Injection type low-nitrogen burner

Abstract

According to the injection type low-nitrogen combustor, a hearth plate is arranged on hearth castable, a combustor shell is arranged on the hearth plate, a primary fuel assembly and an ignition assembly which extend into the combustor shell are arranged in the center of the combustor shell, and a secondary fuel assembly is arranged on the lower portion of the combustor shell; one end of the second-stage fuel assembly penetrates through the hearth pouring material to extend into the hearth, the other end of the second-stage fuel assembly penetrates through the upper portion of the combustor shell to extend outwards, a flame monitor is arranged on the outer wall of the combustor shell and penetrates through the combustor shell and the hearth pouring material, and a flame detection assembly is arranged on a first-stage mounting flange of the first-stage fuel assembly; through the arrangement of the first-stage ejection gap and the second-stage ejection gap, high-speed flowing combustion-supporting air or second-stage fuel is used for guiding flue gas in the furnace to flow back from the first-stage ejection gap and the second-stage ejection gap, so that the flue gas in the furnace participates in secondary combustion, the flame temperature is reduced, and the generation of thermal nitrogen oxides is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of combustor, specifically relates to an ejector type low nitrogen combustor. BACKGROUND

[0002] With the increasing attention to environmental protection and the increasingly strict emission limit of nitrogen oxides of relevant environmental protection regulations, the low nitrogen emission technology of combustion equipment has become a key field of research and development. As a key equipment widely used in many fields such as industrial boiler, furnace, kiln and civil heating, the performance of the combustor directly affects the energy utilization efficiency and the pollution emission level. In the combustion process of the traditional combustor, due to the unreasonable mixing mode of air and fuel gas and the combustion organization form, the combustion is often insufficient, which not only causes energy waste, but also produces a large amount of pollutants such as nitrogen oxides (NOx). Among them, thermal NOx is generated by the reaction of nitrogen and oxygen in air at high temperature, and its generation amount is closely related to the combustion temperature, high temperature zone residence time and oxygen concentration. In order to reduce the emission of NOx, the early combustor mainly adopts simple staged combustion technology, i.e. fuel gas staging and air staging. That is, by controlling the supply of fuel and air in the combustion process, a fuel-rich zone and a fuel-lean zone are formed to try to reduce the temperature of the high temperature zone and thus reduce the generation of thermal NOx. However, this method has limited effect on the reduction of NOx, and it is difficult to meet the current increasingly stringent environmental standards. In recent years, the ejector combustion technology has gradually attracted attention. The ejector combustor uses the pressure energy of the fuel gas to eject the flue gas, realizes the mixing of the flue gas and the fuel gas, and thus reduces the combustion temperature and realizes the reduction of the generation of thermal NOx. However, the existing ejector combustor still has many deficiencies in low nitrogen combustion performance. For example, when the fuel gas flow is small or the fuel gas pressure is low, the amount of flue gas ejection is small, which cannot well reduce the flame temperature to inhibit the generation of thermal NOx. Referring to the patent: Chinese patent CN 214840801 U, an outer ring cavity type fuel gas injection is adopted, and a flue gas ejection structure is formed, and the peripheral fuel gas and air are partially mixed. This structure is beneficial to reducing NOx, but the fuel gas staging capability is relatively weak, the flame is concentrated in the middle, and high temperature area is easy to produce, which leads to the increase of NOx, therefore, a more reasonable and effective low NOx combustor structure of staged flue gas internal circulation combustion is still needed to organize combustion and control pollution emission.

[0003] The air and fuel gas ejector type low nitrogen combustor of the utility model is proposed based on solving the problems in the prior art. SUMMARY

[0004] The technical problem to be solved by the utility model lies in overcoming the deficiencies of the prior art, and providing an ejector type low nitrogen combustor which is reasonable in design, avoids the generation of high temperature zone, increases the flue gas ejection amount to reduce the generation of nitrogen oxides.

[0005] The technical scheme adopted to solve the above technical problems is as follows: an ejector type low-nitrogen combustor, a hearth plate is arranged on a hearth castable, a combustor shell is arranged on the hearth plate, a primary fuel assembly and an ignition assembly are arranged at a central position of the combustor shell and extend into the combustor shell, a secondary fuel assembly is arranged at a lower part of the combustor shell, one end of the secondary fuel assembly extends into the hearth through the hearth castable, and the other end extends outward through an upper part of the combustor shell, a flame monitor is arranged on an outer wall of the combustor shell and extends through the combustor shell and the hearth castable, and a fire detection assembly is arranged on a primary mounting flange of the primary fuel assembly.

[0006] The secondary fuel assembly comprises: a secondary air inlet pipe, an air inlet flange is arranged at an upper end of the secondary air inlet pipe, a secondary mounting flange and a secondary pressure taking pipe are arranged at an upper part of the secondary air inlet pipe, the secondary mounting flange is arranged on the combustor shell, the secondary pressure taking pipe is located at an upper part of the secondary mounting flange, an atomizing nozzle connecting pipe is arranged on the secondary mounting flange, a lower end of the secondary air inlet pipe is communicated with a secondary air inlet ring pipe, the secondary air inlet ring pipe is arranged concentrically and circumferentially with the primary fuel assembly, a plurality of groups of secondary air inlet branch pipes are arranged at intervals on an inner side of the secondary air inlet ring pipe, the secondary air inlet branch pipes are communicated with secondary air inlet nozzles through secondary air inlet elbows, an end part of the secondary air inlet nozzles is provided with a secondary ejector pipe, and a secondary ejecting gap is left between the secondary air inlet nozzles and the secondary ejector pipe.

[0007] A ring plate is horizontally arranged at a bottom part of the secondary air inlet ring pipe, an inner edge of the ring plate is connected with an upper end of a first section of the secondary ejector air duct, the first section of the secondary ejector air duct is connected with the mixed air duct through a plurality of groups of mixed air duct connecting plates arranged on an outer wall, a first ejecting gap is formed between the first section of the secondary ejector air duct and the mixed air duct, the primary air duct is arranged in the first section of the secondary ejector air duct and extends into the mixed air duct through a primary air duct fixing plate, a primary air duct positioning plate is arranged between the mixed air duct and the primary air duct, a primary cone is arranged at a lower part of the primary air duct, the primary cone gradually converges from top to bottom, and a taper of the primary cone is 5-60°.

[0008] The secondary air inlet nozzles and the secondary ejector pipe are connected through a plurality of groups of secondary ejector pipe connecting plates arranged at intervals in a circumferential direction, an outer diameter of the secondary air inlet nozzles is smaller than an inner diameter of the secondary ejector pipe to form the secondary ejecting gap.

[0009] The outer wall of the mixed air duct is provided with a secondary ejector pipe fixing cylinder connecting plate at a lower part, the secondary ejector pipe fixing cylinder connecting plate is provided with a secondary ejector pipe fixing cylinder at an end part, the secondary ejector pipe extends into the secondary ejector pipe fixing cylinder and is fixed in position by a secondary ejector pipe blocking ring arranged on the secondary ejector pipe, and an opening at a lower end of the secondary ejector pipe is processed by an acute angle cutting angle from outside to inside.

[0010] The lower end of the mixed air duct is provided with a mixed cone, the mixed cone gradually diverges from top to bottom, and a taper of the mixed cone is 5-60°.

[0011] The utility model discloses a two-stage ejecting wind cylinder one section lower extreme is provided with the two-stage taper cylinder that converges gradually, and the taper of two-stage taper cylinder is 5~60 DEG, and the lower extreme of two-stage taper cylinder is provided with two-stage ejecting wind cylinder second section, and the lower extreme of two-stage ejecting wind cylinder second section is flush with the upper extreme of mixed wind cylinder or the distance of extending into mixed wind cylinder is 10~50mm, and utilizes the converging two-stage taper cylinder and mixed wind cylinder and forms the first-stage ejecting gap.

[0012] The utility model discloses a combustor casing is: the upper portion of cylindrical casing side plate is provided with casing upper fixed plate, and the lower portion is provided with lower bottom plate, and the lateral wall of casing side plate is provided with combustion-supporting gas inlet in communication, and the upper portion of combustion-supporting gas inlet is provided with pressure detection branch pipe, and the central position of casing upper fixed plate is processed with two-stage gas assembly upper installation hole, and the central position of lower bottom plate is processed with two-stage gas assembly lower installation hole, and the lateral wall of casing side plate and lower bottom plate are processed with fire detection through -hole correspondingly.

[0013] The utility model discloses a first-stage fuel assembly: one end of first-stage air inlet pipe is provided with air inlet flange, and the other end is provided with first-stage fuel gas spray head, and the middle part is provided with first-stage installation flange, and the upper portion of first-stage installation flange on first-stage air inlet pipe is provided with first-stage pressure tapping pipe, and the place close to first-stage fuel gas spray head on first-stage air inlet pipe is provided with cyclone, and the corresponding setting of first-stage installation flange is provided with ignition assembly installation hole, fire detection installation hole.

[0014] The utility model discloses an ignition assembly: one end of ignition fuel gas main pipe extends into ignition air main pipe and is connected through positioning block, and the other end is provided with ignition rod screw joint, and the upper portion of ignition fuel gas main pipe is provided with ignition fuel gas external connection pipe perpendicularly in communication, and the lower end is provided with ignition gun spray head, and ignition rod passes through ignition rod screw joint, ignition gun spray head and extends into ignition air main pipe lower end, and the end of ignition fuel gas external connection pipe is provided with ignition fuel gas connector, and the upper end of ignition air main pipe is provided with ignition air annular baffle, and the lower end is provided with fire cap, and the upper portion is provided with ignition air external connection pipe perpendicularly in communication, and the end of ignition air external connection pipe is provided with ignition air connector.

[0015] The center line of ignition fuel gas external connection pipe and the center line of ignition air external connection pipe are perpendicular to each other.

[0016] Compared with the prior art, the utility model has the following advantages:

[0017] 1, the utility model discloses a two-stage wind cylinder, two-stage ejecting wind cylinder, mixed wind cylinder, make the two-stage ejecting wind cylinder and mixed wind cylinder between the first-stage ejecting gap, the high -speed flow of combustion-supporting wind and draw the flue gas in the furnace from the first-stage ejecting gap back flow, make the flue gas secondary combustion in the furnace, thereby reduce the content of nitrogen oxides.

[0018] 2. The utility model discloses a two-stage injection pipe is arranged outside the mixed air cylinder, and the two-stage injection pipe and the two-stage air inlet nozzle form a two-stage injection gap, and the two-stage injection gap is guided by the high-speed flowing fuel gas to carry out secondary combustion on the flue gas in the furnace, thereby reducing the content of nitrogen oxides.

[0019] 3. The utility model discloses a two-stage cone cylinder is arranged at the lower part of the two-stage injection air cylinder, and the two-stage cone cylinder strengthens the gathering and acceleration effect of the central rotational flow air, so that the flue gas in the furnace is as much as possible backflowed and combusted again by the first-stage injection gap, the flue gas injection amount is increased, the oxygen concentration in the combustion air is further reduced, the generation of nitrogen oxides is effectively reduced, the combustion flame temperature is reduced, and the stable combustion of the flame is ensured.

[0020] 4. The utility model discloses a mixing cone cylinder is arranged at the lower end of the mixed air cylinder, and the gradually diverging mixing cone cylinder can make the flame sprayed by the mixed air cylinder spread outward, so that the central flame temperature is prevented from being too high, and more nitrogen oxides are formed.

[0021] 5. The lower end opening of the two-stage injection pipe is treated by an acute angle chamfering from outside to inside, so that the two-stage fuel gas sprayed by the two-stage injection pipe spreads outward, and the outwardly spreading flame sprayed by the mixed air cylinder is ignited, the design makes the flame burning range wider, the fuel gas combustion is more sufficient, the concentrated combustion of the fuel gas is avoided to form a high-temperature zone of a group of flames, and the generation of nitrogen oxides is reduced.

[0022] 6. The two-stage injection pipe is connected to the flue gas discharging position at the end of the burner and is arranged in a ring shape with high density, so that more flue gas can be injected under the same volume condition, and the flue gas backflow effect is enhanced, the two-stage injection gap of the utility model only needs to improve the original flue gas injection structure, without adding a complex control mechanism, so that the efficient flue gas recovery and nitrogen oxides emission reduction purposes can be realized. DRAWINGS

[0023] Figure 1 It is the structure schematic diagram of the utility model.

[0024] Figure 2 It is the A view of Figure 1 .

[0025] Figure 3 It is the B view of Figure 1 .

[0026] Figure 4 It is the structure schematic diagram of the two-stage fuel assembly 1 in Figure 1 .

[0027] Figure 5 It is the A view of Figure 4 .

[0028] Figure 6 It is the B view ofFigure 4 View B.

[0029] Figure 7 yes Figure 1 A schematic diagram of the structure of the burner housing 2.

[0030] Figure 8 yes Figure 7 A-direction view.

[0031] Figure 9 yes Figure 1 A schematic diagram of the structure of the first-stage fuel assembly 7.

[0032] Figure 10 yes Figure 9 A-direction view.

[0033] Figure 11 yes Figure 9 View B.

[0034] Figure 12 yes Figure 1 A schematic diagram of the structure of the intermediate ignition assembly 6.

[0035] Figure 13 yes Figure 12 A-direction view.

[0036] Figure 14 yes Figure 12 View B.

[0037] Figure 15 This is a schematic diagram of the flue gas circulation principle of this utility model.

[0038] In the figure: 1, secondary fuel assembly; 2, combustor shell; 3, flame monitor; 4, hearth castable; 5, hearth plate; 6, ignition assembly; 7, primary fuel assembly; 1-1, secondary air inlet pipe; 1-2, secondary mounting flange; 1-3, secondary air inlet annular pipe; 1-4, secondary air inlet branch pipe; 1-5, annular plate; 1-6, secondary air inlet elbow; 1-7, secondary air inlet nozzle; 1-8, secondary ejector wind drum section one; 1-9, secondary cone drum; 1-10, secondary ejector wind drum section two; 1-11, primary wind drum; 1-12, mixed wind drum; 1-13, mixed cone drum; 1-14, primary cone drum; 1-15, secondary ejector pipe fixing drum connecting plate; 1-16, primary wind drum positioning plate; 1-17, secondary ejector pipe fixing drum; 1-18, secondary ejector pipe blocking ring; 1-19, secondary ejector pipe; 1-20, secondary ejector pipe connecting piece; 1-21, mixed wind drum connecting plate; 1-22, primary wind drum fixing plate; 1-23, rib plate; 1-24, angle steel; 1-25, atomizing nozzle connecting pipe; 1-26, secondary pressure tapping pipe; 2-1, shell upper fixing plate; 2-2, shell side plate; 2-3, lower bottom plate; 2-4, secondary gas assembly lower mounting hole; 2-5, combustion-supporting gas inlet; 2-6, pressure detection branch pipe; 2-7, secondary gas assembly upper mounting hole; 2-8, flame detection through hole; 2-9, shell lifting lug; 6-1, ignition rod; 6-2, ignition rod threaded joint; 6-3, ignition fuel gas joint; 6-4, ignition fuel gas external connecting pipe; 6-5, ignition air annular baffle; 6-6, ignition air external connecting pipe; 6-7, ignition air joint; 6-8, ignition fuel gas main pipe; 6-9, ignition air main pipe; 6-10, positioning block; 6-11, ignition gun nozzle; 6-12, fire suppression cap; 7-1, primary lifting lug; 7-2, primary pressure tapping pipe; 7-3, primary air inlet pipe; 7-4, primary mounting flange; 7-5, swirler; 7-6, primary fuel gas nozzle; 7-7, flame detection mounting hole; 7-8, ignition assembly mounting hole. DETAILED DESCRIPTION

[0039] The utility model will be made further detailed explanation in combination with the drawings and examples, but the utility model is not limited to these examples.

[0040] Example 1

[0041] In Figures 1 to 15The utility model relates to a kind of low-nitrogen injectors, be provided with hearth plate 5 on furnace castable 4 in the utility model, burner shell 2 is connected and installed on hearth plate 5 by thread fastening connecting piece, the burner shell 2 of the embodiment is connected and is constituted by shell upper fixed plate 2-1, shell side plate 2-2, lower bottom plate 2-3, first stage gas component mounting hole 2-4, combustion-supporting gas inlet 2-5, pressure detection branch pipe 2-6, second stage gas component mounting hole 2-7, fire detection through-hole 2-8, shell lifting lug 2-9, shell upper fixed plate 2-1 is provided on the upper portion of cylindrical shell side plate 2-2, lower bottom plate 2-3 is provided on the lower portion, combustion-supporting gas inlet 2-5 is communicated and is provided on the side wall of shell side plate 2-2, pressure detection branch pipe 2-6 is provided on the upper portion of combustion-supporting gas inlet 2-5, for connecting pressure measuring instrument, shell upper fixed plate 2-1 center position is processed with second stage gas component upper mounting hole 2-7, lower bottom plate 2-3 center position is processed with second stage gas component lower mounting hole 2-4, fire detection through-hole 2-8 is processed on the side wall of shell side plate 2-2 and lower bottom plate 2-3, the center line of fire detection through-hole 2-8 and the center line of first stage fuel component 7 are included angle 20 °, flame monitor 3 is set through fire detection through-hole 2-8 and furnace castable 4, for the convenience of hoisting, shell lifting lug 2-9 is symmetrically set on shell upper fixed plate 2-1. Second stage fuel component 1 passes through second stage gas component upper mounting hole 2-7, second stage gas component lower mounting hole 2-4, furnace castable 4 in sequence and extends into hearth, first stage fuel component 7 passes through second stage flange 1-2 of second stage fuel component 1 and extends into second stage fuel component 1 inside, ignition assembly 6 passes through first stage mounting flange 7-4 of first stage fuel component 7 and extends into second stage fuel component 1 inside, first stage mounting flange 7-4 of first stage fuel component 7 is provided with fire detection component 8, for the convenience of observing the flame condition in hearth, fire hole is provided on first stage fuel component 7 and second stage fuel component 1.

[0042] Second stage fuel component 1 of the embodiment is connected and is constituted by second stage air inlet pipe 1-1, second stage mounting flange 1-2, second stage air inlet ring pipe 1-3, second stage air inlet branch pipe 1-4, ring plate 1-5, second stage air inlet elbow 1-6, second stage air inlet nozzle 1-7, first stage air inlet pipe 1-11, second stage air inlet pipe 1-19, first stage air inlet pipe fixing plate 1-22, rib plate 1-23, angle steel 1-24, atomizing nozzle connecting pipe 1-25, second stage pressure taking pipe 1-26, second stage air inlet pipe 1-1 is provided with air inlet flange on the upper end, second stage mounting flange 1-2 and second stage pressure taking pipe 1-26 are provided with the upper portion, second stage mounting flange 1-2 is fixed and installed on shell upper fixed plate 2-1 by thread fastening connecting piece, second stage pressure taking pipe 1-26 is located on the upper portion of second stage mounting flange 1-2, second stage mounting flange is provided with atomizing nozzle connecting pipe 1-25,

[0043] The lower end of the secondary air inlet pipe 1-1 is communicated with the secondary air inlet ring pipe 1-3, and the lower part of the secondary mounting flange is connected with the upper part of the secondary air inlet ring pipe 1-3 through the angle steel 1-24, so as to ensure the connection stability of the secondary air inlet ring pipe 1-3. The secondary air inlet ring pipe 1-3 is arranged concentrically and circumferentially with the primary fuel assembly 7, and a plurality of groups of secondary air inlet branch pipes 1-4 are arranged at the inner side of the secondary air inlet ring pipe 1-3. The secondary air inlet branch pipes 1-4 are arranged uniformly in 360° phase at the inner side of the secondary air inlet ring pipe 1-3. The secondary air inlet branch pipes 1-4 are communicated with the secondary air inlet nozzle 1-7 through the secondary air inlet elbow 1-6. The end of the secondary air inlet nozzle 1-7 is provided with the secondary injection pipe 1-19. The secondary air inlet nozzle 1-7 and the secondary injection pipe 1-19 are left with a secondary injection gap. The secondary injection gap is used for the secondary combustion of the flue gas in the furnace by the high-speed flowing fuel gas, so as to reduce the content of nitrogen oxides.

[0044] The bottom of the secondary air inlet ring pipe 1-3 is horizontally provided with a ring plate 1-5. The inner edge of the ring plate 1-5 is connected with the upper end of the secondary injection air duct 1-8. In order to ensure the stability of the connection, the rib plate 1-22 is arranged between the ring plate 1-5 and the outer wall of the secondary injection air duct 1-8. The secondary injection air duct 1-8 and the mixed air duct 1-12 are connected through a plurality of groups of mixed air duct connecting plates 1-21 arranged on the outer wall. The secondary injection air duct 1-8 and the mixed air duct 1-12 form a primary injection gap. The high-speed flowing combustion-supporting air is used for the backflow of the flue gas in the furnace from the primary injection gap, so as to realize the secondary combustion of the flue gas in the furnace, thereby reducing the content of nitrogen oxides. The primary air duct 1-11 is arranged in the secondary injection air duct through the primary air duct fixing plate 1-22 and extends into the mixed air duct 1-12. The mixed air duct 1-12 and the primary air duct 1-11 are provided with the primary air duct positioning plate 1-16. The lower part of the primary air duct 1-11 is provided with the primary cone duct 1-14. The primary cone duct 1-14 is gradually convergent from top to bottom. The taper of the primary cone duct 1-14 is 5-60°. The primary cone duct 1-14 is used for the scaling of the mixture of the primary fuel and the primary air after the mixture passes through the cone duct. After being sprayed, the backflow is formed, so that the flue gas after combustion diffuses to the circumferential outside of the burner. In the embodiment, the combustion-supporting gas entering through the combustion-supporting gas inlet 2-4 of the burner shell 2 is divided into two stages. The primary combustion-supporting gas enters the primary air duct 1-11, mixes with the primary fuel gas, and is ignited by the ignition assembly 6. The secondary combustion-supporting gas enters the secondary injection air duct and the mixed air duct 1-12, is ignited by the flame sprayed by the primary air duct 1-11, and the flame sprayed by the mixed air duct 1-12 ignites the secondary fuel gas sprayed in the secondary injection pipe 1-19. The flue gas generated by the combustion is backflowed again for secondary combustion through the primary injection gap and the secondary injection gap.

[0045] The primary fuel assembly 7 of the embodiment is connected by a primary lifting lug 7-1, a primary pressure tapping pipe 7-2, a primary gas inlet pipe 7-3, a primary mounting flange 7-4, a swirler 7-5, and a primary fuel gas nozzle 7-6. In order to facilitate hoisting, the primary gas inlet pipe 7-3 is provided with a primary lifting lug 7-1 at a bend. One end of the primary gas inlet pipe 7-3 is provided with a gas inlet flange, the other end is provided with a primary fuel gas nozzle 7-6, the middle part is provided with a primary mounting flange 7-4. The primary mounting flange 7-4 is provided with a primary pressure tapping pipe 7-2 at the upper part of the primary gas inlet pipe 7-3. The primary gas inlet pipe 7-3 is provided with a swirler 7-5 near the primary fuel gas nozzle 7-6. The swirler 7-5 is installed at the front of the primary fuel assembly. When the combustion-supporting gas flows through the swirler, the axial movement is changed into rotational movement. The airflow is thrown to the surrounding by the inertial centrifugal force, so that the air in the central part of the combustion chamber is thin, forming a low-pressure area. The air around the flame tube and part of the high-temperature gas at the rear flows to the low-pressure area of the flame tube, forming a backflow, so that the axial velocity of the airflow is small, forming a stable ignition source, and improving the combustion efficiency. The primary mounting flange 7-4 is provided with an ignition assembly mounting hole 7-8 and a flame detector mounting hole 7-7. The ignition assembly 6 extends into the secondary combustion assembly 1 through the ignition assembly mounting hole 7-8. The flame detector assembly 8 is installed in the flame detector mounting hole 7-7.

[0046] The ignition assembly 6 of the embodiment is connected by an ignition rod 6-1, an ignition rod threaded joint 6-2, an ignition fuel gas joint 6-3, an ignition fuel gas external pipe 6-4, an ignition air annular baffle 6-5, an ignition air external pipe 6-6, an ignition air joint 6-7, an ignition fuel gas main pipe 6-8, an ignition air main pipe 6-9, a positioning block 6-10, an ignition gun nozzle 6-11, and a fire cap 6-12. One end of the ignition fuel gas main pipe 6-8 extends into the ignition air main pipe 6-9 and is connected by the positioning block 6-10, and the other end is provided with the ignition rod threaded joint 6-2. The ignition fuel gas main pipe 6-8 is provided with the ignition fuel gas external pipe 6-4 at the upper part in a circumferential vertical communication manner, and is provided with the ignition gun nozzle 6-11 at the lower end. The ignition rod 6-1 extends into the lower end of the ignition air main pipe 6-9 through the ignition rod threaded joint 6-2 and the ignition gun nozzle 6-11. The ignition fuel gas external pipe 6-4 is provided with the ignition fuel gas joint 6-3 at the end, and the center line of the ignition fuel gas external pipe 6-4 is perpendicular to the center line of the ignition air external pipe 6-6. The upper end of the ignition air main pipe 6-9 is provided with the ignition air annular baffle 6-5, the lower end is provided with the fire cap 6-12, and the upper part is provided with the ignition air external pipe 6-6 in a circumferential vertical communication manner. The end of the ignition air external pipe 6-6 is provided with the ignition air joint 6-7.

[0047] Embodiment 2

[0048] In the above embodiment 1, the secondary air injection nozzle 1-7 of the present embodiment is connected with the secondary injection pipe 1-19 through a plurality of groups of secondary injection pipe connecting pieces 1-20 arranged at a circumferential interval. The outer diameter of the secondary air injection nozzle 1-7 is smaller than the inner diameter of the secondary injection pipe 1-19 to form a secondary injection gap. The rest of the components and the connection relationship of the components are completely the same as those of embodiment 1.

[0049] Embodiment 3

[0050] In the above embodiment 1, the lower part of the outer wall of the mixed air duct 1-12 of the present embodiment is provided with a secondary injection pipe fixing cylinder connecting plate 1-15, the end of the secondary injection pipe fixing cylinder connecting plate 1-15 is provided with a secondary injection pipe fixing cylinder 1-17, the secondary injection pipe 1-19 extends into the secondary injection pipe fixing cylinder 1-17 and is fixed by the secondary injection pipe stop ring 1-18 arranged on the secondary injection pipe 1-19. The lower end opening of the secondary injection pipe 1-19 is treated by an acute angle chamfering from outside to inside, so that the secondary fuel gas sprayed by the secondary injection pipe 1-19 diffuses outward, and the outwardly diffused flame sprayed by the mixed air duct 1-12 is ignited. This design makes the fuel gas burn more fully and reduces the generation of nitrogen oxides. The rest of the components and the connection relationship of the components are the same as those of embodiment 1.

[0051] Embodiment 4

[0052] In the above embodiment 1, the lower end of the mixed air duct 1-12 of the present embodiment is provided with a mixed cone cylinder 1-13, which gradually diverges from top to bottom. The taper of the mixed cone cylinder 1-13 is 5-60°. The setting of the flared mixed cone cylinder 1-13 can make the flame sprayed by the mixed air duct 1-12 diffuse outward, avoid the central flame temperature being too high, and prevent insufficient combustion and the formation of more nitrogen oxides. The rest of the components and the connection relationship of the components are the same as those of embodiment 1.

[0053] Embodiment 5

[0054] In the above embodiment 1, the lower end of the secondary injection air duct first section 1-8 of the present embodiment is provided with a secondary cone cylinder 1-9 which gradually converges. The taper of the secondary cone cylinder 1-9 is 5-60°. The lower end of the secondary cone cylinder 1-9 is provided with a secondary injection air duct second section 1-10. The secondary injection air duct second section 1-10 regulates the flow of the accelerated air to prevent it from diffusing outward. The lower end of the secondary injection air duct second section 1-10 is flush with the upper end of the mixed air duct 1-12 or extends into the mixed air duct 1-12 by a distance of 10-50 mm. The converging secondary cone cylinder 1-9 and the mixed air duct 1-12 form a primary injection gap. At the same time, the converging secondary cone cylinder 1-9 accelerates the combustion-supporting air. The high-speed flow of the accelerated combustion-supporting air induces the backflow of the flue gas from the primary injection gap, which causes the secondary combustion of the furnace gas and thus reduces the content of nitrogen oxides. The rest of the components and the connection relationship of the components are the same as those of embodiment 1.

[0055] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents. In addition, the terms upper, lower, etc. in the present application are limited to the connection relationship of the parts described in conjunction with the drawings.

Claims

1. An ejector low-nitrogen burner, a hearth castable (4) is provided with a hearth plate (5), and a burner shell (2) is arranged on the hearth plate (5), characterized in that: The burner shell (2) is provided with a primary fuel assembly (7) and an ignition assembly (6) extending into the center of the burner shell (2), and the lower part of the burner shell (2) is provided with a secondary fuel assembly (1) extending into the furnace through the furnace castable (4) and extending outward through the upper part of the burner shell (2), and the outer wall of the burner shell (2) is provided with a flame monitor (3) extending through the burner shell (2) and the furnace castable (4), and the primary fuel assembly (7) is provided with a fire detection assembly (8) on the primary installation flange (7-4).

2. The ejector low NOx combustor of claim 1, wherein The secondary fuel assembly (1) is provided with an air inlet flange on the upper end of a secondary air inlet pipe (1-1), a secondary installation flange (1-2) and a secondary pressure taking pipe (1-26) on the upper part, the secondary installation flange (1-2) is arranged on the burner shell (2), the secondary pressure taking pipe (1-26) is located on the upper part of the secondary installation flange (1-2), the secondary installation flange is provided with an atomizing nozzle connecting pipe (1-25), the lower end of the secondary air inlet pipe (1-1) is communicated with a secondary air inlet ring pipe (1-3), the secondary air inlet ring pipe (1-3) is arranged concentrically and circumferentially with the primary fuel assembly (7), a plurality of groups of secondary air inlet branch pipes (1-4) are arranged on the inner side of the secondary air inlet ring pipe (1-3) at intervals, the secondary air inlet branch pipes (1-4) are communicated with a secondary air inlet nozzle (1-7) through a secondary air inlet elbow (1-6), the end of the secondary air inlet nozzle (1-7) is provided with a secondary ejector pipe (1-19), and a secondary ejecting gap is left between the secondary air inlet nozzle (1-7) and the secondary ejector pipe (1-19); a ring plate (1-5) is horizontally arranged at the bottom of the secondary air inlet ring pipe (1-3), the inner edge of the ring plate (1-5) is connected with the upper end of a secondary ejecting air cylinder (1-8), the secondary ejecting air cylinder (1-8) and a mixing air cylinder (1-12) are connected through a plurality of groups of mixing air cylinder connecting plates (1-21) arranged on the outer wall, a primary ejecting gap is formed between the secondary ejecting air cylinder (1-8) and the mixing air cylinder (1-12), the primary air cylinder (1-11) is arranged in the secondary ejecting air cylinder and extends into the mixing air cylinder (1-12) through a primary air cylinder fixing plate (1-22), a primary air cylinder positioning plate (1-16) is arranged between the mixing air cylinder (1-12) and the primary air cylinder (1-11), and a primary taper cylinder (1-14) is arranged at the lower part of the primary air cylinder (1-11), the primary taper cylinder (1-14) is gradually convergent from top to bottom, and the taper of the primary taper cylinder (1-14) is 5-60°.

3. The ejector low NOx combustor of claim 2, wherein: The secondary air inlet nozzle (1-7) and the secondary ejector pipe (1-19) are connected through a plurality of groups of secondary ejector pipe connecting plates (1-20) arranged circumferentially at intervals, the outer diameter of the secondary air inlet nozzle (1-7) is smaller than the inner diameter of the secondary ejector pipe (1-19) to form the secondary ejecting gap.

4. The ejector low NOx combustor of claim 2, wherein: The lower part of the mixed air duct (1-12) is provided with a two-stage ejector pipe fixing cylinder connecting plate (1-15), the end of the two-stage ejector pipe fixing cylinder connecting plate (1-15) is provided with a two-stage ejector pipe fixing cylinder (1-17), the two-stage ejector pipe (1-19) extends into the two-stage ejector pipe fixing cylinder (1-17) and is fixed by the two-stage ejector pipe stop ring (1-18) arranged on the two-stage ejector pipe (1-19), and the lower end opening of the two-stage ejector pipe (1-19) is treated by sharp angle cutting from outside to inside.

5. The ejector low NOx combustor of claim 2, wherein: The lower end of the mixed air duct (1-12) is provided with a mixed cone cylinder (1-13) which gradually diverges from top to bottom, and the taper of the mixed cone cylinder (1-13) is 5-60°.

6. The ejector low NOx combustor of claim 2, wherein: The lower end of the two-stage ejector air duct first section (1-8) is provided with a two-stage converging cone cylinder (1-9), the taper of the two-stage converging cone cylinder (1-9) is 5-60°, the lower end of the two-stage converging cone cylinder (1-9) is provided with a two-stage ejector air duct second section (1-10), the lower end of the two-stage ejector air duct second section (1-10) is flush with the upper end of the mixed air duct (1-12) or extends into the mixed air duct (1-12) by 10-50mm, and the converging two-stage converging cone cylinder (1-9) and the mixed air duct (1-12) form a first-stage ejector gap.

7. The ejector low NOx combustor of claim 1, wherein The burner shell (2) is: a cylindrical shell side plate (2-2) is provided with a shell upper fixing plate (2-1) at the upper part and a lower bottom plate (2-3) at the lower part, a combustion-supporting gas inlet (2-5) is arranged in communication on the side wall of the shell side plate (2-2), a pressure detection branch pipe (2-6) is arranged at the upper part of the combustion-supporting gas inlet (2-5), a two-stage gas assembly upper mounting hole (2-7) is processed at the center position of the shell upper fixing plate (2-1), a two-stage gas assembly lower mounting hole (2-4) is processed at the center position of the lower bottom plate (2-3), and a fire detection through hole (2-8) is processed on the side wall of the shell side plate (2-2) and the lower bottom plate (2-3) in correspondence.

8. The ejector low NOx combustor of claim 1, wherein The first-stage fuel assembly (7) is: a first-stage air inlet pipe (7-3) is provided with an air inlet flange at one end, a first-stage fuel gas nozzle (7-6) at the other end, and a first-stage mounting flange (7-4) at the middle part, a first-stage pressure taking pipe (7-2) is arranged at the upper part of the first-stage mounting flange (7-4) on the first-stage air inlet pipe (7-3), a cyclone (7-5) is arranged on the first-stage air inlet pipe (7-3) close to the first-stage fuel gas nozzle (7-6), a ignition assembly mounting hole (7-8) and a fire detection mounting hole (7-7) are arranged in correspondence on the first-stage mounting flange (7-4).

9. The ejector low NOx combustor of claim 1, wherein The ignition assembly (6) is characterized in that: one end of an ignition fuel gas main pipe (6-8) extends into an ignition air main pipe (6-9) and is connected by a positioning block (6-10), and the other end is provided with an ignition rod threaded joint (6-2); the upper portion of the ignition fuel gas main pipe (6-8) is provided with an ignition fuel gas external connecting pipe (6-4) in a circumferential vertical communication mode, and the lower end is provided with an ignition gun nozzle (6-11); an ignition rod (6-1) extends into the lower end of the ignition air main pipe (6-9) through the ignition rod threaded joint (6-2) and the ignition gun nozzle (6-11); the end of the ignition fuel gas external connecting pipe (6-4) is provided with an ignition fuel gas joint (6-3); the upper end of the ignition air main pipe (6-9) is provided with an ignition air annular baffle (6-5), the lower end is provided with a fire cap (6-12), and the upper portion is provided with an ignition air external connecting pipe (6-6) in a circumferential vertical communication mode; and the end of the ignition air external connecting pipe (6-6) is provided with an ignition air joint (6-7).

10. The ejector low NOx combustor of claim 9, wherein The center line of the ignition fuel gas external connecting pipe (6-4) is perpendicular to the center line of the ignition air external connecting pipe (6-6).

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