusting the opening of the fuel inlet regulating ball valve. Describe the opening of the main and auxiliary fuel regulating ball valves to control the gas ratio entering the center main gas gun and auxiliary gas gun.

In the aforementioned low NOx gas burner with an air guide cover, an inlet regulating ball valve is provided at the inlet of the inlet hose of the pilot lamp to control the amount of gas entering the pilot lamp.

The above-mentioned low NOx gas burner with an air guide hood, the annular gas drum tube is distributed around the burner cylinder, and is responsible for connecting a group of auxiliary gas spray guns on the top with a main and auxiliary gas spray gun below The hose, the annular gas drum tube is not a whole ring, but designed as a 3/4 ring.

In the above-mentioned low NOx gas burner with an air guide cover, the air regulating mechanism is arranged at the lower part of the burner cylinder.

In the above-mentioned low NOx gas burner with an air guide cover, a refractory material is arranged between the inner and outer layers of the burner barrel.

The beneficial effect of the present invention is that, through the staged combustion of the gas, the amount of main and auxiliary gas can be adjusted in proportion to adapt to different loads; through the Venturi structure composed of the air nozzle, its bottom plate and the burner cylinder, the air and gas The mixing is more uniform, the combustion is more complete, the temperature of the combustion chamber is lower, and the formation of NO _x is effectively suppressed; by setting an air guide connected to the cylinder and leaving a gap at the outlet of the auxiliary gas gun nozzle above the combustion chamber The hood forms an ingenious Venturi structure, which can entrain the flue gas at the bottom of the furnace into the combustion chamber for re-combustion, realize the automatic recirculation of the flue gas, and make the temperature distribution in the furnace more uniform; The gas injected at an angle interweaves, fully mixes, and burns in layers in the combustion chamber and its upper part, which can meet the requirements of petrochemical heating furnaces with stable combustion, high thermal efficiency, and low pollutant emissions.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention is further described;

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a top view of the present invention;

Fig. 3 is the structural representation of air nozzle;

Fig. 4 is the structural representation of central main combustion nozzle;

Fig. 5 is a schematic diagram of the structure of the auxiliary gas nozzle.

In the figure 1. Air shroud, 2. Air nozzle, 3. Bottom plate of air nozzle, 4. Burner barrel, 5. Center main gas gun, 6. Center main combustion nozzle with nozzle, 7. Auxiliary gas Gun, 8. Auxiliary gas nozzle with spray holes, 9. Annular gas drum tube, 10. Immersive light, 11. Fuel inlet hose, 12. Immune light inlet hose, 13. Connecting hose, 14. Air regulating mechanism , 15. Refractory material, 16. Fuel inlet regulating ball valve, 17. Main and auxiliary fuel regulating ball valve, 18. Fire observation hole, 19. Ignition lamp hole, 20. Ignition hole, 21. Fixing bolt, 22. Annular hollow layer.

detailed description

In order to facilitate the understanding of the present invention, one of the design methods of the present invention will be proposed below, but it should be noted that the present invention can be presented in different structures and forms, and is not limited to this design method.

As shown in Figures 1 and 2, a low NOx gas burner with an air guide hood is fixed at the bottom of the furnace, which mainly includes an air guide 1, an air nozzle 2, a bottom plate 3 of the air nozzle, and a burner barrel Body 4, central main gas nozzle 5, central main combustion nozzle with nozzle 6, auxiliary gas nozzle 7, auxiliary gas nozzle with nozzle 8, annular gas drum tube 9, permanent lamp 10, fuel intake hose 11, permanent lamp Air intake hose 12, connecting hose 13, air regulating mechanism 14, refractory material 15, fuel inlet regulating ball valve 16, main and auxiliary fuel regulating ball valve 17, fire viewing hole 18, long light hole 19, ignition hole 20, fixing bolt 21, Annular hollow layer 22 and other parts.

As shown in Figure 1, the air guide cover 1 of a low NOx gas burner with an air guide cover is arranged on the upper part of the burner cylinder 4, and the diameter is equal to the annular fuel drum tube 9. It should be noted that the air guide The flow cover 1 is not directly connected to the burner barrel 4, but an annular hollow layer 22 with a width of 30 mm is arranged at the joint of the two, and is highly aligned with the auxiliary gas nozzle 8 of the auxiliary gas gun 7. When the gas and When the air is mixed and combusted in the combustion chamber, due to the high-speed injection of the auxiliary gas nozzle 8, the flue gas at the bottom of the furnace is sucked into the combustion chamber through the annular hollow layer 22, forming a natural flue gas recirculation structure and effectively reducing _NOx emissions .

As shown in Figure 2, the bottom plate 3 of the air nozzle 2 is arranged below the central main combustion nozzle 6 with spray holes, and the air nozzle 2 is divided into two sizes, which are evenly distributed on the bottom plate with different radii in the circumferential direction, and the number is generally 12 or more. When the combustion-supporting air is sprayed into the combustion chamber from the burner barrel 4 through the air nozzle, for the plane where the bottom plate 3 is located, the air velocity gradually decreases along the direction of increasing radius, and the air velocity in the central area is large and dispersed, ensuring stable flame and No misfiring and no tempering; the peripheral air flow rate is small and uniform, ensuring more uniform mixing with auxiliary gas, lower temperature in the combustion chamber, and effectively reducing _NOx emissions.

As shown in Figure 1, a fuel delivery mechanism of a low NOx gas burner with an air guide cover consists of a fuel inlet regulating ball valve 16, a fuel intake hose 11, an annular gas drum tube 9, a main and auxiliary fuel regulating ball valve 17, Connecting hose 13, center main gas gun 5, center main gas gun nozzle 6, a group of auxiliary gas gun 7, auxiliary gas gun nozzle 8 and other components. Fuel is transported to the annular gas drum pipe 9 through the fuel intake hose 11, a group of auxiliary gas guns 7 are arranged above the annular gas drum pipe, and a connecting hose 13 is arranged below, and is connected with the main gas gun 5 in the center. A fuel inlet regulating ball valve 16 is provided at the entrance of the fuel inlet hose 11, and a main and auxiliary fuel regulating ball valve 17 is provided at the joint between the annular fuel drum pipe 9 and the connecting hose 13. By adjusting the opening of the fuel inlet regulating ball valve 16, it can be Control the amount of gas entering the entire burner. By adjusting the opening of the main and auxiliary fuel regulating ball valve 17, the ratio of gas entering the center main gas gun 5 and auxiliary gas gun 7 can be controlled to achieve the ratio of the main and auxiliary gas amounts. purpose of adjustment.

As shown in Figure 1, a combustion-supporting air delivery mechanism of a low NOx gas burner with an air guide hood is composed of an air regulating mechanism 14, a burner cylinder 4, an air nozzle 2 and its bottom plate 3, an air guide cover 1, The annular hollow layer 22 and other components are composed. The combustion-supporting air enters the burner barrel 4 through the air regulating mechanism 14, a part of the air is sprayed into the combustion chamber through the air nozzle 2 on the bottom plate 3, and the other part of the air directly enters the combustion chamber, and the air passing through the air nozzle 2 is firstly connected with the central main gas gun. The gas injected in 5 is mixed. At this time, due to the small amount of air, the combustion speed is slow and the temperature is low, which suppresses the formation of _NOx . The air in the combustion chamber is mixed, and at this time due to the large amount of air, the flame temperature is lower, because the formation of _NOx is further reduced.

Specifically, the annular gas drum tube 9 is distributed around the burner barrel 4 and is responsible for connecting a group of auxiliary gas spray guns 7 above and a connecting hose 13 below. The annular gas drum tube 9 is not a whole ring, but It is designed as a 3/4 ring, and the two ends are closed and blocked, so as to adjust the distribution of the main and auxiliary gas volume.

The main body of the burner has a hollow structure and is divided into two layers. The middle channel is a combustion-supporting air flow channel, and the outer channel is provided with a heat-insulating refractory material 15, which can reduce the noise generated when the burner is working and reduce the heat dissipation of the burner.

The central main combustion nozzle 6 and the auxiliary gas nozzle 8 are distributed with relatively small holes that can inject fuel, wherein the center main combustion nozzle 6 top has eight nozzles, which are divided into two layers, and four are evenly arranged on one layer. The diameter of the nozzle hole in the first layer is 3mm, and the angle with the vertical direction is 27°; the diameter of the nozzle hole in the second layer is 1.4mm, and the angle with the vertical direction is 65°; the top of the auxiliary gas nozzle 8 is close to the burner barrel There are three nozzle holes in the inner side of the body 4, the first nozzle diameter is 1.4mm, and the angle with the vertical direction is 90°; the second nozzle diameter is 1.5mm, and the angle with the vertical direction is 68° ; The diameter of the third spray hole is 4.9mm, and the included angle with the vertical direction is 29°. The nozzle holes on each auxiliary gas nozzle 8 are all towards the nozzle holes on the central main combustion nozzle 6, so that the interlaced injection can make the mixing of the main and auxiliary gas more uniform.

The above-mentioned low NOx gas burner with an air guide hood can realize the proportional adjustment of the main and auxiliary gas volume by adjusting the ball valve to meet the low _NOx emission requirements under different loads by burning fuel and air in stages; The Venturi effect forms a natural flue gas recirculation structure, and the air and gas are injected into the combustion chamber through the porous structure to fully mix, stratified combustion, and reduce the temperature during combustion, thereby effectively inhibiting the formation of _NOx . Among them, a number of technologies such as flue gas recirculation, gas staged combustion, air staged combustion, and fuel/air forced mixing are applied. The combustion is sufficient and stable, does not go off fire, generates less NO _x , and has a simple structure, which can meet the requirements set by the relevant national departments. Increasingly stringent emission requirements.

The above-mentioned design method only expresses the individual design method of this invention patent, and it cannot be understood that this invention patent only has this design method due to space limitations. Other patents with similar ideas to the patent of the present invention should fall within the scope of protection.

Claims (10)

1. a kind of low NOx gas burners with air conducting cover, are fixed on heating furnace burner hearth bottom, including air conducting cover （1）, air nozzle（2）And its base plate（3）, the main gas gun in center（5）And its shower nozzle（6）, one group of assisted gas rifle（7）And its spray Head（8）, annular fuel gas drum pipe（9）And air adjustment actuator（14）Deng；It is characterized in that：Air conducting cover（1）It is connected to burner tube Body（4）Top, the base plate of air nozzle（3）It is arranged on the main combustion shower nozzle in the center with spray orifice（6）Lower section, several air nozzles （2）Point two-layer is uniformly distributed on its base plate, the main combustion spray gun in center（5）One end through air nozzle base plate（3）, sprayed with band The main combustion shower nozzle in center in hole（6）It is connected, the other end passes through burner cylinder（4）Bottom, through connection flexible pipe（13）With ring Shape combustion gas drum pipe（9）It is connected, annular fuel drum pipe（9）It is circumferentially positioned at burner cylinder（4）Periphery, one group of auxiliary combustion Air gun（7）It is evenly distributed on annular fuel gas drum pipe（9）On, in every assisted gas rifle（7）On be designed with the auxiliary with spray orifice Gas spray head（8）, fuel air flexible pipe（11）Porch is provided with fuel inlet regulation ball valve（16）, annular fuel drum pipe（9） Be connected flexible pipe（13）Connecting place is provided with major-minor fuel adjusting ball valve（17）, altar lamp（10）Centrally disposed main gas gun（5） Side, below through burner cylinder（4）With altar lamp air induction hose（12）It is connected, air adjustment actuator（14）It is arranged on burner tube Body（4）Lower section side, burner cylinder（4）Refractory material is provided between inside and outside wall（15）.

2. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that the sky Gas kuppe（1）Diameter and annular fuel drum pipe（9）It is equal, air conducting cover（1）With burner cylinder（4）And non-immediate company Connect, but both junctions are provided with the annular hollow-out layer that width is 30mm（22）.

3. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that the sky The base plate of gas jets（3）It is arranged on the main combustion shower nozzle in the center with spray orifice（6）Lower section, is provided with the air nozzle （2）, altar lamp hole（19）, flame-observing hole hole（18）, igniting lamp hole hole（20）.

4. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that in described The main gas gun of the heart（5）Including center gun barrel, center holster pipe, the main combustion shower nozzle in the center with spray orifice（6）；The center holster pipe sets Put in the burner cylinder（4）On, the center gun barrel is arranged in the center holster pipe, and its one end sequentially passes through air The base plate of nozzle（3）With burner cylinder（4）Bottom, by connecting flexible pipe（13）With annular fuel gas drum pipe（9）It is connected, separately One end directly with the main combustion shower nozzle in the center with spray orifice（6）It is connected.

5. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that every institute State assisted gas rifle（7）All include auxiliary gun barrel, assist gun sleeve pipe and the assisted gas shower nozzle with spray orifice（8）；The assist gun Sleeve pipe is arranged on the burner cylinder（4）On, the auxiliary gun barrel is arranged in the assist gun sleeve pipe, lower end and the ring Shape combustion gas drum pipe（9）It is connected, upper end is provided with the assisted gas shower nozzle with spray orifice（8）.

6. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that the band The main combustion shower nozzle in center of spray orifice（6）There are eight spray orifices on top, point two-layer, and one layer four evenly distributed, and ground floor injection diameter is 3mm, is 27 ° with the angle of vertical direction, and second layer injection diameter is 1.4mm, is 65 ° with the angle of vertical direction.

7. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that described Group assisted gas rifle（7）It is included in the annular fuel gas drum pipe（9）Upper 4 evenly distributed assisted gas rifles.

8. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that described every One assisted gas shower nozzle with spray orifice（8）Top is near burner cylinder（4）There are three spray orifices, first spray orifice in inner side direction A diameter of 1.4mm, is 90 ° with the angle of vertical direction；Second injection diameter is 1.5mm, and the angle with vertical direction is 68°；3rd injection diameter is 4.9mm, is 29 ° with the angle of vertical direction.

9. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that by adjusting Save the fuel inlet regulation ball valve（16）Aperture, can control enter the ultralow NOx gas burners of whole flue gas self-loopa Gas quantity, by adjusting the major-minor fuel adjusting ball valve（17）Aperture, can control enter the main gas gun in center（5）With Assisted gas rifle（7）Interior combustion gas ratio.

10. a kind of low NOx gas burners with air conducting cover according to claim 1, it is characterised in that the length Bright lamp air induction hose（12）Porch ball valve can be adjusted controlling to enter altar lamp with inlet porting（10）Interior gas quantity.