Production process for reducing environmental pollution of steel rolling heating furnace

Abstract

The invention aims to provide a production process for reducing environmental pollution of a steel rolling heating furnace, which is combined with current heating equipment to improve the removal process of nitrogen oxides, sulfur dioxide and particulate matters one by one, and the indexes of sulfur dioxide and nitrogen oxides in air smoke and soot after transformation reach an ultralow emission standard; flue gas with the sulfur dioxide content of about 250 mg / m < 3 > can be reduced to 20 mg / m < 3 > or below through calcium-based fixed bed dry desulfurization, and the desulfurization effect is obvious; the flue gas with the nitrogen oxide content of 300 mg / m < 3 > can be reduced to 30 mg / m < 3 > or below through SCR denitration, when the use amount of the ammonia water reaches 0.02-0.025 m < 3 > / h, the nitrogen oxide cannot be detected, denitration is thorough, and clean production is completely achieved.

Description

Technical Field

[0001] The invention relates to a production process for reducing environmental pollution of a steel rolling heating furnace. Background Art

[0002] The "Emission Standards for Air Pollutants from the Steel Rolling Industry" stipulates that the pollutant emission indicators for steel rolling heating furnaces are particulate matter, sulfur dioxide, and nitrogen oxides. Conventional heating furnaces and regenerative heating furnaces cannot guarantee that the pollutant indicators in the exhaust gas meet the specified standards by relying on existing process control. Therefore, it is a future development trend to gradually introduce desulfurization and denitrification treatment technologies into steel rolling heating furnaces to ensure that the heating furnaces meet the pollutant emission standards.

[0003] Baosteel's heating furnace uses high-pressure and coke oven mixed gas as the main fuel. The furnace type uses a high-yield, low-consumption, intelligent regenerative heating furnace. By optimizing process control, the production of pollutants is reduced; at the same time, reasonable desulfurization and denitrification technologies are selected to thoroughly control SO2 and NOX in flue gas. A two-pronged approach is used to reduce pollutant emission indicators and realize a "green" factory. Particulate matter, also known as smoke, is mainly a combination of carbonaceous materials, water-soluble particles, mineral dust, heavy metal elements, smoke particles, etc.

[0004] Nitrogen oxides are formed by oxidation of nitrogen contained in fuel and nitrogen in air during high-temperature combustion, and do not react at room temperature. There are three ways to generate nitrogen oxides: the first is that its generation is related to the combustion equipment, oxygen concentration and residence time. When the burner temperature is less than 1500°C, the generation amount is very small, and when the combustion temperature is greater than 1500°C, the generation amount increases dramatically (thermal NO x); the second is that CH free radicals produced by high-temperature decomposition of hydrocarbons react with nitrogen in the air to produce HCN and N, and then further react with oxygen to quickly generate NO (rapid NO x); the third is nitrogen oxides generated by oxidation of nitrogen compounds contained in the fuel during combustion (fuel-type NO x). Therefore, the generation of nitrogen oxides is greatly affected by coal gas combustion. Through process optimization and control, the generation of nitrogen oxides can be effectively reduced, thereby reducing the difficulty of flue gas treatment.

[0005] Sulfur dioxide is mainly a sulfide generated by the chemical reaction of sulfur combustion contained in the fuel. Generally, the sulfur content in blast furnace gas is 40-200mg / m3, of which inorganic sulfur H2S is 10-50mg / m3, and organic sulfur COS, CS2 and other contents are as high as 80-150mg / m3; most of the sulfur in coke oven gas appears in the form of H2S, and its content is greatly affected by the front-end desulfurization process, and the total sulfur content is controlled at about 300mg / m3. Sulfur dioxide comes from fuel and will not increase or decrease due to the chemical combustion process, so the control of sulfur dioxide in the flue gas content of the heating furnace must be carried out by using relevant desulfurization equipment.

[0006] At present, the regenerative heating furnace is 36.5m long and 14.6m wide. The fuel used is high coke oven mixed gas with a calorific value of 1500-2000kcal / m 3 , hourly output 280t / h, 44 groups of regenerative burners are distributed up and down on both sides of the heating furnace, air and gas working arrangement, rated flue gas volume 139584Nm3 / h.

[0007] The comparison of the air smoke and soot pollutant emission data of the regenerative heating furnace in 2022-2023 and the environmental protection indicators of the steel rolling heating furnace proposed in the Opinions on Promoting the Implementation of Ultra-low Emissions in the Steel Industry

[2019] No. 35 is as follows:

[0008]

[0009] It can be seen from this that the current pollutant emission indicators of the regenerative heating furnace cannot meet the ultra-low emission standards. It is urgent to carry out comprehensive treatment of the flue gas of the heating furnace through process optimization and equipment improvement to meet environmental protection emission standards. Summary of the invention

[0010] The purpose of the present invention is to provide a production process for reducing environmental pollution of steel rolling heating furnaces, and to improve the removal processes of nitrogen oxides, sulfur dioxide and particulate matter one by one in combination with current heating equipment.

[0011] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0012] The present invention discloses a production process for reducing environmental pollution of a steel rolling heating furnace, comprising:

[0013] (1) Flue gas desulfurization treatment

[0014] Specifically include:

[0015] Choose dry desulfurization;

[0016] Fixed bed desulfurization;

[0017] Flue gas denitrification treatment

[0018] (2) Specifically include:

[0019] Process Control:

[0020] Reasonably set the excess air coefficient, set it to 0.85-0.95 in the soaking section and the third high-temperature section, so that the furnace has a weak reducing atmosphere; set it to 1.0-1.15 in the second section, so that the furnace has a neutral atmosphere; set it to 1.1-1.2 in the first section, so that the furnace has an oxidizing atmosphere; this setting can not only meet the needs of continuous and stable heating, but also effectively control the oxygen content in the high-temperature section and reduce the production of nitrogen oxides. At the same time, combined with the calorific value of coal gas, set a reasonable air-fuel ratio to ensure that the residual oxygen content in each section is less than 4%

[0021] The reversing cycle of the soaking stage and the third stage is set to 30-45s, and the second and first stages are set to 30-60s, which shortens the residence time of the flue gas at high temperature and reduces the generation of nitrogen oxides.

[0022] Denitrification technology selection:

[0023] Selective catalytic reduction denitrification, namely SCR denitrification technology.

[0024] Furthermore, the dry desulfurization is calcium-based dry desulfurization.

[0025] Furthermore, the SCR denitration system mainly includes: hot blast furnace flue gas heating system, ammonia water storage system, reducing agent delivery system, ammonia water evaporation system, ammonia injection grid, SCR denitration reactor; its process flow:

[0026] After the air smoke and coal smoke from the regenerative heating furnace have undergone the desulfurization process respectively, they enter the primary heat exchanger for heat exchange with the flue gas to be discharged, and the inlet coal smoke is heated from 100°C to 170°C. After the secondary heat exchange with the high-temperature flue gas from the hot blast furnace heating furnace, the flue gas temperature is further increased to above 200°C to reach the optimal temperature for the catalytic reaction. When passing through the ammonia evaporator, the ammonia water is evaporated into ammonia gas, and then the ammonia-containing mixed flue gas is evenly sprayed into the denitrification reactor through the ammonia injection grid. Through the graded reaction of the two catalyst layers, the nitrogen oxides in the flue gas are fully converted into nitrogen and water. After heat exchange with the inlet flue gas temperature in the primary heat exchanger, it is discharged through the booster induced draft fan at a flue gas temperature of 133°C.

[0027] Furthermore, the design and installation of the desulfurization tower: the air smoke and coal smoke of the regenerative heating furnace are discharged and treated separately. According to the flue gas volume, 4 groups of air smoke desulfurization towers and 3 groups of coal smoke desulfurization towers are designed, with a total of 7 unit modules; the flue gas sampling is selected before the original fan outlet pipe is merged into the chimney, and the electric valve is added with two-way control to ensure the original system function and meet the desulfurization tower design requirements; the air smoke source comes from the direct exhaust of the high-temperature auxiliary flue and the air smoke exhaust system, and the origin of the coal smoke comes directly from the exhaust of the coal smoke system;

[0028] The module size of desulfurization tower unit 1-7 is 3.5m long, 3.2m wide, 15.725m high and 78.63m in volume. 3 , filling volume 75.39m 3The desulfurization tower has three floors and four platforms. At the bottom of the first desulfurization tower, there are unloading valves and scrapers, which are responsible for waste transportation; the second floor has a flue gas inlet valve; the third floor has a flue gas outlet valve; the top of the fourth desulfurization tower has a loading port and an electric hoist crane, which are responsible for desulfurizer filling; the air intake layout adopts bottom-in and top-out, and the internal structure adopts return flow to slow down the flue gas flow rate and improve the adsorption capacity of sulfur dioxide; the operation process is negative pressure operation, the working pressure is -4-0kpa, and the pressure drop is 500-2000pa. As the service life is extended, the desulfurizer reaction becomes hardened and the pressure drop gradually increases. The desulfurizer is replaced to ensure smooth exhaust.

[0029] Furthermore, the SCR denitrification technology uses medium and low temperature catalysts.

[0030] Compared with the prior art, the beneficial technical effects of the present invention are:

[0031] After the transformation, the sulfur dioxide and nitrogen oxide indicators of air and coal smoke reached the ultra-low emission standards; the sulfur dioxide content was 250mg / m 3 Flue gas can be reduced to 20mg / m3 by calcium-based fixed bed dry desulfurization. 3 Below, the desulfurization effect is obvious; nitrogen oxide content 300mg / m 3 The flue gas can be reduced to 30mg / m3 through SCR denitrification. 3 Below, and when the amount of ammonia water reaches 0.02-0.025m 3 / h, no nitrogen oxides were detected, denitrification was thorough, and clean production was fully realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below in conjunction with the accompanying drawings.

[0033] Figure 1 This is the flow chart of the coal smoke denitrification system;

[0034] Figure 2 This is a schematic diagram of the process structure of the coal smoke denitrification system. DETAILED DESCRIPTION

[0035] A production process for reducing environmental pollution of a steel rolling heating furnace, comprising:

[0036] 1 Flue gas desulfurization treatment plan

[0037] 1.1 Selection of desulfurization technology

[0038] Common desulfurization processes include wet, semi-dry and dry desulfurization. Compared with traditional wet desulfurization, dry desulfurization has the characteristics of high efficiency, low operating cost and low environmental pollution. Therefore, dry desulfurization is more suitable for desulfurization of flue gas from heating furnaces. Dry desulfurization technologies include activated carbon adsorption, SDS sodium-based dry desulfurization, calcium-based fixed bed dry desulfurization, etc. Considering the equipment construction, operation and maintenance, desulfurization efficiency, secondary pollution, labor intensity and input cost, the activated carbon adsorption method has high production control requirements and complex operation. The sodium-based solid waste formed by SDS dry desulfurization is difficult to handle. Although the cost of calcium-based fixed bed dry desulfurization is high, it has a simple process, high desulfurization efficiency, and easy to handle general solid waste (gypsum). It is unmanned and simple to maintain. It can match the process control of heating furnaces and is more suitable for the current flue gas desulfurization of heating furnaces.

[0039] 1.2 Fixed bed desulfurization

[0040] Calcium-based dry desulfurization principle

[0041] Calcium-based dry desulfurization technology is that when the flue gas passes through a desulfurization tower containing a calcium-based desulfurizer, the sulfur dioxide in the flue gas is adsorbed on the desulfurizer and reacts with it to form calcium sulfate and water.

[0042] Ca(OH)2+SO2=CaSO3+H2O

[0043] Ca(OH)2+SO3=CaSO4+H2O

[0044] Ca(OH)2+HF=CaF2+H2O

[0045] Ca(OH)2+HCl=CaCl2+H2O

[0046] Ca(OH)2+SO2+1 / 2O2=CaSO4+H2O

[0047] Design and installation of desulfurization tower

[0048] The air smoke and coal smoke of the regenerative heating furnace are discharged independently, so they need to be treated separately. According to the flue gas volume, 4 groups of desulfurization towers for air smoke and 3 groups of desulfurization towers for coal smoke are designed, with a total of 7 unit modules. Because it is a retrofit design that needs to be integrated with the original equipment, the flue gas sampling is selected before the original fan outlet pipe is merged into the chimney. The addition of electric valve two-way control can ensure the original system function and meet the desulfurization tower design requirements. The air smoke source comes from the direct exhaust of the high-temperature auxiliary flue and the air smoke exhaust system flue gas, and the origin of the coal smoke comes directly from the exhaust of the coal smoke system.

[0049] The module size of desulfurization tower unit 1-7 is 3.5m long, 3.2m wide, 15.725m high and 78.63m in volume. 3 , filling volume 75.39m 3The desulfurization tower has three floors and four platforms. At the bottom of the first desulfurization tower, there are unloading valves and scrapers, which are responsible for waste transportation; the second floor has a flue gas inlet valve; the third floor has a flue gas outlet valve; the fourth floor has a loading port and an electric hoist crane at the top of the desulfurization tower, which are responsible for desulfurizer filling; the air intake layout adopts bottom-in and top-out, and the internal structure adopts return flow to slow down the flue gas flow rate and improve the adsorption capacity of sulfur dioxide; the operation process is negative pressure operation, the working pressure is -4-0kpa, and the pressure drop is 500-2000pa. As the service life is extended, the desulfurizer reaction becomes hardened and the pressure drop gradually increases, and the desulfurizer needs to be replaced to ensure smooth exhaust.

[0050] 2. Flue gas denitrification treatment plan

[0051] To achieve flue gas denitrification, we need to start from reducing the generation of nitrogen oxides and flue gas denitrification treatment; the optimization of process control can reduce the generation of nitrogen oxides and reduce the difficulty of back-end denitrification; flue gas denitrification treatment is the backup and guarantee, which can achieve precise denitrification.

[0052] 2.1 Process Control

[0053] According to the formation mechanism of nitrogen oxides, it can be concluded that the main measures to control the formation of nitrogen oxides are: lowering the combustion temperature; reducing the oxygen content in combustion; shortening the residence time of flue gas; and reducing the concentration of nitrogen brought into the fuel.

[0054] The regenerative heating furnace burner is a regenerative burner arranged on the left and right. Air and gas are ejected at high speed through nozzle bricks at a certain angle, so that they are gradually mixed in the furnace, achieving the purpose of delaying diffuse combustion and reducing the production of nitrogen oxides.

[0055] In the intelligent transformation of combustion control, the excess air coefficient is set reasonably, and is set to 0.85-0.95 in the equalizing section and the third high-temperature section to make the furnace a weak reducing atmosphere; the second section is set to 1.0-1.15 to make the furnace a neutral atmosphere; the first section is set to 1.1-1.2 to make the furnace an oxidizing atmosphere; this setting can not only meet the needs of continuous and stable heating, but also effectively control the oxygen content in the high-temperature section and reduce the production of nitrogen oxides. At the same time, combined with the calorific value of coal gas, a reasonable air-fuel ratio is set to ensure that the residual oxygen content in each section is less than 4%.

[0056] Due to the characteristics of periodic reversing combustion of regenerative burners, the flue gas temperature does not reach the intense production zone of nitrogen oxides during the combustion process and the reversing period is generally set to 30-45s for the equalizing section and the third section, and 30-60s for the second and first sections, which shortens the residence time of the flue gas at high temperature and reduces the generation of nitrogen oxides.

[0057] 2.2 Denitrification Technology Selection

[0058] The current denitrification technology can be divided into two categories: dry and wet. Dry methods include selective non-catalytic reduction (SNCR), selective catalytic reduction (SCR), adsorption, etc.; wet methods include water absorption, acid absorption, alkali absorption, oxidation absorption, etc. The common method for flue gas denitrification in steel rolling heating furnaces is dry denitrification. SNCR denitrification technology is an early denitrification technology. It is generally installed in the preheating section of a conventional heating furnace with a flue gas temperature of 1000-1080°C. Ammonia water spraying is used to form a curtain. When the high-temperature flue gas passes through, nitrogen oxides react with ammonia water. This method has a complex structure and is difficult to maintain. The denitrification efficiency generally does not exceed 60%, and nitrogen oxides are controlled at 50mg / m 3 If there are abnormal production situations such as waiting for rolling, the ultra-low emission standards cannot be met.

[0059] As long as there is enough ammonia water and a reasonable reaction temperature, the denitration efficiency of SCR denitration can be as high as 90%. The preheating section of the regenerative heating furnace is short, the space is insufficient, and the flue gas temperature is 70-180℃, which is more suitable for SCR denitration technology.

[0060] 2.3 Selective catalytic reduction denitrification

[0061] 2.3.1SCR Denitrification Principle

[0062] SCR flue gas denitrification technology is based on the denitrification reducing agent NH 3 Under certain temperature and catalyst, it "selectively" reacts with NOx in flue gas to generate non-toxic and non-polluting nitrogen and water. The reaction formula is as follows:

[0063] 4NO+4NH 3 +O 2 →4N 2 +6H 2 O

[0064] 2NO 2 +4NH 3 +O 2 →3N 2 +6H 2 O

[0065] Catalyst is the core of SCR denitrification process. Catalyst materials can be divided into three parts based on their functions: active ingredients, carriers and auxiliary materials. 2 It is the most suitable denitrification catalyst carrier, V 2 Os is the main active component with high denitrification efficiency. In recent years, the steel industry has generally adopted medium and low temperature catalysts. By using appropriate catalysts, the denitrification reaction is effectively carried out in the range of 180-230°C, and under the appropriate ammonia nitrogen ratio, efficient denitrification can be achieved.

[0066] 2.3.2 Design and installation of denitrification system

[0067] The SCR denitration system mainly includes: hot blast furnace flue gas heating system, ammonia water storage system, reducing agent delivery system, ammonia water evaporation system, ammonia injection grid, SCR denitration reactor, etc. Its process flow:

[0068] After the air smoke and coal smoke from the regenerative heating furnace have undergone the desulfurization process respectively, they enter the primary heat exchanger for heat exchange with the flue gas to be discharged, and the inlet coal smoke is heated from 100°C to about 170°C. After the secondary heat exchange with the high-temperature flue gas from the hot blast furnace heating furnace, the flue gas temperature is further increased to above 200°C to reach the optimal temperature for the catalytic reaction. When passing through the ammonia evaporator, the ammonia water is evaporated into ammonia gas, and then the ammonia-containing mixed flue gas is evenly sprayed into the denitrification reactor through the ammonia injection grid. Through the graded reaction of the two catalyst layers, the nitrogen oxides in the flue gas are fully converted into nitrogen and water. After heat exchange with the inlet flue gas temperature in the primary heat exchanger, it is discharged through the booster induced draft fan at a flue gas temperature of 133°C.

[0069] The hot blast furnace introduces mixed coal gas and air and ignites it to heat part of the air smoke, generating high-temperature air smoke above 400°C. Part of it passes directly through the air smoke secondary heat exchange pipeline; part of it passes through the coal smoke secondary heat exchanger and then returns to the air smoke pipeline; its purpose is to perform secondary heating (heat exchange) of air smoke and coal smoke to the required temperature for denitrification reaction.

[0070] The ammonia system includes an ammonia storage system, a reducing agent delivery system, an ammonia evaporation system, and an ammonia injection grid. The site is equipped with a 20% ammonia storage tank with a capacity of 37.2m 3 The ammonia water is pressurized by the delivery pump and sent to the ammonia water evaporator for vaporization, and the ammonia-containing flue gas is fully reacted with the denitrification catalyst through the ammonia injection grid.

[0071] 3. The effect achieved

[0072] The desulfurization and denitrification transformation of the regenerative heating furnace has been completed, and the commissioning and operation are normal. The air smoke and soot pollutant emissions have reached a compliance rate of more than 95% through continuous monitoring data of the CEMS online monitoring instrument. It has passed the third-party monitoring certification of the Energy Conservation and Environmental Protection Industry Company. The specific data are as follows:

[0073]

[0074]

[0075] Through data analysis, it can be concluded that the sulfur dioxide and nitrogen oxide indicators of air smoke and coal smoke after the transformation have reached ultra-low emission standards; the sulfur dioxide content is 250mg / m 3 Flue gas can be reduced to 20mg / m3 by calcium-based fixed bed dry desulfurization. 3 Below, the desulfurization effect is obvious; nitrogen oxide content 300mg / m 3The flue gas can be reduced to 30mg / m3 through SCR denitrification. 3 Below, and when the amount of ammonia water reaches 0.02-0.025m 3 / h, no nitrogen oxides were detected, denitrification was thorough, and clean production was fully realized.

[0076] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A production process for reducing environmental pollution of a steel rolling heating furnace, characterized in that: include: (1) Flue gas desulfurization treatment Specifically include: Choose dry desulfurization; Fixed bed desulfurization; Flue gas denitrification treatment (2) Specifically include: Process control: Reasonably set the excess air coefficient, set it to 0.85-0.95 in the soaking section and the third high-temperature section, so that the furnace has a weak reducing atmosphere; set it to 1.0-1.15 in the second section, so that the furnace has a neutral atmosphere; set it to 1.1-1.2 in the first section, so that the furnace has an oxidizing atmosphere; this setting can not only meet the needs of continuous and stable heating, but also effectively control the oxygen content in the high-temperature section and reduce the production of nitrogen oxides. At the same time, combined with the calorific value of coal gas, set a reasonable air-fuel ratio to ensure that the residual oxygen content in each section is less than 4% The reversing cycle of the soaking stage and the third stage is set to 30-45s, and the second and first stages are set to 30-60s, which shortens the residence time of the flue gas at high temperature and reduces the generation of nitrogen oxides. Denitrification technology selection: Selective catalytic reduction denitrification, namely SCR denitrification technology.

2. The production process for reducing environmental pollution of a steel rolling heating furnace according to claim 1, characterized in that: The dry desulfurization is calcium-based dry desulfurization.

3. The production process for reducing environmental pollution of a steel rolling heating furnace according to claim 1, characterized in that: The SCR denitration system mainly includes: hot blast furnace flue gas heating system, ammonia water storage system, reducing agent delivery system, ammonia water evaporation system, ammonia injection grid, SCR denitration reactor; its process flow: After the air smoke and coal smoke from the regenerative heating furnace have undergone the desulfurization process respectively, they enter the primary heat exchanger for heat exchange with the flue gas to be discharged, and the inlet coal smoke is heated from 100°C to 170°C. After the secondary heat exchange with the high-temperature flue gas from the hot blast furnace heating furnace, the flue gas temperature is further increased to above 200°C to reach the optimal temperature for the catalytic reaction. When passing through the ammonia evaporator, the ammonia water is evaporated into ammonia gas, and then the ammonia-containing mixed flue gas is evenly sprayed into the denitrification reactor through the ammonia injection grid. Through the graded reaction of the two catalyst layers, the nitrogen oxides in the flue gas are fully converted into nitrogen and water. After heat exchange with the inlet flue gas temperature in the primary heat exchanger, it is discharged through the booster induced draft fan at a flue gas temperature of 133°C.

4. The production process for reducing environmental pollution of a steel rolling heating furnace according to claim 1, characterized in that: Design and installation of desulfurization tower: The air smoke and coal smoke of the regenerative heating furnace are discharged and treated separately. According to the flue gas volume, 4 groups of desulfurization towers for air smoke and 3 groups of desulfurization towers for coal smoke are designed, with a total of 7 unit modules; the flue gas sampling is selected before the original fan outlet pipe is merged into the chimney, and the electric valve is added with two-way control to ensure the original system function and meet the desulfurization tower design requirements; the air smoke source comes from the direct exhaust of the high-temperature auxiliary flue and the air smoke exhaust system, and the origin of the coal smoke comes directly from the exhaust of the coal smoke system; The module size of desulfurization tower unit 1-7 is 3.5m long, 3.2m wide, 15.725m high and 78.63m in volume. 3 , filling volume 75.39m 3 The desulfurization tower has three floors and four platforms. At the bottom of the first desulfurization tower, there are unloading valves and scrapers, which are responsible for waste transportation; the second floor has a flue gas inlet valve; the third floor has a flue gas outlet valve; the top of the fourth desulfurization tower has a loading port and an electric hoist crane, which are responsible for desulfurizer filling; the air intake layout adopts bottom-in and top-out, and the internal structure adopts return flow to slow down the flue gas flow rate and improve the adsorption capacity of sulfur dioxide; the operation process is negative pressure operation, the working pressure is -4-0kpa, and the pressure drop is 500-2000pa. As the service life is extended, the desulfurizer reaction becomes hardened and the pressure drop gradually increases. The desulfurizer is replaced to ensure smooth exhaust.

5. The production process for reducing environmental pollution of a steel rolling heating furnace according to claim 1, characterized in that: SCR denitrification technology uses medium and low temperature catalysts.

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