Natural ventilation burner with low nitrogen emission

Abstract

The invention discloses a low-nitrogen-emission natural ventilation combustor, which relates to the field of low-nitrogen combustors and comprises a primary air structure, a primary gas structure, a secondary gas structure, a tertiary gas structure, a circulating flue gas structure, an ignition burner, a secondary air structure, a secondary combustion area and an air purging structure. According to the low-nitrogen-emission natural ventilation combustor, the combustion reaction temperature and the reaction rate are reduced, the problem that the combustion air momentum of the natural ventilation combustor is insufficient is solved, unorganized diffusion combustion is restrained, the combustion efficiency is effectively improved, generation of NOx is restrained, multi-layer and multi-direction distribution is adopted for combustor fuel classification, and the combustion efficiency is improved. The combustion stability is enhanced, adjustment and control are carried out according to the use condition, tempering and local high temperature are restrained while high-speed multi-state jet flow and smoke entrainment are adopted, the influence of the environment on the natural ventilation combustor is further restrained, and the natural ventilation combustor has two working modes of natural ventilation and forced air blowing.

Description

Technical Field

[0001] The invention relates to the field of low-nitrogen burners, and in particular to a natural ventilation burner with low nitrogen emissions. Background Art

[0002] Low-nitrogen emission natural ventilation burners are burners with low nitrogen oxide emissions and are mainly used for combustion in heating furnaces. At present, the air supply method used by burners is mainly forced air blowing, but there are still a large number of heating furnaces that have negative pressure conditions in the furnace and can support air supply in the form of natural ventilation. The burner does not need to be equipped with a fan, which can save manufacturing and operating costs. Natural ventilation burners have the characteristics of difficult combustion organization and the operating state is easily affected by the external environment, and have higher NOx emissions. Although with the continuous efforts of engineering and technical personnel, the continuous improvement of the burner structure, and certain progress in flame stability, there is still a problem of high NOx emissions.

[0003] How to achieve relatively efficient, safe and complete combustion under natural ventilation conditions while controlling the generation of pollutants and realizing a natural ventilation burner with lower NOx emissions is a problem that needs to be solved at present. Summary of the invention

[0004] The main purpose of the present invention is to provide a natural ventilation burner with low nitrogen emissions, which can effectively solve the technical problems raised by the background technology.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A natural ventilation burner with low nitrogen emission, comprising a burner tank body, a secondary combustion zone is fixedly installed at the rear end of the burner tank body, a primary air structure is fixedly installed at the inner center of the burner tank body, 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 on the outer side of the primary air structure inside the burner tank body, and the secondary gas structure and the circulating flue gas structure are arranged alternately, a tertiary gas structure is fixedly installed on the outer side of the primary air structure at the front end of the burner tank body, an ignition burner is fixedly installed on the outer side of the burner tank body, a secondary air structure is fixedly installed at the lower end of the burner tank body, and a purge air structure is fixedly installed at the front end of the secondary air structure;

[0007] The primary air structure includes a primary air chamber 1, a primary air inlet adjusting annular orifice plate and a primary air chamber 2. The primary air chamber 1 is fixedly installed at the inner center of the burner tank body, the primary air inlet adjusting annular orifice plate is nested at the front end of the primary air chamber 1, and the primary air chamber 2 is fixedly installed at the rear end of the primary air chamber 1. The primary gas structure includes a primary gas inlet, which is fixedly installed inside the primary air inlet adjusting annular orifice plate.

[0008] As a further solution of the present invention, the primary air structure also includes a primary air chamber three, a primary air internal adjustment ring plate, and a primary combustion zone. The primary air chamber two, the primary air chamber three and the primary combustion zone are arranged and fixedly connected in sequence from front to back, and the primary air internal adjustment ring plate is nested on the outside of the primary air chamber three.

[0009] As a further solution of the present invention, the primary gas structure also includes a primary gas flow pipe, a primary gas nozzle and a primary gas swirl 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 swirl device are arranged in sequence from front to back and fixedly connected. The primary gas inlet passes through the primary air inlet regulating annular orifice plate, the primary air chamber one, the primary air chamber two to 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 100-150m / s.

[0010] As a further solution of the present invention, the secondary gas structure includes a secondary gas inlet, a secondary gas annular cavity, a secondary gas flow pipe, a secondary gas nozzle, a gas collecting pipe, a mixing pipe and a flame stabilizing disk. The secondary gas annular cavity is fixedly installed inside the burner tank body and is located outside the primary air chamber 1. The secondary gas inlet is fixedly installed at the front end of the secondary gas annular cavity. The secondary gas flow pipe, the secondary gas nozzle, the gas collecting pipe, the mixing pipe and the flame stabilizing disk are divided into four groups and are arranged and fixedly connected in sequence from front to back. The four secondary gas flow pipes are fixedly installed at the rear end of the secondary gas annular cavity. The flame stabilizing disk is located in the secondary combustion zone. The spray speed of the secondary gas nozzle is 150-290m / s.

[0011] As a further solution of the present invention, the tertiary gas structure includes a tertiary gas inlet, a tertiary gas annular cavity, a tertiary gas flow pipe and a tertiary gas nozzle. The tertiary gas annular cavity is fixedly installed at the front end of the burner tank body and is located on the outside of the primary air inlet regulating annular orifice plate. The tertiary gas inlet is fixedly installed at the bottom of the tertiary gas annular cavity, four tertiary gas flow pipes are fixedly installed at the rear end of the tertiary gas annular cavity, four tertiary gas nozzles are respectively fixedly installed at the rear ends of the four tertiary gas flow pipes, the tertiary gas annular cavity is sleeved on the outside of the primary air inlet regulating annular orifice plate, and the spray speed of the tertiary gas nozzle is 150-290m / s.

[0012] As a further scheme of the present invention, the circulating flue gas structure includes a circulating flue gas inlet, a smoke ring cavity, an ejector mixing tube and a mixed gas outlet pipe. The smoke ring cavity is fixedly installed inside the burner tank body and is located on the outside of the primary air chamber one. The smoke ring cavity is located behind the secondary fuel gas ring cavity. The circulating flue gas inlet is fixedly installed on the outer top of the smoke ring cavity. Four ejector mixing tubes are fixedly installed at the rear end of the smoke ring cavity. Four mixed gas outlet pipes are respectively fixedly installed at the rear ends of the four ejector mixing tubes. The ejector mixing tube adopts a straight tube structure.

[0013] As a further solution of the present invention, the tertiary gas flow pipe penetrates into the smoke 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 invention, the secondary air structure includes 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 body, 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 through-connected 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 through-connected thereto, and the top of the secondary air manifold is through-connected with the secondary combustion zone.

[0015] As a further scheme of the present invention, the purge air structure includes an air inlet, an adjustment handle, a fan air inlet adjustment annular orifice plate, a fan air inlet annular cavity, a fan air outlet elbow and a fan air outlet expansion tube. The fan air outlet elbow is fixedly installed at the air outlet of the air inlet, two air inlets are fixedly installed at the front end of the secondary air chamber, the fan air outlet expansion tube is fixedly installed at the rear end of the fan air outlet elbow, the adjustment handle is movably installed on the adjacent side of the air inlet, the fan air inlet adjustment annular orifice plate is movably installed between the two air inlets and connected to the adjustment handle, the fan air inlet annular cavity is fixedly installed between the two air inlets and is arranged on the inner side of the fan air inlet adjustment annular orifice plate and is coaxially arranged with the fan air inlet adjustment annular orifice plate, and the fan air outlet elbow and the fan air outlet expansion tube are located inside the secondary air chamber.

[0016] As a further solution of the present invention, the ignition burner includes an ignition gas inlet and an ignition electrode, which are fixedly mounted on the outside of the burner tank body, and are arranged in parallel with each other. The lower ends of the ignition gas inlet and the ignition electrode pass through the burner tank body to the inside of the secondary combustion zone.

[0017] Compared with the prior art, the present invention has the following beneficial effects: by setting up a tertiary combustion structure and a circulating flue gas structure, the flue gas is ejected by utilizing the momentum of the combustion gas, thereby reducing the combustion reaction temperature and reaction rate, and effectively inhibiting the generation of thermal NOx;

[0018] The combustion air is injected by utilizing the momentum of the gas, thus overcoming the problem of insufficient momentum of the combustion air in the natural ventilation burner, suppressing the unorganized diffusion combustion, effectively improving the combustion efficiency, and suppressing the generation of NOx.

[0019] By setting up the primary air structure, primary gas structure and secondary gas structure, the burner fuel grading adopts multi-level and multi-directional distribution, which enhances the stability of combustion and suppresses the impact of the environment on the natural ventilation burner;

[0020] Through the independent pipeline of the primary gas structure, a servo adjustment mechanism can be set to realize automatic adjustment of the primary gas volume. The primary air structure and the secondary air structure have adjustment mechanisms, and a servo adjustment mechanism can be set to realize automatic adjustment of the primary air volume. Adjustment and control can be carried out according to the usage conditions, which is more convenient for control and use in different occasions;

[0021] The high-speed multi-state jet adopted by the circulating flue gas structure can entrain the flue gas while suppressing the flashback and local high temperature, making it more stable to use;

[0022] A two-stage fire hood structure is formed by the primary combustion zone and the secondary combustion zone. Driven by the aerodynamic flow field, the smoke forms a backflow at the fire hood position of the primary combustion zone and the secondary combustion zone, which enhances the stability of combustion and further suppresses the impact of the environment on the natural ventilation burner.

[0023] Through the set purge air structure, it has two working modes: natural ventilation and forced blowing, and the furnace type adaptability is wider. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of a natural ventilation burner with low nitrogen emissions according to the present invention;

[0025] Figure 2 A rear view of a natural draft burner with low nitrogen emission according to the present invention;

[0026] Figure 3 This is a diagram showing the internal structure of a burner tank of a natural ventilation burner with low nitrogen emission according to the present invention;

[0027] Figure 4 It is a partial cross-sectional diagram of a natural ventilation burner with low nitrogen emission according to the present invention;

[0028] Figure 5 A cross-sectional view of a natural draft burner with low nitrogen emission according to the present invention;

[0029] Figure 6 This is an enlarged view of the purge air structure in a natural draft burner with low nitrogen emissions according to the present invention.

[0030] In the figure: 1, burner tank; 100, primary air structure; 110, primary air inlet regulating annular orifice plate; 120, primary air chamber one; 130, primary air chamber two; 140, primary air chamber three; 150, primary air internal regulating annular 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 swirl device; 300, tertiary gas structure; 310, tertiary gas inlet; 320, tertiary gas annular cavity; 330, tertiary gas flow pipe; 340, tertiary gas nozzle; 400, secondary gas structure; 410, secondary gas inlet; 420, secondary gas annular cavity; 430, secondary gas flow pipe; 440, secondary gas Gas nozzle; 450, gas collecting pipe; 460, mixing tube; 470, flame stabilizing disk; 500, circulating flue gas structure; 510, circulating flue gas inlet; 520, flue gas annular cavity; 530, induced mixing tube; 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 regulating flap; 730, secondary air chamber; 740, secondary air manifold; 800, secondary combustion zone; 900, purge air structure; 910, air inlet fan; 920, regulating handle; 930, fan air inlet regulating annular orifice plate; 940, fan air inlet annular cavity; 950, fan air outlet elbow; 960, fan air outlet expansion tube. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

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

[0033] The primary air structure 100 includes a primary air chamber 120, a primary air inlet adjusting annular orifice plate 110 and a primary air chamber 2 130. The primary air chamber 120 is fixedly installed in the inner center of the burner tank body 1. The primary air inlet adjusting annular orifice plate 110 is nested in the front end of the primary air chamber 120. The primary air chamber 2 130 is fixedly installed at the rear end of the primary air chamber 120. The primary gas structure 200 includes a primary gas inlet 210, and the primary gas inlet 210 is fixedly installed inside the primary air inlet adjusting annular orifice plate 110.

[0034] Specifically, the primary air structure 100 further includes a primary air chamber 3 140, a primary air internal adjustment ring plate 150, and a primary combustion zone 160. The primary air chamber 2 130, the primary air chamber 3 140, 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 3 140.

[0035] Please refer to Figure 1-Figure 5The primary air inlet regulating annular orifice plate 110 is nested on the primary air chamber 120 for relative circular rotation. The primary air inlet regulating annular orifice plate 110 is provided with rectangular holes corresponding to the rectangular holes provided in the primary air chamber 120. By adjusting the relative position of the primary air inlet regulating annular orifice plate 110 and the primary air chamber 120, the corresponding degree of the rectangular holes is changed, and the flow area of ​​the air entering the primary air chamber 120 is further changed, thereby controlling the intake amount of the primary air. One end of the primary air chamber 120 is closed, and the other end is connected to the primary air chamber 2 130, the primary air chamber 3 140, and the primary combustion zone 160. The primary air internal regulating ring plate 15 can realize relative sliding movement along the axial direction on the primary air chamber 3 140, and the circular hole on the primary air internal regulating ring plate 150 corresponds to the circular hole on the primary air chamber 3 140. By adjusting the relative position of the primary air internal regulating ring plate 150 and the primary air chamber three 140, the corresponding degree of the circular holes is changed, and the flow area of ​​the air entering the primary air chamber three 140 is further changed, so as to control the air intake of the internal primary air. The primary air enters the primary air chamber one 120 through the primary air inlet regulating ring-shaped orifice plate 110 and the rectangular hole of the primary air chamber one 120, and then enters the primary combustion zone 160 through the primary air chamber two 130 and the primary air chamber three 140, and realizes mixed combustion with the primary fuel gas in the primary combustion zone 160. The burner can also adopt the forced blast operation mode on the basis of the natural ventilation mode. At this time, the primary air enters the primary air chamber three 140 through the circular hole opened in the primary air internal regulating ring plate 150 and further enters the primary combustion zone 160, and realizes mixed combustion with the primary fuel gas in the primary combustion zone 160.

[0036] Specifically, the primary gas structure 200 further includes a primary gas flow pipe 220, a primary gas nozzle 230 and a primary gas swirl 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 swirl device 240 are arranged and fixedly connected in sequence from front to back. The primary gas inlet 210 passes through the primary air inlet regulating annular orifice plate 110, the primary air chamber 1 120, the primary air chamber 2 130 to the primary air chamber 3 140. The primary gas nozzle 230 is located in the primary combustion zone 160, and the spray 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 to the primary gas flow pipe 220, the primary gas nozzle 230, and the primary gas swirl device 240, so that the primary gas enters from the primary gas inlet 210, passes through the primary gas flow pipe 220, and is sprayed into the primary combustion zone 160 by the primary gas nozzle 230 to mix with the primary air passing through the primary gas swirl device 240 for combustion.

[0038] Specifically, the secondary gas structure 400 includes a secondary gas inlet 410, a secondary gas annular 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 disk 470. The secondary gas annular cavity 420 is fixedly installed inside the burner tank body 1 and is located outside the primary air chamber 120. The secondary gas inlet 410 is fixedly installed at the front end of the secondary gas annular 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 disk 470 are divided into four groups and 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 annular cavity 420. The flame stabilizing disk 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 to the secondary gas annular 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 disk 470. Therefore, the secondary gas enters the secondary gas annular cavity 420 and the secondary gas flow pipe 430 in sequence through the secondary gas inlet 410, and then is sprayed into the gas collecting pipe 450 and the mixing pipe 460 by the secondary gas nozzle 440, and then is sprayed out by the flame stabilizing disk 470 into the secondary combustion zone 800. The secondary gas is sprayed into the gas collecting pipe 450 at a relatively high speed. Under the action of a specific nozzle, a negative pressure is generated in the gas collecting pipe 450, thereby entraining secondary air into the gas collecting pipe 450 for preliminary mixing 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 annular cavity 320, a tertiary gas flow pipe 330 and a tertiary gas nozzle 340. The tertiary gas annular cavity 320 is fixedly installed at the front end of the burner tank body 1 and is located outside the primary air inlet regulating annular orifice plate 110. The tertiary gas inlet 310 is fixedly installed at the bottom of the tertiary gas annular cavity 320, four tertiary gas flow pipes 330 are fixedly installed at the rear end of the tertiary gas annular cavity 320, and four tertiary gas nozzles 340 are respectively fixedly installed at the rear ends of the four tertiary gas flow pipes 330. The tertiary gas annular cavity 320 is sleeved on the outside of the primary air inlet regulating annular 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 is connected with the tertiary gas annular cavity 320, the tertiary gas flow tube 330, and the tertiary gas nozzle 340. Therefore, the tertiary gas enters from the tertiary gas inlet 310, flows through the tertiary gas annular cavity 320 and the tertiary gas flow tube 330 in sequence, and is finally ejected from the tertiary gas nozzle 340 into the ejector mixing tube 530. The tertiary gas has a high speed when ejected through the tertiary gas nozzle 340. Under the action of a specific nozzle, a negative pressure is generated at the entrance of the ejector mixing tube 530, and the entrained circulating flue gas enters the ejector mixing tube 530 to mix with the tertiary gas, thereby reducing the reaction rate of the tertiary gas and the reaction temperature of the tertiary gas, thereby reducing 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 ejector mixing tube 530 and a mixed gas outlet pipe 540. The flue gas annular cavity 520 is fixedly installed inside the burner tank body 1 and is located outside the primary air chamber 120. The flue gas annular cavity 520 is located behind the secondary fuel gas annular cavity 420. The circulating flue gas inlet 510 is fixedly installed on the outer top of the flue gas annular cavity 520. Four ejector mixing tubes 530 are fixedly installed at the rear end of the flue gas annular cavity 520. Four mixed gas outlet pipes 540 are respectively fixedly installed at the rear ends of the four ejector mixing tubes 530. The ejector mixing tube 530 adopts a straight tube structure. The tertiary fuel gas flow tube 330 penetrates into the flue gas annular cavity 520. The tertiary fuel gas nozzle 340 is inserted into the ejector mixing tube 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 is connected with the flue gas annular cavity 520, the ejector mixing tube 530 and the mixed gas outlet pipe 540, so that the circulating flue gas enters the flue gas annular cavity 520 and the ejector mixing tube 530 in sequence through the circulating flue gas inlet 510 under the action of the tertiary fuel gas ejection, and is mixed with the tertiary fuel gas in the ejector mixing tube 530 and then ejected from the outlet pipe 540 to enter the secondary combustion zone 800 to mix with the secondary air for combustion. The circulating flue gas reduces the reaction rate of the tertiary fuel gas and the reaction temperature of the tertiary fuel gas, thereby reducing the generation of thermal NOx.

[0044] Specifically, the secondary air structure 700 includes a secondary air inlet 710, a secondary air inlet regulating flap 720, a secondary air chamber 730 and a secondary air manifold 740. The secondary air chamber 730 is fixedly mounted at the lower end of the burner tank body 1, the secondary air inlet regulating flap 720 is movably mounted at the front end of the secondary air chamber 730, the secondary air inlet 710 is opened inside the secondary air chamber 730 and is connected to the secondary air inlet regulating flap 720, the secondary air manifold 740 is fixedly mounted at the top rear end of the secondary air chamber 730 and is connected to the secondary air chamber 730, and the top of the secondary air manifold 740 is connected to the secondary combustion zone 800;

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

[0046] Specifically, the purge air structure 900 includes an air inlet fan 910, an adjustment handle 920, an annular orifice plate 930 for adjusting the air inlet of the fan, an annular cavity 940 for the air inlet of the fan, an air outlet elbow 950 for the fan, and an air outlet expansion pipe 960 for the fan. The air outlet elbow 950 for the fan is fixedly installed at the air outlet of the air inlet fan 910. The two air inlets 910 are fixedly installed at the front end of the secondary air chamber 730. The air outlet expansion pipe 960 for the fan is fixedly installed at the rear end of the air outlet elbow 950 for adjusting the air inlet of the fan. The handle 920 is movably mounted on the adjacent side of the air inlet fan 910, the fan air inlet regulating annular orifice plate 930 is movably mounted between the two air inlets 910 and connected to the regulating handle 920, the fan air inlet annular cavity 940 is fixedly mounted between the two air inlets 910 and arranged on the inner side of the fan air inlet regulating annular orifice plate 930 and arranged coaxially with the fan air inlet regulating annular orifice plate 930, and the fan air outlet elbow 950 and the fan air outlet expansion pipe 960 are located inside the secondary air chamber 730;

[0047] Please refer to Figure 4-Figure 6The fan 910 provides purge air before the burner is started and after it is stopped, and provides combustion-supporting air for the burner when the forced blast operation mode is adopted. The purge air enters the fan air inlet regulating annular orifice plate 930, the fan air inlet annular cavity 940, and the fan air outlet elbow 950 in sequence from the fan 910, and is finally ejected from the fan air outlet expansion pipe 960 into the secondary air chamber 730. The purge air changes direction through the fan air outlet elbow 950, which is more conducive to improving the filling degree of the purge 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. The circular motion of the fan air inlet adjusting annular orifice plate 930 can be realized by adjusting the handle 920. When the fan air inlet adjusting annular orifice plate 930 rotates, the outer shell overlaps with the fan air inlet annular cavity 940. The caliber of the fan air inlet annular cavity 940 can be mechanically adjusted to adjust the air intake amount of the purge air. The adjusting handle 920 can also be connected to a servo mechanism to realize automatic control.

[0049] Specifically, the ignition burner 600 includes an ignition gas inlet 610 and an ignition electrode 620, which are both fixedly mounted on the outside of the burner tank body 1, and are arranged in parallel with each other. The lower ends of the ignition gas inlet 610 and the ignition electrode 620 pass through the burner tank 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 an ignition effect.

[0050] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A natural ventilation burner with low nitrogen emission, comprising a burner tank (1), characterized in that: A secondary combustion zone (800) is fixedly installed at the rear end of the burner tank body (1), a primary air structure (100) is fixedly installed at the center of the interior of the burner tank body (1), a primary gas structure (200) is fixedly installed at the center of the interior of the primary air structure (100), a secondary gas structure (400) and a circulating flue gas structure (500) are fixedly installed inside the burner tank body (1) on the outside of the primary air structure (100), and the secondary gas structure (400) and the circulating flue gas structure (500) are arranged alternately, a tertiary gas structure (300) is fixedly installed at the front end of the burner tank body (1) on the outside of the primary air structure (100), an ignition burner (600) is fixedly installed on the outside of the burner tank body (1), a secondary air structure (700) is fixedly installed at the lower end of the burner tank body (1), and a purge air structure (900) is fixedly installed at the front end of the secondary air structure (700); The primary air structure (100) comprises a primary air chamber 1 (120), a primary air inlet regulating annular orifice plate (110) and a primary air chamber 2 (130); the primary air chamber 1 (120) is fixedly mounted at the inner center of the burner tank body (1); the primary air inlet regulating annular orifice plate (110) is nested at the front end of the primary air chamber 1 (120); the primary air chamber 2 (130) is fixedly mounted at the rear end of the primary air chamber 1 (120); the primary gas structure (200) comprises a primary gas inlet (210); the primary gas inlet (210) is fixedly mounted inside the primary air inlet regulating annular orifice plate (110).

2. A natural ventilation burner with low nitrogen emission according to claim 1, characterized in that: The primary air structure (100) also includes a primary air chamber three (140), a primary air internal adjustment 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 arranged in sequence from front to back and fixedly connected, and the primary air internal adjustment ring plate (150) is nested on the outer side of the primary air chamber three (140).

3. A natural ventilation burner with low nitrogen emission according to claim 2, characterized in that: The primary gas structure (200) further comprises a primary gas flow pipe (220), a primary gas nozzle (230) and a primary gas swirl device (240); the primary gas flow pipe (220) is fixedly mounted 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 swirl device (240) are arranged in sequence from front to back and fixedly connected; the primary gas inlet (210) penetrates the primary air inlet regulating annular 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 spraying speed of the primary gas nozzle (230) is 100-150 m / s.

4. A natural ventilation burner with low nitrogen emission according to claim 3, characterized in that: The secondary gas structure (400) comprises a secondary gas inlet (410), a secondary gas annular 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 disk (470). The secondary gas annular cavity (420) is fixedly installed inside the burner tank body (1) and is located outside the primary air chamber (120). The secondary gas inlet (410) is fixedly installed on the secondary gas annular cavity (420). At the front end of the 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 disk (470) are divided into four groups and are arranged in sequence from front to back and fixedly connected. The four secondary gas flow pipes (430) are fixedly installed at the rear end of the secondary gas ring cavity (420), the flame stabilizing disk (470) is located in the secondary combustion zone (800), and the spray speed of the secondary gas nozzle (440) is 150-290m / s.

5. A natural ventilation burner with low nitrogen emission according to claim 4, characterized in that: The tertiary gas structure (300) comprises a tertiary gas inlet (310), a tertiary gas annular cavity (320), a tertiary gas flow pipe (330) and a tertiary gas nozzle (340); the tertiary gas annular cavity (320) is fixedly mounted at the front end of the burner tank body (1) and is located outside the primary air inlet regulating annular orifice plate (110); the tertiary gas inlet (310) is fixedly mounted at the bottom of the tertiary gas annular cavity (320); four tertiary gas flow pipes (330) are fixedly mounted at the rear end of the tertiary gas annular cavity (320); four tertiary gas nozzles (340) are respectively fixedly mounted at the rear ends of the four tertiary gas flow pipes (330); the tertiary gas annular cavity (320) is sleeved on the outside of the primary air inlet regulating annular orifice plate (110); and the spraying speed of the tertiary gas nozzle (340) is 150-290 m / s.

6. A natural ventilation burner with low nitrogen emission according to claim 5, characterized in that: The circulating flue gas structure (500) comprises a circulating flue gas inlet (510), a flue gas annular cavity (520), an ejector mixing tube (530) and a mixed gas outlet tube (540); the flue gas annular cavity (520) is fixedly mounted inside the burner tank body (1) and is located outside the primary air chamber (120); the flue gas annular cavity (520) is located behind the secondary combustion gas annular cavity (420); the circulating flue gas inlet (510) is fixedly mounted on the top of the outer side of the flue gas annular cavity (520); four ejector mixing tubes (530) are fixedly mounted at the rear end of the flue gas annular cavity (520); four mixed gas outlet tubes (540) are respectively fixedly mounted at the rear ends of the four ejector mixing tubes (530); and the ejector mixing tubes (530) are arranged in a straight tube structure.

7. A natural ventilation burner with low nitrogen emission according to claim 6, characterized in that: The tertiary gas flow pipe (330) penetrates into the smoke 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 natural ventilation burner with low nitrogen emission according to claim 1, characterized in that: The secondary air structure (700) comprises a secondary air inlet (710), a secondary air inlet regulating flap (720), a secondary air chamber (730) and a secondary air manifold (740); the secondary air chamber (730) is fixedly mounted at the lower end of the burner tank body (1); the secondary air inlet regulating flap (720) is movably mounted at the front end of the secondary air chamber (730); the secondary air inlet (710) is disposed inside the secondary air chamber (730) and is in continuous communication with the secondary air inlet regulating flap (720); the secondary air manifold (740) is fixedly mounted at the top rear end of the secondary air chamber (730) and is in continuous communication with the secondary air chamber (730); the top of the secondary air manifold (740) is in continuous communication with the secondary combustion zone (800).

9. A natural ventilation burner with low nitrogen emission according to claim 8, characterized in that: The purge air structure (900) includes an air inlet fan (910), an adjustment handle (920), an annular orifice plate (930) for adjusting the air inlet of the air fan, an annular cavity (940) for adjusting the air inlet of the air fan, an air outlet elbow (950) for the air fan, and an air outlet expansion pipe (960) for the air fan. The air outlet elbow (950) for the air fan is fixedly installed at the air outlet of the air inlet fan (910). The two air inlets (910) are fixedly installed at the front end of the secondary air chamber (730). The air outlet expansion pipe (960) for the air fan is fixedly installed at the rear end of the air outlet elbow (950). The handle (920) is movably mounted on the adjacent side of the air inlet fan (910); the fan air inlet adjustment annular orifice plate (930) is movably mounted between the two air inlets (910) and connected to the adjustment handle (920); the fan air inlet annular cavity (940) is fixedly mounted between the two air inlets (910) and is arranged on the inner side of the fan air inlet adjustment annular orifice plate (930) and is coaxially arranged with the fan air inlet adjustment annular orifice plate (930); the fan air outlet elbow (950) and the fan air outlet expansion pipe (960) are located inside the secondary air chamber (730).

10. A natural ventilation burner with low nitrogen emission according to claim 1, characterized in that: 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 mounted on the outside of 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) pass through the burner tank body (1) to the inside of the secondary combustion zone (800).

Images