Catalytic absorption unit for treating dyeing and printing waste gas

Abstract

This utility model discloses a catalytic absorption unit for treating dyeing and printing waste gas, which includes a cylindrical body with a combined structure of an inner cavity and an outer cavity. The outer cavity surrounds the inner cavity and is located at the lower end of the inner cavity. Both the inner and outer cavities are made of stainless steel. A catalytic chamber is arranged at the top of the inner cavity. The outer cavity has an annular structure for arranging the inner and outer cavities of the absorption chamber. The outer cavity surrounds the inner cavity and forms a rotating airflow channel. The catalytic chamber is arranged at the top of the inner cavity, and the absorption chamber is arranged in an annular structure of the outer cavity.

Description

Technical Field

[0001] This solution relates to the field of textile dyeing waste gas treatment technology, and in particular to a catalytic absorption unit for textile dyeing waste gas treatment. Background Technology

[0002] In textile printing and dyeing, drying operations such as setting are required. During these operations, oily substances, intermediates, or volatile substances in the printing and dyeing raw materials will generate a variety of waste gases. Some of these waste gases are mainly nitrogen oxides, such as nitrogen dioxide, nitric oxide, nitrous oxide, and dinitrogen trioxide. These gases are usually toxic and may also participate in the formation of photochemical smog and acid rain, so they must be effectively treated.

[0003] Existing treatment methods are inefficient, costly, or overly complex. The catalytic absorption unit is a crucial step in exhaust gas treatment, converting nitrogen oxides into harmless nitrogen through catalysis and absorption, which can greatly improve treatment efficiency and ensure the integrity of the treatment process. Summary of the Invention

[0004] This utility model discloses a catalytic absorption unit for treating dyeing and printing waste gas, so as to improve the efficiency of exhaust gas treatment and ensure that the nitrogen oxides in the emitted exhaust gas are within a controllable range.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] The catalytic absorption unit for treating dyeing and printing waste gas includes a cylindrical body with a combined structure of an inner cavity and an outer cavity. The outer cavity surrounds the inner cavity and is located at the lower end of the inner cavity. Both the inner and outer cavities are made of stainless steel. A catalytic chamber is arranged at the top of the inner cavity. The outer cavity has an annular structure for arranging the inner and outer cavities of the absorption chamber. The outer cavity surrounds the inner cavity and forms a rotating airflow channel. The catalytic chamber is arranged at the top of the inner cavity, and the absorption chamber is arranged in an annular structure of the outer cavity.

[0007] Furthermore, cylindrical vanadium-titanium catalysts with a honeycomb structure are arranged inside the catalytic chamber.

[0008] Furthermore, heating elements are arranged around the perimeter of the catalytic chamber.

[0009] Furthermore, the heating component is implemented as a bypass structure of the exhaust gas inlet pipe, utilizing the high-temperature exhaust gas from the exhaust gas inlet pipe as a heat source.

[0010] Furthermore, a porous partition is arranged between the catalytic chamber and the reduction chamber.

[0011] Furthermore, a ring of ceramic corrugated plate structure is arranged in the absorption chamber, and an alkaline spray pipe is arranged on top of the ceramic corrugated plate structure.

[0012] Furthermore, at the ceramic corrugated structure, the residual alkali solution accumulates downwards at the funnel structure of the outer cavity, and a collection chamber is arranged accordingly. One side of the collection chamber is connected to a pipeline and an alkali solution delivery pump, and the alkali solution is continuously delivered to the alkali solution spray pipe through the alkali solution delivery pump.

[0013] Furthermore, an alkali inlet pipe is provided on the other side of the collection chamber.

[0014] Compared with existing technologies, this solution has the following advantages:

[0015] The catalytic absorption unit for treating dyeing and printing waste gas in this solution is implemented through a multi-chamber arrangement of catalytic chambers and reduction chambers. The catalytic chamber is equipped with a honeycomb structure of vanadium-titanium catalyst, which has the characteristics of high catalytic efficiency and resistance to sulfur poisoning. At the same time, the heating component ensures the overall stability of the catalytic operation. It can be used for deep treatment of NOx and convert it into nitrogen. The heating component can be a bypass structure for the tail gas input pipe, which can utilize the high-temperature tail gas as a heat source and reduce the operating cost.

[0016] In the absorption chamber, the use of alkaline solution in conjunction with a ceramic corrugated structure can greatly improve the gas-liquid contact area and efficiency. The alkaline solution used in this solution is a common industrial material with low cost. At the same time, through alkaline solution circulation, the alkaline solution can be fully utilized, achieving low-cost operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment.

[0018] Figure 2 This is a schematic diagram of the internal workings of the overall structure.

[0019] Figure 3 This is a schematic diagram of the internal structure of the preprocessing unit.

[0020] Figure 4 This is a schematic diagram of the internal workings of the preprocessing unit.

[0021] Figure 5 This is a schematic diagram of the internal structure of the oxygen-enhanced unit.

[0022] Figure 6 This is a schematic diagram of the internal structure of the catalytic absorption unit.

[0023] Figure 7 This is a schematic diagram of the internal workings of the catalytic absorption unit.

[0024] Figure 8 This is a schematic diagram of the internal structure of the adsorption and fine treatment unit. Detailed Implementation

[0025] refer to Figures 1 to 8A dyeing and printing waste gas treatment method includes a pretreatment unit 1, an oxygen enhancement unit 2, and a catalytic absorption unit 3, which are connected by pipelines. The rear end is connected to a tail gas emission pipe 42 and a centrifugal negative pressure fan 40, and the front end is connected to the production equipment through a tail gas input pipe 41 to receive high-temperature and high-velocity tail gas.

[0026] The pretreatment unit 1 is a vertical cyclone separator structure. The exhaust gas inlet pipe 41 enters from its top center. An internal spray atomization structure is arranged within it. Specifically, the pretreatment unit 1 includes a vertically arranged cylinder 11 and an air guide mechanism 12 located at its internal center. A cone 13 is arranged at the top of the air guide mechanism 12 for impacting and guiding airflow, and for diffusing the high-speed airflow. A main shaft is arranged at the rear end of the cone 13, and the rear end of the main shaft is fixed to the inner wall of the cylinder 11 by three supports 14. A guide vane 15 is arranged at the rear end of the cone 13, and the guide vane 15 is connected to the main shaft by horizontally arranged bearings. The guide wheel 15 rotates around the main shaft. Multiple guide fins 16 are arranged on the outer side of the guide wheel 15. The guide fins 16 have an inclined tile-shaped arc transition structure. In the vertical direction, the lower end of the guide fin 16 exceeds the upper end of the adjacent guide fin 16, thus forming a relatively continuous air guiding structure. A streamlined guide ring 17 is fixedly arranged on the inner wall of the cylinder 11 around the outer perimeter of the guide fin 16, thus forming a relatively closed air guiding structure around the guide fin 16. A rear cone 18 is attached to the lower end of the guide wheel 15 and retracts inward in the opposite direction.

[0027] Inside the cylinder 11, at the air guide mechanism 12, high-temperature and high-speed exhaust gas is input from the front end, diffused at the top of the cylinder 11, and squeezed at the cone 13 until it enters the air guide fins 16 of the air guide wheel 15. Here, it drives the air guide fins 16 to rotate counterclockwise at high speed. When it passes through the air guide fins 16, it is released and rotated at the rear cone, and its kinetic energy is released quickly, realizing the orderly and stable delivery of exhaust gas flow.

[0028] In actual operation, a water mist spraying mechanism 19 is arranged around the top of the cylinder 11. The water mist spraying mechanism 19 includes a ring-shaped pipe and multiple spray heads arranged on the pipe. The pipe is connected to a water tank and a booster pump, so that the spray heads can quickly spray out a large number of fine water mist particles, which can achieve extremely cold operation of high-temperature exhaust gas. With the joint action of the air guide mechanism 12, the exhaust gas is cooled and stabilized, which can greatly improve the stability of subsequent treatment.

[0029] At the lower end of the cylinder 11 is a cyclone separation structure. The high-temperature exhaust gas undergoes diffusion-compression-diffusion operations and spirals downward at the guide vane 15. Its kinetic energy gradually decreases and it impacts the inner wall of the cylinder 11. The particulate matter, such as unreacted nitrate particles, is collected in the collection chamber at the bottom of the cylinder 11. When appropriate, the corresponding valve can be opened to remove these particulate matter.

[0030] The cylinder 11 has a first output pipe 10 with right-angle rotation at the bottom. The front end of the first output pipe 10 is arranged vertically downward and it passes out of the side wall of the cylinder 11 to deliver the treated exhaust gas outward.

[0031] An oxygen enhancement unit 2 is arranged at the rear end of the first output pipe 10. The main body of the strong oxidation unit 2 is a secondary cylinder 21. The rear end of the first output pipe 10 is connected to the side wall of the secondary cylinder 21, and exhaust gas is input into the secondary cylinder 21 on the side where the center line is shifted. An ozone outlet 22 and a hydrogen peroxide atomizing spray port 23 are arranged at the top of the secondary cylinder 21. The rear end of the ozone outlet 22 is connected to an ozone generator through a pipeline. The rear end of the hydrogen peroxide atomizing spray port 23 is connected to a hydrogen peroxide tank and a delivery pump. Injecting ozone (O3) will rapidly oxidize NO to NO2 (reaction formula: NO + O3 → NO2 + O2). Meanwhile, hydrogen peroxide solution is sprayed into the exhaust gas to catalyze the generation of hydroxyl radicals to enhance the oxidation capacity. Therefore, with the combination of the two, it is possible to oxidize the poorly soluble NO (accounting for more than 90% of NOx) to a higher oxidation state (NO2, HNO3), thereby improving the subsequent absorption efficiency.

[0032] To improve reaction efficiency and enable more uniform and repeated mixing, a spiral guide vane 24 is arranged inside the secondary cylinder 21. The exhaust gas input from the side can continuously swirl within the secondary cylinder 21 under the guidance of the guide vane 24 and gradually sink, thereby improving ozone treatment efficiency. Generally speaking, it can greatly improve its efficiency and eliminate secondary pollution.

[0033] The cross-section of the guide vane 24 is V-shaped, which can guide particulate matter or mixture in the exhaust gas from its V-shaped groove and spiral downwards, reducing secondary contact with the exhaust gas and increasing the difficulty of treatment at the back end of the exhaust gas; a valve is arranged at the bottom of the secondary cylinder 21, which can be used to output the accumulated material inside when appropriate.

[0034] A second output pipe 20 is arranged from bottom to top at the center of the secondary cylinder 21. The second output pipe 20 is used to output the exhaust gas of the second cylinder 21 after oxygen enhancement treatment.

[0035] A catalytic absorption unit 3 is arranged at the rear end of the second output pipe 20. The catalytic absorption unit 3 is used for deep treatment of NOx and converts it into harmless nitrogen gas. Specifically, the catalytic absorption unit 3 includes a three-stage cylinder. The three-stage cylinder has a combined structure of an inner cavity 31 and an outer cavity 32. The outer cavity 32 surrounds the inner cavity 31. The main body of the outer cavity 32 is arranged at the lower end of the inner cavity 31. Both the inner cavity 31 and the outer cavity 32 are made of stainless steel. A catalytic chamber 33 is arranged at the top of the inner cavity 31, and an absorption chamber is arranged in an annular structure in the outer cavity.

[0036] The catalyst chamber 33 is filled with a cylindrical vanadium-titanium catalyst with a honeycomb structure. A typical catalyst is titanium dioxide, which is resistant to sulfur poisoning. A heating element 34 is arranged around the periphery of the catalyst chamber 33 to ensure the stability of the catalytic reaction.

[0037] In some embodiments, the heating element 34 can be a bypass structure of the exhaust gas inlet pipe 41, which can use the high-temperature exhaust gas of the exhaust gas inlet pipe 41 as a heat source. The heating temperature of the heating element can be controlled by controlling the flow rate or frequency through the valve structure, so that the catalyst is always in the best performance state for deep treatment of NOx and conversion into nitrogen.

[0038] A porous baffle 35 is arranged at the bottom of the inner chamber 31, which can reduce or prevent airflow backflow and make the output airflow smoother.

[0039] In the absorption chamber, a ring of ceramic corrugated plate structure 36 is arranged, and an alkaline solution spray pipe 37 is arranged on top of the ceramic corrugated plate structure 36. The alkaline solution can be a commonly used industrial sodium carbonate or sodium hydroxide solution. The corrugated structure of the ceramic corrugated plate 36 can increase the gas-liquid contact area, so that the reaction operation can be fully and completely carried out. The specific reaction formula is as follows:

[0040] 2 NO 2+2 NaOH → NaNO 2+ NaNO 3+ H 2 O

[0041] NO + NO 2+2 NaOH →2 NaNO 2+ H 2 O

[0042] The ceramic corrugated structure 36 operates primarily based on the principle of gas-liquid mass transfer. When the exhaust gas flows from bottom to top and the liquid is sprayed from top to bottom, the ceramic corrugated packing plays a crucial role. Its unique corrugated structure significantly increases the gas-liquid contact area. The liquid forms a liquid film on the corrugated surface, while the gas passes through the liquid film, facilitating mass exchange. Furthermore, the regular structure of the ceramic corrugated structure promotes uniform gas-liquid distribution, reducing channeling and flow deviation, thus greatly improving mass transfer efficiency. Moreover, due to the chemical and thermal stability of ceramic materials, it maintains good performance under various complex operating conditions, ensuring the continuous and efficient operation of the gas-liquid mass transfer process.

[0043] At the ceramic corrugated structure 36, the residual alkali solution accumulates downwards at the funnel structure of the outer cavity 32, and a collection chamber 371 is arranged there. One side of the collection chamber 371 is connected to a pipeline and an alkali solution delivery pump 372, and the other side is provided with an alkali solution input pipe 373. The alkali solution input pipe 373 is used to input alkali solution into the collection chamber 371 to ensure replenishment after the alkali solution is consumed. The alkali solution is continuously delivered to the alkali solution spray pipe 37 through the alkali solution delivery pump 372, so that the tail gas reaction is complete and thorough.

[0044] Under the action of airflow, the outer chamber 32 has a rotating structure 38 around it. In the rotating structure 38, the airflow slows down, and the alkaline particles remaining in the exhaust gas will accumulate at the bottom of the rotating structure 38 and can be output through the collection pipe 39. The treated exhaust gas is output to the outside through the third output pipe 30 on the side wall of the rotating structure 38.

[0045] An adsorption and fine treatment unit 5 is connected to the rear end of the third output tube 30. The main body of the adsorption and fine treatment unit 5 includes a molecular sieve structure layer 52 and an activated carbon fiber structure layer 53 arranged in an upper and lower structure inside the cylinder.

[0046] The molecular sieve structure layer 52 can be mainly composed of hydrated aluminosilicate, which has many channels with uniform pore size and neatly arranged pores. Molecular sieves with different pore sizes separate molecules of different sizes and shapes. Molecular sieves with different pore sizes are obtained according to the different molecular ratios of silicon dioxide and aluminum oxide. Therefore, it has the characteristics of high adsorption capacity, strong selectivity and high temperature resistance. The activated carbon fiber structure layer 53 is used to adsorb the remaining organic matter and odor. The cylinder has a detachable structure for replacing or maintaining the molecular sieve structure layer 52 and activated carbon fiber structure layer 53 inside, and keeping them in a stable working state.

[0047] After passing through the adsorption and fine treatment unit 5, it is connected to the centrifugal negative pressure fan 40, the exhaust pipe 42 and the emission tower. The centrifugal negative pressure fan 40 is connected to a motor, which is used to implement the corresponding negative pressure operation for the entire treatment device, and finally realize the release of safe and harmless exhaust gas, thus completing the entire nitrogen oxide exhaust gas treatment operation.

[0048] In summary, the catalytic absorption unit for treating dyeing and printing waste gas in this solution is implemented through a multi-chamber arrangement of catalytic chambers and reduction chambers. The catalytic chambers are equipped with vanadium-titanium catalysts with a honeycomb structure, which have the characteristics of high catalytic efficiency and resistance to sulfur poisoning. At the same time, heating components are used to ensure the overall stability of catalytic operation. It can be used for deep treatment of NOx and convert it into nitrogen. The heating components can be a bypass structure for the tail gas input pipe, which can utilize high-temperature tail gas as a heat source and reduce operating costs.

[0049] In the absorption chamber, the use of alkaline solution in conjunction with a ceramic corrugated structure can greatly improve the gas-liquid contact area and efficiency. The alkaline solution used in this solution is a common industrial material with low cost. At the same time, through alkaline solution circulation, the alkaline solution can be fully utilized, achieving low-cost operation.

Claims

1. Catalytic absorption unit for the treatment of printing and dyeing exhaust gases, characterized by the fact that it comprises: The device includes a cylindrical body with a combined structure of an inner cavity and an outer cavity. The outer cavity surrounds the inner cavity and is located at the lower end of the inner cavity. Both the inner and outer cavities are made of stainless steel. A catalytic chamber is arranged at the top of the inner cavity. The outer cavity has an annular structure that arranges the inner and outer cavities of the absorption chamber. The outer cavity surrounds the inner cavity and forms a rotating airflow channel. The catalytic chamber is arranged at the top of the inner cavity, and the absorption chamber is arranged in an annular structure of the outer cavity.

2. The catalytic absorption unit for treatment of printing and dyeing exhaust gas according to claim 1, characterized in that: A cylindrical vanadium-titanium catalyst with a honeycomb structure is arranged inside the catalytic chamber.

3. The catalytic absorption unit for treatment of printing and dyeing exhaust gas according to claim 1, characterized in that: Heating components are arranged around the perimeter of the catalytic chamber.

4. The catalytic absorption unit for treatment of printing and dyeing exhaust gas according to claim 3, characterized in that: The heating component is implemented as a bypass structure of the exhaust gas inlet pipe, using the high-temperature exhaust gas in the exhaust gas inlet pipe as a heat source.

5. The catalytic absorption unit for treatment of printing and dyeing exhaust gas according to claim 1, characterized in that: A porous partition is arranged between the catalytic chamber and the reduction chamber.

6. The catalytic absorption unit for treatment of printing and dyeing exhaust gas according to claim 1, characterized in that: A ring of ceramic corrugated plate structure is arranged in the absorption chamber, and an alkaline spray pipe is arranged on top of the ceramic corrugated plate structure.

7. The catalytic absorption unit for treatment of printing and dyeing exhaust gas according to claim 6, characterized in that: At the ceramic corrugated structure, the residual alkali solution accumulates downwards at the funnel structure of the outer cavity, and a collection chamber is arranged accordingly. One side of the collection chamber is connected to a pipeline and an alkali solution delivery pump, and the alkali solution is continuously delivered to the alkali solution spray pipe through the alkali solution delivery pump.

8. The catalytic absorption unit for treatment of printing and dyeing exhaust gas according to claim 6, characterized in that: An alkali inlet pipe is located on the other side of the collection chamber.

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