CN120174166A - Top-burning hot air stove - Google Patents
Top-burning hot air stove Download PDFInfo
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- CN120174166A CN120174166A CN202510443293.9A CN202510443293A CN120174166A CN 120174166 A CN120174166 A CN 120174166A CN 202510443293 A CN202510443293 A CN 202510443293A CN 120174166 A CN120174166 A CN 120174166A
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B9/00—Stoves for heating the blast in blast furnaces
- C21B9/02—Brick hot-blast stoves
- C21B9/04—Brick hot-blast stoves with combustion shaft
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B9/00—Stoves for heating the blast in blast furnaces
- C21B9/14—Preheating the combustion air
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Abstract
本申请公开的顶燃式热风炉，包括依次连通的热风混合室、燃烧室、蓄热室和冷风室，热风混合室设置于顶燃式热风炉的顶部，热风混合室上设置有二次助燃空气入口和热风出口；燃烧室与热风混合室连通，燃烧室设置有稳定火焰装置，稳定火焰装置由多个稳定火焰单元堆叠形成，各个稳定火焰单元均具有多个第一气体通道和第二气体通道，至少部分第二气体通道通过第一气体通道连通，稳定火焰单元呈蜂窝状结构；燃烧器设置于顶燃式热风炉拱顶底部，燃烧器包括一次助燃空气入口、煤气入口、煤气环道、空气环道和混合环道，混合环道通过栅格炉墙连通燃烧室；冷风室设置有冷风入口和烟气出口。本申请公开的顶燃式热风炉，能够降低氮氧化物的生成，提高燃烧效率。
The top-burning hot blast stove disclosed in the present application comprises a hot blast mixing chamber, a combustion chamber, a heat storage chamber and a cold blast chamber which are connected in sequence. The hot blast mixing chamber is arranged at the top of the top-burning hot blast stove, and a secondary combustion air inlet and a hot blast outlet are arranged on the hot blast mixing chamber; the combustion chamber is connected to the hot blast mixing chamber, and the combustion chamber is provided with a stable flame device, which is formed by stacking a plurality of stable flame units, and each stable flame unit has a plurality of first gas channels and second gas channels, and at least part of the second gas channels are connected through the first gas channels, and the stable flame unit has a honeycomb structure; the burner is arranged at the bottom of the top-burning hot blast stove arch, and the burner comprises a primary combustion air inlet, a coal gas inlet, a coal gas annulus, an air annulus and a mixing annulus, and the mixing annulus is connected to the combustion chamber through a grid furnace wall; the cold blast chamber is provided with a cold air inlet and a smoke outlet. The top-burning hot blast stove disclosed in the present application can reduce the generation of nitrogen oxides and improve combustion efficiency.
Description
Technical Field
The application relates to the technical field of hot blast stoves, in particular to a top-combustion hot blast stove.
Background
The hot blast stove is the main equipment of the blast furnace ironmaking process, and provides hot blast heating engineering for blast furnace ironmaking. A blast furnace is usually provided with three or four stoves which are operated alternately by firing and air supply cycles.
According to the arrangement structure of the hot blast stove burner, the main forms are top combustion hot blast stove, internal combustion hot blast stove and external combustion hot blast stove, and as the structure of the top combustion hot blast stove is continuously optimized and perfected, the top combustion hot blast stove gradually becomes the main configuration form of the blast furnace hot blast stove system.
Along with the technical progress of the iron and steel industry, higher requirements are put forward on energy conservation, environmental protection and low carbon of blast furnace ironmaking, and the energy conservation and high efficiency of a top combustion type hot blast stove system and low nitrogen oxide emission of combustion flue gas are important problems of the hot blast stove, so that how to reduce the concentration of nitrogen oxides in the flue gas becomes a technical problem to be solved urgently by a person skilled in the art.
Disclosure of Invention
In view of the above, the present application is directed to a top-combustion stove for reducing the concentration of nitrogen oxides in flue gas.
In order to achieve the above purpose, the present application provides the following technical solutions:
A top-firing hot blast stove comprising:
the hot air mixing chamber is arranged at the top of the top combustion type hot air furnace and is provided with a secondary combustion air inlet and a hot air outlet;
The combustion chamber is communicated with the hot air mixing chamber, and is provided with a flame stabilizing device, wherein the flame stabilizing device is formed by stacking a plurality of flame stabilizing units, each flame stabilizing unit is provided with a plurality of first gas channels and a plurality of second gas channels, and for each flame stabilizing unit, at least part of the second gas channels are communicated through the first gas channels so that each flame stabilizing unit is in a honeycomb structure;
The burner is arranged at the bottom of the vault of the top combustion type hot blast stove and comprises a primary combustion air inlet, a gas loop, an air loop and a mixing loop, wherein a plurality of gas nozzles are arranged on the gas loop, a plurality of air nozzles are arranged on the air loop, each gas nozzle and each air nozzle are communicated with the mixing loop, and the mixing loop is communicated with the combustion chamber through a grid furnace wall;
a regenerator, which is communicated with the combustion chamber;
The cold air chamber is communicated with the regenerator and is provided with a cold air inlet and a flue gas outlet.
Optionally, in the top-fired hot blast stove, for each stable flame unit, each first gas channel communicates with a portion of the second gas channels, and each first gas channel communicates with a centrally located second gas channel, such that each second gas channel communicates;
For each stable flame unit located at the same height, the second gas channel located at the center is communicated.
Optionally, in the top-fired hot blast stove, each first gas channel is U-shaped.
Optionally, in the top combustion type hot blast stove, the air loop is higher than the gas loop, the mixing loop is formed by enclosing an inner wall of the air loop and a grid furnace wall, and the grid furnace wall is provided with a plurality of grid holes for gas to pass through.
Optionally, in the top combustion type hot blast stove, the hot air mixing chamber is provided with a hot air mixing inlet, and the axis of the hot air mixing inlet and the axis of the hot air outlet are positioned at the same height.
Optionally, in the top-combustion hot blast stove, a secondary combustion air inlet is arranged at the top of the hot blast mixing chamber, and a secondary combustion air nozzle is arranged at the secondary combustion air inlet and is opposite to the flame stabilizing device.
Optionally, in the top-combustion stove, the amount of primary combustion air entering through the primary combustion air inlet is 0.5-0.8 times the total amount of combustion air, and the amount of secondary combustion air entering through the secondary combustion air inlet is 0.5-0.2 times the total amount of combustion air.
Alternatively, in the top-firing stove described above, the combustion temperature of the combustion chamber is in the range 1350 ℃ to 1410 ℃.
Optionally, in the top-combustion hot blast stove, the wall of the hot air mixing chamber, the wall of the combustion chamber, the wall of the burner and the wall of the regenerator are connected by adopting a labyrinth.
Optionally, in the top-firing hot blast stove, the burner is a ceramic burner.
According to the scheme, under the blocking effect of the grid furnace wall, coal gas and air are initially mixed in the mixing loop and then enter the combustion chamber for combustion, so that the combustion efficiency of the coal gas can be improved, the generation of nitrogen oxides in the combustion process is reduced, the flame stabilizing device is arranged to reduce the temperature of smoke, realize uniform distribution of the smoke, form short flame combustion, realize uniform distribution of combustion smoke material flow and energy flow, reduce the generation of nitrogen oxides, improve the working efficiency of the top combustion type hot blast furnace, and the primary combustion air and the secondary combustion air are respectively introduced to realize staged combustion, so that the peak temperature of the flame can be reduced, the local highest temperature of the smoke is reduced, in addition, the oxygen concentration in the smoke is reduced, the generation of nitrogen oxides is reduced, meanwhile, the flow direction of the secondary combustion air is opposite to the flow direction of the primary smoke, the reverse flow combustion is formed, the generation of the nitrogen oxides is more complete, and the combustion efficiency is improved.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a top-firing stove according to an embodiment of the present application;
FIG. 2 is a top view of a flame stabilizing device according to an embodiment of the present disclosure;
FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;
FIG. 4 is a side view of a stable flame unit disclosed in an embodiment of the application;
FIG. 5 is a flow chart of gas during the burning of the top-fired hot blast stove according to the embodiment of the application;
FIG. 6 is a flow chart of air during the supply of air to the top-firing stove according to an embodiment of the present application;
FIG. 7 is a flow chart of the combustion chamber gas during the burning of the top-fired hot blast stove according to the embodiment of the application.
Wherein 10 is a hot air mixing chamber, 11 is a secondary combustion air inlet, 12 is a hot air mixing inlet, and 13 is a hot air outlet;
20 is a combustion chamber;
30 is a burner, 31 is a primary combustion air inlet, 32 is a gas inlet, 33 is a gas loop, 34 is an air loop, and 35 is a grid furnace wall;
40 is a regenerator;
50 is a cold air chamber, 51 is a cold air inlet, 52 is a smoke outlet, and 53 is a grate;
Reference numeral 60 denotes a flame stabilizing device, 601 denotes a first gas passage, 602 denotes a second gas passage, 603 denotes a positioning hole, and 61 denotes a flame stabilizing unit.
Detailed Description
In addition to the problems mentioned in the background art, the existing top-firing stoves have the following problems:
(1) The combustion process of the top-combustion hot blast stove has the advantages of high combustion consumption, low energy conversion rate, energy waste and high smoke emission due to low combustion efficiency and low energy conversion efficiency;
(2) Due to the complex blast furnace operating conditions such as high temperature, high pressure, high oxygen enrichment and the like, abnormal damage, potential safety hazard and operation faults occur after production due to the furnace shell, the high-temperature and high-pressure pipeline and the refractory materials of key parts in the high-temperature region of the top-fired hot blast furnace, so that the wind temperature, the service life of the hot blast furnace and the safe operation are restricted.
Interpretation of related terms:
(1) The hot blast furnace is mainly configured for heating air, oxygen or gas and the like blown into the furnace by blast furnace smelting, a regenerative heating furnace is generally adopted, three or four hot blast furnaces are configured by a conventional blast furnace, and the hot blast furnace alternately works to heat the air, the oxygen or the gas.
(2) And a top combustion type hot blast stove, wherein the top of the hot blast stove is provided with a combustion device.
(3) The burner mixes the coal gas and the combustion air into the combustion device in the furnace according to the combustion mechanism.
(4) The hot-blast stove is used for burning, the hot-blast stove heat accumulation is that high-temperature flue gas generated by burning coal gas by a burner heats heat accumulation body checker bricks in the hot-blast stove for heat accumulation, and the hot-blast stove heat accumulation process is called as hot-blast stove burning.
(5) The process of heating and air supplying by the hot blast stove and using the heat stored by the heat accumulator checker bricks in the burning stage for heating air by the hot blast stove is called hot blast stove heating and air supplying.
The main factors influencing the generation of nitrogen oxides in the combustion process are the combustion temperature, the residence time of the flue gas in the high temperature zone, the concentration of various components in the flue gas and the degree of mixing, so that the generation of nitrogen oxides in the combustion process can be reduced by changing the air-fuel ratio, the temperature of combustion air, the degree of cooling of the combustion zone and the shape design of the burner. The application discloses a top-combustion hot blast stove, which starts from reducing the local highest temperature of combustion flue gas and the concentration of oxygen in the flue gas so as to reduce the concentration of nitrogen oxides in the flue gas.
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
As shown in fig. 1, the embodiment of the application discloses a top-combustion hot blast stove, which comprises a hot blast mixing chamber 10, a combustion chamber 20, a burner 30, a regenerator 40 and a cold blast chamber 50, wherein the hot blast mixing chamber 10, the combustion chamber 20, the regenerator 40 and the cold blast chamber 50 are sequentially arranged from the top of the top-combustion hot blast stove and are sequentially communicated, and the burner 30 is arranged around the combustion chamber 20 and the regenerator 40.
Specifically, the hot air mixing chamber 10 is arranged at the top of the top combustion type hot air furnace, the hot air mixing chamber 10 is provided with a secondary combustion air inlet 11 and a hot air outlet 13, and the secondary combustion air inlet 11 is used for introducing secondary combustion air. The combustion chamber 20 is communicated with the hot air mixing chamber 10, the combustion chamber 20 is provided with a flame stabilizing device 60, the flame stabilizing device 60 is formed by stacking a plurality of flame stabilizing units 61, as shown in fig. 2-4, each flame stabilizing unit 61 is provided with a plurality of first gas channels 601 and a plurality of second gas channels 602, and for each flame stabilizing unit 61, at least part of the second gas channels 602 are communicated through the first gas channels 601, so that each flame stabilizing unit 61 is in a honeycomb structure. The corresponding second gas passages 602 of each of the stacked flame stabilizing units 61 are in communication in sequence. The bottom of the flame stabilizing device 60 communicates with the top of the regenerator 40, and in particular, the second gas passage 602 communicates with the checker holes of the regenerative checker bricks of the regenerator 40. The cold air chamber 50 is provided with a cold air inlet 51 and a flue gas outlet 52, and a grate 53 and support columns are arranged in the cold air chamber 50.
Preferably, the second gas channel 602 is arranged in a vertical direction (i.e. in the direction extending from the top to the bottom of the top-fired stove), the first gas channel 601 being arranged perpendicular or inclined to the second gas channel 602.
The burner 30 is arranged at the bottom of the dome of the top-fired hot blast stove, i.e. the burner 30 is arranged around part of the wall of the combustion chamber 20 and part of the wall of the regenerator 40. Specifically, the burner 30 includes a primary combustion air inlet 31, a gas inlet 32, a gas ring 33, an air ring 34, and a mixing ring, a plurality of gas nozzles circumferentially arranged are provided on the gas ring 33, a plurality of air nozzles circumferentially arranged are provided on the air ring 34, each gas nozzle and each air nozzle are communicated with the mixing ring, and the mixing ring is communicated with the combustion chamber 20 through a grid furnace wall 35.
The top combustion type hot blast stove disclosed by the embodiment of the application is characterized in that under the blocking action of the grid furnace wall 35, coal gas and air are initially mixed in a mixing loop and then enter a combustion chamber 20 for combustion, so that the combustion efficiency of the coal gas can be improved, the generation of nitrogen oxides in the combustion process is reduced, the arrangement of a stable flame device 60 can reduce the temperature of smoke, realize uniform distribution of the smoke, form short flame combustion, realize uniform distribution of the material flow and the energy flow of the combustion smoke, reduce the generation of nitrogen oxides, improve the working efficiency of the top combustion type hot blast stove, respectively introduce primary combustion air and secondary combustion air, realize staged combustion, reduce the peak temperature of flame, reduce the local maximum temperature of the smoke, further reduce the oxygen concentration in the smoke, reduce the generation of nitrogen oxides, and simultaneously, the flow direction of the secondary combustion air is opposite to that of the primary smoke, form countercurrent combustion, the generation of the nitrogen oxides is more complete, and the utilization rate of the fuel is improved.
In the combustion stage of the top combustion type hot blast stove, as shown in fig. 5 and 7, black arrows in the drawings indicate the flow direction of air, red arrows indicate the flow direction of gas and smoke, the gas enters a gas loop through a gas inlet 32 and is sprayed out through a gas nozzle, primary combustion air enters an air loop 34 through a primary combustion air inlet 31 and is sprayed out through an air nozzle, under the blocking effect of a grid furnace wall 35, the gas and the primary combustion air enter a combustion chamber 20 through the grid furnace wall 35 after being primarily mixed in the mixing loop, the gas and the primary combustion air are sprayed and distributed along the surface of a stable flame device 60, incomplete combustion occurs at the same time, part of smoke generated by primary combustion (called primary smoke) enters the stable flame device 60 through a first gas channel 601 of the stable flame device 60, heat is transferred to the stable flame device 60, the temperature of the front end of the flame can be reduced, part of primary smoke is more uniformly distributed, the mixed gas and the mixed gas of the gas and the primary combustion air can be preheated along the surface of the stable flame device 60, and the combustion efficiency is improved.
The secondary combustion air flows downwards through the hot air mixing chamber 10 through the secondary combustion air inlet 11 to enter the combustion chamber 20, the flow direction of the secondary combustion air is opposite to that of the primary flue gas, part of the secondary combustion air is further mixed and combusted with the primary flue gas (including residual coal gas and incompletely generated gas of the flue gas) on the surface of the stable flame device 60, part of the secondary combustion air enters the stable flame device 60 through the second gas channel 602 and is mixed and combusted with the incompletely combusted gas of the primary combustion in the stable flame device 60, and a combustion mode that the secondary combustion air and the primary combustion air are wrapped with the coal gas is formed, so that the coal gas and the air are mixed more fully. The secondary flue gas generated by the combustion enters the regenerator 40 downwardly through the second gas channel 602 and then enters the cold plenum 50 and exits the flue gas outlet 52. The top combustion type hot blast stove disclosed by the embodiment of the application can promote the mixing of coal gas and air, and can obviously improve the sufficiency of combustion, thereby improving the combustion efficiency and the thermal efficiency, reducing the pollutant emission, reducing the temperature of flue gas, enabling the flue gas to be uniformly distributed and reducing the generation of nitrogen oxides.
In the stage of supplying air in the top-firing hot blast stove, as shown in fig. 6, cold air is introduced from the cold air inlet 51, sequentially passes through the cold air chamber 50, the regenerator 40 and the flame stabilizing device 60, part of the cold air flows upward through the second air passage 602 of the flame stabilizing device 60, part of the cold air enters the combustion chamber 20 through the first air passage 601, then continues to flow upward into the hot air mixing chamber 10, and after being heated in the regenerator 40 and the flame stabilizing device 60, the cold air becomes hot air and flows out from the hot air outlet 13 of the hot air mixing chamber 10. Compared with the existing top-combustion hot blast stove, the hot air directly enters the top of the hot air mixing chamber 10 and flows out, part of hot air is discharged through the hot air outlet 13, part of hot air continues to flow upwards to reach the vault and then turns back to flow out from the hot air outlet 13, and the vault has a local high-temperature area, so that the accelerated ageing or damage of refractory materials is easily caused. In addition, the flame stabilizing device 60 can further heat the cool air by utilizing the heat of the flue gas, and can reduce the height of the regenerator 40.
Further, the regenerator 40 includes a high temperature heat storage section and a low temperature heat storage section, and the materials of the heat storage checker bricks of the high temperature heat storage section and the low temperature heat storage section are the same or different.
Further, as shown in fig. 2 and 3, for each stable flame unit 61, each first gas passage 601 communicates with a portion of the second gas passage 602, and each first gas passage 601 communicates with the centrally located second gas passage 602, such that each second gas passage 602 communicates, forming a honeycomb structure. That is, all of the first gas channels 601 may be concentrated to the second gas channel 602 that stabilizes the center point of the flame unit 61, with each first gas channel 601 centered as a centrally located second gas channel 602. It should be noted that the stable flame units 61 are preferably porous lattice bricks, the second gas channels 602 herein refer to existing lattice holes of the porous lattice bricks, and extend along the direction from top to bottom (vertical direction) of the top-fired hot blast stove, the channels that are centered on the second gas channels 602 and are communicated with the second gas channels 602 on the same line are first gas channels 601, preferably, the first gas channels 601 are perpendicular to the second gas channels 602, and it should be noted that, for each stable flame unit 61, each first gas channel 601 may be located at the same height, or may include a plurality of channels located at different heights.
As shown in fig. 2-4, each layer of the stable flame units 61 shown in the figures includes three, in total, two layers, wherein each stable flame unit 61 includes six first gas passages 601, and each first gas passage 601 communicates through a central second gas passage 602. Preferably, for the stacked stable flame units 61, the centers of the second gas channels 602 are collinear, and for convenience of positioning, positioning holes 603 are provided on each stable flame unit 61. The shape of the perforated checker brick shown in the drawings is hexagonal, and here, the shape of the perforated checker brick is merely an example, and other shapes such as rectangular may be adopted, and the cross-sectional shapes of the first gas passage 601 and the second gas passage 602 may be circular, rectangular, elliptical or circular arc, and the specific shape is not particularly limited.
Further, for convenience of processing, each first gas channel 601 is U-shaped.
Further, in order to optimize the air flow distribution, the flame stabilizing device 60 is preferably in a shape of a circular truncated cone, and this structure can guide the primary flue gas to flow from the wider bottom to the narrower top, so as to form a gradually contracted flow channel, and mix with the secondary combustion air from the top of the top combustion type hot blast stove for combustion, so that the air flow can be accelerated, and the combustion efficiency can be improved.
Further, as shown in fig. 1, the air ring 34 is higher than the gas ring 33, i.e. the air ring 34 is located above the gas ring 33, and the air can be more uniformly and downwardly diffused and fully mixed with the gas to promote complete combustion. Specifically, the air ring 34 is a circular ring chamber extending along the side wall of the combustion chamber 20, the gas ring 33 is a circular ring chamber extending along the side wall of the regenerator 40, the plurality of gas nozzles are arranged at intervals along the circumference of the gas ring 33, preferably in a uniform arrangement, and the plurality of air nozzles are arranged at intervals along the circumference of the air ring 34, preferably in a uniform arrangement, so that the gas and air inlet rate can be increased, and the mixing effect of the gas and the air can be improved. The mixing loop is formed by enclosing the inner wall of the air loop 34 and the grid furnace wall 35, and the grid furnace wall 35 is provided with a plurality of grid holes for gas to pass through, preferably, the grid holes are uniformly distributed, the uniformly distributed grid holes are favorable for fully mixing the gas and the air to form uniform premixed gas, so that the flame length can be shortened, and short flame combustion can be formed. The gas enters the combustion chamber 20 along the conical spiral swirl, so that the gas flow distribution can be improved, and the gas flow is prevented from being concentrated in a certain area, thereby improving the combustion uniformity.
The formation of nitrogen oxides in the combustion flue gas includes three types of thermal nitrogen oxides, rapid nitrogen oxides and fuel nitrogen oxides, and the nitrogen oxides generated in the combustion process are mainly thermal nitrogen oxides and part of rapid nitrogen oxides. The thermal nitrogen oxide is generated by the reaction of nitrogen and oxygen at high temperature and mainly occurs in a flame high-temperature area, and the rapid nitrogen oxide is generated by the reaction of nitrogen and hydrocarbon free radicals in a fuel-rich area at the flame front. The short flame combustion can reduce the residence time of combustion products in a high temperature region, so that the generation of thermal nitrogen oxides is inhibited, and the short flame is realized by mixing coal gas and air, so that local high temperature peaks can be reduced, and the generation of the thermal nitrogen oxides is reduced.
In order to increase the mixing degree of the gas and the primary combustion air, a grid plate may be further provided on the grid furnace wall 35, and the grid holes of the grid plate are communicated with the grid holes of the grid furnace wall 35. Specifically, the aperture of the grid holes of the grid plate may be smaller than the aperture of the grid holes of the grid furnace wall 35, or the aperture of the grid holes of the grid plate may be larger than the aperture of the grid holes of the grid furnace wall 35.
Further, in order to enable the mixed gas after preliminary mixing of the gas and the primary combustion air to form a certain injection angle, in some specific embodiments, the grid furnace wall 35 is arranged obliquely at a preset angle to the axis of the combustion chamber 20.
Further, in order to make the temperature of the hot air discharged from the hot air outlet 13 reach a preset temperature, the hot air mixing chamber 10 is provided with a hot air mixing inlet 12 as shown in fig. 7, the hot air mixing inlet 12 is used for introducing cold air, and the axis of the hot air mixing inlet 12 and the axis of the hot air outlet 13 are positioned at the same height so that the cold air can be mixed with the hot air, so that the hot air is rapidly cooled, and the temperature of the hot air discharged from the hot air outlet 13 meets the preset temperature.
Further, as shown in fig. 7, in order to make the flow direction of the secondary combustion air flow in the opposite direction to the flow direction of the gas, to promote the sufficient combustion, a secondary combustion air inlet 11 is provided at the top of the hot air mixing chamber 10, and the secondary combustion air inlet 11 is provided with a secondary combustion air nozzle, which is provided opposite to the flame stabilizing device 60. The secondary combustion air is sprayed to the top surface of the flame stabilizing device 60, and can be uniformly distributed along the top surface plane of the flame stabilizing device 60, part of the secondary combustion air burns with the primary flue gas on the surface of the flame stabilizing device 60, and part of the secondary combustion air enters the flame stabilizing device 60 through the second gas channel 602 to burn with the primary flue gas. Meanwhile, the secondary combustion air passes through the hot air mixing chamber 10, so that the top of the top-combustion type hot air furnace can be cooled, the service temperature of the top-combustion type hot air furnace under the working condition of the refractory material is integrally reduced, and the service life of the refractory material is prolonged. The primary combustion air and the secondary combustion air can be sprayed into the top combustion type hot blast stove at the same time, or can be sprayed into the top combustion type hot blast stove according to a preset time and sequence, or the secondary combustion air is introduced when the oxygen concentration measured by a concentration measuring element arranged in the combustion chamber or the concentration of a product generated by combustion reaches a preset value.
Further, the gas injection speed is preferably 25m/s to 50m/s, the primary combustion air injection speed is preferably 30 m/s to 55m/s, and the secondary combustion air injection speed is preferably 40m/s to 55m/s.
Further, in the stage of burning the top-fired hot blast stove, the amount of primary combustion air entering through the primary combustion air inlet 31 is 0.5 to 0.8 times the total amount of combustion air, the amount of secondary combustion air entering through the secondary combustion air inlet 11 is 0.5 to 0.2 times the total amount of combustion air, specifically, when the amount of primary combustion air is 0.5 times the total amount of combustion air, the amount of secondary combustion air is 0.5 times the total amount of combustion air, and when the amount of primary combustion air is 0.8 times the total amount of combustion air, the amount of secondary combustion air is 0.2 times the total amount of combustion air. In the primary combustion zone (combustion chamber 20) the oxygen concentration is low, the combustion process is controlled by the mixing process of the gas and the oxygen, and the oxygen first undergoes combustion reaction with the gas because the combustion reaction activation energy of the oxygen and the gas is lower than the reaction activation energy of the oxygen and nitrogen atoms. Only when oxygen is left, the reaction of oxygen atoms and nitrogen atoms is carried out to generate nitrogen oxides, so that the temperature in the furnace can be uniform as long as the distribution of the oxygen concentration in the furnace is reasonably controlled, local hot spots are not generated, and the highest temperature is restrained. Through simulation and experiments, when the ratio of the primary combustion air to the secondary combustion air meets the ratio, the generation amount of nitrogen oxides is small. The secondary combustion is performed at the top of the flame stabilizing device 60 and inside thereof, and the excess air is introduced from the secondary combustion air inlet 11 so that the total excess air ratio is greater than 1, thereby completely combusting the incompletely combusted gas to reduce the generation of nitrogen oxides.
Further, in order to promote sufficient combustion of the gas and the air, the average combustion temperature of the combustion chamber 20 is in the range of 1350 ℃ to 1410 ℃, and a temperature measuring element is provided in the combustion chamber 20 to measure the combustion temperature of the combustion chamber 20. The applicant found through simulation and experiment that when the dome temperature of the top combustion stove exceeds 1360 ℃, the generation rate of nitrogen oxides starts to increase, when the temperature exceeds 1420 ℃, the generation amount of nitrogen oxides increases sharply, and the longer the reaction time of nitrogen and oxygen under high temperature conditions, the generation amount of nitrogen oxides increases sharply, so that by controlling the combustion temperature of the combustion chamber 20 to meet the above temperature conditions, the generation amount of nitrogen oxides can be reduced.
Further, in order to ensure that the hot air mixing chamber 10, the combustion chamber 20, the burner 30 and the regenerator 40 are not affected by expansion, and also ensure good tightness, the wall of the hot air mixing chamber 10, the wall of the combustion chamber 20, the wall of the burner 30 and the wall of the regenerator 40 are connected by adopting a labyrinth.
Further, the burner 30 is an annular rectangular ceramic burner, and the ceramic burner has good thermal stability at high temperature, can bear thermal shock of rapid heating and cooling, reduces cracks or damages caused by thermal stress, and the combustion capacity of the burner 30 is preferably 20 MW-200 MW.
It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.
The terms "first" and "second" are used below for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.
The principles and embodiments of the present application have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the core concepts of the application. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the application can be made without departing from the principles of the application and these modifications and adaptations are intended to be within the scope of the application as defined in the following claims.
Claims (10)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510443293.9A CN120174166A (en) | 2025-04-09 | 2025-04-09 | Top-burning hot air stove |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510443293.9A CN120174166A (en) | 2025-04-09 | 2025-04-09 | Top-burning hot air stove |
Publications (1)
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|---|---|
| CN120174166A true CN120174166A (en) | 2025-06-20 |
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|---|---|---|---|
| CN202510443293.9A Pending CN120174166A (en) | 2025-04-09 | 2025-04-09 | Top-burning hot air stove |
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| CN (1) | CN120174166A (en) |
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