A system and method for treating malodorous odors

Abstract

The present invention discloses a system and method for treating malodorous odors. The system includes an intake pipeline, a hypochlorous acid generating device, and a spray reaction device. The hypochlorous acid generating device includes a hypochlorous acid generator, which is connected to a hypochlorous acid collection tank and a sodium hydroxide collection tank. The spray reaction device includes a first-stage spray tower, a second-stage spray tower, and a third-stage synergistic reaction tower connected in sequence, as well as a circulating spray path constructed by them and a circulating water tank. The method is to use the treatment system to treat malodorous odors. The system for treating malodorous odors of the present invention has the advantages of low cost, good purification effect, and low risk of secondary pollution. When used to treat different types of malodorous odor gases, it can efficiently remove various malodorous odors in the waste gas, effectively improve the environment around paper mills, and has the advantages of simple process, convenient operation, low cost, high treatment efficiency, good removal effect, etc. Moreover, the dosage of the reagent is small, the output of the waste liquid is small, it is more environmentally friendly, has high use value, and good application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of treatment of malodorous and offensive gases, and relates to a system and method for treating malodorous and offensive odors. Background Art

[0002] The production process of a waste paper pulping and papermaking mill mainly includes the following parts: 1) the wet part of the paper machine; 2) the pre-drying part; 3) the sizing section; 4) the post-drying part; 5) the coating section. Among them, the pre-drying part and the post-drying part are the main sources of malodorous and offensive gases. Among various malodorous and offensive gases, there are mainly malodorous gases such as H2S and SO2, volatile fatty acids, alcohols, benzene, phenols, and some greenhouse gases, etc., as well as various chemicals added in the pulping process and various substances and pulp particles carried by the waste paper itself are volatilized in large amounts. In addition, under the high temperature action in the drying section, the volatilization of various malodorous and offensive gases generates an unpleasant pungent smell, causing a bad impact on the surrounding environment. At the same time, the characteristics of high temperature and high humidity of the exhaust gas in the drying part also increase the treatment difficulty.

[0003] At present, the effective means and devices for treating malodorous and offensive gases with high temperature and complex components in waste paper pulping and papermaking mills mainly include: one is to use an advanced oxidation system based on persulfate for deodorization. This method has a good treatment effect on malodorous pollutants with good water solubility, but the use of conventional persulfate requires the configuration of relevant catalysts for treatment, and it is difficult to effectively purify malodorous and offensive gases with complex components; the other is to use biological methods for deodorization. However, the biological deodorization has a long residence time, is only suitable for small air volume treatment, and the biological growth maintenance conditions are harsh, and it is not well adapted to the complexity of the odor components in waste paper pulp; the third is to use the alkali washing method for deodorization. However, the alkaline agent only has a certain effect on acidic gases and cannot effectively treat characteristic pollutants such as ammonia and trimethylamine, so it cannot effectively purify malodorous and offensive gases.

[0004] Therefore, obtaining a system and method for treating malodorous and offensive odors with low cost, good purification effect, and low risk of secondary pollution is of great significance for effectively improving the environment inside and around the paper mill. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a system and method for treating malodorous and offensive odors with low cost, good purification effect, and low risk of secondary pollution.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A system for treating malodorous and offensive odors includes an intake pipeline, a hypochlorous acid generating device, a spray reaction device, a synergist dosing device, and a spray liquid circulation device;

[0008] The air inlet of the intake duct is connected to the malodorous and odoriferous gas;

[0009] The hypochlorous acid generating device includes a hypochlorous acid generator, and a hypochlorous acid collection tank and a sodium hydroxide collection tank are connected to the hypochlorous acid generator;

[0010] The spray reaction device includes a first spray tower, a second spray tower, and a third enhanced reaction tower connected in sequence; a first circulation water tank is connected to the bottom of the first spray tower, and the water outlet of the first circulation water tank is connected to the spray area of the first spray tower to form a circulating spray path; a second circulation water tank is connected to the bottom of the second spray tower, and the water outlet of the second circulation water tank is connected to the spray area of the second spray tower to form a circulating spray path; a third circulation water tank is connected to the bottom of the third enhanced reaction tower, and the water outlet of the third circulation water tank is connected to the spray area of the third enhanced reaction tower to form a circulating spray path;

[0011] The water outlet of the hypochlorous acid collection tank is respectively connected to the first circulation water tank and the second circulation water tank through a first reversing valve;

[0012] The water outlet of the sodium hydroxide collection tank is respectively connected to the first circulation water tank and the second circulation water tank through a second reversing valve;

[0013] The synergist dosing device includes a first reagent tank, a second reagent tank, and a third reagent tank;

[0014] The spray liquid circulation device includes a first waste liquid collection tank and a second waste liquid collection tank connected in sequence;

[0015] The water outlet of the first reagent tank is respectively connected to the first circulation water tank and the second circulation water tank through a third reversing valve;

[0016] The water outlet of the second reagent tank is connected to the water inlet of the third circulation water tank;

[0017] The water outlet of the third reagent tank is connected to the water inlet of the second waste liquid collection tank;

[0018] The water inlet of the first waste liquid collection tank is connected to the water outlet of the first circulation water tank; a bypass pipe is also provided between the water inlet of the first waste liquid collection tank and the water outlet of the first circulation water tank as an overflow pipe to prevent the liquid in the first circulation water tank from overflowing;

[0019] The water inlet of the second waste liquid collection tank is connected to the water outlet of the second circulation water tank;

[0020] The water outlet of the second waste liquid collection tank is respectively connected to the water inlets of the first circulation water tank and the second circulation water tank through a fourth reversing valve.

[0021] As a further improvement of the above technical solution: a first chemical dosing pump is provided on the pipeline between the first chemical agent tank and the third reversing valve; chemical agent A is stored in the first chemical agent tank; the chemical agent A is at least one of potassium hydrogen phthalate, citric acid, acetic acid, and sulfuric acid.

[0022] As a further improvement of the above technical solution: a second chemical dosing pump is provided on the pipeline between the second chemical agent tank and the three-stage circulating water tank; chemical agent B is stored in the second chemical agent tank; the chemical agent B is at least one of ascorbic acid, sodium thiosulfate, and calcium sulfite.

[0023] As a further improvement of the above technical solution: a third chemical dosing pump is provided on the pipeline between the third chemical agent tank and the second waste liquid collection tank; chemical agent C is stored in the third chemical agent tank; the chemical agent C is at least one of hydrogen peroxide and persulfate.

[0024] As a further improvement of the above technical solution: a transfer pump is provided on the pipeline between the second waste liquid collection tank and the fourth reversing valve.

[0025] As a further improvement of the above technical solution: an intelligent control device is further included; the intelligent control device includes a detection module and a control module.

[0026] As a further improvement of the above technical solution: the detection module includes a first pH meter, a second pH meter, an ORP meter, an ammonia nitrogen on-line monitor, a residual chlorine monitor, a humidity monitor, and a temperature monitor; the first pH meter is connected to the first-stage circulating water tank; the second pH meter is connected to the second-stage circulating water tank; the ORP meter is connected to the second-stage circulating water tank; the ammonia nitrogen on-line monitor is connected to the second waste liquid collection tank; the residual chlorine monitor is connected to the second waste liquid collection tank; the humidity monitor and the temperature monitor are connected to the intake pipeline.

[0027] As a further improvement of the above technical solution: the control module includes a CPU module, an analog quantity module, and a power supply module; the CPU module, the analog quantity module, and the power supply module are electrically connected; the CPU module is electrically connected to the hypochlorous acid generating device, the spraying reaction device, the synergist dosing device, and the spraying liquid circulating device; the analog quantity module is electrically connected to the detection module.

[0028] As a further improvement of the above technical solution: a raw material storage tank is connected to the hypochlorous acid generator; a water storage tank is further connected to the raw material storage tank; a filter is provided on the pipeline between the water storage tank and the raw material storage tank.

[0029] As a further improvement of the above technical solution: a hypochlorous acid dosing pump is provided on the pipeline between the hypochlorous acid collection tank and the first reversing valve.

[0030] As a further improvement of the above technical solution: a sodium hydroxide dosing pump is provided on the pipeline between the sodium hydroxide collection tank and the second reversing valve.

[0031] As a further improvement of the above technical solution: a primary circulation pump is provided on the pipeline between the primary circulation water tank and the spray area of the primary spray tower.

[0032] As a further improvement of the above technical solution: a secondary circulation pump is provided on the pipeline between the secondary circulation water tank and the spray area of the secondary spray tower.

[0033] As a further improvement of the above technical solution: a tertiary circulation pump is provided on the pipeline between the tertiary circulation water tank and the spray area of the tertiary synergistic reaction tower.

[0034] As a further improvement of the above technical solution: the outlet of the intake pipeline is connected to the bottom of the primary spray tower; the outlet of the primary spray tower is located at the top of the tower; the outlet of the primary spray tower is connected to the bottom of the secondary spray tower; the outlet of the secondary spray tower is located at the top of the tower; the outlet of the secondary spray tower is connected to the bottom of the tertiary synergistic reaction tower.

[0035] As a further improvement of the above technical solution: the secondary spray tower is successively from bottom to top a spray reaction area and a demisting area.

[0036] As a further improvement of the above technical solution: the tertiary synergistic reaction tower successively includes a liquid storage tank, a diversion component, a packing component and a spray component from bottom to top; an intake branch pipe is further provided at the bottom of the tertiary synergistic reaction tower, the outlet of the intake branch pipe faces upward and is above the liquid level in the liquid storage tank; the outlet of the intake branch pipe is below the diversion component, and the vertical projection area of the diversion component is larger than the outlet area of the intake branch pipe.

[0037] As a further improvement of the above technical solution: the diversion component is composed of an upper liquid diversion component and a lower gas diversion component; both the upper liquid diversion component and the lower gas diversion component are solid frustum-like shapes with a curved slope; a plurality of overflow grooves are provided at the upper top of the upper liquid diversion component; at least three support brackets are provided at the bottom of the tertiary synergistic reaction tower; the lower gas diversion component is installed on the support brackets so that the lower gas diversion component is installed above the liquid storage tank; the lowest point below the lower gas diversion component is above the outlet of the intake branch pipe.

[0038] As a further improvement of the above technical solution: The packing component includes a bearing element and packing. The outer periphery of the bearing element is connected to the inner wall of the three-stage synergistic reaction tower; the bearing element is stacked by multiple layers of coaxial hollow truncated cones; adjacent coaxial hollow truncated cones are symmetrically arranged; the coaxial hollow truncated cone is coaxially connected by a plurality of conical hollow truncated cone rings with different diameters, and two adjacent conical hollow truncated cone rings are staggered and overlapped in a positive and inverted form, and a V-shaped groove is formed between the two adjacent conical hollow truncated cone rings; the opening angle of the V-shaped groove is 5° to 180°; a plurality of holes are formed on the inner wall of the V-shaped groove; the V-shaped groove is filled with the packing; the packing is at least one of structured packing and random packing; a fixed support structure is provided between two adjacent conical hollow truncated cone rings; the central groove of the lowermost coaxial hollow truncated cone in the bearing element is sleeved above the upper liquid diversion component.

[0039] As a further improvement of the above technical solution: The spraying component includes a spraying distribution pipe, and a plurality of spray heads are distributed on the spraying distribution pipe; the water inlet of the spraying distribution pipe is connected to the water outlet of the three-stage circulation water tank.

[0040] As a general technical concept, the present invention also provides a method for treating malodorous odors, using the above-mentioned system for treating malodorous odors to treat malodorous odors.

[0041] As a further improvement of the above technical solution: When using the system to treat malodorous odors, the following steps are included:

[0042] S1. Turn on the hypochlorous acid generator to produce sodium hydroxide and hypochlorous acid, and respectively transport them to the first-stage circulation water tank and the second-stage circulation water tank according to process requirements to obtain a sodium hydroxide solution and a hypochlorous acid solution;

[0043] S2. Transport the malodorous odor gas from the intake pipe to the first-stage spray tower and the second-stage spray tower in sequence, turn on the first-stage circulation pump and the second-stage circulation pump, and use the sodium hydroxide solution and the hypochlorous acid solution to perform primary oxidation degradation treatment on the malodorous odor gas;

[0044] S3. Transport the waste gas treated by the second-stage spray tower to the three-stage synergistic reaction tower for secondary oxidation degradation treatment to complete the deep purification treatment of the malodorous odor.

[0045] As a further improvement of the above technical solution: In step S1, the pH value of the sodium hydroxide solution in the first-stage circulation water tank is controlled to be 9.5 - 12; the increase in the effective chlorine concentration in the second-stage circulation water tank is controlled to be 5 mg·L -1 ·h -1 ~80 mg·L -1 ·h-1 。

[0046] As a further improvement of the above technical solution: In step S2, turn on the first chemical dosing pump to add chemical agent A to the primary circulation water tank or the secondary circulation water tank; during the primary oxidation degradation process, when the spraying time of the hypochlorous acid solution reaches 4 h to 12 h, according to the discharge volume of the waste liquid being 10% to 50% of the total volume of the waste liquid in the secondary circulation water tank, discharge the waste liquid in the secondary circulation water tank and the first waste liquid collection tank to the second waste liquid collection tank, turn on the third chemical dosing pump, and transport chemical agent C to the second waste liquid collection tank until the concentration of chemical agent C in the second waste liquid collection tank is 0.2 g / L to 1.0 g / L, use chemical agent C to treat the waste liquid in the second waste liquid collection tank until the ammonia nitrogen concentration in the second waste liquid collection tank is less than 1 mg / L, continue to turn on the third chemical dosing pump to make the concentration of chemical agent C in the second waste liquid collection tank 0.4 g / L to 2.4 g / L, use chemical agent C to react with the chloride ions in the second waste liquid collection tank to generate available chlorine until the available chlorine content of the waste liquid in the second waste liquid collection tank reaches 40 mg / L to 200 mg / L, turn off the hypochlorous acid generator, stop transporting hypochlorous acid to the secondary circulation water tank, turn on the transfer pump, and transport the waste liquid in the second waste liquid collection tank to the primary circulation water tank or the secondary circulation water tank until the waste liquid in the second waste liquid collection tank has treated the malodorous gas for 6 h to 12 h, then discharge the waste liquid in the second waste liquid collection tank outward, and at the same time, the hypochlorous acid generator continues to produce hypochlorous acid and uses the hypochlorous acid solution to continue treating the malodorous gas; the excess waste liquid in the second waste liquid collection tank is discharged outward.

[0047] As a further improvement of the above technical solution: In step S3, turn on the second chemical dosing pump to transport chemical agent B to the tertiary circulation water tank; when the humidity of the malodorous gas in the intake pipeline < 90% and the temperature > 65 °C, turn off the first chemical dosing pump, the second chemical dosing pump, and the third chemical dosing pump; when the humidity of the malodorous gas in the intake pipeline > 95% and the temperature < 65 °C, turn on the first chemical dosing pump, the second chemical dosing pump, and the third chemical dosing pump.

[0048] Compared with the prior art, the advantages of the present invention are as follows:

[0049] (1) In the system for treating malodorous and offensive odors of the present invention, the hypochlorous acid generating device can obtain sodium hydroxide and hypochlorous acid simultaneously, which is beneficial to simplifying the complexity of the equipment and reducing the treatment cost. At the same time, after sodium hydroxide and hypochlorous acid are transported to the first-stage circulation water tank and the second-stage circulation water tank, sodium hydroxide solution, sodium hypochlorite solution and hypochlorous acid solution can be configured. On this basis, the sodium hydroxide solution, sodium hypochlorite solution and hypochlorous acid solution are transported to the first-stage spray tower and the second-stage spray tower, and the malodorous and offensive odors gas is continuously sprayed and treated in the first-stage spray tower and the second-stage spray tower. On the one hand, the acidic malodorous and offensive odors gas (such as H2S, SO2) can be removed by using the sodium hydroxide solution, and the refractory malodorous and offensive odors gas such as volatile fatty acids, alcohols, benzene, phenols and some greenhouse gases can be oxidized and degraded by using the sodium hypochlorite solution and hypochlorous acid solution. Therefore, under the combined action of the first-stage spray tower and the second-stage spray tower, the effective purification of various different malodorous and offensive odors gas can be realized. More importantly, after the waste gas treated by the second-stage spray tower is introduced into the third-stage synergistic reaction tower, the oxidation and degradation treatment of the residual malodorous and offensive odors gas can be further realized. Therefore, under the combined action of the first-stage spray tower, the second-stage spray tower and the third-stage synergistic reaction tower, the effective treatment of the complex-component malodorous and offensive odors gas in a large temperature and humidity range can be significantly improved. In addition, in the present invention, by setting the first reversing valve and the second reversing valve, the spraying method can be adjusted in time according to the different properties of the malodorous and offensive odors gas, so as to ensure the effective treatment of the malodorous and offensive odors gas with different properties and better adaptability. The system for treating malodorous and offensive odors of the present invention has the advantages of low cost, good purification effect and small risk of secondary pollution, is suitable for purifying different types of malodorous and offensive odors gas, has an important promoting effect on effectively improving the environment around the paper mill, has high use value and good application prospect.

[0050] (2) In the system for treating malodorous and offensive odors of the present invention, it further includes: a synergist dosing device and a spray liquid circulation device; wherein, by introducing different medicaments in different medicament tanks into the first-stage circulation water tank, the second-stage circulation water tank and the third-stage circulation water tank, the treatment effect of the malodorous odor can be strengthened under the auxiliary action of the medicaments, and the discharge of the malodorous and offensive odors can be effectively avoided; by setting the spray liquid circulation device, not only can the recycling of various medicaments be realized, the reuse efficiency of each effective component in the waste liquid be strengthened, the medicament usage amount be reduced while the treatment cost be reduced, but also the discharge amount of the waste liquid can be reduced, which is beneficial to reducing the treatment difficulty and treatment amount of the waste liquid. It can be seen that under the combined action of the hypochlorous acid generating device, the spray reaction device, the synergist dosing device and the spray liquid circulation device, not only can the malodorous and offensive odors be effectively removed, but also the recycling effect of each medicament can be effectively improved, and at the same time, the treatment difficulty and treatment amount of the washing waste liquid can be reduced.

[0051] (3) In the system for treating malodorous odors of the present invention, it further includes: an intelligent control device. On the one hand, it can use the detection module to timely obtain relevant original data. On the other hand, through the processing of the control module, it can also timely adjust the process parameters of each device in the system, so as to be able to timely and efficiently remove malodorous odors, and at the same time reduce the operating cost of the entire system.

[0052] (4) In the system for treating malodorous odors of the present invention, the three-stage enhanced reaction tower sequentially includes a liquid storage tank, a diversion component, a packing component, and a spraying component from bottom to top. The waste gas entering from the bottom of the three-stage enhanced reaction tower, under the action of the diversion component, changes its flow direction in the three-stage enhanced reaction tower from axial to radial flow, so that the waste gas can be more evenly dispersed in the three-stage enhanced reaction tower. After these waste gases enter the packing component, they will react with the spraying liquid from the spraying component, so as to be able to more thoroughly remove malodorous odors and ensure that the waste gas can meet the emission standards.

[0053] (5) The method for treating malodorous odors of the present invention uses the above-mentioned treatment system for malodorous odors, which can efficiently remove various malodorous odors in the waste gas, with less dosage of chemicals and less production of waste liquid. It has the advantages of simple process, convenient operation, low cost, high treatment efficiency, good removal effect, etc., and can be widely used to purify the malodorous odors from paper mills. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0055] Figure 1 It is a schematic structural diagram of the system for treating malodorous odors in Embodiment 1 of the present invention.

[0056] Figure 2 It is a schematic structural diagram of the three-stage enhanced reaction tower in Embodiment 1 of the present invention.

[0057] Figure 3 It is a schematic diagram of the partial structure inside the three-stage enhanced reaction tower in Embodiment 1 of the present invention.

[0058] Figure 4 It is a top view structural diagram of the bearing element in Embodiment 1 of the present invention.

[0059] Figure 5 For Figure 4 The cross-sectional view at A-A in

[0060] Figure 6 It is a schematic structural diagram of the upper liquid diversion component in Embodiment 1 of the present invention.

[0061] Figure 7This is the purification effect diagram corresponding to the treatment of malodorous and off - flavor gases by the processing system in Embodiments 1 - 2 of the present invention.

[0062] Legend:

[0063] 1. Intake pipeline; 21. Filter; 22. Raw material storage tank; 23. Hypochlorous acid generator; 24. Hypochlorous acid collection tank; 241. Hypochlorous acid dosing pump; 25. Sodium hydroxide collection tank; 251. Sodium hydroxide dosing pump; 31. Primary spray tower; 311. Primary circulation pump; 312. Primary circulation water tank; 32. Secondary spray tower; 321. Secondary circulation pump; 322. Secondary circulation water tank; 323. Demisting area; 324. Spray reaction area; 33. Tertiary efficiency - enhancing reaction tower; 331. Tertiary circulation pump; 332. Tertiary circulation water tank; 333. Liquid storage tank; 334. Flow - guiding component; 3341. Upper liquid flow - guiding component; 33411. Overflow tank; 3342. Lower gas flow - guiding component; 3343. Support frame; 335. Packing component; 3351. Bearing element; 3352. Packing; 3353. Hole; 3354. Fixed support structure; 336. Spray component; 3361. Spray distribution pipe; 3362. Sprinkler head; 41. First reagent tank; 411. First dosing pump; 42. Second reagent tank; 421. Second dosing pump; 43. Third reagent tank; 431. Third dosing pump; 51. Transfer pump; 52. First waste liquid collection tank; 53. Second waste liquid collection tank; 54. First reversing valve; 55. Second reversing valve; 56. Third reversing valve; 57. Fourth reversing valve; 611. First pH meter; 612. Second pH meter; 613. ORP meter; 614. Ammonia nitrogen on - line monitor; 615. Residual chlorine monitor; 616. Humidity monitor; 617. Temperature monitor. Detailed implementation manners

[0064] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0065] In the description of this invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0066] Embodiment 1

[0067] As Figure 1 shown, the system for treating malodorous and offensive odors in this embodiment includes an intake duct 1, a hypochlorous acid generating device, and a spray reaction device. The intake port of the intake duct 1 is connected to the malodorous and offensive odor gas. The hypochlorous acid generating device includes a hypochlorous acid generator 23, and a hypochlorous acid collection tank 24 and a sodium hydroxide collection tank 25 are connected to the hypochlorous acid generator 23. The spray reaction device includes a first-stage spray tower 31, a second-stage spray tower 32, and a third-stage enhanced reaction tower 33 that are connected in sequence. The bottom of the first-stage spray tower 31 is connected to a first-stage circulation water tank 312, and the water outlet of the first-stage circulation water tank 312 is connected to the spray area of the first-stage spray tower 31 to form a circulating spray path. The bottom of the second-stage spray tower 32 is connected to a second-stage circulation water tank 322, and the water outlet of the second-stage circulation water tank 322 is connected to the spray area of the second-stage spray tower 32 to form a circulating spray path. The bottom of the third-stage enhanced reaction tower 33 is connected to a third-stage circulation water tank 332, and the water outlet of the third-stage circulation water tank 332 is connected to the spray area of the third-stage enhanced reaction tower 33 to form a circulating spray path. The water outlet of the hypochlorous acid collection tank 24 is respectively connected to the first-stage circulation water tank 312 and the second-stage circulation water tank 322 through a first reversing valve 54. The water outlet of the sodium hydroxide collection tank 25 is respectively connected to the first-stage circulation water tank 312 and the second-stage circulation water tank 322 through a second reversing valve 55.

[0068] In this embodiment, the collected malodorous and offensive odor gas is sequentially transported through the intake duct 1 to the first-stage spray tower 31, the second-stage spray tower 32, and the third-stage enhanced reaction tower 33, and after being jointly treated by the first-stage spray tower 31, the second-stage spray tower 32, and the third-stage enhanced reaction tower 33, it is discharged up to standard outward from the third-stage enhanced reaction tower 33. During the spraying process, in the hypochlorous acid generator 23, water and sodium chloride are used as raw materials to generate a hypochlorous acid solution and a sodium hydroxide solution. The method for producing the hypochlorous acid solution includes an electrolysis method, a chemical synthesis method, etc. Further, the generated hypochlorous acid solution and sodium hydroxide solution are respectively transported to the hypochlorous acid collection tank 24 and the sodium hydroxide collection tank 25. When in use, the hypochlorous acid solution in the hypochlorous acid collection tank 24 is transported to the first-stage circulation water tank 312 or the second-stage circulation water tank 322 as needed through the adjustment of the first reversing valve 54 by using a hypochlorous acid dosing pump 241, and the sodium hydroxide solution in the sodium hydroxide collection tank 25 is transported to the first-stage circulation water tank 312 or the second-stage circulation water tank 322 as needed through the adjustment of the second reversing valve 55 by using a sodium hydroxide dosing pump 251. Thus, for different malodorous and offensive odor gas situations, a circulating spray can be carried out using one or a combination of a sodium hydroxide solution, a sodium hypochlorite solution, a hypochlorous acid solution, etc., so as to effectively remove the malodorous and offensive odors.

[0069] As Figure 1As shown in the figure, in this embodiment, it further includes: a synergist dosing device and a spray liquid circulation device; the synergist dosing device includes a first chemical tank 41, a second chemical tank 42, and a third chemical tank 43; the spray liquid circulation device includes a first waste liquid collection tank 52 and a second waste liquid collection tank 53 that are connected in sequence; the water outlet of the first chemical tank 41 is respectively connected to the first-stage circulation water tank 312 and the second-stage circulation water tank 322 through a third reversing valve 56; the water outlet of the second chemical tank 42 is connected to the water inlet of the third-stage circulation water tank 332; the water outlet of the third chemical tank 43 is connected to the water inlet of the second waste liquid collection tank 53; the water inlet of the first waste liquid collection tank 52 is connected to the water outlet of the first-stage circulation water tank 312; a bypass pipe is also provided between the water inlet of the first waste liquid collection tank 52 and the water outlet of the first-stage circulation water tank 312; the water inlet of the second waste liquid collection tank 53 is connected to the water outlet of the second-stage circulation water tank 322; the water outlet of the second waste liquid collection tank 53 is respectively connected to the water inlets of the first-stage circulation water tank 312 and the second-stage circulation water tank 322 through a fourth reversing valve 57.

[0070] As Figure 1 shown in the figure, in this embodiment, a first chemical dosing pump 411 is provided on the pipeline between the first chemical tank 41 and the third reversing valve 56; the first chemical tank 41 stores chemical A, where chemical A is at least one of potassium hydrogen phthalate, citric acid, acetic acid, and sulfuric acid. For example, chemical A is potassium hydrogen phthalate, or citric acid, or acetic acid, or sulfuric acid. In this embodiment, chemical A is potassium hydrogen phthalate.

[0071] As Figure 1 shown in the figure, in this embodiment, the first chemical tank 41 is connected to the first-stage circulation water tank 312 and the second-stage circulation water tank 322 through pipelines, so that chemical A can be selectively added to the first-stage circulation water tank 312 and the second-stage circulation water tank 322 through the third reversing valve 56 under the action of the first chemical dosing pump 411. At the same time, under the action of chemical A, it can cooperate with sodium hydroxide, sodium hypochlorite, and hypochlorous acid to jointly improve the effect of removing malodorous odors in the first-stage spray tower 31 and the second-stage spray tower 32.

[0072] As Figure 1 shown in the figure, in this embodiment, a second chemical dosing pump 421 is provided on the pipeline between the second chemical tank 42 and the third-stage circulation water tank 332; the second chemical tank 42 stores chemical B, where chemical B is at least one of ascorbic acid, sodium thiosulfate, and calcium sulfite. For example, chemical B is ascorbic acid, or sodium thiosulfate. In this embodiment, chemical B is calcium sulfite.

[0073] In this embodiment, the second chemical agent tank 42 is connected to the tertiary circulation water tank 332 through a pipeline. Thus, under the action of the second chemical agent adding pump 421, chemical agent B can be added to the tertiary circulation water tank 332. Meanwhile, under the action of chemical agent B, the effect of removing malodorous odor in the tertiary synergistic reaction tower 33 can be effectively improved. In particular, the odor gas volatilized after the spray reaction can be effectively removed.

[0074] As Figure 1 shown, in this embodiment, a third chemical agent adding pump 431 is provided on the pipeline between the third chemical agent tank 43 and the second waste liquid collection tank 53; chemical agent C is stored in the third chemical agent tank 43, where chemical agent C is at least one of hydrogen peroxide and permonosulfate. For example, chemical agent C is hydrogen peroxide or permonosulfate. In this embodiment, chemical agent C is permonosulfate (PMS).

[0075] In this embodiment, a delivery pump 51 is provided on the pipeline between the second waste liquid collection tank 53 and the fourth reversing valve 57.

[0076] In this embodiment, the third chemical agent tank 43 is connected to the second waste liquid collection tank 53 through a pipeline. Chemical agent C can be transported to the second waste liquid collection tank 53 under the action of the third chemical agent adding pump 431 for degrading ammonia nitrogen in the waste liquid. Further, the waste liquid in the second waste liquid collection tank 53 treated with chemical agent C can be selectively transported to the primary circulation water tank 312 and the secondary circulation water tank 322 through the delivery pump 51 and under the action of the fourth reversing valve 57. Thus, the waste liquid can be used to continue rinsing the malodorous smell. While maximizing the utilization rate of the waste liquid, the discharge amount of the waste liquid can also be minimized, which is beneficial to reducing the subsequent treatment difficulty and treatment amount of the waste liquid and can effectively reduce secondary pollution.

[0077] In this embodiment, the primary circulation water tank 312 is connected to the first waste liquid collection tank 52 through a pipeline and is provided with a bypass pipe, so that the waste liquid in the primary circulation water tank 312 can be stored in the first waste liquid collection tank 52. Meanwhile, the first waste liquid collection tank 52 is connected to the second waste liquid collection tank 53 through a pipeline. Thus, the waste liquid (sodium hydroxide solution or hypochlorous acid solution) in the first waste liquid collection tank 52 can be used to adjust the water quality of the waste liquid in the second waste liquid collection tank 53. On the one hand, the usage cycle of the waste liquid can be extended, and on the other hand, the treatment difficulty of the waste liquid can also be reduced.

[0078] As Figure 1 shown, in this embodiment, it further includes: an intelligent control device; the intelligent control device includes a detection module and a control module.

[0079] In this embodiment, the detection module includes a first pH meter 611, a second pH meter 612, an ORP meter 613, an ammonia nitrogen on-line monitor 614, a residual chlorine monitor 615, a humidity monitor 616, and a temperature monitor 617. The first pH meter 611 is connected to the primary circulation water tank 312 for monitoring the pH value of the spray liquid in the primary spray tower 31. The second pH meter 612 is connected to the secondary circulation water tank 322 for detecting the pH value of the spray liquid in the secondary spray tower 32. The ORP meter 613 is connected to the secondary circulation water tank 322 for monitoring the ORP value of the spray liquid in the secondary spray tower 32. The ammonia nitrogen on-line monitor 614 is connected to the second waste liquid collection tank 53 for monitoring the ammonia nitrogen concentration of the waste liquid in the second waste liquid collection tank 53. The residual chlorine monitor 615 is connected to the second waste liquid collection tank 53 for monitoring the residual chlorine content of the waste liquid in the second waste liquid collection tank 53. The humidity monitor 616 and the temperature monitor 617 are connected to the intake pipeline 1 for monitoring the humidity and temperature of the incoming malodorous gas, respectively. An electric current transformer is also installed on the drying cylinder drive motor of the paper machine drying section for monitoring the working state of the drying cylinder drive motor.

[0080] In this embodiment, the control module includes a CPU module, an analog quantity module, and a power supply module. The CPU module, the analog quantity module, and the power supply module are electrically connected. The CPU module is electrically connected to the hypochlorous acid generating device, the spray reaction device, the synergist dosing device, and the spray liquid circulation device. The analog quantity module is electrically connected to the detection module.

[0081] In this embodiment, the preset rules and model algorithms of the control module are used to judge the current production state of the paper machine by entering the waste gas humidity state, temperature state, and the working state of the drying cylinder drive motor, judge the content of hypochlorous acid in the secondary circulation water tank 322 by the ORP value of the spray liquid, judge the addition amount of sodium hydroxide in the primary circulation water tank 312 by the pH value of the spray liquid, judge whether to start the third dosing pump 431 according to the ammonia nitrogen concentration of the waste liquid in the second waste liquid collection tank 53, and judge whether to close the hypochlorous acid dosing pump 241 and send an operation parameter adjustment instruction to the hypochlorous acid generating device, the spray liquid circulation device, and the synergist dosing device according to the residual chlorine concentration of the waste liquid in the second waste liquid collection tank 53.

[0082] In this embodiment, the intelligent control device is mainly a control device such as a PLC device or a DCS device. By detecting the operating state of the paper machine equipment and the operating parameters of each device through the detection module, it can intelligently regulate the operation of the synergist dosing device, the spray liquid circulation device, and the hypochlorous acid generating device, not only can timely adjust the purification process parameters, but also can reduce the operating cost of the entire device.

[0083] Such as Figure 1As shown, in this embodiment, a raw material storage tank 22 is connected to the hypochlorous acid generator 23, and a water storage tank (i.e., the plant water supply) is also connected to the raw material storage tank 22; a filter 21 is provided on the pipeline between the water storage tank and the raw material storage tank 22.

[0084] As Figure 1 shown, in this embodiment, a hypochlorous acid dosing pump 241 is provided on the pipeline between the hypochlorous acid collection tank 24 and the first reversing valve 54, and under the action of the hypochlorous acid dosing pump 241, a hypochlorous acid solution is transported to the primary circulation water tank 312 or the secondary circulation water tank 322.

[0085] As Figure 1 shown, in this embodiment, a sodium hydroxide dosing pump 251 is provided on the pipeline between the sodium hydroxide collection tank 25 and the second reversing valve 55, and under the action of the sodium hydroxide dosing pump 251, a sodium hydroxide solution is transported to the primary circulation water tank 312 or the secondary circulation water tank 322.

[0086] As Figure 1 shown, in this embodiment, a primary circulation pump 311 is provided on the pipeline between the primary circulation water tank 312 and the spray area of the primary spray tower 31. Under the action of the primary circulation pump 311, the circulating spray of the malodorous odor can be realized, and the purification effect can be improved.

[0087] As Figure 1 shown, in this embodiment, a secondary circulation pump 321 is provided on the pipeline between the secondary circulation water tank 322 and the spray area of the secondary spray tower 32. Under the action of the secondary circulation pump 321, the circulating spray of the malodorous odor can be realized, and the purification effect can be improved.

[0088] As Figure 1 shown, in this embodiment, a tertiary circulation pump 331 is provided on the pipeline between the tertiary circulation water tank 332 and the spray area of the tertiary synergistic reaction tower 33. Under the action of the tertiary circulation pump 331, the circulating spray of the malodorous odor can be realized, and the purification effect can be improved.

[0089] As Figure 1 shown, in this embodiment, the outlet of the intake pipeline 1 is connected to the bottom of the primary spray tower 31, the outlet of the primary spray tower 31 is located at the top of the tower, the outlet of the primary spray tower 31 is connected to the bottom of the secondary spray tower 32, the outlet of the secondary spray tower 32 is located at the top of the tower, and the outlet of the secondary spray tower 32 is connected to the bottom of the tertiary synergistic reaction tower 33. At the same time, in this embodiment, the tertiary synergistic reaction tower 33 is located on the top of the secondary spray tower 32, which is beneficial to saving the floor area of the equipment. In another embodiment, the outlet of the secondary spray tower 32 can also be connected to the inlet of the tertiary synergistic reaction tower 33 through a pipeline.

[0090] As Figure 1As shown in the figure, in this embodiment, inside the secondary spray tower 32 from bottom to top are a spray reaction zone 324 and a demisting zone 323 in sequence. After the waste gas is treated in the spray reaction zone 324 and the demisting zone 323, the content of malodorous and peculiar smells is significantly reduced, and the humidity is also significantly reduced, facilitating subsequent oxidative degradation treatment.

[0091] As Figure 1 shown in the figure, in this embodiment, inside the tertiary synergistic reaction tower 33 from bottom to top are included a liquid storage tank 333, a flow guiding component 334, a packing component 335, and a spray component 336 in sequence. At the bottom of the tertiary synergistic reaction tower 33, there is also an intake branch pipe, and the other end of the intake branch pipe is connected to the air outlet of the secondary spray tower 32. At the same time, the outlet of the intake branch pipe faces upward and is above the liquid level in the liquid storage tank 333; the outlet of the intake branch pipe is below the flow guiding component 334, and the vertical projection area of the flow guiding component 334 is larger than the area of the outlet of the intake branch pipe. On the one hand, it can prevent the spray liquid from entering the secondary spray tower 32 through the intake branch pipe, and on the other hand, it is also convenient for the waste gas to be transported upward.

[0092] As Figure 1 、 Figure 2 、 Figure 3 、 Figure 5 、 Figure 6 shown in the figure, in this embodiment, the flow guiding component 334 is composed of an upper liquid flow guiding component 3341 and a lower gas flow guiding component 3342 combined; both the upper liquid flow guiding component 3341 and the lower gas flow guiding component 3342 are similar solid truncated cones with arc-shaped slopes; at the upper top of the upper liquid flow guiding component 3341, there are a plurality of overflow grooves 33411 to prevent the accumulation of spray liquid, and at the same time, it can make the upper spray liquid effectively flow into the box liquid storage tank along the upper liquid flow guiding component 3341; at the bottom of the tertiary synergistic reaction tower 33, there are at least three support frames 3343; the lower gas flow guiding component 3342 is installed on the support frames 3343, so that the lower gas flow guiding component 3342 is installed above the liquid storage tank 333; the lowest point below the lower gas flow guiding component 3342 is above the outlet of the intake branch pipe, whereby the flow direction of the waste gas in the tertiary synergistic reaction tower 33 can be changed from axial flow to radial flow, which is beneficial to increasing the gas-liquid contact probability.

[0093] As Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5As shown in the figure, in this embodiment, the packing component 335 includes a bearing element 3351 and packing 3352. The outer periphery of the bearing element 3351 is connected to the inner wall of the three-stage synergistic reaction tower 33. The bearing element 3351 is formed by stacking multiple layers of coaxial hollow truncated cones. For example, it is formed by stacking two layers of coaxial hollow truncated cones. Adjacent coaxial hollow truncated cones are symmetrically arranged. The coaxial hollow truncated cone is formed by coaxially connecting a plurality of conical hollow truncated cone rings with different diameters. Two adjacent conical hollow truncated cone rings are staggered and overlapped in a vertical and inverted form, and a V-shaped groove is formed between two adjacent conical hollow truncated cone rings. The opening angle of the V-shaped groove is 5° to 180°. In this embodiment, the opening angle of the V-shaped groove is 30°. A number of holes 3353 are formed on the inner wall of the V-shaped groove to facilitate the upward transportation of waste gas. The V-shaped groove is filled with packing 3352. The packing 3352 is at least one of structured packing and random packing. In this embodiment, the packing 3352 is random packing. A fixed support structure 3354 is provided between two adjacent conical hollow truncated cone rings to increase the strength of the bearing element 3351. The central groove of the lowermost coaxial hollow truncated cone in the bearing element 3351 is sleeved above the upper liquid diversion assembly 3341.

[0094] As Figure 2 shown in the figure, in this embodiment, the spraying component 336 includes a spraying distribution pipe 3361. A number of nozzles 3362 are distributed on the spraying distribution pipe 3361. The water inlet of the spraying distribution pipe 3361 is connected to the water outlet of the three-stage circulation water tank 332.

[0095] A method for treating malodorous odor by using the above system of this embodiment includes the following steps:

[0096] S1. Turn on the hypochlorous acid generator to produce sodium hydroxide and hypochlorous acid, and respectively transport them into the first-stage circulation water tank and the second-stage circulation water tank to obtain a sodium hydroxide solution and a hypochlorous acid solution, specifically as follows:

[0097] In this embodiment, the first-stage circulation water tank 312 includes a water tank body and a first pH meter 611. The water tank body is used to store and discharge the spraying circulating liquid. The water inlet of the first-stage circulation water tank 312 is connected to the sodium hydroxide collection tank 25 through a pipeline, and the water outlet of the first-stage circulation water tank 312 is connected to the first waste liquid collection tank 52 through a pipeline. The first pH meter 611 is used to monitor and control the spraying circulating liquid. Specifically, the pH of the spraying circulating liquid is monitored online and maintained at 9.5 - 12. When it is lower than the lower limit of the range, liquid is discharged from the sodium hydroxide collection tank 25, and at the same time, part of the waste liquid is discharged into the first waste liquid collection tank 52. When it reaches the upper limit of the range, the liquid discharge from the sodium hydroxide collection tank 25 is stopped.

[0098] In this embodiment, the secondary circulation water tank 322 includes a water tank body, an ORP meter 613, and a second pH meter 612. The water tank body is used to store and discharge the spray circulation liquid. The spray circulation liquid is alternately used with hypochlorous acid solution and waste liquid treatment liquid. The outlet of the hypochlorous acid collection tank 24, the outlet of the second waste liquid collection tank 53, and the outlet of the first dosing device 41 (agent A) are connected to the inlet of the secondary circulation water tank 322 through pipelines respectively at the inlet of the secondary circulation water tank 322. The outlet of the secondary circulation water tank 322 is connected to the inlet of the second waste liquid collection tank 53 through a pipeline. The second pH meter 612 is used to monitor and control the pH value of the circulation liquid, and the ORP meter 613 is used to monitor and control the oxidation-reduction potential of the effective chlorine content in the solution, so that the hourly increase in the concentration of hypochlorous acid in the secondary circulation water tank 322 from the original liquid in the hypochlorous acid collection tank 24 is 40 mg / (L·h).

[0099] S2. The malodorous and odorous gas is sequentially conveyed from the intake pipeline 1 to the first spray tower 31 and the second spray tower 32, and the first circulation pump 311 and the second circulation pump 321 are turned on to perform primary oxidation degradation treatment on the malodorous and odorous gas by using sodium hydroxide solution and hypochlorous acid solution. Specifically:

[0100] The first dosing pump 411 is turned on to add agent A to the secondary circulation water tank 322, which is used to synergistically regulate the pH of the circulation liquid and at the same time extend the treatment time for malodorous and odorous gas. During the primary oxidation degradation treatment, when the spraying time of the hypochlorous acid solution reaches 8 h, according to the discharged volume of the waste liquid being 50% of the total volume of the waste liquid in the secondary circulation water tank 322, the waste liquid in the secondary circulation water tank 322 and the first waste liquid collection tank 52 is discharged into the second waste liquid collection tank 53. The third dosing pump 431 is turned on to convey agent C to the second waste liquid collection tank 53 until the concentration of agent C in the second waste liquid collection tank 53 is 0.2 g / L - 1.0 g / L. The waste liquid in the second waste liquid collection tank 53 is treated with agent C for 2 h until the ammonia nitrogen concentration in the second waste liquid collection tank 53 is less than 1 mg / L. The third dosing pump 431 is continuously turned on to make the concentration of agent C in the second waste liquid collection tank 53 be 0.4 g / L - 2.4 g / L, and agent C reacts with the chloride ions in the second waste liquid collection tank 53 to generate effective chlorine until the effective chlorine content of the waste liquid in the second waste liquid collection tank 53 reaches 40 mg / L - 200 mg / L. The hypochlorous acid generator 23 is turned off, and the conveyance of hypochlorous acid to the secondary circulation water tank 322 is stopped. The conveying pump 51 is turned on to convey the waste liquid in the second waste liquid collection tank 53 to the secondary circulation water tank 322 until the waste liquid in the second waste liquid collection tank 53 has treated the malodorous and odorous gas for 8 h. Then the waste liquid in the second waste liquid collection tank 53 is discharged outwards, and at the same time, the hypochlorous acid generator 23 continues to produce hypochlorous acid and uses the hypochlorous acid solution to continue treating the malodorous and odorous gas; the excess waste liquid in the second waste liquid collection tank 53 is discharged outwards.

[0101] S3. Convey the waste gas treated by the secondary spray tower 32 to the tertiary synergistic reaction tower 33 for secondary oxidation and degradation treatment to complete the purification treatment of the malodorous odor.

[0102] In step S3, turn on the second chemical dosing pump 421 to convey chemical agent B to the tertiary circulation water tank 332; when the humidity of the malodorous odor gas in the intake pipeline 1 < 90% and the temperature > 65 °C, turn off the first chemical dosing pump 411, the second chemical dosing pump 421, and the third chemical dosing pump 431; when the humidity of the malodorous odor gas in the intake pipeline 1 > 95% and the temperature < 65 °C, turn on the first chemical dosing pump 411, the second chemical dosing pump 421, and the third chemical dosing pump 431.

[0103] In this embodiment, the collected malodorous odor is the malodorous gas discharged from the end of the papermaking process of the paper mill, and its parameters are: air volume is 20000 m³ / h, temperature is 57 - 60 °C, main components and concentrations: ammonia 1.5 - 2.5 ppm, hydrogen sulfide 0.35 - 0.5 ppm, trimethylamine 4.5 - 10 ppm, methanethiol 0.5 - 2.0 ppm, dimethyl sulfide 1.5 - 2.0 ppm, dimethyl disulfide 0.5 - 1.5 ppm, carbon disulfide 0.7 - 1.8 ppm, styrene 7 - 13 ppm, odor concentration 500 - 600 (dimensionless).

[0104] The steps of treating the malodorous odor using the above system are as follows:

[0105] (1) Convey the malodorous gas into the primary spray tower through the intake pipeline and spray it with sodium hydroxide solution with pH = 10 - 11.

[0106] (2) Convey the malodorous gas treated by the primary spray tower into the secondary spray tower through the pipeline, and use a mixed solution of 0.5 g / L potassium hydrogen phthalate (chemical agent A), hypochlorous acid solution (200 ppm, pH = 4.0) and the waste liquid treated by PMS (chemical agent C) as the spray liquid, and alternately spray and treat with the circulating liquid.

[0107] (3) Directly convey the gas treated by the secondary spray tower into the tertiary synergistic reaction tower, and use 0.5 g / L calcium sulfite solution as the spray liquid for spray treatment, and finally discharge the treated air from the tail end.

[0108] Comparative example 1:

[0109] The spray liquid of the secondary spray tower used is hypochlorous acid solution with 200 ppm and pH = 4.0, replacing the mixed solution of 0.5 g / L potassium hydrogen phthalate (chemical agent A), hypochlorous acid solution (200 ppm, pH = 4.0) and the waste liquid treated by PMS (chemical agent C) used in Example 1, and other conditions are the same as those in Example 1.

[0110] Comparative Example 2:

[0111] The spray liquid of the secondary spray tower used is a mixed liquid of 0.5 g / L potassium hydrogen phthalate (agent A) and a hypochlorous acid solution of 200 ppm and pH = 4.0, replacing the mixed liquid of 0.5 g / L potassium hydrogen phthalate (agent A), hypochlorous acid solution (200 ppm, pH = 4.0) and the waste liquid treated with PMS (agent C) used in Example 1. Other conditions are the same as those in Example 1.

[0112] Comparative Example 3:

[0113] The spray liquid of the tertiary enhanced reaction tower is industrial water, used to replace the 0.5 g / L calcium sulfite solution used in Example 1. Other conditions are the same as those in Example 1.

[0114] Comparative Example 4:

[0115] The spray liquid of the secondary spray tower used is dilute sulfuric acid with pH = 4.0 - 5.0, replacing the mixed liquid of 0.5 g / L potassium hydrogen phthalate (agent A), hypochlorous acid solution (200 ppm, pH = 4.0) and the waste liquid treated with PMS (agent C) used in Example 1. Other conditions are the same as those in Example 1.

[0116] Example 2:

[0117] Based on the basic situation of Example 1, adjust the first reversing valve, the second reversing valve, the third reversing valve, and the fourth reversing valve so that the hypochlorous acid solution is discharged from the hypochlorous acid collection tank into the primary circulation water tank; the sodium hydroxide solution is discharged into the secondary circulation water tank; the agent A is discharged into the primary circulation water tank; the waste liquid in the second waste liquid collection tank is connected to the primary circulation water tank through a pipeline to facilitate the discharge of the waste liquid treatment liquid into the primary circulation water tank; adjust the reversing valve, that is, the primary spray tower alternately circulates and uses the hypochlorous acid solution and the waste liquid treatment liquid as the spray liquid, and the secondary spray tower circulates and uses the sodium hydroxide solution spray liquid.

[0118] The exhaust gases discharged in Examples 1 - 2 and Comparative Examples 1 - 3 were detected, and the results are shown in Table 1. At the same time, the treatment efficiency of different treatment methods was calculated with ammonia as the detection component, and the results are as Figure 7 shown.

[0119] Table 1 Data on the removal effect of exhaust gases after different treatment methods

[0120]

[0121] Combined with Table 1 and Figure 7As can be seen from the results, compared with Comparative Examples 1, 3 - 4, Examples 1 - 2 of the present invention have better treatment effects. They can not only efficiently remove various malodorous odors in the waste gas, but also effectively treat waste gas with more complex components, and at the same time have a longer waste gas treatment time under the same conditions. In addition, although the malodorous odors can be effectively purified in Comparative Example 2, it does not use the waste liquid treated with PMS (agent C). On the one hand, this will increase the usage amount of hypochlorous acid solution, thereby increasing the cost of treating malodorous odors. On the other hand, due to the increase in the usage amount of hypochlorous acid solution, the production of hypochlorous acid waste liquid will also increase, resulting in a relatively higher treatment cost for hypochlorous acid waste liquid. Therefore, from the perspectives of the treatment cost of malodorous odors and the treatment cost of waste liquid, the treatment method in Example 1 uses less reagent, produces less waste liquid, has lower cost, and is more environmentally friendly and green.

[0122] As can be seen from the above results, the system for treating malodorous odors of the present invention has the advantages of low cost, good purification effect, and low risk of secondary pollution. When used to treat different types of malodorous odor gases, it can efficiently remove various malodorous odors in the waste gas, effectively improve the environment around the paper mill, and has the advantages of simple process, convenient operation, low cost, high treatment efficiency, good removal effect, etc. Moreover, it uses less reagent, produces less waste liquid, is more environmentally friendly and green, has high use value, and good application prospects.

[0123] The above embodiments are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A system for treating malodorous and offensive odors, characterized in that, It includes an intake pipe (1), a hypochlorous acid generating device, a spray reaction device, a synergist dosing device, and a spray liquid circulation device; The air inlet of the intake pipe (1) is communicated with the malodorous gas; The hypochlorous acid generating device includes a hypochlorous acid generator (23), and a hypochlorous acid collection tank (24) and a sodium hydroxide collection tank (25) are communicated with the hypochlorous acid generator (23); The spray reaction device includes a first-stage spray tower (31), a second-stage spray tower (32), and a third-stage synergistic reaction tower (33) which are communicated in sequence; a first-stage circulation water tank (312) is connected to the bottom of the first-stage spray tower (31), and the water outlet of the first-stage circulation water tank (312) is communicated with the spray area of the first-stage spray tower (31) to form a circulating spray path; a second-stage circulation water tank (322) is connected to the bottom of the second-stage spray tower (32), and the water outlet of the second-stage circulation water tank (322) is communicated with the spray area of the second-stage spray tower (32) to form a circulating spray path; a third-stage circulation water tank (332) is connected to the bottom of the third-stage synergistic reaction tower (33), and the water outlet of the third-stage circulation water tank (332) is communicated with the spray area of the third-stage synergistic reaction tower (33) to form a circulating spray path; Inside the third-stage synergistic reaction tower (33), there are successively a liquid storage tank (333), a flow guiding component (334), a packing component (335), and a spray component (336) from bottom to top; an intake branch pipe is also provided at the bottom of the third-stage synergistic reaction tower (33), and the outlet of the intake branch pipe faces upward and is above the liquid level in the liquid storage tank (333); the outlet of the intake branch pipe is below the flow guiding component (334), and the vertical projection area of the flow guiding component (334) is larger than the outlet area of the intake branch pipe; the flow guiding component (334) is composed of an upper liquid flow guiding component (3341) and a lower gas flow guiding component (3342); both the upper liquid flow guiding component (3341) and the lower gas flow guiding component (3342) are similar solid frustum shapes with arc-shaped slopes; a plurality of overflow grooves (33411) are provided at the upper top of the upper liquid flow guiding component (3341); at least three support brackets (3343) are provided at the bottom of the third-stage synergistic reaction tower (33); the lower gas flow guiding component (3342) is installed on the support brackets (3343) so that the lower gas flow guiding component (3342) is installed above the liquid storage tank (333); the lowest point below the lower gas flow guiding component (3342) is above the outlet of the intake branch pipe; The water outlet of the hypochlorous acid collection tank (24) is respectively communicated with the first-stage circulation water tank (312) and the second-stage circulation water tank (322) through a first reversing valve (54); The water outlet of the sodium hydroxide collection tank (25) is respectively communicated with the first-stage circulation water tank (312) and the second-stage circulation water tank (322) through a second reversing valve (55); The synergist dosing device includes a first reagent tank (41), a second reagent tank (42) and a third reagent tank (43); reagent A is stored in the first reagent tank (41); reagent A is at least one of potassium hydrogen phthalate, citric acid, acetic acid, sulfuric acid; reagent B is stored in the second reagent tank (42); reagent B is at least one of ascorbic acid, sodium thiosulfate, calcium sulfite; reagent C is stored in the third reagent tank (43); reagent C is at least one of hydrogen peroxide, peroxysulfate; The spray liquid circulation device includes a first waste liquid collection tank (52) and a second waste liquid collection tank (53) connected in sequence; The water outlet of the first reagent tank (41) is connected to the first-stage circulation water tank (312) and the second-stage circulation water tank (322) respectively through a third reversing valve (56); The water outlet of the second reagent tank (42) is connected to the water inlet of the third-stage circulation water tank (332); The water outlet of the third reagent tank (43) is connected to the water inlet of the second waste liquid collection tank (53); The water inlet of the first waste liquid collection tank (52) is connected to the water outlet of the first-stage circulation water tank (312); a bypass pipe is also provided between the water inlet of the first waste liquid collection tank (52) and the water outlet of the first-stage circulation water tank (312); The water inlet of the second waste liquid collection tank (53) is connected to the water outlet of the second-stage circulation water tank (322); The water outlet of the second waste liquid collection tank (53) is connected to the water inlets of the first-stage circulation water tank (312) and the second-stage circulation water tank (322) respectively through a fourth reversing valve (57).

2. The system for treating malodorous and offensive odors according to claim 1, characterized in that, A first dosing pump (411) is provided on the pipeline between the first reagent tank (41) and the third reversing valve (56); A second dosing pump (421) is provided on the pipeline between the second reagent tank (42) and the third-stage circulation water tank (332); A third dosing pump (431) is provided on the pipeline between the third reagent tank (43) and the second waste liquid collection tank (53); A transfer pump (51) is provided on the pipeline between the second waste liquid collection tank (53) and the fourth reversing valve (57).

3. The system for treating malodorous and offensive odors according to claim 2, wherein It further includes: An intelligent control device; the intelligent control device includes a detection module and a control module; The detection module includes a first pH meter (611), a second pH meter (612), an ORP meter (613), an ammonia nitrogen on-line monitor (614), a residual chlorine monitor (615), a humidity monitor (616) and a temperature monitor (617); the first pH meter (611) is connected to the primary circulation water tank (312); the second pH meter (612) is connected to the secondary circulation water tank (322); the ORP meter (613) is connected to the secondary circulation water tank (322); the ammonia nitrogen on-line monitor (614) is connected to the second waste liquid collection tank (53); the residual chlorine monitor (615) is connected to the second waste liquid collection tank (53); the humidity monitor (616) and the temperature monitor (617) are connected to the intake pipe (1); The control module includes a CPU module, an analog module and a power module; the CPU module, the analog module and the power module are electrically connected; the CPU module is electrically connected to the hypochlorous acid generating device, the spray reaction device, the synergist dosing device and the spray liquid circulation device; the analog module is electrically connected to the detection module.

4. The system for treating malodorous and offensive odors according to claim 3, characterized in that, A raw material storage tank (22) is connected to the hypochlorous acid generator (23); a water storage tank is also connected to the raw material storage tank (22); a filter (21) is provided on the pipeline between the water storage tank and the raw material storage tank (22); A hypochlorous acid dosing pump (241) is provided on the pipeline between the hypochlorous acid collection tank (24) and the first reversing valve (54); A sodium hydroxide dosing pump (251) is provided on the pipeline between the sodium hydroxide collection tank (25) and the second reversing valve (55); A primary circulation pump (311) is provided on the pipeline between the primary circulation water tank (312) and the spray area of the primary spray tower (31); A secondary circulation pump (321) is provided on the pipeline between the secondary circulation water tank (322) and the spray area of the secondary spray tower (32); A tertiary circulation pump (331) is provided on the pipeline between the tertiary circulation water tank (332) and the spray area of the tertiary synergistic reaction tower (33).

5. The system for treating malodorous and offensive odors according to claim 4, characterized in that, The outlet of the intake pipe (1) is connected to the bottom of the primary spray tower (31); the outlet of the primary spray tower (31) is located at the top of the tower; the outlet of the primary spray tower (31) is connected to the bottom of the secondary spray tower (32); the outlet of the secondary spray tower (32) is located at the top of the tower; the outlet of the secondary spray tower (32) is connected to the bottom of the tertiary synergistic reaction tower (33); Inside the secondary spray tower (32), there are successively from bottom to top a spray reaction area (324) and a demisting area (323).

6. The system for treating malodorous and offensive odors according to claim 5, wherein, The packing component (335) includes a bearing element (3351) and packing (3352). The outer periphery of the bearing element (3351) is connected to the inner wall of the three-stage synergistic reaction tower (33). The bearing element (3351) is formed by stacking multiple layers of coaxial hollow truncated cones. Adjacent coaxial hollow truncated cones are symmetrically arranged. The coaxial hollow truncated cone is formed by coaxially connecting a plurality of conical hollow truncated cone rings with different diameters. Two adjacent conical hollow truncated cone rings are staggeredly lapped in a right-side-up and inverted form, and a V-shaped groove is formed between two adjacent conical hollow truncated cone rings. The opening angle of the V-shaped groove is 5° to 180°. A plurality of holes (3353) are formed on the inner wall of the V-shaped groove. The V-shaped groove is filled with the packing (3352). The packing (3352) is at least one of structured packing and random packing. A fixed support structure (3354) is provided between two adjacent conical hollow truncated cone rings. The central groove of the lowermost coaxial hollow truncated cone in the bearing element (3351) is sleeved above the upper liquid diversion component (3341). The spraying component (336) includes a spraying distribution pipe (3361), and a plurality of spray nozzles (3362) are distributed on the spraying distribution pipe (3361). The water inlet of the spraying distribution pipe (3361) is connected to the water outlet of the three-stage circulation water tank (332).

7. A method for treating malodorous and offensive odors, characterized in that, Use the system for treating malodorous odor according to claim 6 to treat malodorous odor.

8. The method according to claim 7, characterized in that When using the system to treat malodorous odor, the following steps are included: S1. Start the hypochlorous acid generator (23) to produce sodium hydroxide and hypochlorous acid, and respectively transport them to the primary circulation water tank (312) and the secondary circulation water tank (322) according to process requirements. S2. Sequentially transport the malodorous odor gas from the intake pipe (1) to the primary spray tower (31) and the secondary spray tower (32), start the primary circulation pump (311) and the secondary circulation pump (321), and use the sodium hydroxide solution and the hypochlorous acid solution to perform primary oxidation and degradation treatment on the malodorous odor gas. S3. Transport the waste gas treated by the secondary spray tower (32) to the three-stage synergistic reaction tower (33) for secondary oxidation and degradation treatment to complete the deep purification treatment of the malodorous odor.

9. The method according to claim 8, wherein In step S1, the pH value of the sodium hydroxide solution in the primary circulation water tank (312) is controlled to be 9.5 - 12; the increase in the effective chlorine concentration in the secondary circulation water tank (322) is controlled to be 5 mg·L -1 ·h -1 ~80 mg·L -1 ·h -1 .

10. The method according to claim 9, characterized in that, In step S2, turn on the first chemical dosing pump (411) to add chemical agent A to the primary circulation water tank (312) or the secondary circulation water tank (322); during the primary oxidation degradation process, when the spraying time of the hypochlorous acid solution reaches 4 h to 12 h, discharge the waste liquid in the secondary circulation water tank (322) and the first waste liquid collection tank (52) to the second waste liquid collection tank (53) according to the discharged volume of the waste liquid being 10% to 50% of the total volume of the waste liquid in the secondary circulation water tank (322). Turn on the third chemical dosing pump (431) to transport chemical agent C to the second waste liquid collection tank (53) until the concentration of chemical agent C in the second waste liquid collection tank (53) is 0.2 g / L to 1.0 g / L. Use chemical agent C to treat the waste liquid in the second waste liquid collection tank (53) until the ammonia nitrogen concentration in the second waste liquid collection tank (53) is less than 1 mg / L. Continue to turn on the third chemical dosing pump (431) to make the concentration of chemical agent C in the second waste liquid collection tank (53) 0.4 g / L to 2.4 g / L. React chemical agent C with the chloride ions in the second waste liquid collection tank (53) to generate available chlorine until the available chlorine content of the waste liquid in the second waste liquid collection tank (53) reaches 40 mg / L to 200 mg / L. Then turn off the hypochlorous acid generator (23), stop transporting hypochlorous acid to the secondary circulation water tank (322), and turn on the transfer pump (51) to transport the waste liquid in the second waste liquid collection tank (53) to the primary circulation water tank (312) or the secondary circulation water tank (322). Until the waste liquid in the second waste liquid collection tank (53) has treated the malodorous gas for 6 h to 12 h, discharge the waste liquid in the second waste liquid collection tank (53) outward. At the same time, the hypochlorous acid generator (23) continues to produce hypochlorous acid and uses the hypochlorous acid solution to continue treating the malodorous gas; the excess waste liquid in the second waste liquid collection tank (53) is discharged outward; In step S3, turn on the second chemical dosing pump (421) to transport chemical agent B to the tertiary circulation water tank (332); when the humidity of the malodorous gas in the intake pipeline (1) < 90% and the temperature > 65 °C, turn off the first chemical dosing pump (411), the second chemical dosing pump (421), and the third chemical dosing pump (431); when the humidity of the malodorous gas in the intake pipeline (1) > 95% and the temperature < 65 °C, turn on the first chemical dosing pump (411), the second chemical dosing pump (421), and the third chemical dosing pump (431).

Images