Low-nitrogen combustion device for furnace kiln

Abstract

The utility model discloses a low-nitrogen combustion device for a furnace kiln. The low-nitrogen combustion device comprises a combustible material supply unit, a comburent supply unit, a gas mixer and a circulating combustor, the combustible supply unit and the comburent supply unit are communicated with the gas mixer 3 through pipelines; the gas mixer is fixed on a burner fixing part on the kiln; the circulating burner is arranged in the kiln; the gas mixer is connected with an inner diameter spigot of the circulating combustor; the gas mixer is connected with an external flange of the circulating combustor; and the gas mixer and the circulating combustor generate a secondary Venturi effect to guide gas which is not fully combusted in the kiln to be fully mixed and combusted. A high-temperature flue gas sampling analysis instrument is arranged in a kiln firing area, the concentration of CO, O2, NOx and the like in flue gas is analyzed on line, and according to flue gas component on-line monitoring data, a PLC controls the oxygen amount supplied by a combustible material supply unit and the combustible gas flow of a combustion-supporting material supply unit; and an oxygen-deficient combustion environment is realized in a fuel combustion process, so that the generation amount of nitrogen oxides is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of burners for kilns, and particularly relates to a low-nitrogen combustion device for furnaces and kilns. Background Art

[0002] In modern industrial kilns such as boilers, precalcining furnaces, heating furnaces, and rotary kilns, the burner is the core of the equipment. During the combustion process of industrial kilns, the emission control index of NOx is becoming increasingly strict. In the industry, staged combustion technology measures are mainly adopted to reduce the generation of NOx; staged combustion is to reduce the excess air coefficient of the primary air in the initial combustion stage of the fuel, so as to form an oxygen-deficient combustion environment in the initial combustion stage of the fuel, which is beneficial to the reduction of NOx and reduces the generation of NOx. This method of staged combustion that forms an oxygen-deficient combustion environment by reducing the excess air coefficient of the primary air (i.e., reducing the primary air volume) may change the flame shape or combustion temperature field due to the reduction of the primary air volume in practice, affecting the combustion efficiency or usage requirements of industrial kilns. Summary of the Invention

[0003] The purpose of the present invention is to solve the above problems, and provide a low-nitrogen combustion device for furnaces and kilns.

[0004] A low-nitrogen combustion device for furnaces and kilns includes: a combustible supply unit, an oxidant supply unit, a gas mixer, a circulating burner, and a PLC controller; the combustible supply unit and the oxidant supply unit are connected to the gas mixer through pipelines; the gas mixer is fixed on the burner fixing part of the furnace and kiln; the circulating burner is arranged inside the furnace and kiln; the inner diameter stop of the gas mixer is connected to the circulating burner; the outer flanges of the gas mixer and the circulating burner are connected; the gas mixer and the circulating burner generate a secondary Venturi effect to draw the unburned gas in the furnace and kiln for full mixing and combustion.

[0005] The gas mixer is provided with: a first gas inlet pipe of the gas mixer, a second gas inlet pipe of the gas mixer, a gas jet port of the gas mixer, and a first compression nozzle; the first gas inlet pipe of the gas mixer is arranged at one end of the gas mixer; the gas jet port of the gas mixer is arranged at the other end of the gas mixer; the second gas inlet pipe of the gas mixer is arranged on one side of the first gas inlet pipe of the gas mixer; the first compression nozzle is arranged inside the gas mixer; the first gas inlet pipe of the gas mixer is connected to the combustible supply unit through a pipeline; the second gas inlet pipe of the gas mixer is connected to the oxidant supply unit through a pipeline;

[0006] The combustible supply unit includes: a fuel tank, a first gas pump, a first flow sensor, and a first flow control valve; the fuel tank, the first gas pump, the first flow sensor, and the first flow control valve are connected in sequence through pipelines.

[0007] The oxidant supply unit includes: an oxygen tank, a second gas pump, a second flow sensor, and a second flow control valve; the oxygen tank, the second gas pump, the second flow sensor, and the second flow control valve are connected through pipelines.

[0008] The described gas mixer is provided with: a first gas inlet pipe of the gas mixer, a second gas inlet pipe of the gas mixer, a gas jet outlet of the gas mixer, and a first compression nozzle; the first gas inlet pipe of the gas mixer is arranged at one end of the gas mixer; the gas jet outlet of the gas mixer is arranged at the other end of the gas mixer; the second gas inlet pipe of the gas mixer is arranged on one side of the first gas inlet pipe of the gas mixer; the first compression nozzle is arranged inside the gas mixer; a first negative pressure chamber and a first mixing throat section are arranged inside the gas mixer; the nozzle opening of the first compression nozzle is arranged at the junction of the first negative pressure chamber and the first mixing throat section; the first gas inlet pipe of the gas mixer is connected to the first flow control valve through a combustible material delivery pipe; one end of the second gas inlet pipe of the gas mixer is provided with an access pipe connection part, and the access pipe connection part is connected to the second flow control valve through an oxidant delivery pipe; the other end of the second gas inlet pipe of the gas mixer is connected to the first negative pressure chamber of the gas mixer.

[0009] The nozzle opening inner diameter of the described first compression nozzle is smaller than the inner diameter of the first gas inlet pipe of the gas mixer.

[0010] The described circulating burner is provided with a first burner air inlet, a second burner air inlet, a burner gas jet outlet, and a second compression nozzle; the first burner air inlet and the burner gas jet outlet are respectively arranged at both ends of the circulating burner, and the second burner air inlet is arranged on the side of the circulating burner; the second compression nozzle is arranged inside the circulating burner; a second negative pressure chamber and a second mixing throat section are arranged inside the circulating burner; the nozzle opening of the second compression nozzle is arranged at the junction of the second negative pressure chamber and the second mixing throat section; one end of the second burner air inlet is in the firing area of the kiln; the other end of the second burner air inlet is connected to the second negative pressure chamber.

[0011] The nozzle opening inner diameter of the described second compression nozzle is smaller than the inner diameter of the first burner air inlet; the inner diameter of the burner gas jet outlet is smaller than the inner diameter of the first burner air inlet.

[0012] The high-temperature flue gas sampling and analysis instrument is arranged in the tail flue chamber of the kiln; the PLC controller is arranged outside the kiln; the first gas pump, the first flow sensor, the first flow control valve, the second gas pump, the second flow sensor and the second flow control valve, and the high-temperature flue gas sampling and analysis instrument are electrically connected to the PLC controller.

[0013] The present technical solution provides a low-nitrogen combustion device for a furnace, comprising: a combustible supply unit, an oxidant supply unit, a gas mixer, and a circulating burner; the combustible supply unit and the oxidant supply unit are connected to the gas mixer through pipelines; the gas mixer is fixed to the burner fixing part on the furnace; the circulating burner is arranged inside the furnace; the inner diameter stop of the gas mixer and the circulating burner are connected; the outer flanges of the gas mixer and the circulating burner are connected; the gas mixer and the circulating burner generate a secondary Venturi effect to draw in the unburned gas in the furnace for full mixing and combustion. A high-temperature flue gas sampling and analysis instrument is arranged in the firing area of the furnace to online analyze the concentrations of CO, O2, NOx, etc. in the flue gas. According to the online monitoring data of the flue gas composition, the PLC controller controls the oxygen supply of the combustible supply unit and the flow rate of the combustible gas of the oxidant supply unit; an oxygen-deficient combustion environment is achieved during the fuel combustion process to reduce the generation amount of nitrogen oxides. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is the overall schematic diagram of a low-nitrogen combustion device for a furnace;

[0015] Figure 2 is the schematic diagram of the burner of a low-nitrogen combustion device for a furnace;

[0016] Figure 3 is the schematic diagram of the structure of the gas mixer of a low-nitrogen combustion device for a furnace;

[0017] Figure 4 is the schematic diagram of the structure of the circulating burner of a low-nitrogen combustion device for a furnace;

[0018] Figure 5 is the schematic diagram of the principle of a low-nitrogen combustion device for a furnace;

[0019] In the figure: 1. Combustible supply unit, 11. Fuel tank, 12. First gas pump, 13. First flow sensor, 14. First flow control valve, 2. Oxidant supply unit, 21. Oxygen tank, 22. Second gas pump, 23. Second flow sensor, 24. Second flow control valve, 3. Gas mixer, 31. First intake pipe of the gas mixer, 311. Connecting external thread, 321. Access pipe connecting part, 332. Gas mixer connecting flange, 32. Second intake pipe of the gas mixer, 33. Gas mixer jet nozzle, 331. Connecting pipe concave stop, 332. Gas mixer connecting flange, 34. First compression nozzle, 4. Circulating burner, 41. First intake port of the burner, 411. Connecting pipe convex stop, 412. Circulating burner connecting flange, 42. Second intake port of the burner, 43. Burner jet nozzle, 44. Second compression nozzle, 5. PLC controller, 9. Furnace, 91. Burner fixing part. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following will further clearly and completely describe the technical solution in combination with the attached drawings of the present technical solution. The described embodiments are only a part of the technical solution, rather than all the embodiments. Based on the present technical solution, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present utility model. Embodiment

[0021] See Figures 1 to 5 As shown, a low-nitrogen combustion device for a furnace includes: a combustible supply unit 1, an oxidant supply unit 2, a gas mixer 3, a circulating burner 4, and a PLC controller 5;

[0022] The combustible supply unit 1 and the oxidant supply unit 2 are connected to the gas mixer 3 through pipelines.

[0023] The gas mixer 3 is fixed on the burner fixing part 91 of the furnace; the circulating burner 4 is arranged in the furnace 9; the gas mixer 3 and the circulating burner 4 are flange-connected; the gas mixer 3 and the circulating burner 4 generate a secondary Venturi effect to draw and fully mix the unburned gas in the furnace for combustion.

[0024] The combustible supply unit 1 includes: a fuel tank 11, a first gas pump 12, a first flow sensor 13, and a first flow control valve 14; the fuel tank 11, the first gas pump 12, the first flow sensor 13, and the first flow control valve 14 are connected in sequence through pipelines;

[0025] The fuel tank 11 is a natural gas storage tank.

[0026] The oxidant supply unit 2 includes: an oxygen tank 21, a second gas pump 22, a second flow sensor 23, and a second flow control valve 24; the oxygen tank 21, the second gas pump 22, the second flow sensor 23, and the second flow control valve 24 are connected through pipelines.

[0027] The gas mixer 3 is a gas mixing device with a Venturi effect;

[0028] The gas mixer 3 is provided with: a first gas inlet pipe 31 of the gas mixer, a second gas inlet pipe 32 of the gas mixer, a gas jet port 33 of the gas mixer, and a first compression nozzle 34; the first gas inlet pipe 31 of the gas mixer is arranged at one end of the gas mixer 3; the gas jet port 33 of the gas mixer is arranged at the other end of the gas mixer 3; the second gas inlet pipe 32 of the gas mixer is arranged on one side of the first gas inlet pipe 31 of the gas mixer; the first compression nozzle 34 is arranged in the gas mixer 3;

[0029] The first gas mixer inlet pipe 31 is connected to the first flow control valve 14 through the combustible delivery pipe 15; the second gas mixer inlet pipe 32 is connected to the second flow control valve 24 through the combustion-supporting substance delivery pipe 25; that is, the first gas mixer inlet pipe 31 is connected to the combustible supply unit 1 through a pipeline; the second gas mixer inlet pipe 32 is connected to the combustion-supporting substance supply unit 2 through a pipeline.

[0030] The gas mixer 3 is provided with a first negative pressure chamber 35 and a first mixing throat portion 36; the nozzle of the first compression nozzle 34 is arranged at the junction of the first negative pressure chamber 35 and the first mixing throat portion 36.

[0031] The outer diameter of the first gas mixer inlet pipe 31 is provided with an external connecting thread 311; this facilitates the pipeline connection between the first gas mixer inlet pipe 31 and the first flow control valve 14.

[0032] One end of the second gas mixer inlet pipe 32 is provided with an access pipe connection portion 321; the other end of the second gas mixer inlet pipe 32 is connected to the first negative pressure chamber 35 of the gas mixer 3.

[0033] The gas mixer jet port 33 is arranged inside the furnace 9; the inner diameter of the gas mixer jet port 33 is provided with a connecting pipe concave stop 331, and the outer diameter of the gas mixer jet port 33 is provided with a gas mixer connecting flange 332.

[0034] The inner diameter of the nozzle of the first compression nozzle 34 is smaller than the inner diameter of the first gas mixer inlet pipe 31.

[0035] The circulating burner 4 is a microcirculation combustion device with a Venturi effect.

[0036] The circulating burner 4 is provided with: a first burner air inlet 41, a second burner air inlet 42, a burner jet port 43, and a second compression nozzle 44; the first burner air inlet 41 and the burner jet port 43 are respectively arranged at both ends of the circulating burner 4, and the second burner air inlet 42 is arranged on the side of the circulating burner 4; the second compression nozzle 44 is arranged inside the circulating burner 4.

[0037] The inner diameter of the first burner air inlet 41 is provided with a connecting pipe convex stop 411; the outer diameter of the first burner air inlet 41 is provided with a circulating burner connecting flange 412; the connecting pipe concave stop 331 is tightly connected to the connecting pipe convex stop 411; the gas mixer connecting flange 332 and the circulating burner connecting flange 412 are connected and locked by bolts.

[0038] The inner side of the circulating burner 4 is provided with a second negative pressure chamber 45 and a second mixing throat portion 46; the nozzle of the second compression nozzle 44 is arranged at the junction of the second negative pressure chamber 45 and the second mixing throat portion 46.

[0039] One end of the second air inlet 42 of the burner is in the firing area of the furnace 9; the other end of the second air inlet 42 of the burner is connected to the second negative pressure chamber 45;

[0040] The inner diameter of the nozzle opening of the second compression nozzle 44 is smaller than the inner diameter of the first air inlet 41 of the burner; the inner diameter of the burner jet opening 43 is smaller than the inner diameter of the first air inlet 41 of the burner.

[0041] The first gas pump 12, the first flow sensor 13, the first flow control valve 14, the second gas pump 22, the second flow sensor 23 and the second flow control valve 24 are electrically connected to the PLC controller 5.

[0042] Working principle:

[0043] With the low-nitrogen combustion device for this furnace, the combustible supply unit 1 and the combustion-supporting supply unit 2 are arranged near the furnace 9, the gas mixer 3 is fixed on the burner fixing part 91 outside the furnace; the circulating burner 4 is arranged in the furnace 9; the inner diameter stop of the gas mixer 3 and the circulating burner 4 are connected; the gas mixer 3 and the circulating burner 4 are connected by external flanges; a high-temperature flue gas sampling and analysis instrument is arranged in the firing area of the furnace 9 to online analyze the concentrations of CO, O2, NOx, etc. in the flue gas. According to the online monitoring data of the flue gas composition, the PLC controller 5 controls the oxygen flow rate provided by the second gas pump 22 and the second flow control valve 24; the PLC controller 5 controls the combustible gas flow rate of the combustible gas pump 12 and the flow control valve 14; an oxygen-deficient combustion environment is realized during the fuel combustion process to reduce the generation amount of nitrogen oxides.

Claims

1. A low nitrogen combustion device for a furnace, comprising: A combustible material supply unit (1), a combustion-supporting material supply unit (2), an aerator (3), and a circulating burner (4); characterized in that: the combustible material supply unit (1) and the combustion-supporting material supply unit (2) are connected to the aerator (3) through a pipeline; the aerator (3) is fixed to a burner fixing part (91) outside the kiln; the circulating burner (4) is arranged in the kiln (9); the aerator (3) and the circulating burner (4) are connected by inner diameter stoppers; the aerator (3) and the circulating burner (4) are connected by external flanges; the aerator (3) and the circulating burner (4) generate a secondary Venturi effect to guide the incompletely burned gas in the kiln to be fully mixed and burned.

2. The low nitrogen combustion device for furnace according to claim 1, characterized in that: The aerator (3) is provided with: a first aerator air inlet pipe (31), a second aerator air inlet pipe (32), a mixer jet port (33), and a first compression nozzle (34); the first aerator air inlet pipe (31) is arranged at one end of the aerator (3); the aerator jet port (33) is arranged at the other end of the aerator (3); the second aerator air inlet pipe (32) is arranged at one side of the first aerator air inlet pipe (31); the first compression nozzle (34) is arranged in the aerator (3); the first aerator air inlet pipe (31) is connected to the pipeline of the combustible material supply unit (1); and the second aerator air inlet pipe (32) is connected to the pipeline of the combustion-supporting material supply unit (2).

3. The low nitrogen combustion device for a furnace according to claim 2, characterized in that: The combustible material supply unit (1) comprises: a fuel tank (11), a first gas pump (12), a first flow sensor (13), and a first flow control valve (14); the fuel tank (11), the first gas pump (12), the first flow sensor (13), and the first flow control valve (14) are connected in sequence by pipelines.

4. The low nitrogen combustion device for a furnace according to claim 3, characterized in that: The combustion-supporting material supply unit (2) comprises: an oxygen tank (21), a second gas pump (22), a second flow sensor (23), and a second flow control valve (24); the oxygen tank (21), the second gas pump (22), the second flow sensor (23), and the second flow control valve (24) are connected by pipelines.

5. The low nitrogen combustion device for a kiln according to claim 4, characterized in that: The aerator (3) is provided with a first negative pressure chamber (35) and a first mixing throat section (36); the mouth of the first compression nozzle (34) is arranged at the junction of the first negative pressure chamber (35) and the first mixing throat section (36); the first air inlet pipe (31) of the aerator is connected to the first flow control valve (14) pipeline through the combustible material delivery pipe (15); one end of the second air inlet pipe (32) of the aerator is provided with an access pipe connection section (321), and the access pipe connection section (321) is connected to the second flow control valve (24) through the combustion-supporting material delivery pipe (25); the other end of the second air inlet pipe (32) of the aerator is connected to the first negative pressure chamber (35) of the aerator (3).

6. The low nitrogen combustion device for a kiln according to claim 5, characterized in that: The inner diameter of the mouth of the first compression nozzle (34) is smaller than the inner diameter of the first air inlet pipe (31) of the mixer.

7. The low nitrogen combustion device for a kiln according to claim 6, characterized in that: The circulating burner (4) is provided with a first burner air inlet (41), a second burner air inlet (42), a burner jet port (43), and a second compression nozzle (44); the first burner air inlet (41) and the burner jet port (43) are respectively arranged at two ends of the circulating burner (4), and the second burner air inlet (42) is arranged on the side of the circulating burner (4); the second compression nozzle (44) is arranged in the circulating burner (4); a second negative pressure chamber (45) and a second mixing throat (46) are arranged on the inner side of the circulating burner (4); the mouth of the second compression nozzle (44) is arranged at the junction of the second negative pressure chamber (45) and the second mixing throat (46); one end of the burner second air inlet (42) is in the firing area of ​​the kiln (9); the other end of the burner second air inlet (42) is connected to the second negative pressure chamber (45).

8. The low nitrogen combustion device for a furnace according to claim 7, characterized in that: The inner diameter of the mouth of the second compression nozzle (44) is smaller than the inner diameter of the first air inlet (41) of the burner; the inner diameter of the burner jet port (43) is smaller than the inner diameter of the first air inlet (41) of the burner.

9. The low nitrogen combustion device for a furnace according to claim 8, characterized in that: It also includes a PLC controller (5) and a high-temperature flue gas sampling and analysis instrument, wherein the high-temperature flue gas sampling and analysis instrument is arranged in the kiln firing area; the PLC controller (5) is arranged outside the kiln; a first gas pump (12), a first flow sensor (13), a first flow control valve (14), a second gas pump (22), a second flow sensor (23) and a second flow control valve (24), and the high-temperature flue gas sampling and analysis instrument are electrically connected to the PLC controller (5).

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