Organic waste gas treatment device

Abstract

The utility model relates to an organic waste gas treatment device which comprises a reaction tower, a circulating water tank, a waste gas distributor, a micro-electrolysis structure layer, a micro-nano bubble releaser, a demisting layer and a peroxymonosulfate box, and the circulating water tank, the waste gas distributor, the micro-electrolysis structure layer, the micro-nano bubble releaser and the demisting layer are arranged in the reaction tower from bottom to top. The peroxymonosulfate tank is communicated with the circulating water tank through a doser, the micro-nano bubble releaser is connected with the circulating water tank through a high-pressure pump, a purified waste gas outlet is formed in the upper end of the reaction tower, and a waste gas inlet is formed in the side wall of the waste gas distributor. According to the device, the micro-nano bubbles are coupled with the peroxymonosulphide in cooperation with micro-electrolysis, so that the device has relatively strong pertinence and complementarity, the treatment effect is far better than that of single micro-nano bubbles or peroxymonosulphide, on one hand, the removal rate of pollutants is improved, stable and standard emission of the pollutants is realized, and on the other hand, the cost can be saved.

Description

Technical Field

[0001] The utility model relates to an organic waste gas treatment device, in particular to an organic waste gas treatment device based on micro-nano bubbles coordinated micro-electrolysis coupled monosulfur salt. Background Art

[0002] With the sustained and rapid economic development, the total amount of volatile organic compounds emitted by industrial sources has increased year by year, and environmental pollution problems have become increasingly prominent. Volatile organic compounds refer to organic compounds with a saturated vapor pressure greater than 133.32 Pa at room temperature and a boiling point below 50-260°C at normal pressure, or any organic solid or liquid that can volatilize at room temperature and pressure. Most VOCs are highly toxic and are one of the important precursors to the formation of photochemical smog and PM2.5. They have an important impact on regional atmospheric ozone, PM2.5 pollution and human health.

[0003] At present, the main methods for treating volatile organic compound waste gas include activated carbon adsorption, direct combustion, catalytic combustion and adsorption-catalytic combustion. Their respective advantages and disadvantages are as follows:

[0004] (1) Activated carbon adsorption method

[0005] Advantages: high adsorption efficiency, strong capacity, able to treat multiple mixed organic waste gases at the same time; simple maintenance and management; low engineering cost. Disadvantages: not suitable for large air volume systems; only suitable for low-concentration organic waste gas treatment; high operating costs; large wind resistance coefficient, high fan power consumption; produces hazardous solid waste, causing secondary pollution; waste activated carbon management is cumbersome and difficult to supervise.

[0006] (2) Direct combustion method

[0007] Advantages: simple process, low investment; suitable for high-concentration, small-volume exhaust gas; high VOC purification rate; can treat various organic exhaust gases, no need for preheating, few unstable factors, high reliability; can reuse heat energy under high exhaust gas concentration and reasonable design conditions. Disadvantages: high processing temperature, high energy consumption, high operating costs; secondary pollution, especially halogen-containing VOCs will produce highly toxic dioxins when burned; combustion device, combustion chamber, heat recovery device are expensive and difficult to maintain; high requirements for safety technology and operation; high decomposition temperature, potential safety hazards.

[0008] (3) Catalytic combustion method

[0009] Advantages: low ignition temperature, fast reaction rate, energy saving; high treatment efficiency, low emission of secondary pollutants and greenhouse gases; wide application range, catalytic combustion can treat almost all hydrocarbon organic waste gas and odorous gas. Disadvantages: pipelines and equipment caused by high temperature are easily damaged; if the heat storage body is agglomerated, the life span is not long; the pressure in the furnace changes greatly, causing a large amount of heat to overflow, and failing to achieve the actual energy saving effect; daily maintenance and cost increase; high requirements for safety technology and operation.

[0010] (4) Adsorption-catalytic combustion method

[0011] Advantages: simple process, low engineering investment; stable, small pressure drop, good adsorption performance, high VOC purification rate; significant energy saving by utilizing heat energy and continuous operation; large air volume range. Disadvantages: secondary pollution and saturation replacement of waste activated carbon; high requirements for safety technology and operation; unobvious energy saving for intermittent operation, high energy consumption and high operating cost; lower decomposition temperature than direct combustion, with certain safety risks; difficult to supervise activated carbon saturation for discontinuous production.

[0012] Chinese patent CN 107243234A discloses a method for oxidative degradation of organic waste gas with micro-nano bubbles in cooperation with persulfate. The persulfate described in the patent is a mixture of any two or three of Na2S2O8, K2S2O8, and (NH4)2S2O8 in any mass ratio. The disadvantage of this method is that the temperature of the micro-nano bubble generating liquid must be 40-50°C and the pH must be adjusted to 3-11 with sulfuric acid or sodium hydroxide with a mass concentration of 98%.

[0013] Chinese patent CN206935069U discloses a device for treating organic waste gas by combining a microbubble system with a negative ion purification device. The disadvantage of this device is that the organic waste gas purification efficiency is low and secondary pollution (ozone) is generated.

[0014] Therefore, there is an urgent need to develop an efficient device for treating volatile organic waste gas based on micro-nano bubbles coordinated micro-electrolysis coupled with monosulfide. Utility Model Content

[0015] The technical problem to be solved by the utility model is to provide an organic waste gas treatment device based on micro-nano bubbles coordinated micro-electrolysis coupled with monosulfide salts, which can effectively solve the problems in the background technology.

[0016] The technical solution to solve the above technical problems is: an organic waste gas treatment device, including a reaction tower, a circulating water tank, a waste gas distributor, a micro-electrolysis structure layer, a micro-nano bubble releaser, a demisting layer and a permonosulfate tank, wherein the circulating water tank, the waste gas distributor, the micro-electrolysis structure layer, the micro-nano bubble releaser and the demisting layer are arranged in the reaction tower from bottom to top, the permonosulfate tank is connected through the doser and the circulating water tank, the micro-nano bubble releaser is connected to the circulating water tank through a high-pressure pump, the upper end of the reaction tower is provided with a purified waste gas outlet, and the side wall of the waste gas distributor is provided with a waste gas inlet. A micro-electrolysis structure layer manhole is provided on the side wall of the micro-electrolysis structure layer, a nano bubble releaser layer manhole is provided on the side wall of the micro-nano bubble releaser, and a demisting layer manhole is provided on the side wall of the demisting layer.

[0017] A further technical solution of the utility model is: the bottom of the micro-electrolysis structure layer is a supporting plate with perforations, the perforation diameter is 2~4mm, the thickness of the micro-electrolysis structure layer is 30~60cm, the micro-electrolysis structure layer is composed of activated carbon and iron filings, the particle sizes of the activated carbon and the iron filings are 5~10mm respectively, and the volume ratio of activated carbon to iron filings is 1:0.5~1:1.

[0018] The exhaust gas distributor includes a main pipe and several branch pipes with injection holes. One end of the branch pipe is connected to the main pipe and the other end is closed. There are 2-5mm injection holes on the branch pipe, and the injection holes are distributed in a fan-shaped area of ​​150º below the branch pipe.

[0019] The demisting layer has turbulent balls and folding plates from bottom to top. The bottom of the demisting layer is a tray with perforations, on which polypropylene hollow balls are placed. The folding plates are arranged in the reaction tower through a supporting plate with through holes, and the baffles are guide plates arranged in an inclined manner.

[0020] The permonosulfate tank is connected to the circulating water tank through the spiral doser and ORP. The ORP value in the circulating water tank is 500mV~650mV. The spiral doser is interlocked with the ORP meter to realize automatic dosing of permonosulfate. When the ORP of the circulating water tank is less than 500mV, the feedback signal is given to the spiral doser, and the spiral doser starts to dosing permonosulfate to the circulating water tank. When the ORP of the circulating water tank is greater than 650mV, the feedback signal is given to the spiral doser, and the spiral doser stops dosing permonosulfate to the circulating water tank.

[0021] The peroxymonosulfate is any one of sodium peroxymonosulfate and potassium peroxymonosulfate or a mixture of the two in any mass ratio.

[0022] Due to the adoption of the above technical solution, the organic waste gas treatment device of the utility model has the following beneficial effects:

[0023] 1. The utility model combines micro-nano bubbles with micro-electrolysis to couple monosulfide salts, which has strong pertinence and complementarity. The treatment effect is far better than that of single micro-nano bubbles or monosulfide salts. On the one hand, it improves the removal rate of pollutants and achieves stable emission of pollutants in compliance with standards. On the other hand, it can save costs and is the main direction for the future treatment of volatile organic waste gas.

[0024] 2. The utility model is based on the conventional micro-nano bubble organic waste gas treatment device, and adds persulfate with strong oxidizing ability. The persulfate is activated by micro-nano bubbles to produce oxidative free radicals, such as hydroxyl, excited oxygen, sulfate, etc. Their reduction potential E0 = +2.6V~+2.8V, with extremely strong oxidizing properties, can quickly degrade organic pollutants and mineralize them into carbon dioxide and water.

[0025] 3. The utility model is based on the conventional persulfate organic waste gas treatment device, and adds micro-nano bubbles and micro-electrolysis structures. The micro-nano bubbles and micro-electrolysis structures synergistically activate persulfate to produce oxidative free radicals, thereby improving the yield and concentration of oxidative free radicals, significantly shortening the degradation reaction time of organic waste gas pollutants, and improving the system treatment efficiency.

[0026] 4. The utility model uses peroxymonosulfate instead of the persulfate of the prior art, which has the advantages of not needing to heat the micro-nano bubble generating liquid and not needing to use 98% mass concentration sulfuric acid or sodium hydroxide to adjust the pH to 3-11.

[0027] Below, the technical features of an organic waste gas treatment device of the present utility model are further explained in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 : A structural schematic diagram of an organic waste gas treatment device.

[0029] Figure 2 : Schematic diagram of the top view of the micro-electrolysis structure layer.

[0030] Figure 3 : Schematic diagram of the release tube distribution status of the micro-nano bubble releaser.

[0031] Figure 4 : Schematic diagram of the jet pipe distribution status of the exhaust gas distributor.

[0032] Figure 5 : Schematic diagram of the cross section of the demisting layer.

[0033] Figure 6 : Degradation curves of xylene under different systems.

[0034] In the above drawings, the descriptions of the reference numerals are as follows:

[0035] 1-exhaust gas outlet for purification, 2-demist layer, 3-micro-nano bubble releaser, 4-micro-electrolysis structure layer, 5-exhaust gas distributor, 6-permonosulfate tank, 7-spiral doser, 8-ORP meter, 9-high-pressure water pump, 10-circulating water tank, 11-exhaust gas inlet, 12-purification tower wall, 13-micro-electrolysis structure layer manhole, 14-micro-nano bubble releaser layer manhole, 15-demist layer manhole. DETAILED DESCRIPTION

[0036] An organic waste gas treatment device comprises a reaction tower, a circulating water tank, a waste gas distributor, a micro-electrolysis structure layer, a micro-nano bubble releaser, a demisting layer and a permonosulfate tank. The circulating water tank, the waste gas distributor, the micro-electrolysis structure layer, the micro-nano bubble releaser and the demisting layer are arranged in the reaction tower from bottom to top. The permonosulfate tank is connected with the circulating water tank through a doser, the micro-nano bubble releaser is connected with the circulating water tank through a high-pressure pump, a purified waste gas outlet is arranged at the upper end of the reaction tower, and a waste gas inlet is arranged at the side wall of the waste gas distributor. A micro-electrolysis structure layer manhole is arranged at the side wall of the micro-electrolysis structure layer, a nano bubble releaser layer manhole is arranged at the side wall of the micro-nano bubble releaser, and a demisting layer manhole is arranged at the side wall of the demisting layer. The ORP value in the circulating water tank is 500mV~650mV. Permonosulfate is a mixture of any one of sodium permonosulfate and potassium permonosulfate or two mixed in any mass ratio. "Manhole" is an inspection hole for inspection and maintenance.

[0037] The bottom of the micro-electrolysis structure layer is a support plate with perforations, the diameter of the perforations is 2~4mm, and the thickness of the micro-electrolysis structure layer 4 is 30~60cm. According to the shape of the reaction tower, the micro-electrolysis structure layer presents a corresponding structure (such as a cylinder). The micro-electrolysis structure is composed of graded activated carbon and iron filings. The particle size of activated carbon and iron filings is 5~10mm, and the volume ratio of activated carbon and iron filings is 1:0.5~1:1. The exhaust gas distributor includes a main pipe and several branch pipes with injection holes. One end of the branch pipe is connected to the main pipe, and the other end of the branch pipe is closed. There are 2-5mm injection holes distributed on the branch pipe, and the injection holes are distributed in the fan-shaped area of ​​150º at the bottom of the branch pipe. The exhaust gas distributor is located above the liquid level of the circulating water tank. The demisting layer has turbulent balls and folded plates from bottom to top. The bottom of the demisting layer is a tray with perforations, and polypropylene hollow balls are placed on the tray. The folded plate is set in the reaction tower through a support plate with through holes, and the baffle is a guide plate set in an inclined manner.

[0038] The micro-nano bubble releaser and the spiral doser can be existing ones. The micro-nano bubble releaser includes an outer sleeve, a boost plug and an outlet pagoda head. The outer sleeve is provided with 0.5-1 mm micropores around the outer sleeve. The micropores are directly opposite to the annular groove of the boost plug. The threaded end of the outlet pagoda head of the micro-nano bubble releaser presses the boost plug tightly, and the micro-nano bubble is released through the narrow notch of the threaded end of the outlet pagoda head. The spiral doser includes a support, a silo, a motor and a conveying section. A screw conveyor is arranged in the conveying section. A feed port is arranged at one end of the conveying section near the motor, and the feed port is connected to the silo. A discharge port is arranged at one end of the conveying section away from the motor. A support is radially arranged in the reaction tower body, and the support is connected to the tower wall and is subjected to force by the tower wall. The micro-electrolysis structure layer, the micro-nano bubble releaser, etc. are installed on the support.

[0039] The permonosulfate tank is connected to the circulating water tank through the spiral doser and ORP. The spiral doser is interlocked with the ORP meter to achieve automatic dosing of permonosulfate. When the ORP of the circulating water tank is less than 500mV, a feedback signal is given to the spiral doser, and the spiral doser starts to dosing permonosulfate to the circulating water tank. When the ORP of the circulating water tank is greater than 650mV, a feedback signal is given to the spiral doser, and the spiral doser stops dosing permonosulfate to the circulating water tank.

[0040] Volatile organic waste gas enters the reaction tower from the waste gas inlet and is evenly distributed at the bottom of the reaction tower through the waste gas distributor. The waste gas passes through the micro-electrolysis structure layer from bottom to top, and meets the micro-nano bubbles containing permonosulfate released by the micro-nano bubble releaser layer in the micro-electrolysis structure layer and undergoes a series of chemical reactions. The volatile organic waste gas undergoes an oxidation-reduction reaction here, and the volatile organic matter is mineralized into carbon dioxide and water. The purified waste gas continues to rise and pass through the demisting layer, where the water mist is removed. The purified waste gas after the water mist is removed is discharged through the outlet, completing the waste gas treatment work.

[0041] Under the coupling effect of micro-electrolysis and micro-nano bubbles, permonosulfate produces oxidative free radicals, such as hydroxyl, excited oxygen, sulfate, etc. Their reduction potential E0 = +2.6V~+2.8V, with extremely strong oxidizing properties, can quickly degrade organic pollutants and mineralize them into carbon dioxide and water. The specific process is as follows:

[0042]

[0043] Xylene was used as a representative of volatile organic compounds in the test.

[0044] (1) Micro-nano bubbles (MBs) acting alone

[0045] The xylene inlet concentration was set to 200 mg / m³, the xylene residence time was set to 2s, 4s, 6s, 8s, 10s, 12s, 14s, 16s, 18s, 20s, the MBs dosage (expressed as the ratio of the spray liquid to the exhaust gas volume, i.e., the liquid-gas ratio, 4L / m³) (MBs generator was turned on), the spray liquid pH value was 7, and the xylene degradation rate under the set conditions was as follows. Figure 2 shown.

[0046] (2) Peroxymonosulfate (PMS) acting alone

[0047] The xylene inlet concentration was set to 200 mg / m³, the xylene residence time was set to 2s, 4s, 6s, 8s, 10s, 12s, 14s, 16s, 18s, 20s, the MBs dosage (expressed as the ratio of the spray liquid to the exhaust gas volume, i.e., the liquid-gas ratio, 4L / m³) (MBs generator was not turned on), the PMS dosage was 5mM / L, the spray liquid pH value was 7, and the xylene degradation rate under the set conditions was as follows. Figure 2 shown.

[0048] (3) Synergistic effect of micro-nano bubbles (MBs) and peroxymonosulfate (PMS)

[0049] The xylene inlet concentration was set to 200 mg / m³, the xylene residence time was set to 2s, 4s, 6s, 8s, 10s, 12s, 14s, 16s, 18s, 20s, the MBs dosage (expressed as the ratio of the spray liquid to the exhaust gas volume, i.e., the liquid-gas ratio, 4L / m³) (MBs generator was turned on), the PMS dosage was 5mM / L, the spray liquid pH value was 7, and the xylene degradation rate under the set conditions was as follows. Figure 2 shown.

Claims

1. An organic waste gas treatment device, characterized in that: It includes a reaction tower, a circulating water tank, an exhaust gas distributor, a micro-electrolysis structure layer, a micro-nano bubble releaser, a demisting layer and a permonosulfate tank. The circulating water tank, the exhaust gas distributor, the micro-electrolysis structure layer, the micro-nano bubble releaser and the demisting layer are arranged in the reaction tower from bottom to top. The permonosulfate tank is connected with the circulating water tank through a dosing device. The micro-nano bubble releaser is connected with the circulating water tank through a high-pressure pump. A purified exhaust gas outlet is provided at the upper end of the reaction tower, and an exhaust gas inlet is provided at the side wall of the exhaust gas distributor.

2. The organic waste gas treatment device according to claim 1, characterized in that: The bottom of the micro-electrolysis structure layer is a supporting plate with perforations, the diameter of the perforations is 2~4mm, the thickness of the micro-electrolysis structure layer is 30~60cm, and the micro-electrolysis structure layer is composed of activated carbon and iron filings. The particle sizes of the activated carbon and iron filings are 5~10mm respectively, and the volume ratio of activated carbon to iron filings is 1:0.5~1:

1.

3. The organic waste gas treatment device according to claim 1, characterized in that: The exhaust gas distributor includes a main pipe and several branch pipes with injection holes. One end of the branch pipe is connected to the main pipe, and the other end of the branch pipe is closed. There are 2-5mm injection holes distributed on the branch pipe.

4. The organic waste gas treatment device according to claim 1, characterized in that: The demisting layer has turbulent balls and folding plates from bottom to top. The bottom of the demisting layer is a tray with perforations, on which polypropylene hollow balls are placed. The folding plates are arranged in the reaction tower through a supporting plate with through holes, and the baffles are guide plates arranged in an inclined manner.

5. The organic waste gas treatment device according to claim 1, characterized in that: The permonosulfate tank is connected to the circulating water tank through a spiral doser and ORP.

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