An organic waste gas multi-stage purification equipment and process integrating a regeneration oxidation function

Abstract

The present invention relates to an organic waste gas multi-stage purification device and process integrating a regeneration and oxidation function, comprising: a tower, a circulating water tank, a biological packing layer, a spiral nozzle, a first heat exchanger, a steam collection hood, an activated carbon layer and a molecular sieve layer which are sequentially arranged inside the tower from bottom to top; an exhaust gas inlet arranged on the side wall of the tower body and located between the circulating water tank and the biological packing layer; a steam inlet and an exhaust gas outlet arranged at the top of the tower; and a circulating pump arranged outside the tower.

Description

Technical Field

[0001] The present invention relates to an organic waste gas multi-stage purification device and process integrating a regeneration and oxidation function, and belongs to the field of organic gas treatment. Background Art

[0002] A large amount of organic waste gas is generated in industrial activities, among which the waste gas with a large air volume and low concentration is the most common. The adsorption concentration method and the biological purification method are generally used to treat the organic waste gas with a large air volume and low concentration. The disadvantages of the adsorption concentration method are as follows: after the organic waste gas is adsorbed and concentrated to obtain a high-concentration desorbed gas, relevant equipment needs to be configured separately for processes such as catalytic oxidation, regenerative oxidation, and solvent recovery to treat the high-concentration desorbed gas, which not only has high investment costs and operating expenses, but also is prone to generating secondary pollutants. Although the biological purification method can directly treat the waste gas, with relatively low investment costs and operating expenses and fewer secondary pollutants, the purification effect of the biological method is not good, and the purification effect is not ideal when used alone.

[0003] At present, most organic waste gas treatment devices integrate adsorption and desorption functions, such as activated carbon fixed beds, molecular sieve fixed beds, zeolite rotors / rotating drums, etc. The waste gas with a large air volume and low concentration is converted into a desorbed gas with a small air volume and high concentration through the adsorption-desorption process, so as to achieve the purpose of adsorption concentration. However, the existing organic waste gas treatment devices do not have the ability to treat high-concentration desorbed gas, that is, there is no device that integrates the three functions of adsorption, desorption, and desorption gas treatment.

[0004] The patent "An Online Circulation Regeneration Organic Waste Gas Treatment Method and Device" with the publication number of CN105944503B discloses an online circulation regeneration organic waste gas treatment device, including a cyclone tower, a storage tank, a sedimentation tank, a biological desorption chamber, and a storage chamber arranged on one side of the biological desorption chamber; the bottom of the cyclone tower is connected to the sedimentation tank through a pipeline; a centrifugal pump is arranged at the bottom of the sedimentation tank, and the adsorbent particle balls with a microporous structure inside are transported to the biological desorption chamber through the centrifugal pump; a plurality of tangentially arranged swirl atomizing nozzles are distributed at intervals on the lower side wall of the cyclone tower; the organic absorbent solution, the desorbed adsorbent particle balls, and the organic waste gas are sprayed into the cyclone tower in a tangential manner by the swirl atomizing nozzles for full mixing, and flow circumferentially along the inner wall of the cyclone tower and spiral upward. This device integrates the adsorption recovery method, the absorption method, and the biological method into a new device, overcomes the deficiencies of traditional purification, realizes the online circulation regeneration of the adsorbent, improves the purification efficiency, reduces the operating cost, and solves the problem of low regeneration efficiency of the adsorbent. Summary of the Invention

[0005] To solve the problems existing in the above-mentioned prior art, the present invention provides an organic waste gas multi-stage purification device integrated with a regeneration oxidation function, which combines the advantages of the biological method and the adsorption method, integrates the regeneration oxidation function, does not require an external set of oxidation or recovery equipment, and reduces the floor area and investment operation cost.

[0006] The technical solution of the present invention is as follows:

[0007] An organic waste gas multi-stage purification device integrated with a regeneration oxidation function, comprising: a tower, a circulation water tank, a biological packing layer, a spiral spray head, a first heat exchanger, a steam collection hood, an activated carbon layer, and a molecular sieve layer, which are sequentially arranged inside the tower from bottom to top; an exhaust gas inlet provided on the side wall of the tower body and located between the circulation water tank and the biological packing layer; a steam inlet and an exhaust gas outlet provided at the top of the tower; a circulation pump provided outside the tower;

[0008] A steam cooling inlet is provided at the top of the first heat exchanger, and a steam cooling outlet is provided at the bottom. Both ends of the first heat exchanger penetrate through the tower body, one end is a cooling water inlet, and the other end is a cooling water outlet; the steam collection hood is fixedly connected to the steam cooling inlet;

[0009] The circulation water tank, the circulation pump, and the spiral spray head are sequentially connected through pipelines; the circulation water tank stores spray liquid and activated sludge.

[0010] Further, it further includes a demisting layer provided inside the tower, and the demisting layer is located between the spiral spray head and the first heat exchanger.

[0011] Further, a second heat exchanger is also provided between the circulation pump and the spiral spray head, and the second heat exchanger is used to cool the spray liquid.

[0012] Further, a purging port is also provided on the side wall of the tower body, and the purging port is located below the activated carbon layer and is used to purge the activated carbon layer and the molecular sieve layer.

[0013] Further, the biological packing layer, the activated carbon layer, and the molecular sieve layer are all provided with inspection ports.

[0014] Further, a chemical addition port is also provided on the circulation water tank.

[0015] Further, a drain port is also provided on the circulation water tank.

[0016] Further, an organic waste gas multi-stage purification process integrated with a regeneration oxidation function includes the following steps:

[0017] S1. Adsorb and process the organic waste gas:

[0018] Open the exhaust gas inlet and the exhaust gas outlet;

[0019] The fan drives the organic waste gas to enter the tower from the waste gas inlet. The inlet temperature of the organic waste gas is < 40°C, and the superficial gas velocity of the empty tower is ≤ 1.5 m / s.

[0020] The organic waste gas sequentially passes through the biological packing layer, the demisting layer, the activated carbon layer, and the molecular sieve layer. The thickness of the biological packing layer is 1.5 m - 4.5 m and is filled with the first packing. The thickness of the demisting layer is 0.5 m - 1 m and is filled with the second packing. The thickness of the activated carbon layer is 0.5 m - 1 m and is filled with the third packing. The thickness of the molecular sieve layer is 0.5 m - 1 m, and the pore diameter of the sieve holes is

[0021] After the organic waste gas is treated by adsorption and meets the emission standards, it is discharged into the atmosphere.

[0022] S2. Desorb the saturated activated carbon layer and molecular sieve layer:

[0023] Detect the gas concentration at the waste gas outlet. If the gas concentration exceeds the emission standards, desorb the activated carbon layer and the molecular sieve layer. The desorption time is 1 - 2 hours:

[0024] Close the waste gas inlet and the waste gas outlet, and open the steam inlet, the spiral nozzle, the circulation pump, and the first heat exchanger.

[0025] The circulation pump transports the spraying liquid to the spiral nozzle; the spiral nozzle sprays the spraying liquid, and the spraying volume is 0.8 - 1 m 3 / ㎡.h;

[0026] The high-temperature steam enters the tower from the steam inlet. The inlet temperature of the high-temperature steam is 100 - 120°C; the high-temperature steam sequentially passes through the molecular sieve layer and the activated carbon layer, and the high-temperature steam is transformed into desorption steam; the desorption steam is first cooled by the first heat exchanger, and the temperature of the desorption steam is ≤ 40°C; the desorption steam is secondarily cooled by the spiral nozzle to condense into desorption condensate water entrained with organic solvents.

[0027] S3. Treat the desorbed gas:

[0028] The desorption condensate water flows into the circulation water tank; the activated sludge in the circulation water tank performs biochemical treatment on the organic solvents; the activated sludge takes flocculent sludge as the carrier and contains microorganisms, and the mass concentration of the microorganisms is 1500 - 2500 mg / L.

[0029] Furthermore, the spraying liquid is transported to the spiral nozzle through the circulation pump and the second heat exchanger, and the second heat exchanger controls the outlet temperature of the circulating liquid ≤ 30°C.

[0030] Furthermore, after the desorption of the activated carbon layer and the molecular sieve layer is completed, air is introduced through the purging port to purge the activated carbon layer and the molecular sieve layer, and the purging time is 0.5 - 1 hour.

[0031] The present invention has the following beneficial effects:

[0032] 1. Combining the advantages of the biological method and the adsorption method, the present invention sets up a three-stage purification mechanism of biological absorption + activated carbon adsorption + molecular sieve adsorption. Biological film hanging is used for deodorization, activated carbon comprehensively adsorbs VOCs, and molecular sieve selectively adsorbs VOCs. The three-stage purification has different focuses and cooperates with each other to comprehensively and efficiently achieve the treatment of organic waste gas.

[0033] 2. The equipment of the present invention integrates the function of regeneration and oxidation, eliminating the need for an external set of oxidation or recovery equipment, reducing the floor area and investment operation costs. The regeneration and oxidation function is achieved through the biological oxidation method. The traditional methods for treating desorbed gas are generally catalytic oxidation, regenerative oxidation, solvent recovery, etc., which have a large demand for electricity, gas, etc., and are also prone to secondary pollution of equipment due to incomplete oxidation. The present invention adopts the biological oxidation method to oxidize and decompose pollutants through activated sludge, reducing the generation of secondary pollutants, resourcefully treating desorbed gas, with very low operating energy consumption and little demand for electricity and gas.

[0034] 3. Through the spray liquid, circulation pump, and spiral nozzle in the circulation water tank, the present invention circularly utilizes the pollutants in the waste gas as the carbon source, nitrogen source, sulfur source, etc. for the growth of microorganisms in the biological packing layer, realizing the resourceization, greening, and circulation of waste gas treatment.

[0035] 4. The present invention sets up a multi-stage desorption system to improve safety. The flammability of activated carbon has led to frequent occurrence of high-temperature desorption fire accidents. This equipment adopts a two-stage steam desorption method of molecular sieve first and then activated carbon. Utilizing the high-temperature tolerance property of the molecular sieve, the molecular sieve layer is first desorbed, and then the activated carbon is desorbed after the steam temperature drops, ensuring both the desorption effect and the operation safety of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of the present invention.

[0037] In the figure: 1. Spray pipeline; 2. Circulation water tank; 3. Waste gas inlet; 4. Biological packing layer; 5. Demisting layer; 6. Cooling water inlet; 7. Steam collection hood; 8. Activated carbon layer; 9. Molecular sieve layer; 10. Steam inlet; 11. Waste gas outlet; 12. Maintenance opening; 13. Cooling water outlet; 14. Blowing port; 15. Spiral nozzle; 16. Chemical addition port; 17. Drain port; 18. Circulation pump; 19. Second heat exchanger; 20. Steam cooling inlet; 21. Steam cooling outlet; 22. First heat exchanger. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0039] Embodiment 1

[0040] An organic waste gas multi-stage purification device integrating a regeneration and oxidation function, comprising: a tower, a circulation water tank 2, a biological packing layer 4, a spiral spray head 15, a demisting layer 5, a first heat exchanger 22, a steam collection hood 7, an activated carbon layer 8, and a molecular sieve layer 9 which are sequentially arranged inside the tower from bottom to top; an exhaust gas inlet 3 provided on the side wall of the tower body and located between the circulation water tank 2 and the biological packing layer 4; a steam inlet 10 and an exhaust gas outlet 11 provided at the top of the tower; and a circulation pump 18 provided outside the tower.

[0041] The exhaust gas inlet 3 is used to introduce organic waste gas. The biological packing layer 4, the activated carbon layer 8, and the molecular sieve layer 9 are used for adsorbing and treating the organic waste gas. Specifically:

[0042] The biological packing layer 4 is filled with packing such as multi-faceted balls, volcanic rocks, Pall rings, cascade rings, and broken bamboo charcoal. The packing is a carrier for the attachment and growth of microorganisms. The microorganisms attach to the carrier and grow to form a biological film, absorbing the malodorous components and some organic pollutants (i.e., NH3, H2S, CO2, and some water-soluble VOCs) in the organic waste gas. The above pollution components are absorbed and degraded by the microorganisms as nutrients.

[0043] The demisting layer 5 is filled with packing such as baffle plates and wire meshes. The water mist and liquid droplets entrained in the organic waste gas are removed under the action of inertial force, reducing the humidity of the waste gas and avoiding the influence of excessive humidity on the adsorption effects of the activated carbon layer 8 and the molecular sieve layer 9.

[0044] The activated carbon layer 8 is filled with activated carbon adsorption materials such as granular carbon, honeycomb carbon, and fiber carbon. Under the action of van der Waals force, the organic pollutants (VOCs components) in the organic waste gas are adsorbed and treated.

[0045] Compared with activated carbon, molecular sieves have the advantages of large adsorption capacity, strong adsorption selectivity, and high desorption temperature. Therefore, the molecular sieve layer 9 is used to further adsorb and treat the VOCs components in the organic waste gas. In actual use, molecular sieves with different pore sizes are selected for specific pollution components. Generally, the pore size is It can enhance the pertinence, selectivity, and specificity of the device for treating organic waste gas.

[0046] The exhaust gas outlet 11 is used to discharge the organic waste gas that has been adsorbed and treated.

[0047] The adsorption capacities of activated carbon and molecular sieves are limited. As the equipment operates, organic pollutants begin to penetrate and gradually reach adsorption saturation. Therefore, it is necessary to desorb the activated carbon layer 8 and the molecular sieve layer 9. The steam inlet 10 introduces high-temperature steam. Since the molecular sieve has good heat resistance, desorption treatment is carried out first. The VOCs adsorbed in the molecular sieve layer 9 are desorbed under high-temperature conditions and flow out with the steam. At this time, the steam temperature drops, and then it enters the activated carbon layer 8 with relatively poor high-temperature resistance for desorption treatment. The two-stage desorption design improves the safety performance of the equipment. At this time, the high-temperature steam is transformed into desorption steam.

[0048] At the top of the first heat exchanger 22, there is a steam cooling inlet 20, and at the bottom, there is a steam cooling outlet 21. Both ends of the first heat exchanger 22 penetrate through the tower body. One end is the cooling water inlet 6, and the other end is the cooling water outlet 13; the steam collection hood 7 is fixedly connected to the steam cooling inlet 20, and is used to collect the desorption steam flowing out from the activated carbon layer 8 and introduce it into the steam cooling inlet 20; the first heat exchanger 22 is used to cool the desorption steam.

[0049] The circulating water tank 2, the circulating pump 18, and the spiral nozzle 15 are connected in sequence through pipelines. The circulating water tank 2 and the circulating pump 18 are connected through a spray pipeline 1. The circulating water tank 2 stores spray liquid and activated sludge. The circulating pump 18 is used to transport the spray liquid to the spiral nozzle 15; the spiral nozzle 15 is used to uniformly spray the spray liquid to wet the biological packing layer 4 and further cool the desorption steam. The desorption steam is cooled by the first heat exchanger 22 and the spiral nozzle 15 and is transformed into desorption condensate.

[0050] The spray liquid contains nutrient components required for maintaining the growth of microorganisms, including P, S, metal elements, and trace elements, etc. The remaining necessary C element is provided by components such as VOCs and CO2 in the organic waste gas, and the N element is provided by components such as NH3 and NOx in the organic waste gas. The activated sludge uses flocculent sludge as a carrier and contains a large number of microorganisms such as bacteria, fungi, and algae, which is equivalent to an aerobic treatment tank. The microorganisms carry out biochemical treatment on pollution components such as COD in the desorption condensate to achieve biodegradation of the VOCs components adsorbed by the activated carbon and molecular sieves.

[0051] In this embodiment, the equipment of the present invention can adopt a PLC or DCS control system, equipped with a liquid crystal touch screen for operation, and set automatic control valves and instrument meters with signal transmission to realize the automatic operation of the system.

[0052] Embodiment 2

[0053] Furthermore, a second heat exchanger 19 is also provided between the circulating pump 18 and the spiral nozzle 15, and the second heat exchanger 19 is used to cool the spray liquid to control the temperature of the spray liquid within the range suitable for the growth of microorganisms.

[0054] Example III

[0055] Furthermore, a purging port 14 is provided on the side wall of the tower body, and the purging port 14 is located below the activated carbon layer 8.

[0056] After steam desorption, the activated carbon and molecular sieve are occupied by a large number of water molecules at the adsorption active sites. Fresh air needs to be introduced through the purging port 14 to purge the activated carbon layer 8 and the molecular sieve layer 9 to remove moisture and restore their adsorption performance.

[0057] Example IV

[0058] Furthermore, a chemical addition port 16 is provided on the circulating water tank 2, and the pH value of the spraying liquid in the circulating water tank 2 is manually controlled or controlled in a linked manner by a pH meter to be maintained within the range of 6 - 9. Nutrients can also be supplemented to the spraying liquid through the chemical addition port 16.

[0059] Furthermore, a liquid discharge port 17 is provided on the circulating water tank 2. As impurities such as cell metabolites and dust particles gradually accumulate, the circulating liquid begins to age and inhibits the growth of microorganisms. The aged circulating liquid needs to be discharged to update the circulating liquid in a timely manner.

[0060] The discharge of the spraying liquid in the circulating water tank 2 is manually controlled or controlled in a linked manner by a conductivity meter through the liquid discharge port 17. When the conductivity value of the spraying liquid or the equipment operation time reaches the design value, the liquid discharge port 17 is opened to discharge the spraying liquid. In this example, the liquid discharge port 17 is opened regularly according to the actual use conditions of the equipment, such as the dust content of the waste gas, the growth of microorganisms, and the physical and chemical indexes of the circulating liquid.

[0061] Example V

[0062] Furthermore, maintenance ports 12 are provided on the biological packing layer 4, the activated carbon layer 8, and the molecular sieve layer 9, and each layer is maintained, serviced, loaded, and unloaded through the maintenance ports 12. In this example, differential pressure gauges are installed on each layer, and when the differential pressure exceeds the set value, the maintenance ports 12 are opened for inspection.

[0063] Example VI

[0064] Collect the organic waste gas. For specific information such as the source of the organic waste gas, please refer to the following table;

[0065] Exhaust gas source Waste gas from packaging and printing Exhaust gas volume <![CDATA[10000m 3 / h]]> VOCs concentration <![CDATA[200mg / m 3 > Pollution components <![CDATA[NH3, ethyl acetate, isopropanol, etc.]]>

[0066] Open the waste gas inlet 3 and the waste gas outlet 11.

[0067] The fan drives the organic waste gas to enter the tower from the waste gas inlet 3. The inlet temperature of the organic waste gas is 25°C, and the superficial gas velocity is 1.5 m / s.

[0068] The organic waste gas first enters the biological packing layer 4 with a thickness of 3 m. The biological packing layer 4 is filled with multi-faceted balls as carriers for the attachment and growth of microorganisms, and the microorganisms form a biological film to absorb NH3 in the organic waste gas.

[0069] After being treated by the biological packing layer 4, the organic waste gas enters the demisting layer 5 with a thickness of 1 m. The demisting layer 5 is filled with baffle plates, which remove the water mist and liquid droplets entrained in the organic waste gas and reduce the humidity of the organic waste gas.

[0070] After being treated by the demisting layer 5, the organic waste gas enters the activated carbon layer 8 with a thickness of 0.5 m. The activated carbon layer 8 is filled with granular carbon, and the granular carbon adsorbs VOCs components such as ethyl acetate and isopropanol in the organic waste gas;

[0071] After being treated by the activated carbon layer 8, the organic waste gas enters the molecular sieve layer 9 with a thickness of 0.5 m, and the pore diameter of the sieve holes is The molecular sieve layer 9 further adsorbs the VOCs components in the organic waste gas.

[0072] After being treated by the molecular sieve layer 9, the organic waste gas reaches the emission standard and is discharged into the atmosphere.

[0073] Detect the concentrations of the waste gas inlet 3 and the waste gas outlet 11. If the outlet concentration reaches or is close to the emission standard, desorption treatment is carried out on the saturated activated carbon layer 8 and the molecular sieve layer 9, and the desorption time is 2 hours.

[0074] Close the waste gas inlet 3 and the waste gas outlet 11, and open the steam inlet 10, the spiral nozzle 15, the circulation pump 18, the second heat exchanger 19 and the first heat exchanger 22.

[0075] The circulation pump 18 extracts the spray liquid in the circulation water tank 2. The spray liquid passes through the circulation pump 18 and the second heat exchanger 19 at a flow rate of 0.8 m 3 / ㎡.h and is transported to the spiral nozzle 15. The spiral nozzle 15 sprays the spray liquid at an outlet flow rate of 0.08 m 3 / h / unit, and the spray liquid evenly wets the biological packing layer 4. The spray liquid contains the nutrients required to maintain the growth of microorganisms, including 0.05% P element, 0.01% S element, metal elements and trace elements. The second heat exchanger 19 is used to cool the spray liquid to control the temperature of the spray liquid at 25 °C. The total heat exchange area of the second heat exchanger 19 is 2 ㎡, and the cooling water flow rate is 2 m 3 / h.

[0076] High-temperature steam enters the tower from the steam inlet 10. The inlet temperature of the high-temperature steam is 100 - 120 °C, and the inlet speed of the high-temperature steam is 30 m / s.

[0077] High-temperature steam sequentially passes through the molecular sieve layer 9 and the activated carbon layer 8, desorbing and carrying out the VOCs components in the molecular sieve layer 9 and the activated carbon layer 8, and the high-temperature steam is transformed into desorption steam.

[0078] The desorption steam is collected by the steam collection hood 7 and introduced into the steam cooling inlet 20. The desorption steam is indirectly heat-exchanged through the first heat exchanger 22 to cool the desorption steam for the first time. The total heat exchange area of the first heat exchanger 22 is 35 ㎡, and the water inlet flow rate of the cooling water inlet 6 is 50 m 3 / h, and the water outlet flow rate of the cooling water outlet 13 is 50 m 3 / h.

[0079] The desorption steam is directly heat-exchanged through the spiral spray head 15 to cool the desorption steam for the second time; the desorption steam is cooled twice and condensed into desorption condensate water entraining organic solvents; the desorption condensate water flows through the biological packing layer 4 and flows into the circulation water tank 2; the capacity of the circulation water tank 2 is 2.5 m 3 .

[0080] The activated sludge in the circulation water tank 2 performs biochemical treatment on the organic solvents.

[0081] Open the purge port 14, introduce fresh air to purge the activated carbon layer 8 and the molecular sieve layer 9, remove moisture and restore the adsorption performance of the activated carbon layer 8 and the molecular sieve layer 9. The purge time is 0.5 hours and the air flow rate is 12 m / s.

[0082] Example Seven

[0083] Collect organic waste gas. For specific information such as the source of the organic waste gas, please refer to the following table;

[0084] Exhaust gas source Odor from garbage station Exhaust gas volume <![CDATA[8000m 3 / h]]> VOCs concentration <![CDATA[50mg / m 3 > Pollution components <![CDATA[H2S, NH3, methyl mercaptan, etc.]]>

[0085] Open the waste gas inlet 3 and the waste gas outlet 11.

[0086] The fan drives the organic waste gas to enter the tower from the waste gas inlet 3. The inlet temperature of the organic waste gas is 30 °C, and the superficial gas velocity is 1.2 m / s.

[0087] The organic waste gas first passes through the biological packing layer 4. The thickness of the biological packing layer is 4.5 m. The biological packing layer 4 is filled with volcanic rock as the carrier for the attachment and growth of microorganisms. The microorganisms form a biological film to absorb H2S and NH3 in the organic waste gas.

[0088] After being treated by the biological packing layer 4, the organic waste gas passes through the demisting layer 5. The thickness of the demisting layer 5 is 1 m and is filled with wire mesh. The wire mesh removes the water mist and liquid droplets entrained in the organic waste gas and reduces the humidity of the organic waste gas.

[0089] The organic waste gas is treated by the demisting layer 5 and then introduced into the activated carbon layer 8. The thickness of the activated carbon layer 8 is 0.5 m, and it is filled with honeycomb carbon, which adsorbs VOCs components such as methyl mercaptan in the organic waste gas.

[0090] The organic waste gas is treated by the activated carbon layer 8 and then introduced into the molecular sieve layer 9. The thickness of the molecular sieve layer is 0.5 m, and the pore diameter of the sieve holes is The molecular sieve layer 9 further adsorbs the VOCs components in the organic waste gas.

[0091] After being treated by the molecular sieve layer 9, the organic waste gas meets the emission standard and is discharged into the atmosphere.

[0092] The concentrations of the waste gas inlet 3 and the waste gas outlet 11 are detected. If the outlet concentration reaches or approaches the emission standard, the saturated activated carbon layer 8 and the molecular sieve layer 9 are desorbed, and the desorption time is 2 hours.

[0093] The waste gas inlet 3 and the waste gas outlet 11 are closed, and the steam inlet 10, the spiral spray head 15, the circulation pump 18, the second heat exchanger 19, and the first heat exchanger 22 are opened.

[0094] The circulation pump 18 pumps the spray liquid in the circulation water tank 2. The spray liquid passes through the circulation pump 18 and the second heat exchanger 19 at a flow rate of 1 m 3 / ㎡.h and is transported to the spiral spray head 15. The spiral spray head 15 sprays the spray liquid at an outlet flow rate of 0.12 m 3 / h / unit, and the spray liquid evenly wets the biological packing layer 4. The spray liquid contains the nutrients required to maintain the growth of microorganisms, including 0.05% of P element, metal elements, and trace elements. The second heat exchanger 19 is used to cool the spray liquid so that the temperature of the spray liquid is controlled at 28 °C. The total heat transfer area of the second heat exchanger 19 is 2.7 ㎡, and the cooling water flow rate is 2.5 m 3 / h.

[0095] The high-temperature steam enters the tower from the steam inlet 10. The inlet temperature of the high-temperature steam is 100 - 120 °C, and the inlet velocity of the high-temperature steam is 24 m / s.

[0096] The high-temperature steam sequentially passes through the molecular sieve layer 9 and the activated carbon layer 8, absorbs the VOCs components in the molecular sieve layer 9 and the activated carbon layer 8, and the high-temperature steam is transformed into desorption steam.

[0097] The desorption steam is collected by the steam collection hood 7 and introduced into the steam cooling inlet 20. The desorption steam is indirectly heated by the first heat exchanger 22 to cool the desorption steam for the first time. The total heat transfer area of the first heat exchanger 22 is 28 ㎡, the inlet flow rate of the cooling water at the cooling water inlet 6 is 45 m 3 / h, and the outlet flow rate of the cooling water at the cooling water outlet 13 is 45 m 3 / h.

[0098] The desorbed steam is directly heat-exchanged through the spiral nozzle 15 to cool the desorbed steam for the second time; the desorbed steam is cooled twice and condensed into desorbed condensed water entrained with organic solvents; the desorbed condensed water flows through the biological packing layer 4 and into the circulation water tank 2; the capacity of the circulation water tank 2 is 2.5 m 3 .

[0099] The activated sludge in the circulation water tank 2 performs biochemical treatment on the organic solvents.

[0100] Open the purging port 14 to introduce fresh air to purge the activated carbon layer 8 and the molecular sieve layer 9, remove moisture and restore the adsorption performance of the activated carbon layer 8 and the molecular sieve layer 9. The purging time is 0.5 hours and the air flow rate is 12 m / s.

[0101] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. An organic waste gas multi-stage purification device integrating a regeneration oxidation function, characterized in that, It includes: a tower, a circulating water tank (2), a biological packing layer (4), a spiral nozzle (15), a first heat exchanger (22), a steam collection hood (7), an activated carbon layer (8) and a molecular sieve layer (9) which are arranged in the tower from bottom to top in sequence; an exhaust gas inlet (3) arranged on the side wall of the tower body and located between the circulating water tank (2) and the biological packing layer (4); a steam inlet (10) and an exhaust gas outlet (11) arranged at the top of the tower; a circulating pump (18) arranged outside the tower; and a demisting layer (5) arranged inside the tower, and the demisting layer (5) is located between the spiral nozzle (15) and the first heat exchanger (22); a steam cooling inlet (20) is arranged at the top of the first heat exchanger (22), a steam cooling outlet (21) is arranged at the bottom of the first heat exchanger (22), both ends of the first heat exchanger (22) penetrate through the tower body, one end is a cooling water inlet (6), and the other end is a cooling water outlet (13); the steam collection hood (7) is fixedly connected to the steam cooling inlet (20); the circulating water tank (2), the circulating pump (18) and the spiral nozzle (15) are connected in sequence through pipelines; the circulating water tank (2) stores spraying liquid and activated sludge; a second heat exchanger (19) is further arranged between the circulating pump (18) and the spiral nozzle (15), and the second heat exchanger (19) is used for cooling the spraying liquid; a cleaning port (14) is further arranged on the side wall of the tower body, and the cleaning port (14) is located below the activated carbon layer (8) and is used for purging the activated carbon layer (8) and the molecular sieve layer (9); 2. The organic waste gas multi-stage purification equipment integrating the function of regenerative oxidation according to claim 1, characterized in that, maintenance ports (12) are arranged on the biological packing layer (4), the activated carbon layer (8) and the molecular sieve layer (9); 3. The organic waste gas multi-stage purification equipment integrating the regeneration oxidation function according to claim 2, characterized in that, a chemical adding port (16) is further arranged on the circulating water tank (2); 4. An organic waste gas multi-stage purification device integrating a regeneration and oxidation function according to claim 3, characterized in that, a liquid discharging port (17) is further arranged on the circulating water tank (2); 5. An organic waste gas multi-stage purification process integrating a regeneration oxidation function, which is realized based on the organic waste gas multi-stage purification equipment integrating a regeneration oxidation function described in any one of claims 1-4, is characterized in that It includes the following steps: S1. Adsorbing and treating organic waste gas: Opening the exhaust gas inlet (3) and the exhaust gas outlet (11); Driving the organic waste gas to enter the tower from the exhaust gas inlet (3) by a fan, the inlet temperature of the organic waste gas < 40°C, and the superficial gas velocity of the empty tower ≤ 1.5 m / s; The organic waste gas is successively introduced into a biological packing layer (4), a demisting layer (5), an activated carbon layer (8), and a molecular sieve layer (9); the biological packing layer (4) has a thickness of 1.5 m - 4.5 m and is filled with a first packing; the demisting layer (5) has a thickness of 0.5 m - 1 m and is filled with a second packing; the activated carbon layer (8) has a thickness of 0.5 m - 1 m and is filled with a third packing; the molecular sieve layer (9) has a thickness of 0.5 m - 1 m, and the aperture of the sieve pores is Discharging the organic waste gas to the atmosphere after being adsorbed and treated to meet the emission standard; S2. Desorbing the saturated activated carbon layer (8) and molecular sieve layer (9): Detecting the gas concentration at the exhaust gas outlet (11), if the gas concentration exceeds the emission standard, desorbing the activated carbon layer (8) and the molecular sieve layer (9), and the desorbing time is 1 - 2 hours; Closing the exhaust gas inlet (3) and the exhaust gas outlet (11), and opening the steam inlet (10), the spiral nozzle (15), the circulating pump (18) and the first heat exchanger (22); The circulation pump (18) transports the spray liquid to the spiral nozzle (15); the spiral nozzle (15) sprays the spray liquid, and the spray volume is 0.8 - 1 m 3 / ㎡.h; Letting the high-temperature steam enter the tower from the steam inlet (10), the inlet temperature of the high-temperature steam is 100 - 120°C; the high-temperature steam sequentially passes through the molecular sieve layer (9) and the activated carbon layer (8), and the high-temperature steam is transformed into desorbing steam; the desorbing steam is firstly cooled by the first heat exchanger (22), and the temperature of the desorbing steam ≤ 40°C; the desorbing steam is secondly cooled by the spiral nozzle (15) and condensed into desorbing condensed water entraining organic solvents; S3. Treating the desorbing gas: The desorbed condensed water flows into the circulation water tank (2); the activated sludge in the circulation water tank (2) performs biochemical treatment on the organic solvent; the activated sludge uses flocculent sludge as a carrier and contains microorganisms, and the mass concentration of the microorganisms is 1500 - 2500 mg / L.

6. An organic waste gas multi-stage purification process integrating a regeneration oxidation function, as claimed in claim 5, wherein The spray liquid is transported to the spiral nozzle (15) through the circulation pump (18) and the second heat exchanger (19), and the second heat exchanger (19) controls the outlet temperature of the circulating liquid ≤ 30 °C.

7. An organic waste gas multi-stage purification process integrating a regeneration oxidation function according to claim 6, characterized in that, It also includes that after the desorption of the activated carbon layer (8) and the molecular sieve layer (9) is completed, air is introduced through the purging port (14) to purge the activated carbon layer (8) and the molecular sieve layer (9), and the purging time is 0.5 - 1 hour.

Images