CN113883897A

CN113883897A - A kind of anti-channel air system and air flow control method in preheating section of chain grate machine

Info

Publication number: CN113883897A
Application number: CN202010624968.7A
Authority: CN
Inventors: 胡兵; 曾辉; 刘臣; 魏进超
Original assignee: Zhongye Changtian International Engineering Co Ltd
Current assignee: Zhongye Changtian International Engineering Co Ltd
Priority date: 2020-07-01
Filing date: 2020-07-01
Publication date: 2022-01-04
Anticipated expiration: 2040-07-01
Also published as: WO2022001109A1; BR112022004907A2; CN113883897B

Abstract

The invention discloses an anti-channeling wind system in the preheating section of a chain grate machine and a method for controlling air flow by using the system. The system includes a chain grate machine and a rotary kiln. The chain grate machine is sequentially provided with a blast drying section, a suction drying section, a first section of preheating and a second section of preheating. The second preheating section is communicated with the flue gas outlet of the rotary kiln through the first pipeline. A blow-by air device is arranged between the preheating first stage and the preheating second stage. In the invention, a movable air flow balance plate is added between the PH section and the TPH section of the chain grate machine, and the position change of the air flow balance plate is used to control the air pressure in the TPH section to be greater than or equal to the air pressure in the PH section, so as to prevent the high NOx waste gas in the PH section from flowing to the TPH section. The problem of the increase of NOx content in the flue gas in the TPH section caused by the blow-by wind. Ultra-low NOx emissions are achieved through precise regulation of the air flow control method.

Description

Air channeling prevention system for preheating section of chain grate machine and air flow control method thereof

Technical Field

The invention relates to an anti-air-channeling system of a chain grate machine, in particular to an anti-air-channeling system of a preheating section of the chain grate machine and an air flow control method thereof, and belongs to the technical field of flue gas treatment of the chain grate machine.

Background

NOx is a main reason for forming photochemical smog, acid rain and dust haze weather, aggravating ozone layer damage and promoting greenhouse effect, and has great harm to the ecological environment. The ecological environment department of 2019 issues 'comments on ultra-low emission in the promotion and implementation of the steel industry', and the pellet roasting smoke is definitely required to have the hourly mean emission concentration of NOx not higher than 50mg/m under the condition that the reference oxygen content is 18%³. If the oxygen content is higher than 18%, the NOx concentration is evaluated as a value converted to the reference oxygen content. Therefore, the method is an effective technical measure to meet the emission requirements of atmospheric pollutants in steel sintering and pellet industries and simultaneously reduce the concentration of NOx and the concentration of oxygen in roasting flue gas. From the production conditions of most pelletizing plants, the NOx emission concentration is generally 100-300 mg/m³And the oxygen content in the waste gas is 17-19 percent.

The NOx generation in the pellet production process mainly comes from two forms of fuel type and thermal type, and although the NOx generation amount in the grate-kiln pellet production process can be reduced by reducing the pellet yield, namely reducing the coal gas or coal powder injection amount, reducing the pellet strength requirement, namely reducing the rotary kiln temperature, and adopting measures of raw materials and fuels with lower NOx and the like, the NOx generation amount is difficult to meet the environment-friendly requirement of ultralow emission.

In the prior art, due to the fact that no systematic research and reliable technology for generating and controlling low NOx in the pellet production process of the chain grate machine-rotary kiln exist, NOx emission in the production process of a pellet factory does not reach the standard and becomes a normal state, and the method is one of the biggest challenges facing enterprises. Therefore, enterprises can only reduce the output of the pellets, thereby reducing the injection amount of coal gas or coal powder, reducing the strength requirement of the pellets, reducing the temperature of the rotary kiln, and reducing the generation of NOx by adopting lower NOx raw materials and fuels and the like. These methods not only affect pellet production in terms of yield and quality, have high quality requirements on raw fuels, cause cost increase, but also cannot fundamentally solve the problem of low-NOx pellet production.

Currently, the preferred NOx removal technologies rely primarily on Selective Catalytic Reduction (SCR) and selective non-catalytic reduction (SNCR) techniques to remove NOx at the end and in the process, respectively. For SNCR denitration techniques, a temperature range of 800 ℃ to 1100 ℃ is generally considered to be suitable. In the production process of the grate-rotary kiln pellets, an SNCR denitration technology is applied, and the flue gas denitration is usually carried out by spraying a reducing agent (ammonia water or urea) into the flue gas at a preheating section (the temperature is 850-1100 ℃). The SNCR technology is connected with the SCR technology in series and is an effective means for realizing ultralow emission of pellet flue gas. In the face of strong environment-friendly air pressure, a production system for ultralow NOx emission of pellet smoke is provided (201821480691.X), and the ultralow NOx emission in the production process of the chain grate-rotary kiln pellets can be realized through the effective combination of an SNCR + SCR double denitration mechanism. However, the problem of air cross-ventilation caused by the difference between the temperature and the air pressure between the PH section and the TPH section in the production system of the chain grate machine is often solved, namely, the high NOx waste gas in the PH section is cross-ventilated to the TPH section, so that the NOx content in the smoke gas in the TPH section is increased. And then difficult to realize accurate control of denitration and the discharge to reach standard of NOx.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the air channeling prevention system for the preheating section of the chain grate machine. The airflow balance plate is opened before the airflow of the grate air-channeling prevention system is unbalanced, and the airflow is closed in time after being stabilized, so that the grate system is positively influenced: namely, the SNCR + SCR denitration treatment is carried out on the PH section waste gas (about 1/3) to meet the requirement of ultralow emission of pellet NOx, and the investment and operation cost are greatly reduced. Meanwhile, the air flow balance plate is controlled to move towards the TPH end, so that the TPH section is indirectly selectively merged into the PH section by an air box close to the PH section, the high-temperature preheating time of the pellets is prolonged, and the effect of improving the strength of the preheated pellets is achieved.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

according to a first embodiment of the present invention, there is provided a grate preheating section blow-by preventing system comprising a grate and a rotary kiln. According to the trend of the materials, the chain grate machine is sequentially provided with a blast drying section, an air draft drying section, a preheating section and a preheating section. The preheating section is communicated with a smoke outlet of the rotary kiln through a first pipeline. And an anti-air-channeling device is arranged between the preheating first section and the preheating second section.

Preferably, the anti-blow-by device comprises an airflow balance plate, a moving platform, rollers and a slot. The airflow balance plate is arranged inside the chain grate machine. The mobile platform is arranged on two sides of the lower end of the outer part of the preheating section I and the preheating section II. The roller is arranged at the bottom of the mobile platform. The slots are arranged on two sides of the upper end of the outer part of the preheating section and the preheating section. The mobile platform is also provided with a fixed seat. The fixing seat is provided with an upright post. The top end of the upright post is connected with the top end of the airflow balance plate after passing through the slot. And a moving motor is also arranged outside the moving platform. The moving motor drives the moving platform to move on the roller. The moving platform drives the fixed seat and the upright post to move so as to drive the airflow balance plate to move in the chain grate machine.

Preferably, the air flow balance plate is composed of an outer plate and an inner plate. The outer plate is a plate body with a hollow inner part. The inner plate is sleeved in the inner cavity of the outer plate. The inner plate is also connected with a lifting motor. The lifting motor controls the inner plate to move in the vertical direction of the inner cavity of the outer plate.

Preferably, the system also comprises an ammonia agent denitration device. The ammonia agent denitration device is arranged in the preheating section and/or the first pipeline.

Preferably, the ammonia agent denitration device comprises a first sprayer, a second sprayer and an ammonia agent storage tank. The first sprayer is disposed within the preheating section. The second sprinkler is disposed within the first conduit. The ammonia agent storage tank is connected with the first sprayer through a second pipeline. A third pipeline is branched from the second pipeline and is connected with a second sprayer.

Preferably, the system also comprises an SCR denitration device and a dust removal device. And the air outlet of the preheating second section is communicated to the air inlet of the air draft drying section through a fourth pipeline. And an air outlet of the air draft drying section is communicated to a chimney through a fifth pipeline. The SCR denitration device is arranged on the fourth pipeline. The dust removal device is arranged on the fifth pipeline.

Preferably, the system further comprises a circulation cooler. The ring cooling machine is sequentially provided with a ring cooling first section, a ring cooling second section and a ring cooling third section. And an air outlet of the annular cooling section is communicated to an air inlet of the rotary kiln through a sixth pipeline. And the air outlet of the annular cooling second section is communicated to the air inlet of the preheating first section through a seventh pipeline. And the air outlet of the annular cooling three sections is communicated to the air inlet of the blast drying section through an eighth pipeline. And the air outlet of the preheating section is communicated to a fifth pipeline through a ninth pipeline. And an air outlet of the blowing and drying section is communicated to a chimney through a tenth pipeline.

Preferably, the system further comprises a first pressure detector, a second pressure detector, a first temperature detector, a second temperature detector, a first flow detector, a second flow detector and a flue gas analyzer. The first pressure detector, the first temperature detector and the flue gas analyzer are arranged in the preheating section. The second pressure detector and the second temperature detector are arranged in the preheating two-stage section. The first flow rate detector is arranged on the seventh pipeline. The second flow rate detector is arranged on the first pipeline.

According to a second embodiment of the invention, there is provided a method for controlling the air flow of the preheating section of the chain grate machine or the air flow control method using the anti-blow-by system of the preheating section of the chain grate machine in the first embodiment, the method comprising the steps of:

1) according to the trend of the materials, the green pellets enter a chain grate machine, sequentially pass through a blast drying section, an air draft drying section, a preheating section and a preheating section, and are conveyed into a rotary kiln for oxidizing roasting. And conveying the oxidized pellets after the oxidizing roasting to a circular cooler for cooling.

2) According to the flow direction of the hot air, the hot air discharged from the ring cooling section is conveyed into the rotary kiln through a sixth pipeline and then conveyed into the preheating section through the first pipeline. And hot air exhausted from the annular cooling section is conveyed into the preheating section through a seventh pipeline.

3) And adjusting the horizontal position of an airflow balance plate arranged between the preheating first section and the preheating second section to ensure that the pressure in the preheating first section is greater than or equal to the pressure in the preheating second section.

4) The hot air in the preheating section is finally discharged through a ninth pipeline. The hot air in the preheating section is finally discharged through a fourth pipeline.

Preferably, the method further comprises: a first pressure detector is arranged in the preheating section and used for detecting the air pressure in the preheating section to be p1 Pa in real time. The first temperature detector is also arranged to detect the gas stability in the preheating section to be c1, K in real time.

Preferably, a second pressure detector is provided in the preheating stage to detect the pressure p2, Pa in real time in the preheating stage. And a second temperature detector is also arranged to detect the gas stability in the preheating section to be c2, K in real time.

Preferably, the seventh pipeline is further provided with a first flow rate detector for detecting the flow rate q1, Nm of the gas delivered into the preheating section in real time³H is used as the reference value. The first pipeline is provided with a second flow detector for detecting the flow of the gas delivered into the preheating second section in real time as q2 Nm³H is used as the reference value. The mass of gas fed into the preheating stage is m1, g:

formula I, where m1 is ρ q 1.

The mass of gas fed into the preheating section is m2, g:

formula II is denoted by m2 ═ ρ × q2 ·.

In formula I and formula II, ρ is the gas average density, g/m³. t is the gas delivery time, h.

According to an ideal gas state equation, the following results are obtained:

formula III, p1 × v1 ═ ρ × q1 × t × R × c1/m.

Formula IV, p2 × v2 ═ ρ × q2 × t × R × c2/m.

In formulas III and IV, v1 is the volume of the preheating section, m³. v2 is the volume of the two preheating stages, m³. R is a gas constant, J/(mol. K). M is the average molar mass of the gas, g/mol.

Preferably, the length of the preheating section is a1, the width is b1, and the height is h1, which are all m units. The length of the preheating section is a2, the width is b2, and the height is h2, which are m. Then:

v1 ═ k1 a1 ═ b1 · h1..

Formula VI, v2 ═ k2 ═ a2 ═ b2 · h2..

In formulas V and VI, k1 is the volume correction ratio for the preheat section. k2 is the volume correction ratio for the preheat section.

Substituting formula V into formula III to obtain:

formula VII, p1 ═ ρ × q1 ═ R × c1/(M × k1 × a1 × b1 × h1).

Substituting formula VI into formula IV to obtain:

formula VII, p2 ═ ρ × q2 ═ R × c2/(M × k2 × a2 × b2 × h2).

And setting the horizontal movement quantity of the airflow balance plate to the preheating section direction as delta a, m. Then:

formula VIII. Z ═ p1/p2 ═ q1 ═ c1 × k2 (a2- Δ a) × b2 × h2]/[ q2 × c2 × k1 (a1 +. Δ a) × b1 × h1.

When Z is 1, the minimum amount Δ a of movement of the air flow balance plate is equal to_minComprises the following steps:

the horizontal movement quantity delta a of the airflow balance plate is adjusted to be larger than or equal to the calculated value delta a of the formula IX_minM, such that Z is ≧ 1, i.e., p1 ≧ p 2.

Preferably, when the horizontal displacement of the airflow balance plate is adjusted to Δ a, the airflow balance plate is adjusted in steps, and the adjustment times are set to N, then:

n | (p2-p1)/(0.05 × p1) | formula X.

When the required horizontal displacement of the airflow balance plate is delta a, the moving times of the airflow balance plate are the calculated value N of the formula X.

Preferably, a flue gas analyzer Y is arranged in the preheating section for detecting the content of NOx in the preheating section in real time to be less than or equal to 40mg/m³。

In the prior art, the NOx emission in the production process of a pellet mill does not reach the standard and becomes the normal state due to the fact that no systematic research and reliable technology for generating and controlling low NOx in the production process of the grate-rotary kiln pellets exist, and the method is one of the biggest challenges faced by enterprises. Therefore, enterprises can only reduce the output of the pellets, thereby reducing the injection amount of coal gas or coal powder, reducing the strength requirement of the pellets, reducing the temperature of the rotary kiln, and reducing the generation of NOx by adopting lower NOx raw materials and fuels and the like. These methods not only affect pellet production in terms of yield and quality, have high quality requirements on raw fuels, cause cost increase, but also cannot fundamentally solve the problem of low-NOx pellet production. In addition, through add denitrification facility behind main air exhauster, if adopt selective catalytic reduction technology (SCR) and non-selective catalytic reduction technology (SNCR), although can reach the requirement of low NOx emission, nevertheless because its investment cost is high, the equipment requirement is high, the energy consumption is big, denitration cost is high and there is secondary pollution, does not get popularization and application in the pelletizing enterprise, and the NOx control mode of pellet factory at home and abroad is mainly still realized through process control at present.

In the existing production process of pellet by chain grate machine-rotary kiln, the chain grate machine is divided into an air blowing drying section, an air draft drying section, a preheating section and a preheating section, and the ring cooling machine is divided into a ring cooling section, a ring cooling section and a ring cooling section. Wherein, the air of the first section of the circular cooling directly enters a rotary kiln to roast pellets, the pellets are preheated by the second section of the preheating, heated and then blown into an air draft drying section to carry out air draft drying on the pellets, and then the pellets are discharged outside by the air draft drying section (the pellets are subjected to flue gas purification treatment before being discharged); the air in the annular cooling second section enters the preheating first section to heat the preheating ball and then is discharged outwards; and air of the ring cooling three sections enters an air blowing and drying section to perform air blowing and drying on the green pellets, so that closed circulation of the grate-rotary kiln-ring cooler air flow system is realized. And simultaneously, a selective non-catalytic reduction technology (SNCR) is connected with a selective catalytic reduction technology (SCR) in series, and NOx is removed in the process (in the preheating section) and at the tail end (after the preheating section exhaust port). For example, the production system (201821480691.X) with ultralow NOx emission in pellet smoke can realize ultralow NOx emission in the production process of chain grate-rotary kiln pellets by effectively combining an SNCR + SCR double denitration mechanism. However, the problem of air channeling caused by the difference between the temperature and the air pressure of the PH section and the TPH section in the grate production system is often solved, namely, the high NOx waste gas in the PH section is mixed with the air in the TPH section, so that the NOx content in the flue gas in the TPH section is increased. And then difficult to realize accurate control of denitration and the discharge to reach standard of NOx.

In the invention, in order to solve the problem of air cross in the PH section and the TPH section of the production system for ultralow NOx emission of pellet flue gas, and implement accurate denitration control and standard NOx emission, a movable airflow balance plate is additionally arranged between the PH section and the TPH section of the chain grate, and the air pressure P1 of the TPH section is mainly controlled to be more than or equal to the air pressure P2 of the PH section by utilizing the position change of the balance plate, namely P1 is more than or equal to P2, so that the high NOx waste gas in the PH section is prevented from air cross to the TPH section, and the NOx content in the flue gas of the TPH section is increased. The airflow balance plate is opened before the airflow system of the chain grate machine is unbalanced, and is closed in time after being stabilized, so that the chain grate machine system is positively influenced: the ultra-low emission requirement of pellet NOx can be met only by carrying out SNCR + SCR denitration treatment on PH section waste gas (about 1/3), and the investment and operation cost is greatly reduced; a plurality of bellows (generally 1-5, can carry out reasonable regulation setting according to operating condition) that are close to the PH section with TPH section merge PH section of selectivity, have prolonged the pelletizing high temperature preheating time indirectly, play the effect that improves and preheat ball intensity.

In the invention, a first pressure detector is arranged in the preheating section to detect the pressure p1 Pa in the preheating section in real time. And a second pressure detector is arranged in the preheating second section and used for detecting the air pressure in the preheating second section to be p2 Pa in real time. The detected p1 and p2 values are compared. If the detected p1 is more than or equal to p2, the system is not adjusted (the position of the airflow balance plate is kept unchanged); if the detected p1 is less than p2, the position movement of the airflow balance plate is controlled and adjusted, so that the p1 is more than or equal to the p 2. So as to prevent the high NOx waste gas in the PH section from blowing to the TPH section.

In the invention, the anti-wind-channeling device comprises an airflow balance plate, a moving platform, a roller and a slot. The airflow balance plate is arranged inside the chain grate machine. The mobile platform is arranged on two sides of the lower end of the outer part of the preheating section I and the preheating section II. The roller is arranged at the bottom of the mobile platform. The slots are arranged on two sides of the upper end of the outer part of the preheating section and the preheating section. The mobile platform is also provided with a fixed seat. The fixing seat is provided with an upright post. The top end of the upright post penetrates through the open groove and then is connected with the top end of the airflow balance plate (the top end of the upright post penetrates through the open groove and then is connected with the top end of the airflow balance plate after being transversely bent). And a moving motor is also arranged outside the moving platform. The moving motor drives the moving platform to move on the roller. The moving platform drives the fixed seat and the upright post to move so as to drive the airflow balance plate to move in the chain grate machine (from the PH section to the TPH section).

Further, the air flow balance plate is composed of an outer plate and an inner plate. The outer plate is a plate body with a hollow inner part. The inner plate is sleeved in the inner cavity of the outer plate. The inner plate is also connected with a lifting motor. The lifting motor controls the inner plate to move in the vertical direction of the inner cavity of the outer plate. According to actual need, adjust the removal of inner panel, and then change the whole height of air current balance plate in order to satisfy the operating mode demand of co-altitude, prevent the emergence of scurrying the wind phenomenon.

In the present invention, the thickness of the inner plate is 1 to 20cm, preferably 2 to 15cm, and more preferably 3 to 10 cm. The thickness of the outer plate (i.e. the overall thickness of the airflow balancing plate) is 3-25cm, preferably 5-20cm, more preferably 8-15 cm. The thickness of the inner cavity of the outer plate is larger than that of the inner plate (for example, the thickness of the inner cavity of the outer plate is larger than that of the inner plate by 0.5cm, 1cm, 1.5cm, 2cm and the like, and can be selected according to the actual working condition requirement).

In the present invention, the heat treatment is carried out by heating in a preheating sectionA first temperature detector is arranged to detect the temperature of the gas in the preheating section as c1 and K in real time. And a second temperature detector is arranged in the preheating second section and used for detecting the temperature of the gas in the preheating second section as c2 and K in real time. The seventh pipeline is also provided with a first flow detector for detecting the flow rate of the gas delivered into the preheating section as q1 and Nm in real time³H is used as the reference value. The first pipeline is provided with a second flow detector for detecting the flow of the gas delivered into the preheating second section in real time as q2 Nm³H is used as the reference value. The mass of gas delivered to the preheating stage can be calculated as m1, g:

formula I, where m1 is ρ q 1.

Further, the mass of gas delivered to the preheating stage is m2, g:

formula II is denoted by m2 ═ ρ × q2 ·.

From the ideal gas state equation (pV ═ nRT ═ mRT/M), one can obtain:

formula III, p1 × v1 ═ ρ × q1 × t × R × c1/m.

Formula IV, p2 × v2 ═ ρ × q2 × t × R × c2/m.

v1 ═ k1 a1 ═ b1 · h1..

Formula VI, v2 ═ k2 ═ a2 ═ b2 · h2..

In the present invention, when the inner cavity of the preheating section or the preheating section is shaped as a regular rectangular body: k 1-k 2-1. When the lumen of the preheating section or the preheating section is shaped as an irregular rectangular body, in order to correct the error value of the volume calculation formula (length × width × height), correction values k1 and k2 are introduced so that the calculated volume is closest to the actual volume. Generally, the values of k1 and k2 are a fixed constant for the same chain grate.

Further, substituting formula V into formula III yields:

formula VII, p1 ═ ρ × q1 ═ R × c1/(M × k1 × a1 × b1 × h1).

Further, substituting formula VI into formula IV yields:

formula VII, p2 ═ ρ × q2 ═ R × c2/(M × k2 × a2 × b2 × h2).

When p1 is less than p2, the airflow balance plate (the initial position of the airflow balance plate is the boundary of the preheating section and the preheating section) needs to be moved to ensure that p1 is more than or equal to p2, and the horizontal movement amount of the airflow balance plate towards the preheating section is set to be delta a, m. Then:

When Z is equal to 1 (i.e. p1 is equal to p2), the minimum amount Δ a of movement of the air balance plate is equal to the minimum amount Δ a of movement_minComprises the following steps:

In the invention, when the horizontal displacement of the airflow balance plate is regulated to be delta a, the airflow balance plate is regulated step by step, and the regulation times is set to be N, then:

n | (p2-p1)/(0.05 × p1) | formula X.

It should be noted that the calculated Δ a cannot be simply and roughly adjusted in place, but needs to be adjusted slowly, and the change of the real-time parameters is continuously detected during the adjustment process and corrected in time, so as to avoid the influence on the production quality caused by the violent production fluctuation due to the excessively large adjustment strideAnd (4) marking. Here, the adjustment step size needs to be set: l ═ delta a/N (taking the value of delta a as delta a)_minFor example), N is adjusted in N-times, (p2-p1)/(0.05 × p1), N is rounded. Further, the determination of N is a preferred calculation method, but not limited to this method, and in principle, the determination of N value needs to be based on the adjustment urgency (the more p1 is less than p2, the less the adjustment times should be, because the pressure difference should be reduced as soon as possible). However, after each step size adjustment, a new pressure detection is needed, and the process is continued if the target (p1 ≧ p2) is not reached. If the target is reached, the adjustment is stopped.

Further, a flue gas analyzer is arranged in the preheating section for detecting the content of NOx in the preheating section in real time to be less than or equal to 40mg/m³. Or the final emission concentration of NOx is lower than 50mg/m according to the national ultra-low emission standard³And (4) finishing.

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

1. according to the system, the movable airflow balance plate is additionally arranged between the PH section and the TPH section of the chain grate machine, the air pressure of the TPH section is mainly controlled to be more than or equal to that of the PH section by utilizing the position change of the balance plate, and the high NOx waste gas of the PH section is prevented from leaking air to the TPH section, so that the NOx content in the smoke of the TPH section is increased. Effectively reducing the direct discharge of pollutants.

2. The grate air flow system can meet the requirement of ultralow emission of pellet NOx only by carrying out SNCR + SCR denitration treatment on PH section waste gas (about 1/3), and the investment and operation cost is greatly reduced; meanwhile, the TPH section and the part of the air box close to the PH section can be selectively merged into the PH section, so that the high-temperature preheating time of the pellets is indirectly prolonged, and the effect of improving the strength of the preheated pellets is achieved.

3. The system disclosed by the invention has the advantages of simple structure, easiness in operation, low cost investment, remarkable wind control and emission reduction effects, and stronger application prospect and greater economic benefit.

4. The air flow control method is simple and accurate, has short control flow, can make a response in a very short time through real-time data monitoring, and simultaneously realizes dynamic fine adjustment in a mode of calculating the movement variation of the air flow balance plate, so that the adjustment of the air flow balance plate is more scientific and reasonable, and the problem that the production quality index is influenced due to violent production fluctuation caused by overlarge adjustment stride can be effectively avoided.

Drawings

Fig. 1 is a schematic structural view of a blow-by preventing system of a preheating section of a chain grate machine.

Fig. 2 is a schematic structural diagram of the detection mechanism of the anti-blow-by system for the preheating section of the chain grate machine.

Fig. 3 is a schematic structural view of the anti-blow-by device of the present invention.

Fig. 4 is a schematic structural view of the airflow balance plate of the present invention.

Fig. 5 is a top view structural view of the wind channeling preventing device of the present invention.

FIG. 6 is a flow chart of the wind flow control and regulation method of the present invention.

Reference numerals: 1: a chain grate machine; 2: a rotary kiln; 3: a wind channeling prevention device; 4: an ammonia agent denitration device; 5: an SCR denitration device; 6: a dust removal device; 7: a circular cooler; UDD: a forced air drying section; DDD: an air draft drying section; TPH: preheating for one section; pH: a second preheating stage; 301: an airflow balancing plate; 30101: an outer plate; 30102: an inner plate; 30103: a lifting motor; 302: a mobile platform; 30201: a fixed seat; 30202: a column; 30203: a moving motor; 303: a roller; 304: grooving; 401: a first sprayer; 402: a second sprayer; 403: an ammonia agent storage tank; c1: cooling in a ring for one section; c2: a ring cooling section; c3: ring cooling for three sections; l1: a first conduit; l2: a second conduit; l3: a third pipeline; l4: a fourth conduit; l5: a fifth pipeline; l6: a sixth pipeline; l7: a seventh pipe; l8: an eighth conduit; l9: a ninth conduit; l10: a tenth conduit; p1: a first pressure detector; p2: a second pressure detector; c1: a first temperature detector; c2: a second temperature detector; q1: a first flow detector; q2: a second flow rate detector; y: flue gas analyzer.

Detailed Description

The technical solution of the present invention is illustrated below, and the claimed scope of the present invention includes, but is not limited to, the following examples.

According to a first embodiment of the present invention, there is provided a grate preheating section blow-by preventing system comprising a grate 1 and a rotary kiln 2. According to the trend of the materials, the chain grate 1 is sequentially provided with an air blowing drying section UDD, an air exhausting drying section DDD, a preheating section TPH and a preheating section PH. The preheating section PH is communicated with a smoke outlet of the rotary kiln 2 through a first pipeline L1. And an air channeling prevention device 3 is arranged between the preheating section TPH and the preheating section PH.

Preferably, the anti-blow-by device 3 includes an airflow balance plate 301, a moving platform 302, rollers 303, and a slot 304. The air flow balancing plate 301 is arranged inside the chain grate 1. The moving platforms 302 are disposed at both sides of the outer lower ends of the preheating section PH and the preheating section PH. The rollers 303 are disposed at the bottom of the moving platform 302. The slots 304 are formed at both sides of the outer upper ends of the preheating section PH and the preheating section PH. The mobile platform 302 is further provided with a fixed seat 30201. The fixed seat 30201 is provided with an upright post 30202. The top end of the upright 30202 is connected to the top end of the air flow balance plate 301 after passing through the slot 304. A moving motor 30203 is also provided outside the moving platform 302. The moving motor 30203 drives the moving platform 302 to move on the roller 303. The moving platform 302 moves to drive the fixed seat 30201 and the upright post 30202 to move, and then the airflow balance plate 301 moves in the chain grate 1.

Preferably, the airflow balance plate 301 is composed of an outer plate 30101 and an inner plate 30102. The outer plate 30101 is a hollow plate. The inner plate 30102 is sleeved in the inner cavity of the outer plate 30101. The inner plate 30102 is also connected to a lift motor 30103. The lifting motor 30103 controls the inner plate 30102 to move in the vertical direction of the inner cavity of the outer plate 30101.

Preferably, the system also comprises an ammonia agent denitration device 4. The ammonia agent denitration device 4 is arranged in the preheating section PH and/or the first pipeline L1.

Preferably, the ammonia denitration device 4 includes a first sprayer 401, a second sprayer 402, and an ammonia storage tank 403. The first sprayer 401 is disposed in the preheating section PH. The second sprinkler 402 is disposed in the first pipe L1. The ammonia agent storage tank 403 is connected to the first sparger 401 through a second pipe L2. A third pipeline L3 is branched from the second pipeline L2 and connected with the second sprinkler 402.

Preferably, the system further comprises an SCR denitration device 5 and a dust removal device 6. And an air outlet of the preheating second section PH is communicated to an air inlet of the exhausting and drying section DDD through a fourth pipeline L4. And an air outlet of the induced draft drying section DDD is communicated to a chimney through a fifth pipeline L5. The SCR denitration device 5 is provided on the fourth duct L4. The dust removing device 6 is provided on the fifth pipe L5.

Preferably, the system further comprises a circulator 7. The ring cooling machine 7 is sequentially provided with a ring cooling first section C1, a ring cooling second section C2 and a ring cooling third section C3. An air outlet of the annular cooling section C1 is communicated to an air inlet of the rotary kiln 2 through a sixth pipeline L6. An air outlet of the annular cooling section C2 is communicated to an air inlet of the preheating section TPH through a seventh pipeline L7. And an air outlet of the annular cooling three-section C3 is communicated to an air inlet of the forced air drying section UDD through an eighth pipeline L8. The air outlet of the pre-heated section of TPH is communicated to a fifth pipeline L5 through a ninth pipeline L9. And an air outlet of the air blowing drying section UDD is communicated to a chimney through a tenth pipeline L10.

Preferably, the system further comprises a first pressure detector P1, a second pressure detector P2, a first temperature detector C1, a second temperature detector C2, a first flow detector Q1, a second flow detector Q2, and a flue gas analyzer Y. The first pressure detector P1, the first temperature detector C1 and the smoke analyzer Y are arranged in the preheating section of TPH. The second pressure gauge P2 and the second temperature gauge C2 are disposed within the preheating section PH. The first flow rate detector Q1 is provided on the seventh conduit L7. The second flow rate detector Q2 is provided on the first conduit L1.

1) according to the trend of materials, green pellets enter a chain grate machine 1 and are conveyed into a rotary kiln 2 for oxidizing roasting after sequentially passing through a blast drying section UDD, an exhaust drying section DDD, a preheating section TPH and a preheating section PH. And conveying the oxidized pellets after the oxidizing roasting to the circular cooler 7 for cooling.

2) According to the flow direction of the hot air, the hot air discharged from the annular cooling section C1 is delivered into the rotary kiln 2 through the sixth pipeline L6, and then delivered into the preheating section PH through the first pipeline L1. The hot wind discharged from the ring cooling section C2 is delivered into the pre-heating section TPH via the seventh duct L7.

3) The horizontal position of the air flow balance plate 301 disposed between the preheating section TPH and the preheating section PH is adjusted so that the pressure in the preheating section TPH is greater than or equal to the pressure in the preheating section PH.

4) The hot air in the preheated one stage TPH is finally discharged through a ninth conduit L9. The hot air in the preheating section PH is finally discharged through the fourth pipe L4.

Preferably, the method further comprises: a first pressure detector P1 is arranged in the preheating section of TPH for detecting the pressure in the preheating section of TPH to be P1 and Pa in real time. The first temperature detector C1 is also arranged to detect the gas temperature in the preheating section of TPH as C1 and K in real time.

Preferably, the second pressure detector P2 is provided in the preheating stage PH to detect the pressure P2, Pa in the preheating stage PH in real time. And a second temperature detector C2 is also arranged to detect the temperature of the gas in the preheating section PH to be C2 and K in real time.

Preferably, a first flow rate detector Q1 is further arranged on the seventh pipeline L7 for detecting the flow rate Q1, Nm of the gas delivered into the preheating section TPH in real time³H is used as the reference value. A second flow rate detector Q2 is arranged on the first pipeline L1 to detect the flow rate of the gas delivered into the preheating section PH as Q2 and Nm in real time³H is used as the reference value. The mass of gas fed into the pre-heated section of TPH is m1, g:

formula I, where m1 is ρ q 1.

The mass of gas delivered to the preheated section of TPH is m2, g:

formula II is denoted by m2 ═ ρ × q2 ·.

According to an ideal gas state equation, the following results are obtained:

formula III, p1 × v1 ═ ρ × q1 × t × R × c1/m.

P2 × v2 ═ ρ × q2 × t × R × c2/m.

In formulas III and IV, v1 is the volume of the preheated section of TPH, m³. v2 is the volume of the preheating two-stage PH, m³. R is a gas constant, J/(mol. K). M is the average molar mass of the gas, g/mol.

Preferably, the length of the preheating section TPH is a1, the width is b1, and the height is h1, and the units are m. The preheating section PH is set to have a length of a2, a width of b2, and a height of h2 in m. Then:

v1 ═ k1 a1 ═ b1 · h1..

V2 ═ k2 a2 ═ b2 · h2..

In formulas V and VI, k1 is the volume correction ratio for the preheated section of TPH. k2 is the volume correction ratio for the preheat section PH.

Substituting formula V into formula III to obtain:

formula VII, p1 ═ ρ × q1 ═ R × c1/(M × k1 × a1 × b1 × h1).

Substituting formula VI into formula IV to obtain:

p2 ═ ρ × q2 ═ R × c2/(M × k2 × a2 × b2 × h2.. formula VII.

The horizontal movement amount of the air flow balance plate 301 in the direction of the preheated stage TPH is set to Δ a, m. Then:

When Z is 1, the minimum amount Δ a of movement of the airflow balance plate 301 is equal to_minComprises the following steps:

the amount of horizontal movement Deltaa of the airflow balance plate 301 is adjusted to be equal to or larger than the calculated value Deltaa of the formula IX_minM, such that Z is ≧ 1, i.e., p1 ≧ p 2.

Preferably, when the horizontal displacement of the airflow balance plate 301 is adjusted to Δ a, the adjustment is performed in steps, and the number of times of adjustment is N, then:

n ═ p2-p1)/(0.05 × p 1.

When the required horizontal displacement of the airflow balance plate 301 is Δ a, the number of times of movement of the airflow balance plate 301 is the calculated value N of the equation X.

Preferably, a flue gas analyzer Y is arranged in the preheating section of TPH for detecting the content of NOx in the preheating section of TPH in real time to be less than or equal to 40mg/m³。

Example 1

As shown in fig. 1, the system for preventing the blow-by of the preheating section of the chain grate machine comprises a chain grate machine 1 and a rotary kiln 2. According to the trend of the materials, the chain grate 1 is sequentially provided with an air blowing drying section UDD, an air exhausting drying section DDD, a preheating section TPH and a preheating section PH. The preheating section PH is communicated with a smoke outlet of the rotary kiln 2 through a first pipeline L1. And an air channeling prevention device 3 is arranged between the preheating section TPH and the preheating section PH.

Example 2

Embodiment 1 is repeated except that the blow-by preventing device 3 includes an airflow balance plate 301, a moving platform 302, rollers 303, and a slot 304. The air flow balancing plate 301 is arranged inside the chain grate 1. The moving platforms 302 are disposed at both sides of the outer lower ends of the preheating section PH and the preheating section PH. The rollers 303 are disposed at the bottom of the moving platform 302. The slots 304 are formed at both sides of the outer upper ends of the preheating section PH and the preheating section PH. The mobile platform 302 is further provided with a fixed seat 30201. The fixed seat 30201 is provided with an upright post 30202. The top end of the upright 30202 is connected to the top end of the air flow balance plate 301 after passing through the slot 304. A moving motor 30203 is also provided outside the moving platform 302. The moving motor 30203 drives the moving platform 302 to move on the roller 303. The moving platform 302 moves to drive the fixed seat 30201 and the upright post 30202 to move, and then the airflow balance plate 301 moves in the chain grate 1.

Example 3

Embodiment 2 is repeated except that the air flow balance plate 301 is composed of an outer plate 30101 and an inner plate 30102. The outer plate 30101 is a hollow plate. The inner plate 30102 is sleeved in the inner cavity of the outer plate 30101. The inner plate 30102 is also connected to a lift motor 30103. The lifting motor 30103 controls the inner plate 30102 to move in the vertical direction of the inner cavity of the outer plate 30101.

Example 4

Example 3 was repeated except that the system further included an ammonia denitration device 4. The ammonia agent denitration device 4 is arranged in the preheating section PH and/or the first pipeline L1.

Example 5

Example 4 was repeated except that the ammonia agent denitration device 4 included a first sparger 401, a second sparger 402, and an ammonia agent storage tank 403. The first sprayer 401 is disposed in the preheating section PH. The second sprinkler 402 is disposed in the first pipe L1. The ammonia agent storage tank 403 is connected to the first sparger 401 through a second pipe L2. A third pipeline L3 is branched from the second pipeline L2 and connected with the second sprinkler 402.

Example 6

Example 5 was repeated except that the system further included SCR denitration device 5 and dust removal device 6. And an air outlet of the preheating second section PH is communicated to an air inlet of the exhausting and drying section DDD through a fourth pipeline L4. And an air outlet of the induced draft drying section DDD is communicated to a chimney through a fifth pipeline L5. The SCR denitration device 5 is provided on the fourth duct L4. The dust removing device 6 is provided on the fifth pipe L5.

Example 7

Example 6 is repeated except that the system also includes a circulator 7. The ring cooling machine 7 is sequentially provided with a ring cooling first section C1, a ring cooling second section C2 and a ring cooling third section C3. An air outlet of the annular cooling section C1 is communicated to an air inlet of the rotary kiln 2 through a sixth pipeline L6. An air outlet of the annular cooling section C2 is communicated to an air inlet of the preheating section TPH through a seventh pipeline L7. And an air outlet of the annular cooling three-section C3 is communicated to an air inlet of the forced air drying section UDD through an eighth pipeline L8. The air outlet of the pre-heated section of TPH is communicated to a fifth pipeline L5 through a ninth pipeline L9. And an air outlet of the air blowing drying section UDD is communicated to a chimney through a tenth pipeline L10.

Example 8

Example 7 is repeated except that the system further includes a first pressure gauge P1, a second pressure gauge P2, a first temperature gauge C1, a second temperature gauge C2, a first flow meter Q1, a second flow meter Q2, and a flue gas analyzer Y. The first pressure detector P1, the first temperature detector C1 and the smoke analyzer Y are arranged in the preheating section of TPH. The second pressure gauge P2 and the second temperature gauge C2 are disposed within the preheating section PH. The first flow rate detector Q1 is provided on the seventh conduit L7. The second flow rate detector Q2 is provided on the first conduit L1.

Method embodiment

The length of a section of TPH preheated by the chain grate machine is set to be 12m at a1, 4.5m at a b1 and 3m at a h1. The preheating section PH was set to have a length a2 of 15m, a width b2 of 4.5m, and a height h2 of 3 m. The volume correction ratio k1 for the preheated section TPH is 1. The volume correction ratio k2 for the preheating section PH is 1 (i.e., both the preheating section TPH and the preheating section PH of the chain grate machine are rectangular). When the gas flow balance plate 301 is in the initial position (i.e., the interface between the preheat primary TPH and the preheat secondary PH):

the volume of the preheated primary TPH is as follows: v 1-1 × 12 × 4.5 × 3-162 m³。

The volume of the preheating section PH is as follows: v2 ═ 1 × 15 × 4.5 × 3 ═ 202.5m³。

The flow rate of gas q1 delivered to the pre-heating section TPH was detected to be 100Nm³H is used as the reference value. The flow rate of the gas q2 fed into the preheating section PH was detected to be 150Nm³H is used as the reference value. The gas temperature in the pre-heated section of TPH was detected as c1 of 858.15K. The gas temperature c2 in the preheating section PH was detected to be 1250.15K.

In the running process of the system, if the pressure p1 in the preheating section of TPH is detected to be-900 Pa; the pressure P2 in the pre-heating section PH was detected to be-400 Pa. The following calculation is performed according to formula VIII and formula IX:

namely:

△a_min＝(12×4.5×3×1250.15×150-15×4.5×3×858.15×100)/(150×1250.15×4.5×3+100×858.15×4.5×3)＝9.47

calculating the horizontal displacement of the airflow balance plate 301 as Δ a ═ Δ a according to the formula X_minThe required adjustment times N are as follows:

n ═ p2-p1)/(0.05 × p 1.

Namely:

n (-400+900)/(0.05 x-900) | 11.11

When the airflow balance plate 301 is adjusted STEP by STEP, the single adjustment STEP is STEP: STEP ═ Δ_amin/Adjusting the airflow balance plate 301 (from the PH section to the TPH end) according to the calculated value of STEP, wherein the STEP length of each adjustment is 0.85m, detecting p1 and p2 after the adjustment is finished, and finishing the adjustment of the airflow balance plate 301 if p1 is not less than p 2; if p1 < p2, the adjustment of the airflow balance plate 301 is continued with a STEP size STEP of 0.85m until p1 ≧ p 2.

Claims

1. An anti-channeling wind system in the preheating section of a chain grate machine is characterized in that: the system comprises a chain grate machine (1) and a rotary kiln (2); There are blast drying section (UDD), exhaust drying section (DDD), preheating section (TPH) and preheating second section (PH); the preheating second section (PH) passes through the first pipeline (L1) and the rotary kiln The flue gas outlet of (2) is connected; an anti-channel wind device (3) is arranged between the first stage of preheating (TPH) and the second stage of preheating (PH).

2. The system according to claim 1, characterized in that: the anti-wind blowing device (3) comprises an airflow balance plate (301), a moving platform (302), a roller (303) and a slot (304); The airflow balance plate (301) is arranged inside the chain grate machine (1); the moving platform (302) is arranged on both sides of the outer lower ends of the first stage of preheating (PH) and the second stage of preheating (PH); the The rollers (303) are arranged at the bottom of the moving platform (302); the slots (304) are provided on both sides of the outer upper ends of the first stage of preheating (PH) and the second stage of preheating (PH); the moving platform (302) A fixing seat (30201) is also arranged on the fixing seat (30201); a column (30202) is arranged on the fixing seat (30201); The mobile platform (302) is also provided with a mobile motor (30203) outside; the mobile motor (30203) drives the mobile platform (302) to move on the rollers (303); the movement of the mobile platform (302) drives the The movement of the fixed seat (30201) and the upright column (30202) further drives the movement of the airflow balance plate (301) in the chain grate machine (1);

Preferably, the airflow balance plate (301) is composed of an outer plate (30101) and an inner plate (30102); the outer plate (30101) is a hollow plate body; the inner plate (30102) is sleeved outside the inner cavity of the plate (30101); the inner plate (30102) is also connected to a lift motor (30103); the lift motor (30103) controls the inner plate (30102) to move in the vertical direction of the inner cavity of the outer plate (30101) .

3. The system according to claim 1 or 2, characterized in that: the system further comprises an ammonia agent denitration device (4); the ammonia agent denitration device (4) is arranged in the second preheating stage (PH) and/or or in the first pipeline (L1);

Preferably, the ammonia agent denitration device (4) includes a first sprayer (401), a second sprayer (402) and an ammonia agent storage tank (403); the first sprayer (401) is arranged at a pre- in the second hot stage (PH); the second sprinkler (402) is arranged in the first pipeline (L1); the ammonia agent storage tank (403) communicates with the first sprinkler (401) through the second pipeline (L2) ) is connected; a third pipe (L3) is branched from the second pipe (L2) and is connected with the second sprinkler (402).

4. The system according to any one of claims 1-3, characterized in that: the system further comprises an SCR denitration device (5) and a dust removal device (6); The air outlet is connected to the air inlet of the extraction and drying section (DDD) through the fourth pipeline (L4); the air outlet of the extraction and drying section (DDD) is connected to the chimney through the fifth pipeline (L5); the SCR denitration device (5) is arranged on the fourth duct (L4); the dust removal device (6) is arranged on the fifth duct (L5).

5. The system according to any one of claims 1-4, characterized in that: the system further comprises a ring cooler (7); the ring cooler (7) is sequentially provided with a ring cooling section (C1) , the second stage of annular cooling (C2) and the third stage of annular cooling (C3); the air outlet of the first stage of annular cooling (C1) is connected to the air inlet of the rotary kiln (2) through the sixth pipeline (L6); the annular cooling The air outlet of the second stage (C2) is connected to the air inlet of the preheating first stage (TPH) through the seventh duct (L7); the air outlet of the third annular cooling stage (C3) is connected to the blast through the eighth duct (L8). The air inlet of the drying section (UDD); the air outlet of the preheating section (TPH) is connected to the fifth duct (L5) through the ninth duct (L9); the air outlet of the blast drying section (UDD) passes through the Ten pipes (L10) are connected to the chimney.

6. The system according to claim 5, characterized in that: the system further comprises a first pressure detector (P1), a second pressure detector (P2), a first temperature detector (C1), a second temperature detector A detector (C2), a first flow detector (Q1), a second flow detector (Q2), and a flue gas analyzer (Y); the first pressure detector (P1), the first temperature detector (C1) ) and the flue gas analyzer (Y) are arranged in the first stage of preheating (TPH); the second pressure detector (P2) and the second temperature detector (C2) are arranged in the second stage of preheating (PH); The first flow detector (Q1) is arranged on the seventh pipeline (L7); the second flow detector (Q2) is arranged on the first pipeline (L1).

7. A method for controlling air flow in the preheating section of a chain grate machine or a method for controlling air flow using the anti-channeling wind system in the preheating section of the chain grate machine according to any one of claims 1 to 6, wherein the method comprises the following steps: Follow the steps below:

1) According to the direction of the material, the raw balls enter the chain grate machine (1), and then pass through the blast drying section (UDD), the exhaust drying section (DDD), the first stage of preheating (TPH) and the second stage of preheating (PH) and then conveyed. Carry out oxidative roasting in the rotary kiln (2); the oxidized pellets after the oxidative roasting is completed are transported to the ring cooler (7) for cooling;

2) According to the flow direction of the hot air, the hot air discharged from the first stage (C1) of the ring cooling is transported to the rotary kiln (2) through the sixth pipeline (L6), and then transported to the second preheating stage (PH) through the first pipeline (L1) Inside; the hot air discharged from the second stage of ring cooling (C2) is transported to the first stage of preheating (TPH) through the seventh pipeline (L7);

3) Adjust the horizontal position of the airflow balance plate (301) set between the preheating first stage (TPH) and the preheating second stage (PH), so that the pressure in the preheating first stage (TPH) is greater than or equal to the preheating second stage ( PH) pressure;

4) The hot air in the first stage of preheating (TPH) is finally discharged through the ninth pipe (L9); the hot air in the second stage of preheating (PH) is finally discharged through the fourth pipe (L4).

8. The method according to claim 7, characterized in that: the method further comprises: a first pressure detector (P1) is provided in the preheating section (TPH) to detect the air pressure in the preheating section (TPH) in real time as p1, Pa; also provided with a first temperature detector (C1) real-time detection of the gas temperature in the preheating section (TPH) is c1, K;

A second pressure detector (P2) is arranged in the second preheating stage (PH) to detect the air pressure in the second preheating stage (PH) in real time as p2, Pa; a second temperature detector (C2) is also arranged to detect the preheating pressure in real time. The gas temperature in the second hot stage (PH) is c2, K;

A first flow detector (Q1) is also provided on the seventh pipeline (L7) to detect the gas flow delivered to the first stage of preheating (TPH) in real time as q1, Nm ³ /h; set on the first pipeline (L1) There is a second flow detector (Q2) for real-time detection of the gas flow delivered to the second preheating stage (PH) as q2, Nm ³ /h; then the gas mass delivered to the first stage of preheating (TPH) is m1, g:

m1=ρ*q1*t... formula I;

The mass of gas delivered to the preheating section (TPH) is m2, g:

m2=ρ*q2*t... formula II;

In Formula I and Formula II, ρ is the average density of the gas, g/m ³ ; t is the gas delivery time, h;

According to the ideal gas equation of state, we get:

p1*v1=ρ*q1*t*R*c1/M... Formula III;

p2*v2=ρ*q2*t*R*c2/M... Formula IV;

In Formula III and Formula IV, v1 is the volume of the first stage of preheating (TPH), m ³ ; v2 is the volume of the second stage of preheating (PH), m ³ ; R is the gas constant, J/(mol·K); M is the average molar mass of the gas, g/mol.

9. The method according to claim 8, characterized in that: the length of the preheating one stage (TPH) is set as a1, the width is b1, the height is h1, and the unit is m; the set preheating stage two (PH) The length is a2, the width is b2, the height is h2, and the unit is m; then:

v1=k1*a1*b1*h1...Formula V;

v2=k2*a2*b2*h2...Formula VI;

In Formula V and Formula VI, the k1 is the volume correction ratio of the first stage of preheating (TPH); k2 is the volume correction ratio of the second stage of preheating (PH);

Substituting formula V into formula III, we get:

p1=ρ*q1*t*R*c1/(M*k1*a1*b1*h1)...Formula VII;

Substituting formula VI into formula IV, we get:

p2=ρ*q2*t*R*c2/(M*k2*a2*b2*h2)... formula VII;

Set the horizontal movement amount of the airflow balance plate (301) to the preheating stage (TPH) direction as Δa, m; then:

Z=p1/p2=[q1*c1*k2*(a2-△a)*b2*h2]/[q2*c2*k1*(a1+△a)*b1*h1]...Formula VIII;

When Z=1, the minimum amount of movement Δa _min of the airflow balance plate (301) is:

By adjusting the horizontal movement amount Δa of the airflow balance plate (301) to be greater than or equal to the calculated value Δa _min ,m of formula IX, Z≥1, that is, p1≥p2.

10. The method according to claim 9, characterized in that: when adjusting the horizontal displacement of the airflow balance plate (301) to be Δa, it is a step-by-step adjustment, and the number of adjustments is set to N, then:

N=|(p2-p1)/(0.05*p1)|...Formula X;

When the required horizontal displacement of the airflow balance plate (301) is Δa, the number of movements of the airflow balance plate (301) is the calculated value N of the formula X;

Preferably, a flue gas analyzer (Y) is also provided in the first stage of preheating (TPH) to detect in real time the NOx content in the first stage of preheating (TPH) is less than or equal to 40 mg/m ³ .