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CN-115999312-B - Waste gas treatment method for aluminum veneer spraying line

CN115999312BCN 115999312 BCN115999312 BCN 115999312BCN-115999312-B

Abstract

The invention belongs to the technical field of aluminum veneer processing, in particular to a method for treating waste gas of an aluminum veneer spraying line, which comprises the following steps that normal-temperature low-concentration waste gas containing organic matters is subjected to control of proper air quantity through valves or frequency converters by using various exhaust fans, then is subjected to removal of 1-5um dust by using 4-stage filter boxes respectively, and enters a molecular sieve rotating wheel, when the waste gas passes through a molecular sieve bed layer arranged in the rotating wheel, low-boiling-point organic matters are fully adsorbed in micropores of a molecular sieve, and clean air with high air quantity reaching standards is discharged into the atmosphere through a chimney; with the slow rotation of the rotating wheel, when the molecular sieve reaches the set adsorption amount, one of the subareas enters the desorption area. The invention can burn and decompose the organic waste gas into clean water and carbon dioxide high-temperature gas, and send the high-temperature gas into the curing oven again through the automatic temperature adjusting device to serve as auxiliary heat energy to cure the product, thereby achieving the effect of energy conservation.

Inventors

  • NI CHENGPENG
  • LIU PANWEI
  • LIN YETING
  • SHI MUCHAO

Assignees

  • 江苏雅泰科技产业园有限公司

Dates

Publication Date
20260512
Application Date
20230220

Claims (6)

  1. 1. The aluminum veneer spraying line waste gas treatment method is characterized by comprising the following steps of: S1, controlling proper air quantity of normal-temperature low-concentration waste gas containing organic matters through valves or frequency converters by using various exhaust fans, respectively removing 1-5um dust through a 4-stage filter box, entering a molecular sieve rotating wheel, and fully adsorbing low-boiling-point organic matters in micropores of a molecular sieve when the waste gas passes through a molecular sieve bed layer arranged in the rotating wheel, wherein clean air with high air quantity and up to standard is discharged into the atmosphere through a chimney; S2, along with the slow rotation of the rotating wheel, when the molecular sieve reaches a set adsorption capacity, one partition enters a desorption area, 180 ℃ hot air is introduced to desorb organic matters adsorbed in micropores of the molecular sieve through a desorption air passage, the desorbed high-concentration gas containing the organic matters with temperature is sent into a regenerator oxidizer to be burnt at high temperature to be decomposed into nontoxic and harmless carbon dioxide and water and further emit heat, the regenerator oxidizer in the step S2 comprises a first regenerator, a second regenerator, a third regenerator, a first combustion chamber and a second combustion chamber, and the regenerator oxidizer comprises the following specific steps when in use: (1) Organic waste gas firstly enters a first heat storage chamber under the action of a blower, absorbs heat and then enters a first combustion chamber, the first heat storage chamber is cooled due to heat release, gas after combustion and temperature rise enters a second heat storage chamber, heat is stored in a ceramic heat storage body of the second heat storage chamber through heat exchange, and then the heat is discharged; (2) After a certain time, the direction of the air flow is changed, the air flow enters the second combustion chamber from the second heat storage chamber, the air flow is heated by the heat absorption of the second heat storage chamber, is cracked at high temperature in the hearth, and finally is discharged after heat exchange of the third heat storage chamber; (3) Meanwhile, the first regenerator is in a back blowing state, after a break time, the air flow changes direction again and continuously circulates alternately, so that the temperature of the combustion chamber is ensured to be more than 800 ℃; S3, the organic waste gas entering the regenerator oxidizer is preheated through the regenerator, then enters the oxidation chamber and is heated to 830 ℃ so as to oxidize and decompose VOCs in the waste gas into carbon dioxide and water; S4, when the heat release of the organic matters is enough to maintain the heat of the operation of the regenerator, the whole operation equipment reaches the optimal reactive operation state without consuming natural gas, and when the heat release of the organic matters is insufficient to maintain the heat of the operation of the regenerator, the matched burner is started, and the natural gas is combusted to supplement heat so as to ensure that the treated gas reaches the emission standard.
  2. 2. The method for treating the waste gas of the aluminum veneer spraying line according to claim 1, wherein the step S1 is characterized in that the waste gas enters a molecular sieve rotating wheel for concentration by 25 times, the molecular sieve treatment efficiency is 90%, and the total non-methane hydrocarbon in the outer exhaust body is reduced to less than or equal to 50mg/m < 3 > after the treatment by the method and reaches the standard for emission.
  3. 3. The method for treating waste gas of aluminum veneer spraying line according to claim 2, wherein in the step S1, the dust content of the gas entering the rotating wheel through the 4-stage filter box is required to be lower than 100ppm, the particle size is required to be lower than 1um and smaller than the ventilation aperture of the molecular sieve, so that the particles are ensured not to accumulate on the surface of the molecular sieve, and the effect of stabilizing the concentration treatment effect is achieved.
  4. 4. The method for treating waste gas of aluminum veneer spraying line according to claim 1, wherein in the step S2, when the organic matter adsorbed by the molecular sieve in the rotating wheel is gradually increased, the fresh air is heated by extracting part of the high temperature gas in the oxidation chamber of the regenerator, the molecular sieve entering the desorption zone is desorbed at high temperature through the desorption air passage, the organic matter is gradually desorbed into gas state at high temperature of 180 ℃ and is sent into the regenerator together with the oven waste gas to burn at high temperature along with the desorption gas, and the organic matter is decomposed into nontoxic and harmless carbon dioxide and water and gives off heat.
  5. 5. The method for treating waste gas of an aluminum veneer spray line according to claim 4, wherein the air volume of the heating fresh air is 1/25 of the treated air volume, and the fresh air temperature is heated to a set temperature of 180 ℃.
  6. 6. The method for treating exhaust gas of an aluminum veneer spray line according to claim 5, wherein the step S3 is a process of continuously and circularly regenerating, each regenerator is alternately switched between the mode of inputting exhaust gas and the mode of discharging treated gas, and the switching time is adjusted according to the actual situation.

Description

Waste gas treatment method for aluminum veneer spraying line Technical Field The invention relates to the technical field of aluminum veneer processing, in particular to an aluminum veneer spraying line waste gas treatment method. Background Aluminum veneers are mostly fluorocarbon liquid paints in consideration of durability of building products. The paint of the above kind needs to be baked and cured at high temperature, and the liquid paint contains more than 30% of toxic and harmful organic solvents, and the main components are toluene, xylene, ketone, lipid and other organic solvents, and organic solvent gas can be generated during baking. The traditional baking process has weak environmental protection consciousness due to the consideration of cost, and the generated organic gas is directly discharged, so that the baking process is not only environment-friendly, but also energy waste. Therefore, we propose an exhaust gas treatment method for aluminum veneer spray line to solve the above problems. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides a waste gas treatment method for an aluminum veneer spraying line. In order to achieve the above purpose, the present invention adopts the following technical scheme: an aluminum veneer spraying line waste gas treatment method comprises the following steps: S1, controlling proper air quantity of normal-temperature low-concentration waste gas containing organic matters through valves or frequency converters by using various exhaust fans, respectively removing 1-5um dust through a 4-stage filter box, entering a molecular sieve rotating wheel, and fully adsorbing low-boiling-point organic matters in micropores of a molecular sieve when the waste gas passes through a molecular sieve bed layer arranged in the rotating wheel, wherein clean air with high air quantity and up to standard is discharged into the atmosphere through a chimney; S2, along with the slow rotation of the rotating wheel, when the molecular sieve reaches a set adsorption capacity, one partition enters a desorption area, 180 ℃ hot air is introduced to desorb organic matters adsorbed in micropores of the molecular sieve through a desorption air passage, and desorbed high-concentration gas containing the organic matters with temperature is sent into a regenerator oxidizer to be subjected to high-temperature incineration and decomposition to be nontoxic and harmless carbon dioxide and water, and heat is further released; S3, the organic waste gas entering the regenerator oxidizer is preheated through the regenerator, then enters the oxidation chamber and is heated to 830 ℃ so as to oxidize and decompose VOCs in the waste gas into carbon dioxide and water; S4, when the heat release of the organic matters is enough to maintain the heat of the operation of the regenerator, the whole operation equipment reaches the optimal reactive operation state without consuming natural gas, and when the heat release of the organic matters is insufficient to maintain the heat of the operation of the regenerator, the matched burner is started, and the natural gas is combusted to supplement heat so as to ensure that the treated gas reaches the emission standard. In the method for treating the waste gas of the aluminum veneer spraying line, the step S1 is performed with concentration of 25 times by entering a molecular sieve rotating wheel, the molecular sieve treatment efficiency is 90%, and the total non-methane hydrocarbon in the external exhaust body is reduced to less than or equal to 50mg/m < 3 > to be discharged after the treatment by the process. In the above method for treating waste gas of aluminum veneer spraying line, the dust content of the gas entering the rotating wheel through the 4-stage filter box in the step S1 needs to be lower than 100ppm, the particle size needs to be lower than 1um and smaller than the ventilation aperture of the molecular sieve, so that the particles are ensured not to accumulate on the surface of the molecular sieve, and the effect of stabilizing the concentration treatment effect is achieved. In the above method for treating waste gas of aluminum veneer spraying line, in the step S2, when the organic matters adsorbed by the molecular sieve in the rotating wheel are gradually increased, the fresh air is heated by extracting part of the high temperature gas in the oxidation chamber of the regenerator oxidizer, the molecular sieve entering the desorption zone is desorbed at high temperature through the desorption air passage, the organic matters are gradually desorbed into gas phase at the high temperature of 180 ℃ and sent into the regenerator oxidizer together with the desorption gas to burn at high temperature together with the oven waste gas, and the organic matters are decomposed into nontoxic and harmless carbon dioxide and water and release heat. In the above method for treating waste gas of aluminum veneer spraying line, the air