A low-nitrogen emission natural draft burner

Abstract

The application discloses a kind of low nitrogen emission natural draft burners, it is related to low nitrogen burner field, including primary air structure, primary gas structure, secondary gas structure, tertiary gas structure, circulating flue gas structure, ignition burner, secondary air structure, secondary combustion zone, purging air structure.The low nitrogen emission natural draft burner of the application reduces the combustion reaction temperature and reaction rate, overcomes the problem of insufficient combustion air momentum of natural draft burner, inhibits unorganized diffusion combustion, effectively improves the efficiency of combustion, inhibits the generation of NOx, the fuel staging of burner uses multi-level, multi-direction distribution, strengthens the stability of combustion, adjusts control according to use, uses high-speed multi-state jet, while inhibiting backfire and local high temperature, further inhibits the influence of environment on natural draft burner, with natural ventilation and forced air blowing two working modes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of low-nitrogen burners, in particular to a natural draft burner with low nitrogen emission. BACKGROUND

[0002] The natural draft burner with low nitrogen emission is a burner with low nitrogen oxide emission, which is mainly used for combustion in heating furnaces. At present, the air distribution mode of the burner is mainly forced air blowing. However, there are still a large number of heating furnaces that have negative pressure conditions in the furnace and can support air distribution in the form of natural draft. The burner does not need to be equipped with a fan, which can save manufacturing and operating costs. The natural draft burner has the characteristics of difficult combustion organization and operation state easily affected by external environment, and has high NOx emission. Although the structure of the burner has been continuously improved with the continuous efforts of engineering and technical personnel, the flame stability has made some progress, but there is still a problem of high NOx emission.

[0003] How to effectively and safely fully combust under natural draft conditions and control the generation of pollutants to achieve a natural draft burner with low NOx emission is a problem to be solved at present. SUMMARY

[0004] The main purpose of the present application is to provide a natural draft burner with low nitrogen emission, which can effectively solve the technical problems proposed in the background art.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A natural draft burner with low nitrogen emission, comprising a burner tank, a secondary combustion zone is fixedly installed at the rear end of the burner tank, a primary air structure is fixedly installed at the inner center of the burner tank, a primary gas structure is fixedly installed at the inner center of the primary air structure, a secondary gas structure and a circulating flue gas structure are fixedly installed at the outer side of the primary air structure in the burner tank, and the secondary gas structure and the circulating flue gas structure are staggered, a tertiary gas structure is fixedly installed at the outer side of the primary air structure at the front end of the burner tank, an ignition burner is fixedly installed at the outer side of the burner tank, a secondary air structure is fixedly installed at the lower end of the burner tank, and a purge air structure is fixedly installed at the front end of the secondary air structure.

[0007] The primary air structure comprises a primary air chamber one, a primary air inlet adjusting ring-shaped hole plate and a primary air chamber two, the primary air chamber one is fixedly installed at the inner center of the burner pot body, the primary air inlet adjusting ring-shaped hole plate is nested at the front end of the primary air chamber one, and the primary air chamber two is fixedly installed at the rear end of the primary air chamber one.

[0008] As a further scheme of the present application, the primary air structure further comprises a primary air chamber three, a primary air internal adjusting ring plate and a primary combustion zone, the primary air chamber two, the primary air chamber three and the primary combustion zone are sequentially arranged and fixedly connected from front to back, and the primary air internal adjusting ring plate is nested at the outer side of the primary air chamber three.

[0009] As a further scheme of the present application, the primary gas structure further comprises a primary gas flow pipe, a primary gas nozzle and a primary gas cyclone device, the primary gas flow pipe is fixedly installed at the rear end of the primary gas inlet, the primary gas flow pipe, the primary gas nozzle and the primary gas cyclone device are sequentially arranged and fixedly connected from front to back, the primary gas inlet penetrates the primary air inlet adjusting ring-shaped hole plate, the primary air chamber one, the primary air chamber two and the primary air chamber three, the primary gas nozzle is located in the primary combustion zone, and the spray speed of the primary gas nozzle is 100-150 m / s.

[0010] As a further scheme of the present application, the secondary gas structure comprises a secondary gas inlet, a secondary gas ring cavity, a secondary gas flow pipe, a secondary gas nozzle, a gas collecting pipe, a mixing pipe and a flame stabilizing disc, the secondary gas ring cavity is fixedly installed at the inner side of the burner pot body and located at the outer side of the primary air chamber one, the secondary gas inlet is fixedly installed at the front end of the secondary gas ring cavity, the secondary gas flow pipe, the secondary gas nozzle, the gas collecting pipe, the mixing pipe and the flame stabilizing disc are divided into four groups and sequentially arranged and fixedly connected from front to back, four secondary gas flow pipes are fixedly installed at the rear end of the secondary gas ring cavity, the flame stabilizing disc is located in the secondary combustion zone, and the spray speed of the secondary gas nozzle is 150-290 m / s.

[0011] As a further scheme of the present application, the tertiary gas structure comprises a tertiary gas inlet, a tertiary gas ring cavity, a tertiary gas flow pipe and a tertiary gas nozzle, the tertiary gas ring cavity is fixedly installed at the front end of the burner pot body and located at the outer side of the primary air inlet adjusting ring-shaped hole plate, the tertiary gas inlet is fixedly installed at the bottom of the tertiary gas ring cavity, four tertiary gas flow pipes are fixedly installed at the rear end of the tertiary gas ring cavity, and four tertiary gas nozzles are respectively fixedly installed at the rear end of the four tertiary gas flow pipes, the tertiary gas ring cavity is sleeved at the outer side of the primary air inlet adjusting ring-shaped hole plate, and the spray speed of the tertiary gas nozzle is 150-290 m / s.

[0012] As a further scheme of the present application, the circulating flue gas structure comprises a circulating flue gas inlet, a flue gas ring cavity, an injection mixing pipe and a mixed gas outlet pipe, the flue gas ring cavity is fixedly installed inside the burner tank and located outside the primary air chamber I, the flue gas ring cavity is located behind the secondary gas ring cavity, the circulating flue gas inlet is fixedly installed at the top outside of the flue gas ring cavity, four injection mixing pipes are fixedly installed at the rear end of the flue gas ring cavity, four mixed gas outlet pipes are fixedly installed at the rear end of the four injection mixing pipes respectively, and the injection mixing pipe adopts a straight pipe structure.

[0013] As a further scheme of the present application, the tertiary gas flow pipe penetrates into the flue gas ring cavity, the tertiary gas nozzle is inserted into the injection mixing pipe, and the mixed gas outlet pipe is located inside the secondary combustion zone.

[0014] As a further scheme of the present application, the secondary air structure comprises a secondary air inlet, a secondary air inlet adjusting flap, a secondary air chamber and a secondary air manifold, the secondary air chamber is fixedly installed at the lower end of the burner tank, the secondary air inlet adjusting flap is movably installed at the front end of the secondary air chamber, the secondary air inlet is opened inside the secondary air chamber and is in through connection with the secondary air inlet adjusting flap, the secondary air manifold is fixedly installed at the top rear end of the secondary air chamber and is in through connection therewith, and the top of the secondary air manifold is in through connection with the secondary combustion zone.

[0015] As a further scheme of the present application, the purge air structure comprises an air inlet fan, an adjusting handle, a fan air inlet adjusting annular orifice plate, a fan air inlet ring cavity, a fan air outlet elbow pipe and a fan air outlet expansion pipe, the fan air outlet elbow pipe is fixedly installed at the air outlet of the air inlet fan, two air inlet fans are fixedly installed at the front end of the secondary air chamber, the fan air outlet expansion pipe is fixedly installed at the rear end of the fan air outlet elbow pipe, the adjusting handle is movably installed at the adjacent side of the air inlet fan, the fan air inlet adjusting annular orifice plate is movably installed between the two air inlet fans and is connected with the adjusting handle, the fan air inlet ring cavity is fixedly installed between the two air inlet fans and is arranged inside the fan air inlet adjusting annular orifice plate coaxially with the fan air inlet adjusting annular orifice plate, and the fan air outlet elbow pipe and the fan air outlet expansion pipe are located inside the secondary air chamber.

[0016] As a further scheme of the present application, the ignition burner comprises an ignition gas inlet and an ignition electrode, both of which are fixedly installed outside the burner tank and are arranged in parallel, and the lower ends of the ignition gas inlet and the ignition electrode penetrate through the burner tank to the inside of the secondary combustion zone.

[0017] Compared with the prior art, the low-nitrogen emission natural draft burner has the following beneficial effects: the three gas structures and the circulating flue gas structure are arranged, the flue gas is injected by using the gas momentum, the combustion reaction temperature and the reaction rate are reduced, and the generation of thermal NOx is effectively inhibited;

[0018] The combustion air is injected by using the gas momentum, the problem of insufficient combustion air momentum of the natural draft burner is overcome, the unorganized diffusion combustion is inhibited, the combustion efficiency is effectively improved, and the generation of NOx is inhibited;

[0019] The burner fuel is graded in multiple layers and multiple directions through the primary air structure, the primary gas structure and the secondary gas structure, the stability of combustion is improved, and the influence of the environment on the natural draft burner is inhibited;

[0020] The primary gas structure has an independent pipeline, a servo adjusting mechanism can be arranged, automatic adjustment of the primary gas amount is realized, the primary air structure and the secondary air structure have adjusting mechanisms, servo adjusting mechanisms can be arranged, automatic adjustment of the primary air amount is realized, and adjustment control is carried out according to use conditions, so that the control and use of different occasions are more convenient;

[0021] The high-speed multi-state jet flow adopted by the circulating flue gas structure can suck flue gas while inhibiting backfire and local high temperature, and the use is more stable;

[0022] The two-stage flame hood structure formed by the primary combustion zone and the secondary combustion zone forms a backflow at the position of the flame hood in the primary combustion zone and the secondary combustion zone under the driving of the aerodynamic flow field, the stability of combustion is improved, and the influence of the environment on the natural draft burner is further inhibited;

[0023] The sweep air structure has two working modes of natural draft and forced draft, and the furnace type is more suitable for a wider range. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a whole structure schematic view of the low-nitrogen emission natural draft burner;

[0025] Figure 2 It is a rear view of the low-nitrogen emission natural draft burner;

[0026] Figure 3 It is an internal structure view of the burner pot body of the low-nitrogen emission natural draft burner;

[0027] Figure 4 It is a partial analysis view of the low-nitrogen emission natural draft burner;

[0028] Figure 5 It is a sectional view of the low-nitrogen emission natural draft burner;

[0029] Figure 6 Enlarged view of purge air structure in a low nitrogen emission natural draft burner of the present invention.

[0030] In the figure: 1, burner pot; 100, primary air structure; 110, primary air inlet adjusting ring type orifice plate; 120, primary air chamber one; 130, primary air chamber two; 140, primary air chamber three; 150, primary air internal adjusting ring plate; 160, primary combustion zone; 200, primary gas structure; 210, primary gas inlet; 220, primary gas flow pipe; 230, primary gas nozzle; 240, primary gas cyclone device; 300, tertiary gas structure; 310, tertiary gas inlet; 320, tertiary gas ring chamber; 330, tertiary gas flow pipe; 340, tertiary gas nozzle; 400, secondary gas structure; 410, secondary gas inlet; 420, secondary gas ring chamber; 430, secondary gas flow pipe; 440, secondary gas nozzle; 450, gas collecting pipe; 460, mixing pipe; 470, flame stabilizing disc; 500, circulating flue gas structure; 510, circulating flue gas inlet; 520, flue gas ring chamber; 530, ejecting mixing pipe; 540, mixed gas outlet pipe; 600, ignition burner; 610, ignition gas inlet; 620, ignition electrode; 700, secondary air structure; 710, secondary air inlet; 720, secondary air inlet adjusting flap; 730, secondary air chamber; 740, secondary air manifold; 800, secondary combustion zone; 900, purge air structure; 910, air inlet fan; 920, adjusting handle; 930, fan air inlet adjusting ring type orifice plate; 940, fan air inlet ring chamber; 950, fan air outlet elbow pipe; 960, fan air outlet expansion pipe. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, purposes and effects of the present invention easy to understand, the present invention is further described below in combination with specific embodiments.

[0032] As Figures 1-6As shown, a low-nitrogen emission natural draft burner includes a burner pot body 1, a secondary combustion zone 800 fixedly installed at the rear end of the burner pot body 1, a primary air structure 100 fixedly installed at the inner center of the burner pot body 1, a primary gas structure 200 fixedly installed at the inner center of the primary air structure 100, a secondary gas structure 400 and a circulating flue gas structure 500 fixedly installed at the outer side of the primary air structure 100 inside the burner pot body 1, and the secondary gas structure 400 and the circulating flue gas structure 500 are staggered, a tertiary gas structure 300 fixedly installed at the front end of the primary air structure 100 outside the burner pot body 1, an ignition burner 600 fixedly installed outside the burner pot body 1, a secondary air structure 700 fixedly installed at the lower end of the burner pot body 1, and a purge air structure 900 fixedly installed at the front end of the secondary air structure 700.

[0033] The primary air structure 100 includes a primary air chamber one 120, a primary air inlet adjusting ring-shaped hole plate 110, and a primary air chamber two 130, the primary air chamber one 120 is fixedly installed at the inner center of the burner pot body 1, the primary air inlet adjusting ring-shaped hole plate 110 is nested at the front end of the primary air chamber one 120, and the primary air chamber two 130 is fixedly installed at the rear end of the primary air chamber one 120.

[0034] Specifically, the primary air structure 100 further includes a primary air chamber three 140, a primary air internal adjusting ring plate 150, and a primary combustion zone 160, the primary air chamber two 130, the primary air chamber three 140, and the primary combustion zone 160 are sequentially fixedly connected from front to back, and the primary air internal adjusting ring plate 150 is nested at the outer side of the primary air chamber three 140.

[0035] Please refer to Figures 1-5The primary air inlet adjusting ring-shaped hole plate 110 is nested on the primary air chamber 120 and rotates relatively in the circumferential direction. The primary air inlet adjusting ring-shaped hole plate 110 is provided with a rectangular hole corresponding to the rectangular hole of the primary air chamber 120. By adjusting the relative position of the primary air inlet adjusting ring-shaped hole plate 110 and the primary air chamber 120, the corresponding degree of the rectangular hole is changed, the flow area of the air entering the primary air chamber 120 is further changed, and thus the air intake of the primary air is controlled. The primary air chamber 120 is closed at one end and is in communication with the primary air chamber two 130, the primary air chamber three 140 and the primary combustion zone 160 at the other end. The primary air internal adjusting ring plate 150 can realize relative sliding motion along the axial direction on the primary air chamber three 140. The circular hole on the primary air internal adjusting ring plate 150 corresponds to the circular hole on the primary air chamber three 140. By adjusting the relative position of the primary air internal adjusting ring plate 150 and the primary air chamber three 140, the corresponding degree of the circular hole is changed, the flow area of the air entering the primary air chamber three 140 is further changed, and thus the air intake of the internal primary air is controlled. The primary air enters the primary air chamber 120 through the rectangular hole of the primary air inlet adjusting ring-shaped hole plate 110 and the primary air chamber 120, and then enters the primary combustion zone 160 through the primary air chamber two 130 and the primary air chamber three 140. The mixed combustion of the primary air and the primary gas is realized in the primary combustion zone 160. The burner can also operate in the forced air blowing mode on the basis of the natural ventilation mode. At this time, the primary air enters the primary combustion zone 160 through the circular hole of the primary air internal adjusting ring plate 150 and the primary air chamber three 140, and the mixed combustion of the primary air and the primary gas is realized in the primary combustion zone 160.

[0036] Specifically, the primary gas structure 200 further comprises a primary gas flow pipe 220, a primary gas nozzle 230 and a primary gas cyclone device 240. The primary gas flow pipe 220 is fixedly installed at the rear end of the primary gas inlet 210. The primary gas flow pipe 220, the primary gas nozzle 230 and the primary gas cyclone device 240 are sequentially arranged and fixedly connected from front to back. The primary gas inlet 210 penetrates the primary air inlet adjusting ring-shaped hole plate 110, the primary air chamber 120, the primary air chamber two 130 and the primary air chamber three 140. The primary gas nozzle 230 is located in the primary combustion zone 160. The jet speed of the primary gas nozzle 230 is 100-150 m / s.

[0037] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 5The primary gas inlet 210 is connected with the primary gas flow pipe 220, the primary gas nozzle 230 and the primary gas cyclone device 240, so that the primary gas enters from the primary gas inlet 210, is sprayed into the primary combustion zone 160 by the primary gas nozzle 230 after passing through the primary gas flow pipe 220, and is mixed with the primary air to burn after passing through the primary gas cyclone device 240.

[0038] Specifically, the secondary gas structure 400 includes a secondary gas inlet 410, a secondary gas ring cavity 420, secondary gas flow pipes 430, secondary gas nozzles 440, a gas collecting pipe 450, a mixing pipe 460 and a flame stabilizing disc 470. The secondary gas ring cavity 420 is fixedly installed inside the burner pot body 1 and located outside the primary air chamber I 120. The secondary gas inlet 410 is fixedly installed at the front end of the secondary gas ring cavity 420. The secondary gas flow pipes 430, the secondary gas nozzles 440, the gas collecting pipe 450, the mixing pipe 460 and the flame stabilizing disc 470 are arranged and fixedly connected in sequence from front to back. The four secondary gas flow pipes 430 are fixedly installed at the rear end of the secondary gas ring cavity 420. The flame stabilizing disc 470 is located in the secondary combustion zone 800. The spray speed of the secondary gas nozzle 440 is 150-290 m / s.

[0039] Please refer to Figure 1 and Figure 2 The secondary gas inlet 410 is connected with the secondary gas ring cavity 420, the secondary gas flow pipes 430, the secondary gas nozzles 440, the gas collecting pipe 450, the mixing pipe 460 and the flame stabilizing disc 470, so that the secondary gas enters the secondary gas ring cavity 420, the secondary gas flow pipes 430 and then is sprayed into the gas collecting pipe 450 and the mixing pipe 460 by the secondary gas nozzles 440, and is sprayed out by the flame stabilizing disc 470 into the secondary combustion zone 800. The secondary gas sprayed into the gas collecting pipe 450 has a high speed, and under the action of a specific nozzle, negative pressure is generated in the gas collecting pipe 450, so that the secondary air is sucked into the gas collecting pipe 450 and preliminarily mixed with the secondary gas, thereby improving the combustion efficiency of the secondary gas.

[0040] Specifically, the tertiary gas structure 300 includes a tertiary gas inlet 310, a tertiary gas ring cavity 320, tertiary gas flow pipes 330 and tertiary gas nozzles 340. The tertiary gas ring cavity 320 is fixedly installed at the front end of the burner pot body 1 and located outside the primary air inlet adjusting ring type orifice plate 110. The tertiary gas inlet 310 is fixedly installed at the bottom of the tertiary gas ring cavity 320. The four tertiary gas flow pipes 330 are fixedly installed at the rear end of the tertiary gas ring cavity 320. The four tertiary gas nozzles 340 are respectively fixedly installed at the rear end of the four tertiary gas flow pipes 330. The tertiary gas ring cavity 320 is sleeved outside the primary air inlet adjusting ring type orifice plate 110. The spray speed of the tertiary gas nozzle 340 is 150-290 m / s.

[0041] Please refer to Figure 1 , Figure 3 and Figure 5 , the tertiary gas inlet 310 penetrates the tertiary gas annular cavity 320, the tertiary gas flow pipe 330 and the tertiary gas nozzle 340, so that the tertiary gas enters from the tertiary gas inlet 310, sequentially flows through the tertiary gas annular cavity 320 and the tertiary gas flow pipe 330, and is finally sprayed out by the tertiary gas nozzle 340 into the entraining mixing pipe 530. When the tertiary gas is sprayed out by the tertiary gas nozzle 340, it has a high speed, and under the action of a specific nozzle, a negative pressure is generated at the inlet of the entraining mixing pipe 530, which entrains the circulating flue gas into the entraining mixing pipe 530 to mix with the tertiary gas, reduces the reaction rate of the tertiary gas, reduces the reaction temperature of the tertiary gas, and thus reduces the generation of thermal Nox.

[0042] Specifically, the circulating flue gas structure 500 includes a circulating flue gas inlet 510, a flue gas annular cavity 520, an entraining mixing pipe 530 and a mixed gas outlet pipe 540. The flue gas annular cavity 520 is fixedly installed inside the combustor pot body 1 and located outside the primary air chamber 120. The flue gas annular cavity 520 is located behind the secondary gas annular cavity 420. The circulating flue gas inlet 510 is fixedly installed at the top outside of the flue gas annular cavity 520. Four entraining mixing pipes 530 are fixedly installed at the rear end of the flue gas annular cavity 520. Four mixed gas outlet pipes 540 are fixedly installed at the rear end of the four entraining mixing pipes 530. The entraining mixing pipe 530 is arranged in a straight pipe structure. The tertiary gas flow pipe 330 penetrates into the flue gas annular cavity 520. The tertiary gas nozzle 340 is inserted into the entraining mixing pipe 530. The mixed gas outlet pipe 540 is located inside the secondary combustion zone 800.

[0043] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 5 , the circulating flue gas inlet 510 penetrates the flue gas annular cavity 520, the entraining mixing pipe 530 and the mixed gas outlet pipe 540, so that the circulating flue gas enters the flue gas annular cavity 520 and the entraining mixing pipe 530 in sequence under the entraining action of the tertiary gas through the circulating flue gas inlet 510, mixes with the tertiary gas in the entraining mixing pipe 530, and is sprayed out by the outlet pipe 540 after mixing with the tertiary gas, enters the secondary combustion zone 800 to mix and burn with the secondary air, reduces the reaction rate of the tertiary gas, reduces the reaction temperature of the tertiary gas, and thus reduces the generation of thermal Nox.

[0044] Specifically, the secondary air structure 700 includes a secondary air inlet 710, a secondary air inlet adjusting flap 720, a secondary air chamber 730, and a secondary air manifold 740. The secondary air chamber 730 is fixedly installed at the lower end of the burner pot body 1. The secondary air inlet adjusting flap 720 is movably installed at the front end of the secondary air chamber 730. The secondary air inlet 710 is formed in the interior of the secondary air chamber 730 and is in through connection with the secondary air inlet adjusting flap 720. The secondary air manifold 740 is fixedly installed at the top rear end of the secondary air chamber 730 and is in through connection therewith. The top of the secondary air manifold 740 is in through connection with the secondary combustion zone 800.

[0045] Please refer to Figures 1-5 The secondary air inlet 710 is a rectangular inlet and is in through connection with the secondary air inlet adjusting flap 720, the secondary air chamber 730, and the secondary air manifold 740. After the secondary air enters through the secondary air inlet 710, it successively flows through the secondary air inlet adjusting flap 720, the secondary air chamber 730, and the secondary air manifold 740, and finally enters the secondary combustion zone 800. The amount of secondary air can be adjusted by the secondary air inlet adjusting flap 720. The secondary air inlet adjusting flap 720 can be connected to a servo to realize automatic air-fuel ratio control.

[0046] Specifically, the purge air structure 900 includes an air inlet fan 910, an adjusting handle 920, a fan air inlet adjusting annular hole plate 930, a fan air inlet ring cavity 940, a fan air outlet elbow pipe 950, and a fan air outlet expansion pipe 960. The fan air outlet elbow pipe 950 is fixedly installed at the air outlet of the air inlet fan 910. Two air inlet fans 910 are fixedly installed at the front end of the secondary air chamber 730. The fan air outlet expansion pipe 960 is fixedly installed at the rear end of the fan air outlet elbow pipe 950. The adjusting handle 920 is movably installed at the adjacent side of the air inlet fan 910. The fan air inlet adjusting annular hole plate 930 is movably installed between the two air inlet fans 910 and is connected with the adjusting handle 920. The fan air inlet ring cavity 940 is fixedly installed between the two air inlet fans 910 and is arranged inside the fan air inlet adjusting annular hole plate 930 coaxially with the fan air inlet adjusting annular hole plate 930. The fan air outlet elbow pipe 950 and the fan air outlet expansion pipe 960 are located in the interior of the secondary air chamber 730.

[0047] Please refer to Figures 4-6, the fan 910 provides purging air before the burner starts and after the burner stops, and provides combustion-supporting air for the burner when the forced air operation mode is adopted, the purging air enters the fan air inlet adjusting annular orifice plate 930, the fan air inlet annular cavity 940 and the fan air outlet elbow pipe 950 in turn from the fan 910, and is finally sprayed out from the fan air outlet expansion pipe 960 into the secondary air chamber 730, the purging air changes direction through the fan air outlet elbow pipe 950, which is more conducive to improving the fullness of the purging air in the secondary air chamber 730;

[0048] The outer shell of the fan air inlet adjusting annular orifice plate 930 is a double-layer structure, and the circumferential movement of the fan air inlet adjusting annular orifice plate 930 can be realized through the adjusting handle 920, when the fan air inlet adjusting annular orifice plate 930 rotates, the outer shell overlaps the fan air inlet annular cavity 940, and the caliber of the fan air inlet annular cavity 940 is mechanically adjusted, so as to adjust the air inlet amount of the purging air, and the adjusting handle 920 can also be connected with a servo mechanism to realize automatic control.

[0049] Specifically, the ignition burner 600 includes an ignition gas inlet 610 and an ignition electrode 620, the ignition gas inlet 610 and the ignition electrode 620 are both fixedly installed on the outside of the burner pot body 1, the ignition gas inlet 610 and the ignition electrode 620 are arranged in parallel between them, the lower ends of the ignition gas inlet 610 and the ignition electrode 620 pass through the burner pot body 1 to the inside of the secondary combustion zone 800, and the ignition gas inlet 610 and the ignition electrode 620 cooperate with each other to achieve the effect of ignition.

[0050] The basic principles and main features of the present application and the advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A low nitrogen emission natural draft burner comprising a burner pot (1), characterized in that: The rear end of the burner pot body (1) is fixedly installed with a secondary combustion zone (800), the inner center of the burner pot body (1) is fixedly installed with a primary air structure (100), the inner center of the primary air structure (100) is fixedly installed with a primary gas structure (200), the inside of the burner pot body (1) is fixedly installed with a secondary gas structure (400) and a circulating flue gas structure (500) outside the primary air structure (100), and the secondary gas structure (400) and the circulating flue gas structure (500) are staggered, the front end of the burner pot body (1) is fixedly installed with a tertiary gas structure (300) outside the primary air structure (100), the outer side of the burner pot body (1) is fixedly installed with an ignition burner (600), the lower end of the burner pot body (1) is fixedly installed with a secondary air structure (700), and the front end of the secondary air structure (700) is fixedly installed with a purge air structure (900); The primary air structure (100) comprises a primary air chamber one (120), a primary air inlet adjusting ring-shaped hole plate (110) and a primary air chamber two (130), the primary air chamber one (120) is fixedly installed at the inner center of the burner pot body (1), the primary air inlet adjusting ring-shaped hole plate (110) is nested at the front end of the primary air chamber one (120), and the primary air chamber two (130) is fixedly installed at the rear end of the primary air chamber one (120), the primary gas structure (200) comprises a primary gas inlet (210), and the primary gas inlet (210) is fixedly installed in the primary air inlet adjusting ring-shaped hole plate (110); The secondary air structure (700) comprises a secondary air inlet (710), a secondary air inlet adjusting flap (720), a secondary air chamber (730) and a secondary air manifold (740), the secondary air chamber (730) is fixedly installed at the lower end of the burner pot body (1), the secondary air inlet adjusting flap (720) is movably installed at the front end of the secondary air chamber (730), the secondary air inlet (710) is formed in the secondary air chamber (730) and is in through connection with the secondary air inlet adjusting flap (720), the secondary air manifold (740) is fixedly installed at the top rear end of the secondary air chamber (730) and is in through connection therewith, and the top of the secondary air manifold (740) is in through connection with the secondary combustion zone (800); The purge air structure (900) comprises an air inlet fan (910), an adjusting handle (920), a fan air inlet adjusting ring-shaped hole plate (930), a fan air inlet ring cavity (940), a fan air outlet elbow pipe (950) and a fan air outlet expansion pipe (960), the fan air outlet elbow pipe (950) is fixedly installed at the air outlet of the air inlet fan (910), two air inlet fans (910) are fixedly installed at the front end of the secondary air chamber (730), and the fan air outlet expansion pipe (960) is fixedly installed at the rear end of the fan air outlet elbow pipe (950).

2. A low-nitrogen emission natural draft burner according to claim 1, characterized in that: The primary air structure (100) further comprises a primary air chamber three (140), a primary air internal adjustment ring plate (150), a primary combustion zone (160), the primary air chamber two (130), the primary air chamber three (140) and the primary combustion zone (160) are sequentially arranged and fixedly connected from front to back, and the primary air internal adjustment ring plate (150) is nested on the outer side of the primary air chamber three (140).

3. A low NOx natural draft burner as claimed in claim 2, wherein: The primary gas structure (200) further comprises a primary gas flow pipe (220), a primary gas nozzle (230) and a primary gas cyclone device (240), the primary gas flow pipe (220) is fixedly installed at the rear end of the primary gas inlet (210), the primary gas flow pipe (220), the primary gas nozzle (230) and the primary gas cyclone device (240) are sequentially arranged and fixedly connected from front to back, the primary gas inlet (210) penetrates the primary air inlet adjustment ring type orifice plate (110), the primary air chamber one (120), the primary air chamber two (130) to the primary air chamber three (140), the primary gas nozzle (230) is located in the primary combustion zone (160), and the injection speed of the primary gas nozzle (230) is 100-150 m / s.

4. A low NOx natural draft burner as set forth in claim 3, characterized in that: The secondary gas structure (400) comprises a secondary gas inlet (410), a secondary gas ring cavity (420), a secondary gas flow pipe (430), a secondary gas nozzle (440), a gas collecting pipe (450), a mixing pipe (460) and a flame stabilizing disc (470), the secondary gas ring cavity (420) is fixedly installed in the inside of the burner pot body (1) and located on the outer side of the primary air chamber one (120), the secondary gas inlet (410) is fixedly installed at the front end of the secondary gas ring cavity (420), the secondary gas flow pipe (430), the secondary gas nozzle (440), the gas collecting pipe (450), the mixing pipe (460) and the flame stabilizing disc (470) are divided into four groups and sequentially arranged and fixedly connected from front to back, the four secondary gas flow pipes (430) are fixedly installed at the rear end of the secondary gas ring cavity (420), the flame stabilizing disc (470) is located in the secondary combustion zone (800), and the injection speed of the secondary gas nozzle (440) is 150-290 m / s.

5. A low NOx natural draft burner as claimed in claim 4, wherein: The tertiary gas structure (300) comprises a tertiary gas inlet (310), a tertiary gas ring cavity (320), a tertiary gas flow pipe (330) and a tertiary gas nozzle (340), the tertiary gas ring cavity (320) is fixedly installed at the front end of the burner pot body (1) and located on the outer side of the primary air inlet adjustment ring type orifice plate (110), the tertiary gas inlet (310) is fixedly installed at the bottom of the tertiary gas ring cavity (320), the four tertiary gas flow pipes (330) are fixedly installed at the rear end of the tertiary gas ring cavity (320), the four tertiary gas nozzles (340) are respectively fixedly installed at the rear end of the four tertiary gas flow pipes (330), the tertiary gas ring cavity (320) is sleeved on the outer side of the primary air inlet adjustment ring type orifice plate (110), and the injection speed of the tertiary gas nozzle (340) is 150-290 m / s.

6. A low NOx natural draft burner as set forth in claim 5, characterized in that: The circulating flue gas structure (500) comprises a circulating flue gas inlet (510), a flue gas ring cavity (520), an injection mixing pipe (530) and a mixed gas outlet pipe (540), the flue gas ring cavity (520) is fixedly installed inside the burner tank body (1) and located outside the primary air chamber I (120), the flue gas ring cavity (520) is located behind the secondary gas ring cavity (420), the circulating flue gas inlet (510) is fixedly installed at the top outside of the flue gas ring cavity (520), four injection mixing pipes (530) are fixedly installed at the rear end of the flue gas ring cavity (520), and four mixed gas outlet pipes (540) are fixedly installed at the rear end of the four injection mixing pipes (530), the injection mixing pipe (530) is provided in a straight pipe structure.

7. A low-nitrogen emission natural draft burner according to claim 6, characterized in that: The tertiary gas flow pipe (330) penetrates into the flue gas ring cavity (520), the tertiary gas nozzle (340) is inserted into the injection mixing pipe (530), and the mixed gas outlet pipe (540) is located inside the secondary combustion zone (800).

8. A low NOx natural draft burner as set forth in claim 1, wherein: The adjusting handle (920) is movably installed on the adjacent side of the air fan (910), the fan air inlet adjusting ring orifice plate (930) is movably installed between the two air fans (910) and connected with the adjusting handle (920), the fan air inlet ring cavity (940) is fixedly installed between the two air fans (910) and arranged inside the fan air inlet adjusting ring orifice plate (930) coaxially with the fan air inlet adjusting ring orifice plate (930), and the fan air outlet elbow pipe (950) and the fan air outlet expansion pipe (960) are located inside the secondary air chamber (730).

9. A low NOx natural draft burner as set forth in claim 1, wherein: The ignition burner (600) comprises an ignition gas inlet (610) and an ignition electrode (620), the ignition gas inlet (610) and the ignition electrode (620) are both fixedly installed outside the burner tank body (1), the ignition gas inlet (610) and the ignition electrode (620) are arranged in parallel, and the lower ends of the ignition gas inlet (610) and the ignition electrode (620) penetrate through the burner tank body (1) to the inside of the secondary combustion zone (800).

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