Summary of construction specification standards for exhaust gas stacks (chimneys) and requirements regarding chimney height

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In the design and construction of chimneys, many enterprises may not pay sufficient attention to industry-specific emission standards. As a result, the final configuration of the exhaust stacks often fails to meet environmental protection requirements. Today, we will compile various waste gas emission standards set by the Ministry of Ecology and Environment and discuss them in light of practical circumstances. Specifically, we will explore how enterprises should design chimney specifications and what height requirements apply to chimneys across different industries. It is hoped that this information will be useful to construction entities. I hope to receive criticism, corrections, and feedback regarding my shortcomings. I. General provisions for the design of specifications for exhaust chimneys (exhaust stacks) 1. The structural design of chimneys shall comply with the requirements of the \"Code for Design of Chimneys\" (GB 50051–2002) and the \"Code for Design of Steel Structures\" (GB 50017–2003). 2. When designing a chimney, factors such as operating conditions, functional requirements, chimney height, material availability, and construction conditions should be considered to determine whether to use a brick chimney, a reinforced concrete chimney, or a steel chimney. 3. Brick chimneys should not be used in the following situations: ① Important chimneys or those with a height exceeding 60 m; ② Chimneys located in areas with a seismic intensity of 9 degrees; ③ For chimneys situated in Site Categories III and IV when the seismic intensity is 8 degrees. 4. Plate foundations are generally recommended for chimney foundations. Slab foundations can be ring-shaped or circular. Shell foundations can be used when conditions permit. 5. The heating temperatures of the chimney shaft walls and foundations shall comply with the following requirements: ① The maximum heating temperature of the shaft walls made of ordinary sintered clay bricks shall not exceed 400°C; ② The heating temperatures of reinforced concrete shaft walls and foundations, as well as plain concrete foundations, shall not exceed 150°C; ③ The maximum heating temperature of steel chimney shaft walls shall comply with relevant regulations. 6. The loads and actions on chimneys can be classified into the following three categories: ① Permanent loads and actions: self-weight of the structure, weight of soil. Earth pressure, tension in the tie rods; ② Variable loads and their effects; ③ Accidental loads: rare earthquakes, breakage of tie rods, impacts, explosions, etc. 7. The height of the chimney shall meet both the **pollutant emission standards and the requirements of environmental assessment. II. Provisions on the height of exhaust stacks under various air emission standards 1 Maximum allowable emission concentration: The concentration of any pollutant in the exhaust stack after treatment shall not exceed this limit at any given hour ； 2 Maximum permissible emission rate: The limit beyond which the mass of pollutants emitted per hour from a stack at a certain height must not exceed ； 3. Unorganized emissions: Any smoke, dust, productive particulates, and other harmful pollutants that escape without passing through chimneys or exhaust systems are considered unorganized emissions ； \"Emission Standards for Air Pollutants from Boilers\" 2014: \"Emission Standards for Air Pollutants in the Cement Industry\" – provisions regarding the minimum height of exhaust stacks, etc. 4. Provisions in the \"Emission Standards for Pollutants from Electroplating Processes\": Production processes that generate air pollutants must be equipped with local gas collection systems and centralized purification units; the purified gas is then emitted through exhaust stacks. The height of exhaust stacks shall be no less than 15 m; for stacks emitting hydrogen cyanide-containing gases, the height shall be no less than 25 m. The height of the exhaust stack should be at least 5 meters higher than the heights of the buildings within a 200-meter radius around it ； For exhaust stacks that cannot reach the required height, the limits shall be applied at 50% of the emission concentration limit. 5. Provisions in the \"Emission Standards for Air Pollutants in the Cement Industry\": Except for individual dust removal systems at the bottom of storage areas, pits, and material transfer points, the height of other exhaust stacks should be no less than 15 meters. The exhaust stack should be at least 3 meters above the main building structure. When there are buildings within a 200-meter radius around the stack of a cement kiln and its waste heat utilization system, the height of the stack must be at least 3 meters higher than that of the tallest building. 6. Provisions in the \"Emission Standards for Pollutants in the Coking Chemical Industry\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m (the height of exhaust stacks discharging hydrogen cyanide-containing waste gases shall be no less than 25 m). When there are buildings within a 200-meter radius around the stack, the height of the stack must be at least 3 meters higher than that of the tallest building. Existing and newly built coking plants must install automatic ignition and venting devices for raw gas. 7. Provisions in the \"Emission Standards for Air Pollutants in the Steelmaking Industry\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 8. Provisions in the “Emission Standards for Air Pollutants from the Ironmaking Industry”: Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure compliant emissions. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 9. As stipulated in the \"Emission Standards for Air Pollutants in the Steel Rolling Industry\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 10. As stipulated in the \"Emission Standards for Air Pollutants in the Steel Sintering and Pelletizing Industry\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems as well as purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 11. As stipulated in the “Emission Standards for Air Pollutants from the Ferroalloy Industry”: Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure compliant emissions. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 12. Provisions in the \"Emission Standards for Pollutants from Iron Ore Mining and Processing Industries\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 13. Provisions in the \"Emission Standards for Pollutants in the Nitric Acid Industry\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 13. Provisions in the “Emission Standards for Pollutants from the Sulfuric Acid Industry”: Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure compliant emissions. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 14. As stipulated in the “Emission Standards for Pollutants from the Lead and Zinc Industries”: Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure compliant emissions. The height of all exhaust stacks shall be no less than 15 m; when there are buildings within a radius of 200 m around the exhaust stack, its height shall also be at least 3 m higher than that of the tallest building. 15. As stipulated in the \"Emission Standards for Pollutants in the Aluminum Industry\": the height of all exhaust stacks must be no less than 15 m. When there are buildings within a radius of 200 m around the exhaust stack, its height must also be at least 3 m higher than that of the tallest building. 16. Provisions in the \"Emission Standards for Pollutants in the Copper, Nickel, and Cobalt Industries\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m (the height of exhaust stacks emitting chlorine shall be no less than 25 m). When there are buildings within a 200-meter radius around the stack, the height of the stack must be at least 3 meters higher than that of the tallest building. 17. Provisions in the \"Emission Standards for Pollutants in the Ceramic Industry\": Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and purification devices to ensure emissions meet the specified standards. The height of all exhaust stacks shall be no less than 15 m (the height of exhaust stacks emitting hydrogen chloride shall be no less than 25 m). When there are buildings within a 200-meter radius around the stack, the height of the stack must be at least 3 meters higher than that of the tallest building. 18. As stipulated in the “Emission Standards for Pollutants from the Synthetic Leather and Artificial Leather Industry”: Production processes and equipment that generate air pollutants must be equipped with local or overall gas collection systems and centralized purification devices; the purified gas is then discharged through exhaust stacks. The height of exhaust stacks should generally be no less than 15 meters, and at least 3 meters higher than the buildings within a radius of 200 meters around them; exhaust stacks that do not meet this requirement are not acceptable. The emission concentration limits must be strictly adhered to at 50%. 19. According to the Standards for Pollutant Emissions in the Coal Industry, the height of the exhaust stacks for dust removal equipment in the coal industry should be no less than 15 meters.