High humidity high viscosity oil-containing organic waste gas treatment device

Abstract

The application discloses a high-humidity high-viscosity oily organic waste gas treatment device, and belongs to the technical field of organic waste gas treatment. The device comprises a blower fan, which provides power for conveying the high-humidity high-viscosity oily organic waste gas; a water seal tank, which is in sealing connection with the air outlet of the blower fan through an air inlet, and is used for blocking backfire counter-pressure in the device; a first absorption tower and a second absorption tower, which are arranged in series, and the lower air inlet of the first absorption tower is in sealing connection with the air outlet of the water seal tank through a flange. The device can reduce the humidity of waste gas from above 95% to below 30% through a two-stage absorption tower low-temperature absorption and condenser deep dehumidification process, solve the problem of moisture absorption of activated carbon, improve the adsorption efficiency by more than 30%, restore the adsorption capacity to more than 95% after regeneration, remove VOCs by more than 95%, and lower the emission concentration to below 30 mg / m³, so that the special emission limit requirement is met, and resource recycling is realized.

Description

Technical Field

[0001] This application relates to the field of organic waste gas treatment technology, and more specifically, to a device for treating high-humidity, high-viscosity, oily organic waste gas. Background Technology

[0002] During the process of industrial transformation and upgrading, high-humidity, high-viscosity, oily organic waste gas has become an environmental challenge for many industries such as petrochemicals, coating, and pharmaceuticals due to its complex composition and difficulty in treatment.

[0003] The relative humidity of this type of exhaust gas is usually as high as 85%-95%, and it contains volatile organic compounds (VOCs) such as benzene series compounds, esters, and ketones, with a concentration of 600-1200 mg / m³. If it is directly emitted, it will not only cause air pollution and violate relevant emission standards, but also waste VOCs resources with recycling value.

[0004] However, in traditional activated carbon adsorption technology, high humidity waste gas easily causes the pores of activated carbon to become damp and clogged, resulting in a sharp drop in adsorption efficiency of 30%-50%. The recovery rate of adsorption capacity after regeneration is low. Single spray absorption methods often use pure water as the absorbent, which has low solubility for hydrophobic VOCs such as esters, with a removal rate of only 40%-50%, making it difficult to meet emission standards. Most devices adopt a single adsorption tank design, which requires shutdown during activated carbon regeneration, and cannot meet the waste gas treatment needs of enterprises that produce continuously for 24 hours. The VOCs after desorption are mostly recovered by single-stage condensation, with a purity of less than 85%, making it difficult to achieve resource reuse.

[0005] In view of this, we propose a treatment device for high humidity, high viscosity, and oily organic waste gas. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art and solve at least one of the technical problems mentioned in the background art, this application proposes a high humidity, high viscosity, oily organic waste gas treatment device.

[0007] This application provides a device for treating high-humidity, high-viscosity, oily organic waste gas, comprising: The blower provides power for transporting high-humidity, high-viscosity, oily organic waste gas; A water seal tank, wherein the air inlet of the water seal tank is sealed to the air outlet of the blower to prevent backfire and back pressure within the device; The first absorption tower and the second absorption tower are arranged in series. The lower air inlet of the first absorption tower is sealed to the air outlet of the water seal tank through a flange. The lower air inlet of the second absorption tower is connected to the top air outlet of the first absorption tower through a pipe, and the inner wall of the pipe is coated with a polytetrafluoroethylene anti-corrosion coating. The bottom of the first and second absorption towers are provided with a first circulating liquid tank and a second circulating liquid tank. The first and second circulating liquid tanks are fixedly installed with a first coil heat exchanger and a second coil heat exchanger, and also include a first circulating pump and a second circulating pump. The inlets of the first and second circulating pumps are connected to the first and second circulating liquid tanks, and the outlets are connected to the spray device inside the absorption tower. The condenser has its air inlet connected to the top air outlet of the second absorption tower for deep dehumidification of the exhaust gas; the condenser has a chilled water inlet at the bottom, a chilled water outlet at the top, and a condensate discharge outlet at the bottom. A heater, wherein the air inlet of the heater is connected to the air outlet of the condenser through an insulated pipe to prevent condensation of exhaust gas, and the heater is an electric heater; The main fan, whose air inlet is connected to the air outlet of the heater, provides power for the waste gas to enter the adsorption box; Activated carbon adsorption box A and activated carbon adsorption box B are arranged in parallel. The air outlet of the main fan is connected to the air inlet of the two adsorption boxes through control valves. Both adsorption boxes are equipped with purified gas outlets and are connected to nitrogen inlet pipes and steam inlet pipes. A condensation recovery device, wherein the air inlet of the condensation recovery device is connected to the desorption gas outlet of activated carbon adsorption box A and activated carbon adsorption box B through a pipeline, for the purpose of realizing VOCs resource recovery; The PLC control unit is electrically connected to the control components on the blower, the first circulation pump and the second circulation pump, the heater, the main blower, the control valves, the nitrogen inlet pipe and the steam inlet pipe, respectively, to realize the automatic control of the device.

[0008] As an optional solution to the technical solution in this application, the water seal tank is provided with a U-shaped water seal channel inside, the water seal height is 300-500mm, and the tank wall is provided with a level gauge and a water inlet.

[0009] As an optional solution to the technical solution in this application, the spraying device in the first and second absorption towers is a spiral nozzle with a nozzle orifice diameter of 1.5-2.5 mm and a spraying density of 15-20 m³ / (m²・h); the absorbent in the first and second circulating liquid tanks is an ethanol aqueous solution with a mass concentration of 5-8%.

[0010] As an optional solution to the technical solution in this application, the heat exchange tubes of the first and second coil heat exchangers are made of 316L stainless steel with an outer diameter of 20-25mm and a tube spacing of 25-30mm. The ratio of the heat exchange area to the cross-sectional area of ​​the absorption tower is (8-10):1. The first and second coil heat exchangers are provided with chilled water inlet and outlet.

[0011] As an optional solution to the technical solution in this application, the condenser is a shell-and-tube structure, with the shell side being the exhaust gas passage and the tube side being the chilled water passage. The chilled water temperature is controlled at 5-8℃, and the condensation efficiency is not less than 90%. The condensate discharge port is connected to a wastewater treatment pipeline.

[0012] As an optional solution to the technical solution in this application, the outlet temperature control range of the heater is 25-30℃; the outer walls of the first absorption tower, the second absorption tower and the condenser are all provided with a heat insulation layer with a thickness of 100-200mm.

[0013] As an optional solution to the technical solution of this application, the activated carbon filled in the activated carbon adsorption box A and activated carbon adsorption box B is coal-derived columnar activated carbon with a diameter of 3-4 mm, a carbon tetrachloride adsorption rate of 70-95%, and an iodine value of 1000-1300 mg / g; the inner wall of the activated carbon adsorption box A and activated carbon adsorption box B is provided with a heat insulation layer with a thickness of 100-200 mm, and the material is aluminum silicate cotton.

[0014] As an optional solution to the technical solution in this application, the nitrogen inlet pipe is equipped with a flow meter, the purity of the nitrogen gas introduced is not less than 99.99%, the nitrogen purging flow rate is 2-3 times the volume of the activated carbon adsorption box per hour, and the purging time is 30-45 minutes; the steam inlet pipe is equipped with a pressure regulating valve, the steam introduced is saturated steam, the pressure is 0.3-0.5 MPa, and the purging time is 60-90 minutes.

[0015] As an optional solution to the technical solution in this application, the condensation recovery device includes a primary condensation device, a secondary condensation device, and a solvent recovery tank. Both the primary and secondary condensation devices are equipped with chilled water inlets and outlets. The condensed liquid VOCs are introduced into the solvent recovery tank through the bottom interface. The secondary condensation device is equipped with a non-condensable gas discharge port at the top. The temperature difference of the primary condensation is 15-20℃, the temperature difference of the secondary condensation is 5-10℃, and the purity of the recovered VOCs is not less than 92%.

[0016] As an optional solution to the technical solution in this application, a pressure sensor is installed on the pipeline between the main fan and activated carbon adsorption box A and activated carbon adsorption box B; and a VOCs online monitoring instrument is installed at the purified gas outlet of activated carbon adsorption box A and activated carbon adsorption box B.

[0017] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: (1) This application uses a two-stage absorption tower for low-temperature absorption and a condenser for deep dehumidification to reduce the humidity of the exhaust gas from more than 95% to less than 30%, which solves the problem of activated carbon being damp and increases the adsorption efficiency by more than 30%. The regeneration capacity recovery rate is more than 95%. At the same time, a two-stage treatment of low-temperature ethanol aqueous solution absorption and activated carbon adsorption is adopted, and the VOCs removal rate is more than 95%, and the emission concentration is less than 30mg / m³, which meets the special emission limit requirements, thereby realizing resource reuse.

[0018] (2) This application sets up two adsorption boxes in parallel and uses a PLC control device to realize alternating adsorption and desorption. Regeneration does not require shutdown and the system can run continuously for 24 hours. Attached Figure Description

[0019] Figure 1 This is a system flow diagram of a high-humidity, high-viscosity, oily organic waste gas treatment device disclosed in a preferred embodiment of this application.

[0020] Explanation of the labels in the diagram: 1. Blower; 2. Water seal tank; 201. Level gauge; 202. Water inlet; 3. First absorption tower; 301. First circulating liquid tank; 302. First coil heat exchanger; 303. First circulating pump; 4. Second absorption tower; 401. Second circulating liquid tank; 402. Second coil heat exchanger; 403. Second circulating pump; 5. Condenser; 501. Chilled water inlet; 502. Chilled water outlet; 503. Condensate drain. 6. Heater; 7. Main fan; 8. Activated carbon adsorption box A; 9. Activated carbon adsorption box B; 10. Condensation recovery device; 1001. Primary condensation device; 1002. Secondary condensation device; 1003. Solvent recovery tank; 11. Nitrogen inlet pipe; 1101. Flow meter; 12. Steam inlet pipe; 1201. Pressure regulating valve; 13. Pressure sensor; 14. VOCs online monitor; 15. PLC control device. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the accompanying drawings.

[0022] Reference Figure 1This application discloses a high humidity, high viscosity, oily organic waste gas treatment device, including a blower 1, a water seal tank 2, a first absorption tower 3, a second absorption tower 4, a condenser 5, a heater 6, a main blower 7, an activated carbon adsorption box A8, an activated carbon adsorption box B9, a condensation recovery device 10, and a PLC control device 15. First, the outlet of the blower 1 is sealed to the inlet of the water seal tank 2. The water seal tank 2 has a U-shaped water seal channel inside, with a water seal height of 300-500mm. The tank wall is equipped with a level gauge 201 and a water inlet 202. Liquid isolation prevents backfire or back pressure damage to the front-end equipment. The outlet of the water seal tank 2 is sealed to the lower inlet of the first absorption tower 3 via a flange. The top outlet of the first absorption tower 3 is connected to the lower inlet of the second absorption tower 4 in series via a pipeline. The inner wall of the pipeline is coated with a polytetrafluoroethylene anti-corrosion coating to resist acidic components. The bottom of both the first absorption tower 3 and the second absorption tower 4 is equipped with a first circulating liquid tank 301 and a second circulating liquid tank 401, which are equipped with a first coil heat exchanger 302 and a second coil heat exchanger 402. The first circulating pump 303 and the second circulating pump 403 are connected to the circulating liquid tank and the spraying device to drive the absorption liquid to circulate and spray. The spraying device is a spiral nozzle with a nozzle orifice diameter of 1.5-2.5mm and a spray density of 15-20m³ / (m²・h). The absorption liquid is a 5-8% ethanol aqueous solution. The heat exchanger coil is made of 316L stainless steel with an outer diameter of 20-25mm and a tube spacing of 25-30mm. The heat exchange area to absorption tower cross-sectional area ratio is (8-10):1. 5-8℃ chilled water is introduced to lower the temperature inside the tower. The outer walls of both the absorption tower and the condenser are equipped with a 100-200mm thick aluminum silicate cotton insulation layer to reduce cold loss. The top outlet of the second absorption tower 4 is connected to the inlet of the condenser 5. The condenser is a shell-and-tube type. The structure features a chilled water temperature controlled at 5-8℃, a condensation efficiency of no less than 90%, and a bottom condensate discharge port 503 connected to a wastewater treatment pipeline. The outlet of the condenser 5 is connected to the heater 6 via an insulated pipe. The heater is electrically heated, with an outlet temperature controlled at 25-30℃ to prevent condensation of exhaust gas. The outlet of the heater 6 is connected to the inlet of the main fan 7. The outlet of the main fan 7 is connected to activated carbon adsorption boxes A8 and B9 via control valves. The two adsorption boxes are arranged in parallel. The adsorption boxes are filled with coal-derived columnar activated carbon, 3-4mm in diameter, with a carbon tetrachloride adsorption rate of 70-95% and an iodine value of 1000-1300mg / g. The inner wall of the box is insulated. Each adsorption box is connected to a nitrogen inlet pipe 11 and a steam inlet pipe 12. The gas purity is not less than 99.99%, the purging flow rate is 2-3 times the volume of the adsorption box per hour, and the purging time is 30-45 min; the steam pressure is 0.3-0.5 MPa, and the purging time is 60-90 min. The desorbed gas outlet of the activated carbon adsorption box is connected to the condensation recovery device 10. This device adopts a two-stage condensation structure, with a first-stage condensation temperature difference of 15-20℃ and a second-stage condensation temperature difference of 5-10℃. The VOCs recovery purity is not less than 92%. The condensed liquid VOCs are fed into the solvent recovery tank 1003 for secondary utilization. A pressure sensor 13 is installed on the pipeline between the main fan and the adsorption box. A VOCs online monitoring instrument 14 is installed at the purified gas outlet of the adsorption box. The PLC control device 15 is electrically connected to each piece of equipment to realize automatic control.

[0023] Reference Figure 1 The water seal tank 2 is equipped with a U-shaped water seal channel inside, with a water seal height of 300-500mm. The tank wall of the water seal tank 2 is equipped with a level gauge 201 and a water inlet 202. After the high-humidity, high-viscosity, oily organic waste gas is transported to the water seal tank 2 by the blower 1, the U-shaped water seal channel inside the water seal tank 2 will form a stable liquid seal using the liquid stored in the tank. The liquid seal height is strictly controlled within the range of 300-500mm. This height can effectively prevent backfire that may occur in subsequent treatment stages of the device. At the same time, the level gauge 201 on the tank wall of the water seal tank 2 can monitor the liquid level in the tank in real time. When the water level is lower than the set liquid seal height due to evaporation, leakage, or other reasons, the staff can replenish the liquid in time through the water inlet 202 to ensure that the U-shaped water seal channel always maintains an effective seal. This step solves the problems of existing organic waste gas treatment devices lacking a reliable backfire prevention structure, being prone to damage to the front-end conveying equipment (such as the blower) due to backfire or back pressure, and the inability to monitor the water seal level in real time and the unstable sealing effect.

[0024] Reference Figure 1 The spraying devices in the first absorption tower 3 and the second absorption tower 4 are spiral nozzles with a nozzle orifice diameter of 1.5-2.5 mm and a spray density of 15-20 m³ / (m²·h). The absorbent in the first circulating liquid tank 301 and the second circulating liquid tank 401 is an ethanol-water solution with a mass concentration of 5-8%. After the waste gas enters the first absorption tower 3 through the water seal tank 2, the absorbent in the first circulating liquid tank 301 and the second circulating liquid tank 401 at the bottom of the first absorption tower 3 and the second absorption tower 4 will be transported to the spiral spraying device in the absorption tower under the drive of the first circulating pump 303 and the second circulating pump 403. The nozzle orifice diameter of the spraying device is controlled to be 1.5-2.5 mm, and... The spray density is maintained at 15-20 m³ / (m²·h). This aperture allows the ethanol aqueous solution to be atomized into fine droplets, while the spray density of 15-20 m³ / (m²·h) ensures that the waste gas is in full contact with the absorbent in the tower, resulting in efficient dissolution and absorption of hydrophobic VOCs such as benzene series compounds and esters in the waste gas. The unabsorbed waste gas continues to enter the second absorption tower 4, and further removes VOCs through the same spray absorption process. This step solves the problem that in the traditional organic waste gas treatment, pure water is used as the absorbent, which has low solubility for hydrophobic VOCs and a removal rate of only 40%-50%, which cannot meet the removal requirements of hydrophobic VOCs in high humidity, high viscosity and oily waste gas.

[0025] Reference Figure 1The first coil heat exchanger 302 and the second coil heat exchanger 402 are made of 316L stainless steel, with an outer diameter of 20-25mm and a tube spacing of 25-30mm. The heat exchange area to the cross-sectional area of ​​the absorption tower is (8-10):1. The first coil heat exchanger 302 and the second coil heat exchanger 402 are equipped with chilled water inlets and outlets. While the first absorption tower 3 and the second absorption tower 4 are performing spray absorption, low-temperature chilled water (entering from the chilled water inlet and exiting from the chilled water outlet) is introduced into the first coil heat exchanger 302 and the second coil heat exchanger 402, which are fixedly installed inside the first circulating liquid tank 301 and the second circulating liquid tank 401. The heat exchange tubes of the first coil heat exchanger 302 and the second coil heat exchanger 402 are made of 316L stainless steel. Made of stainless steel, it can resist the corrosion of heat exchange tubes by oil mist and trace acidic components (such as acetic acid) in high-humidity and high-viscosity exhaust gas. At the same time, the outer diameter of the heat exchange tubes is controlled at 20-25mm and the tube spacing is 25-30mm. The ratio of heat exchange area to absorption tower cross-sectional area is strictly designed according to (8-10):1. This size and area ratio can ensure sufficient heat exchange between chilled water and the ethanol aqueous solution in the first circulating liquid tank 301 and the second circulating liquid tank 401, and quickly reduce the temperature in the absorption tower to the optimal absorption temperature range of 10-15℃. This step solves the problems in existing absorption devices where the absorption temperature is too high, resulting in a decrease in VOCs solubility and low absorption efficiency, and the heat exchange tube material has poor corrosion resistance and is easily blocked by high-viscosity oil mist, and the heat exchange area is insufficient, resulting in poor cooling effect.

[0026] Reference Figure 1 The condenser 5 is a shell-and-tube structure, with the shell side serving as the waste gas passage and the tube side as the chilled water passage. The chilled water temperature is controlled at 5-8℃, and the condensation efficiency is not less than 90%. The condensate discharge port 503 is connected to the wastewater treatment pipeline. The waste gas, after being absorbed in two stages by the second absorption tower 4, enters the condenser 5. The condenser 5 adopts a shell-and-tube structure, with the shell side serving as the waste gas passage and the tube side as the chilled water passage. The chilled water temperature is strictly controlled at 5-8℃. When the low-temperature chilled water flows in the tube side, it undergoes efficient heat exchange with the waste gas in the shell side, and the water vapor in the waste gas... Upon cooling, the condensate will condense into liquid water. This condensate will collect along the inner wall of the condenser 5 to the condensate discharge port 503 at the bottom, and finally be discharged into the wastewater treatment pipeline through the condensate discharge port 503. The condensation efficiency of the entire condensation process is not less than 90%, which can reduce the relative humidity of the exhaust gas from more than 70% to less than 40%. This step solves the problem in the existing device that the exhaust gas after absorption still maintains high humidity, and directly entering the activated carbon adsorption stage will cause the activated carbon pores to become damp and blocked, the adsorption efficiency to drop sharply by 30%-50%, and the adsorption capacity recovery rate after regeneration to be low.

[0027] Reference Figure 1The outlet temperature of the heater 6 is controlled within the range of 25-30℃. The outer walls of the first absorption tower 3, the second absorption tower 4, and the condenser 5 are all equipped with insulation layers, with a thickness of 100-200mm. After deep dehumidification by the condenser 5, the temperature of the exhaust gas drops to 5-8℃. At this point, the exhaust gas enters the heater 6 through an insulated pipe. The heater 6 uses electric heating, and its outlet temperature is strictly controlled within 25-30℃. This temperature range is higher than the dew point temperature of residual VOCs in the exhaust gas, effectively preventing the exhaust gas from being discharged due to temperatures below the dew point in subsequent conveying pipelines and activated carbon adsorption boxes 8 and 9. The activated carbon condenses into a liquid state, preventing pipe blockage or VOCs adhering to the surface of the activated carbon and affecting the adsorption effect. At the same time, the outer walls of the first absorption tower 3, the second absorption tower 4, and the condenser 5 are all equipped with a 100-200mm thick insulation layer, which can significantly reduce the cold loss during low-temperature absorption in the absorption tower, the cold loss during dehumidification in the condenser 5, and the heat loss of the exhaust gas after heating by the heater 6 during the transportation process. This step solves the problem in the existing device that the low-temperature exhaust gas after dehumidification is prone to condensation due to the temperature being lower than the dew point, which leads to pipe blockage, reduced activated carbon adsorption efficiency, and large heat and cold losses and high energy consumption of the equipment.

[0028] Reference Figure 1 The activated carbon filled in activated carbon adsorption boxes A8 and B9 is coal-derived columnar activated carbon with a diameter of 3-4 mm, a carbon tetrachloride adsorption rate of 70-95%, and an iodine value of 1000-1300 mg / g. The inner walls of activated carbon adsorption boxes A8 and B9 are equipped with a heat insulation layer with a thickness of 100-200 mm, made of aluminum silicate cotton. The exhaust gas, heated by heater 6, enters activated carbon adsorption box A8 or B9 under the drive of main fan 7. The diameter of the coal-derived columnar activated carbon filled in the adsorption box is strictly controlled to 3-4 mm. This size ensures uniform pores between the activated carbon particles, reduces exhaust gas flow resistance, increases the adsorption surface area, and enhances the carbon tetrachloride adsorption rate. With a carbon adsorption rate of 70-95% and an iodine value of 1000-1300 mg / g, it possesses excellent VOCs adsorption capacity and rate, and can deeply adsorb residual VOCs in waste gas. The purified waste gas is discharged from the purified gas outlet of the adsorption box. In addition, the inner walls of the activated carbon adsorption boxes A8 and B9 are equipped with a 100-200 mm thick aluminum silicate cotton insulation layer. During steam desorption in the adsorption boxes, this reduces the heat loss from the boxes to the outside, ensuring that the desorption temperature remains stable within the optimal range. This step solves the problems of small activated carbon adsorption capacity and slow adsorption rate in existing devices, as well as large heat loss and incomplete desorption due to the lack of an insulation layer, and large flow resistance and high energy consumption caused by unreasonable activated carbon particle size.

[0029] Reference Figure 1The nitrogen inlet pipe 11 is equipped with a flow meter 1101. The nitrogen introduced has a purity of not less than 99.99%, and the nitrogen purging flow rate is 2-3 times the volume of the activated carbon adsorption box per hour, with a purging time of 30-45 minutes. The steam inlet pipe 12 is equipped with a pressure regulating valve 1201. The introduced steam is saturated steam with a pressure of 0.3-0.5 MPa, and the purging time is 60-90 minutes. When the activated carbon in activated carbon adsorption box A8 or activated carbon adsorption box B9 is saturated, the device will first start the nitrogen purging process. Nitrogen with a purity of not less than 99.99% is introduced into the adsorption box through the nitrogen inlet pipe 11. The flow meter 1101 on the nitrogen inlet pipe 11 will precisely control the purging flow rate to 2-3 times the volume of the activated carbon adsorption box per hour, and the purging time is set to 30-45 minutes. High-purity nitrogen can prevent impurities from mixing into the subsequent desorption gas and affecting VOCs recovery. To ensure purity, the flow rate and time are carefully matched to fully vent residual purified gas from the adsorption chamber, preventing VOCs from mixing with air and forming explosive gases during desorption. After nitrogen purging, the steam desorption process is initiated. Saturated steam at a pressure of 0.3-0.5 MPa is introduced into the adsorption chamber through steam inlet pipe 12. The pressure regulating valve 1201 on steam inlet pipe 12 stabilizes the steam pressure, and the purging time is controlled at 60-90 minutes. The saturated steam at 0.3-0.5 MPa has a moderate temperature, which effectively desorbs VOCs adsorbed by activated carbon without damaging the activated carbon structure due to excessive temperature. The 60-90 minute purging time ensures complete desorption of VOCs. This step solves the problems in existing devices where residual gas during activated carbon regeneration affects the purity of VOCs recovery, unstable steam pressure leads to incomplete desorption or damage to activated carbon, and unreasonable purging parameters result in low regeneration efficiency.

[0030] Reference Figure 1The condensation recovery device 10 includes a primary condensation device 1001, a secondary condensation device 1002, and a solvent recovery tank 1003. Both the primary condensation device 1001 and the secondary condensation device 1002 are equipped with chilled water inlets and outlets. The condensed liquid VOCs are introduced into the solvent recovery tank 1003 through the bottom interface. The secondary condensation device 1002 has a non-condensable gas discharge port at the top. The temperature difference for the primary condensation is 15-20℃, and the temperature difference for the secondary condensation is 5-10℃. The VOCs recovery purity is not less than 92%. High-concentration VOCs gas (desorption gas) generated by desorption from activated carbon adsorption box A8 or activated carbon adsorption box B9 is transported to the condensation recovery device 10 through pipelines. This device adopts a two-stage condensation structure; the desorption gas first enters the primary condensation device 1001, and the temperature difference for the primary condensation is controlled at 15℃. At -20℃, high-boiling-point VOCs (such as isopropanol and butyl acetate) in the desorbed gas can be quickly condensed into liquid. The desorbed gas after the first-stage condensation enters the second-stage condensation unit 1002. The temperature difference of the second-stage condensation is controlled at 5-10℃, which can further condense low-boiling-point VOCs (such as ethanol and acetone) into liquid. The liquid VOCs generated by the two-stage condensation will flow into the solvent recovery tank 1003 through their respective bottom interfaces to realize the resource recovery of VOCs. The non-condensable gas discharge port set at the top of the second-stage condensation unit 1002 can discharge a small amount of inert gas (such as nitrogen) that cannot be condensed. After testing and meeting the standards, it can be safely discharged. This step solves the problems of existing devices that use single-stage condensation to recover VOCs with a purity of less than 85%, which cannot realize resource reuse and have a low recovery rate of low-boiling-point VOCs.

[0031] Reference Figure 1A pressure sensor 13 is installed on the pipeline between the main fan 7 and the activated carbon adsorption boxes A8 and B9; a VOCs online monitoring instrument 14 is installed at the purified gas outlet of the activated carbon adsorption boxes A8 and B9; during the process of exhaust gas entering the activated carbon adsorption boxes, the pressure sensor 13 installed on the pipeline between the main fan 7 and the activated carbon adsorption boxes A8 and B9 will monitor the gas pressure in the pipeline in real time. When the activated carbon becomes clogged due to the adsorption of oil mist and impurities, the pipeline pressure will increase. If the pressure exceeds the set threshold (e.g., 3000Pa), the pressure sensor 13 will send a signal to the PLC control device 15 to prompt the operator to adjust the activated carbon adsorption system. The activated carbon is replaced or regenerated. Simultaneously, the VOCs online monitoring instrument 14 installed at the purified gas outlet of activated carbon adsorption boxes A8 and B9 will monitor the VOCs concentration in the purified gas in real time. If the concentration exceeds the emission standard (e.g., 30 mg / m³), the VOCs online monitoring instrument 14 will immediately issue an alarm and trigger the PLC control device 15 to automatically switch to another adsorption box (e.g., switching to box B if box A is currently in use), ensuring that the purified gas always meets emission standards. This step solves the problem that existing devices cannot monitor activated carbon blockage in real time, which can easily lead to excessive pressure and equipment damage due to blockage, and the purified gas emission concentration cannot be monitored in real time, posing a risk of exceeding emission standards.

[0032] In summary, the high-humidity, high-viscosity, oily organic waste gas treatment device disclosed in this application is used in the following way: the high-humidity, high-viscosity, oily organic waste gas is transported by the blower 1, and after passing through the water seal tank 2 to prevent backfire and back pressure, it enters the first absorption tower 3 and the second absorption tower 4, where most of the VOCs are removed by spraying with low-temperature ethanol aqueous solution; then the waste gas enters the condenser 5 for deep dehumidification, and the condensate is discharged; the dehumidified waste gas is heated by the heater 6 and pushed by the main blower 7 to the activated carbon adsorption box A8 or B9 for deep adsorption, and the purified gas is discharged in compliance with standards; after adsorption saturation, the residual gas is purged with nitrogen and then desorbed with steam, and the high-concentration VOCs gas enters the condensation recovery device 10 to recover liquid VOCs. The entire process is automatically monitored and controlled by the PLC control device 15 to ensure efficient and safe operation.

Claims

1. A device for treating high-humidity, high-viscosity, oily organic waste gas, characterized in that, Include: The blower (1) provides power for the transport of high humidity, high viscosity, oily organic waste gas; Water seal tank (2), the air inlet of the water seal tank (2) is sealed to the air outlet of the blower (1) to block backfire pressure in the device; The first absorption tower (3) and the second absorption tower (4) are arranged in series. The lower air inlet of the first absorption tower (3) is connected to the air outlet of the water seal tank (2) by a flange seal. The lower air inlet of the second absorption tower (4) is connected to the top air outlet of the first absorption tower (3) by a pipe. The inner wall of the pipe is coated with a polytetrafluoroethylene anti-corrosion coating. The bottom of the first absorption tower (3) and the second absorption tower (4) are provided with a first circulating liquid tank (301) and a second circulating liquid tank (401). The first circulating liquid tank (301) and the second circulating liquid tank (401) are fixedly installed inside the first circulating liquid tank (301) and the second circulating liquid tank (401). The first circulating pump (303) and the second circulating pump (403) are also included. The inlets of the first circulating pump (303) and the second circulating pump (403) are connected to the first circulating liquid tank (301) and the second circulating liquid tank (401), and the outlets are connected to the spray device inside the absorption tower. The condenser (5) has an air inlet connected to the top air outlet of the second absorption tower (4) for deep dehumidification of the exhaust gas; the condenser (5) has a chilled water inlet (501) at the bottom, a chilled water outlet (502) at the top, and a condensate discharge outlet (503) at the bottom. Heater (6), the air inlet of the heater (6) is connected to the air outlet of the condenser (5) through a heat-insulating pipe to prevent condensation of exhaust gas, the heater (6) is an electric heating type; The main fan (7) is connected to the air outlet of the heater (6) to provide power for the waste gas to enter the adsorption box; Activated carbon adsorption box A (8) and activated carbon adsorption box B (9) are arranged in parallel. The air outlet of the main fan (7) is connected to the air inlet of the two adsorption boxes through control valves. Both adsorption boxes are equipped with purified gas outlets and are connected to nitrogen inlet pipe (11) and steam inlet pipe (12). The condensation recovery device (10) is connected to the desorption gas outlet of the activated carbon adsorption box A (8) and the activated carbon adsorption box B (9) through a pipeline to realize VOCs resource utilization. The PLC control device (15) is electrically connected to the control components on the blower (1), the first circulation pump (303), the second circulation pump (403), the heater (6), the main blower (7), the control valve, the nitrogen inlet pipe (11), and the steam inlet pipe (12) to realize automatic control of the device.

2. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: The water seal tank (2) is equipped with a U-shaped water seal channel inside, and the water seal height is 300-500mm. The tank wall of the water seal tank (2) is equipped with a level gauge (201) and a water inlet (202).

3. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: The spraying device in the first absorption tower (3) and the second absorption tower (4) is a spiral nozzle; the absorption liquid in the first circulating liquid tank (301) and the second circulating liquid tank (401) is an aqueous ethanol solution.

4. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: The heat exchange tubes of the first coil heat exchanger (302) and the second coil heat exchanger (402) are made of stainless steel. The first coil heat exchanger (302) and the second coil heat exchanger (402) are provided with chilled water inlet and outlet.

5. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: The condenser (5) has a shell-and-tube structure, with the shell side being the exhaust gas passage and the tube side being the chilled water passage. The condensate discharge port (503) is connected to the wastewater treatment pipeline.

6. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: The outer walls of the first absorption tower (3), the second absorption tower (4), and the condenser (5) are all provided with a heat insulation layer.

7. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: The activated carbon filled in the activated carbon adsorption box A (8) and activated carbon adsorption box B (9) is coal-derived columnar activated carbon; the inner wall of the activated carbon adsorption box A (8) and activated carbon adsorption box B (9) is provided with a heat insulation layer.

8. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: A flow meter (1101) is provided on the nitrogen inlet pipe (11); a pressure regulating valve (1201) is provided on the steam inlet pipe (12).

9. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: The condensation recovery device (10) includes a primary condensation device (1001), a secondary condensation device (1002), and a solvent recovery tank (1003). Both the primary condensation device (1001) and the secondary condensation device (1002) are equipped with chilled water inlet and outlet. The condensed liquid VOCs are introduced into the solvent recovery tank (1003) through the bottom interface. The secondary condensation device (1002) is equipped with a non-condensable gas discharge port at the top.

10. The high-humidity, high-viscosity, oily organic waste gas treatment device according to claim 1, characterized in that: Pressure sensors (13) are installed on the pipeline between the main fan (7) and the activated carbon adsorption box A (8) and activated carbon adsorption box B (9); VOCs online monitoring instruments (14) are installed at the purified gas outlets of the activated carbon adsorption box A (8) and activated carbon adsorption box B (9).

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