1. A device capable of effectively reducing emission of sintering NOx comprises a sintering preheating drying furnace (1) and a sintering ignition furnace (2), and is characterized in that: the furnace top of the sintering preheating drying furnace (1) is provided with a precast beam (8), and a preheating air channel (10) is arranged between the furnace top of the sintering preheating drying furnace (1) and the precast beam (8); the top of the sintering preheating drying furnace (1) is provided with preheating curtain type nozzles (7) among the preheating air channels (10), and the preheating curtain type nozzles (7) are respectively connected with the gas pipeline (4) and the primary air pipeline (5); the bottom of sintering preheating drying furnace (1) is equipped with steel support (3), and the bottom of steel support (3) bears on the support travelling wheel (12) of both sides, sintering preheating drying furnace (1) strides the top of putting up in the sintering platform truck, 1 of its length and mounted position and sintering convulsions bellows (14) 1^#And 2^#The air boxes correspond to each other; the sintering ignition furnace (2) is positioned at one side of the sintering preheating drying furnace (1), the sintering ignition furnace (2) is spanned above the sintering trolley through a steel bracket (3) and a supporting travelling wheel (12), and the length and the installation position of the sintering ignition furnace and 3 of a sintering air draft air box (14)^#And 4^#The air boxes correspond to each other; an ignition curtain type burner (11) is arranged at the top of the sintering ignition furnace (2), and the ignition curtain type burner (11) is respectively connected with the gas pipeline (4), the primary air pipeline (5) and the secondary air pipeline (6).

2. The apparatus of claim 1, wherein the means for effectively reducing sintered NOx emissions comprises: the height of the hearth of the sintering preheating drying furnace (1) is 600-800mm away from the upper edge (13) of the sintering trolley.

3. The apparatus of claim 1, wherein the means for effectively reducing sintered NOx emissions comprises: the length of the preheating air channel (10) is equal to the width of the sintering trolley.

4. The apparatus of claim 1, wherein the means for effectively reducing sintered NOx emissions comprises: the preheated air of the preheated air channel (10), the primary air pipeline (5) and the secondary air pipeline (6) is taken from the hot waste gas in the middle-high temperature region of the sintering circular cooler or the belt cooler, and the temperature is 350-450 ℃.

5. The apparatus of claim 1, wherein the means for effectively reducing sintered NOx emissions comprises: the height of the hearth of the sintering ignition furnace (2) is 350mm away from the upper edge (13) of the sintering trolley.

6. The apparatus of claim 1, wherein the means for effectively reducing sintered NOx emissions comprises: and corresponding ignition holes (9) are formed in one side of the upper edge (13) of the sintering trolley of the preheating curtain type burner (7) and the ignition curtain type burner (11).

Background

The sintering process is an important process in the production chain of the iron and steel integrated enterprises, and the demand for iron ore is increasing with the rapid development of the iron and steel industry. However, direct-fired iron making has become less and less rich, necessitating significant mining and use of lean ore resources. The direct smelting of lean ores in the furnace can deteriorate the production index of the blast furnace. The sintering machine is used for agglomerating the iron ore powder. The metallurgical property of the sintered mineral is greatly improved, and great economic benefit is brought to blast furnace production. Moreover, the sintering method has strong adaptability to raw materials, and not only can produce sintered ores by using iron ore powder, but also can treat industrial iron-containing miscellaneous materials.

However, the sintering process provides good ore for blast furnace and brings great environmental pollution. Wherein the SO discharged in the sintering process is₂About SO in steel production₂85% of the total emission; the NOx emission amount accounts for more than 50% of the total emission amount in industrial production; dioxin accounts for about 17.6 percent of the total discharge capacity; meanwhile, the discharge amount of the ultrafine dust also accounts for a considerable proportion.

The research and application of preheating and drying of the sintering mixture in China are relatively few, and the particles are dried after high-moisture granulation in the prior art, so that the utilization coefficient of the sintering machine can be improved. The main conclusions obtained are as follows: 1) by adopting a high-moisture granulation combined drying treatment process, the moisture evaporation time of a wet zone of a sinter bed can be shortened, so that the sintering flame front speed is effectively improved; 2) the high-moisture granulation is combined with the drying treatment process, and the moisture of the sintering mixture is reduced, so that the burning efficiency of the coke powder is improved, the heat generated in a sintering material layer is increased, and the finished product rate of the sintering ore can be improved; 3) when a high moisture granulation is used in combination with a drying process, the critical moisture needs to be set to avoid collapse in the dry state after granulation.

The prior art is mainly used for treating the tail end of sintering flue gas, has huge investment cost and operation cost, is easy to generate secondary pollution, and is difficult to realize the cooperative emission reduction of various pollutants. Or certain process emission reduction is carried out, basically a single pollutant process suppression emission reduction mode is adopted, and the method for simultaneously carrying out the coordinated emission reduction on the pollutants is less and is difficult to be directly suitable for the sintering plant with the shaped process equipment flow.

Through patent search, a part of related technical schemes are disclosed. Such as: a device and a method for removing sulfur dioxide and dioxin from sintering flue gas (CN201110173596.1), a system and a process for the coordinated treatment of desulfurization and denitrification of sintering pellet flue gas (CN201410072049.8), a sintering flue gas desulfurization, dioxin removal and dust removal integrated device (CN201310713790.3) without electric dust removal, and the like; although the technical scheme can realize synchronous emission reduction of SO2 and dioxin, the technical scheme belongs to terminal treatment, is absorption type emission reduction with large smoke volume and low content, does not realize online pollutant emission reduction in the sintering process, has huge investment and operation cost for pollutant emission reduction, and can inhibit the pollutant emission reduction of steel enterprises, greatly increase the emission reduction burden of the enterprises, and secondary pollution is very easily generated by emission reduction products.

In addition, there is already concern about online SO during sintering₂The technical scheme related to emission reduction is disclosed as follows: an on-line desulfurization method for sintering process (CN99111573.2), an iron ore sintering process desulfurization method based on addition of an inhibitor (CN201110022407.0), an on-line desulfurization method for sintering process (CN201410109130.9), etc.; according to the technical scheme, the ammonia substance is added into the sintering material layer, so that the online desulfurization in the sintering process is realized. Related technical schemes have also been disclosed for online dioxin emission reduction in the sintering process: the technical scheme is that ammonia substances are added into a sinter bed to be used as a reducing agent in the sintering process of iron ore (CN201110180658.1), a novel energy-saving and emission-reducing sintering machine system and a sintering method (CN201310167718.5) and the likeThe additive is generated for the dioxin, so that the emission reduction of the dioxin in the sintering process is realized. The disclosed technical scheme provides three ammonia additives, (1) the ammonia additives are all mixed and added into the sinter layer, (2) the ammonia additives are added at a certain height of the sinter layer, and (3) the ammonia additives are sprayed on the sinter layer.

Chinese patent CN104694742B discloses a sintering process SO based on layered material preparation and distribution₂The invention relates to a dioxin cooperative emission reduction method, which comprises the following specific scheme: sintering the mixed materials to prepare a sintered mixed material and a mixed material with an additive, wherein the additive is urea particles; step two, sintering and distributing, namely paving a bottom material layer on the sintering trolley; paving the sintering mixture on the bedding material layer to form a first mixture layer; then laying the mixture with the additive on the first mixed material layer to form a synergistic emission reduction material layer; then paving the sintering mixture on the synergistic emission reduction material layer to form a second mixture layer; and step three, collecting and treating the smoke in a centralized manner, and collecting the smoke in an air box at the middle rear part of the trolley into a bag-type dust collector through a booster pump.

Patent CN201014885Y discloses a dry economizer that preheats of sinter mixture, it relates to a dry economizer that preheats of sinter mixture, it comprises pipeline 1, the hot-blast cover 2 of charge level, sintering machine platform truck 3, bellows 4, flap valve 5 and flue 6, pipeline 1 one end draws from the hot exhaust gas pipe of sintering ring cold machine, another communicates with hot-blast cover 2, hot-blast cover 2 covers on the mixture bed of material of sintering machine platform truck 3, platform truck 3 sits on bellows 4, flap valve 5 is connected between bellows 4 and flue 6, flue 6 links to each other with main air exhauster. Hot exhaust gas passes through the hot air hood 2 from the pipeline 1, is dried and preheated through a material layer in the sintering machine trolley 3, and is discharged from the flue 6 through the flap valve 5 and the air box 4. Its advantages are use of waste heat, saving energy, low cost, high air permeability and temp of mixed sinter material, and high output per machine hour. In the patent, because the heat source is unstable due to the fluctuation of the production process and the hot air uniformity in the hot air hood is difficult to realize by the device, the drying and preheating effects of the materials of the sintering material layer covered by the heat source are influenced, so the effects of improving the air permeability and the productivity are limited.

Disclosure of Invention

The present invention aims to provide a device which can effectively reduce the emission of sintering NOx so as to solve the problems in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme: a device capable of effectively reducing the emission of sintering NOx comprises a sintering preheating drying furnace and a sintering ignition furnace, wherein the top of the sintering preheating drying furnace is provided with a precast beam, and a preheating air channel is arranged between the top of the sintering preheating drying furnace and the precast beam; the top of the sintering preheating drying furnace is provided with preheating curtain type nozzles among the preheating air channels, and the preheating curtain type nozzles are respectively connected with a gas pipeline and a primary air pipeline; the bottom of the sintering preheating drying furnace is provided with a steel support, the bottom of the steel support bears the weight of the supporting travelling wheels on two sides, the sintering preheating drying furnace is spanned above the sintering trolley, and the length and the installation position of the sintering preheating drying furnace and 1 of a sintering air draft bellows are arranged^#And 2^#The air boxes correspond to each other; the sintering ignition furnace is positioned on one side of the sintering preheating drying furnace, the sintering ignition furnace is spanned above the sintering trolley through a steel bracket and a supporting travelling wheel, and the length and the installation position of the sintering ignition furnace and 3 of the sintering air draft bellows^#And 4^#The air boxes correspond to each other; and the top of the sintering ignition furnace is provided with an ignition curtain type burner which is respectively connected with the gas pipeline, the primary air pipeline and the secondary air pipeline.

Preferably, the height of the hearth of the sintering preheating drying furnace is 600-800mm away from the upper edge of the sintering trolley.

Preferably, the length of the preheating air channel is equal to the width of the sintering trolley.

Preferably, the preheated air of the preheated air channel, the primary air pipeline and the secondary air pipeline is taken from hot waste gas in the middle-high temperature region of the sintering circular cooler or the belt cooler, and the temperature of the preheated air is 350-450 ℃.

Preferably, the height of the hearth of the sintering ignition furnace is 350mm away from the upper edge of the sintering trolley.

Preferably, the preheating curtain type burner and the ignition curtain type burner are provided with corresponding ignition holes at one side of the upper edge of the sintering trolley.

Compared with the prior art, the invention has the following beneficial effects:

1. the device can effectively reduce the emission of NOx in sintering, and can meet the requirements of sintering, preheating and drying of a sintering mixture and a normal ignition process.

2. The device capable of effectively reducing the emission of the sintering NOx can realize the utilization of the hot waste gas of the medium-high temperature region generated by the sintering circular cooler or the belt cooler in the sintering production process, and is used for preheating, drying and igniting the sintering mixture.

3. This device that can effectively reduce sintering NOx and discharge preheats the drying furnace simultaneously and can realize automatic afterburning technique to reach sintering mixture and preheat dry stability and homogeneity.

4. According to the device capable of effectively reducing the emission of the sintering NOx, as the sintering mixture is preheated and dried in advance, the material temperature of the sintering mixture is obviously improved, and when the sintering ignition furnace ignites, low-temperature ignition control can be realized, so that the normal ignition process requirements of sintering production can be met, and the gas consumption of the device is obviously reduced compared with that of the traditional ignition holding furnace.

5. According to the device capable of effectively reducing the emission of the sintering NOx, the sintering mixture is preheated and dried, the temperature of the material layer is gradually increased, the moisture of the material layer is evaporated into steam, the heat transfer speed of the sintering material layer is accelerated, the width of an over-wet belt is reduced, the improvement of the thermal state air permeability in the sintering process is facilitated, and the vertical sintering speed and the utilization coefficient are improved; meanwhile, the improvement of thermal state air permeability strengthens the oxidizing atmosphere in the sintering process, and is beneficial to the generation of high-quality calcium ferrite binding phase, thereby improving the quality of sintered ore; meanwhile, the cooling speed is relatively reduced, the generation of amorphous structure glass is reduced, the microstructure of the sintered ore is more reasonable, the sintered ore forming condition is improved, the silicate and ferrite bonded phase is more sufficiently crystallized, more bonded phases with higher strength are formed, the strength of the sintered ore is increased, and the yield is increased.

6. The device can effectively reduce the emission of NOx in sinteringAfter partial drying, the moisture content of the mixture is reduced, and the temperature of the mixture is raised, so that the stroke of an over-wet belt in the sintering process is reduced, the thermal state air permeability in the sintering process is improved, the air throughput is increased, and the mass concentration of NOx in smoke is reduced; meanwhile, the improvement of thermal state air permeability strengthens the oxidizing atmosphere in the sintering process, is favorable for the generation of high-quality calcium ferrite binding phase, and promotes the generated NOx to N₂The reduction reaction of (2) occurs; as the mixture is gradually dried completely, partial pulverization is generated in the material layer, the heat transfer speed is reduced in the sintering process, the sintering temperature is reduced, the thickness of a sintering belt is increased, the air permeability of the material layer is deteriorated, the oxygen content in the fuel combustion atmosphere is reduced, and the conversion of fuel nitrogen to NOx is inhibited; at O₂Deficiency of CO₂In the presence of the catalyst, the CO balance is broken, and CO₂Can be reacted with O₂The reaction proceeds, and the excess of solid carbon shifts the equilibrium of the boolean reaction to the right, thereby strengthening the reducing atmosphere in the reactor, facilitating the reduction reaction with NOx, and suppressing the conversion of fuel nitrogen to NOx.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

In the figure: 1. sintering, preheating and drying furnace; 2. sintering an ignition furnace; 3. a steel bracket; 4. a gas pipeline; 5. a primary air duct; 6. a secondary air duct; 7. preheating a curtain type burner; 8. prefabricating a beam; 9. an ignition hole; 10. a preheated air channel; 11. igniting the curtain burner; 12. supporting the travelling wheels; 13. sintering the upper edge of the trolley; 14. sintering air draft bellows.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to FIG. 1, an apparatus for effectively reducing NOx emissions from sinteringThe device comprises a sintering preheating drying furnace 1 and a sintering ignition furnace 2, wherein the height of a hearth of the sintering preheating drying furnace 1 is 800mm from the upper edge 13 of a sintering trolley, a precast beam 8 is arranged on the top of the sintering preheating drying furnace 1, a preheating air channel 10 is arranged between the top of the sintering preheating drying furnace 1 and the precast beam 8, and the length of the preheating air channel 10 is equal to the width of the sintering trolley; the top of the sintering preheating drying furnace 1 is provided with preheating curtain type burners 7 among the preheating air channels 10, the preheating curtain type burners 7 adopt short flame type burners, and the flame of the preheating curtain type burners does not ignite the sintering mixture in the trolley below the preheating drying furnace 1 under the height of the hearth of the sintering preheating drying furnace 1; the number of the preheating curtain type burner nozzles 7 is set according to the width of the sintering trolley and the requirement of heat supplement, the preheating curtain type burner nozzles 7 are respectively connected with a gas pipeline 4 and a primary air pipeline 5, the gas can be coke oven gas, blast furnace gas, converter gas or other types of gas, a steel bracket 3 is arranged at the bottom of the sintering preheating drying furnace 1, the bottom of the steel bracket 3 bears on supporting travelling wheels 12 at two sides, the sintering preheating drying furnace 1 is spanned above the sintering trolley, and the length and the installation position of the sintering preheating drying furnace 1 and the sintering air draft bellows 141 are as same as each other^#And 2^#The air boxes are corresponding, the opening degree of butterfly valves corresponding to No. 1 and No. 2 sintering air boxes is set within the range of 45% -95% during normal use, and preheating and drying hot air in the sintering and preheating drying furnace 1 downwards passes through a sintering trolley mixture layer under the suction action of a sintering main exhaust fan, so that the preheating and drying effects on sintering mixtures are realized.

At 400m²Sintering machines are taken as examples: the length of the No. 1 air box and the length of the No. 2 air box can be set to be 4.0 m; when the speed in normal production of sintering is 1.40m/min, the preheating and drying time of the sintering mixture in the sintering preheating and drying furnace 1 is about 5.71 min; the length of the sintering preheating drying furnace 1 and the length of the corresponding sintering air draft air box 14 can be reasonably designed in advance according to the normal sintering speed during production, so that the preheating and drying time of the sintering mixture in the sintering preheating drying furnace 1 is longer than 3 min; because the sintering mixture is preheated and dried, the temperature of the material layer is gradually raised, the water in the material layer is evaporated into steam, the heat transfer speed of the sintering material layer is accelerated, the width of the over-wet belt is reduced, and the hot air permeability in the sintering process is facilitatedThe vertical sintering speed and the utilization coefficient are improved; meanwhile, the improvement of thermal state air permeability strengthens the oxidizing atmosphere in the sintering process, and is beneficial to the generation of high-quality calcium ferrite binding phase, thereby improving the quality of sintered ore; meanwhile, the cooling speed is relatively reduced, the generation of amorphous structure glass is reduced, the microstructure of the sintered ore is more reasonable, the sintered ore forming condition is improved, the silicate and ferrite bonded phase is more sufficiently crystallized, more bonded phases with higher strength are formed, the strength of the sintered ore is increased, and the yield is increased.

In this embodiment, the sintering ignition furnace 2 is located at one side of the sintering preheating drying furnace 1, and the sintering ignition furnace 2 is spanned above the sintering trolley through the steel bracket 3 and the supporting traveling wheels 12, and the length and the installation position of the sintering ignition furnace 2 are equal to 3 of the sintering air draft bellows 14^#And 4^#Bellows correspond to, 3 of the sintering draft bellows 14^#And 4^#The opening of the butterfly valve of the air box is 5-20 percent so as to realize the requirement of micro-negative pressure ignition control on the sintering ignition furnace 2; the top of the sintering ignition furnace 2 is provided with an ignition curtain type burner 11, and the preheating curtain type burner 7 and the ignition curtain type burner 11 are provided with corresponding ignition holes 9 on one side of the upper edge 13 of the sintering trolley; the ignition curtain type burner 11 is respectively connected with the gas pipeline 4, the primary air pipeline 5 and the secondary air pipeline 6, the ignition curtain type burner 11 adopts a long flame type burner, the ignition requirement of a sinter bed in the range of 600 plus 1000mm is met, and meanwhile, the optimal adjustment of the flame length can be realized through the adjustment of the primary air pipeline 5 and the secondary air pipeline 6.

In the above embodiment, the sintering ignition furnace 2 can ignite the sintering mixture that has been preheated and dried, and the ignition control thereof is controlled by both the ignition intensity and the ignition temperature.

In the embodiment, the preheated air of the preheated air channel 10, the primary air pipeline 5 and the secondary air pipeline 6 is taken from hot waste gas in a middle-high temperature region of a sintering circular cooler or a belt cooler, and the temperature of the preheated air is 350-450 ℃; because the temperature of the hot waste gas in the middle-high temperature area of the sintering circular cooler or the belt cooler is easy to fluctuate greatly in the sintering production process, the temperature of the preheated air entering each preheated air channel 10 of the sintering preheating drying furnace 1 and the temperature of the preheated air entering the primary air pipeline 5 cannot be continuously ensured to be difficult to be stably controlled within the reasonable temperature range of preheating and drying at 350-450 ℃, and the afterburning technology of two rows of preheating curtain type burners 7 is adopted, so that the temperature of the preheating and drying air entering the sintering preheating drying furnace 1 can meet the requirement of the temperature control range; the afterburning of the two rows of preheating curtain type burners 7 and the detection temperature mean value of a multipoint thermocouple arranged in the sintering preheating drying furnace 1 are controlled in an interlocking manner, namely when the average temperature detected by the thermocouple is lower than 350 ℃, the automatic ignition control is carried out to ignite the two rows of preheating curtain type burners 7 for afterburning, otherwise, when the average temperature detected by the thermocouple is higher than 450 ℃, the gas and the corresponding air flow of the burners are automatically adjusted, so that the average temperature detected by the thermocouple is controlled within the temperature requirement range; if the gas and the corresponding air flow of the burner are automatically adjusted to a certain minimum safe flow, and the temperature detected by the thermocouple is still higher than the temperature control upper limit of 450 ℃, the automatic flameout and cut-off control is carried out on the two rows of preheating curtain type burners 7, and an automatic ignition device is arranged in the sintering preheating drying furnace 1.

In the above embodiment, the distance between the hearth height of the sintering ignition furnace 2 and the upper edge 13 of the sintering trolley is 300-350mm, and since the hearth height of the sintering ignition furnace 2 is lower than the hearth height of the sintering preheating drying furnace 1, the side of the sintering ignition furnace 2 close to the sintering preheating drying furnace 1 can realize radiation and convection heat transfer to the sintering preheating drying furnace 1 in the normal working state.

Because the sintering mixture is preheated and dried in the sintering preheating drying furnace 1 in advance, the material temperature of the sintering mixture is obviously improved, the normal ignition temperature control of the sintering ignition furnace 2 can be properly reduced when the sintering ignition furnace 2 is ignited, and when the preheating drying and ignition device is used, the ignition temperature of the sintering ignition furnace 2 can be controlled to be reduced to about 850 +/-50 ℃ from the original 1050 +/-50 ℃ for control, so that the requirement of the ignition process of normal sintering production can be met; due to the realization of the low-temperature ignition control, the gas consumption of the device is obviously reduced compared with that of the traditional ignition holding furnace.

Moisture content of the mixture after partial dryingThe material temperature is reduced and increased, so that the stroke of an over-wet belt in the sintering process is reduced, the thermal state air permeability in the sintering process is improved, the air throughput is increased, and the mass concentration of NOx in smoke is reduced; meanwhile, the improvement of thermal state air permeability strengthens the oxidizing atmosphere in the sintering process, is favorable for the generation of high-quality calcium ferrite binding phase, and promotes the generated NOx to N₂The reduction reaction of (2) occurs; as the mixture is gradually dried completely, partial pulverization is generated in the material layer, the heat transfer speed is reduced in the sintering process, the sintering temperature is reduced, the thickness of a sintering belt is increased, the air permeability of the material layer is deteriorated, the oxygen content in the fuel combustion atmosphere is reduced, and the conversion of fuel nitrogen to NOx is inhibited; at O₂Deficiency of CO₂In the presence of the catalyst, the CO balance is broken, and CO₂Can be reacted with O₂The reaction proceeds, and the excess of solid carbon shifts the equilibrium of the boolean reaction to the right, thereby strengthening the reducing atmosphere in the reactor, which facilitates the reduction reaction with NOx, while suppressing the conversion of fuel nitrogen to NOx.

In summary, the following steps: the device capable of effectively reducing the emission of the sintering NOx realizes the preheating, drying and normal ignition of the sintering mixture through the sintering preheating and drying furnace 1 and the sintering ignition furnace 2, and can realize the utilization of the hot waste gas in a middle and high temperature area generated by a sintering ring cooling machine or a belt cooling machine in the sintering production process for the preheating, drying and ignition of the sintering mixture; the sintering preheating drying furnace 1 can realize an automatic afterburning technology so as to achieve the stability and uniformity of preheating and drying of the sintering mixture; and on the basis, the low-temperature ignition control of the sintering ignition furnace 2 is realized; because the sintering mixture is preheated and dried, the temperature of the material layer is gradually raised, the water in the material layer is evaporated into steam, the heat transfer speed of the sintering material layer is accelerated, the width of the over-wet belt is reduced, the improvement of the thermal state air permeability in the sintering process is facilitated, and the vertical sintering speed and the utilization coefficient are improved; meanwhile, the improvement of thermal state air permeability strengthens the oxidizing atmosphere in the sintering process, and is beneficial to the generation of high-quality calcium ferrite binding phase, thereby improving the quality of sintered ore; meanwhile, the cooling speed is relatively reduced, the generation of amorphous structure vitreous is reduced, the microstructure of the sinter is more reasonable, the sinter forming conditions are improved, and silicate and ferriteThe bonding phase is more sufficiently crystallized, more bonding phases with higher strength are formed, so that the strength of the sintered ore is increased, and the yield is increased; after partial drying, the moisture content of the mixture is reduced, and the temperature of the mixture is increased, so that the stroke of an over-wet belt in the sintering process is reduced, the thermal state air permeability in the sintering process is improved, the air throughput is increased, and the mass concentration of NOx in smoke is reduced; meanwhile, the improvement of thermal state air permeability strengthens the oxidizing atmosphere in the sintering process, is favorable for the generation of high-quality calcium ferrite binding phase, and promotes the generated NOx to N₂The reduction reaction of (2) occurs; as the mixture is gradually dried completely, partial pulverization is generated in the material layer, the heat transfer speed is reduced in the sintering process, the sintering temperature is reduced, the thickness of a sintering belt is increased, the air permeability of the material layer is deteriorated, the oxygen content in the fuel combustion atmosphere is reduced, and the conversion of fuel nitrogen to NOx is inhibited; at O₂Deficiency of CO₂In the presence of the catalyst, the CO balance is broken, and CO₂Can be reacted with O₂The reaction proceeds, and the excess of solid carbon shifts the equilibrium of the boolean reaction to the right, thereby strengthening the reducing atmosphere in the reactor, which facilitates the reduction reaction with NOx, while suppressing the conversion of fuel nitrogen to NOx.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.