Modified perlite filler for horizontal wet-type electric washing tower and application system of modified perlite filler

Abstract

The invention discloses a modified perlite filler for a horizontal wet-type electric washing tower and an application system of the modified perlite filler. The modified perlite filler takes expanded perlite as a matrix and carries amino groups through surface modification; in the pretreatment area of the application system, namely the horizontal wet-type electric washing tower, acid gases such as tetrahydride and water in waste gas can be effectively adsorbed, pollutants with large particle sizes can be intercepted, and the load of a subsequent electrostatic field is reduced. Spraying liquid in the spraying system arranged in the horizontal wet-type electric washing tower can absorb acid gas which is not absorbed by the filler again, and the overflow rate of the acid gas is reduced. The modified perlite filler provided by the invention is large in specific surface area, can effectively remove large-particle-size particles, acid gas and moisture in waste gas, and can be recycled as a building material; meanwhile, the horizontal wet-type electric washing tower provided by the invention is not easy to corrode equipment, and has relatively long service life and relatively good environment-friendly application prospect.

Description

Technical Field

[0001] The invention relates to the field of preparation of fillers and application systems thereof, and in particular to a modified perlite filler for a horizontal wet electric power washing tower and an application system thereof. Background Art

[0002] In general industrial production, sulfur dioxide and residual sulfur trioxide can usually be removed by alkaline washing. However, since the organic acid mist entrained in the tail gas will produce a large amount of foam during the alkaline washing process, which affects the normal progress of the alkaline washing, the wire mesh demister can only remove the acid mist with a particle size of more than 1μm. The acid mist with a particle size of 0.1-1μm is difficult to remove by general separation equipment or chemical absorption methods. The most effective method is to use an electrostatic demister for treatment.

[0003] Electrostatic precipitator (ESP) applies negative high voltage (10-50kV) generated by high-voltage rectifier power supply device to the corona electrode of ESP (metal wire placed in the center of metal tube, cathode), so that a huge non-uniform high voltage electric field is generated between the corona electrode and the dust collecting electrode (metal tube wall, anode). When the voltage rises above the corona initiation voltage, the gas in the area near the corona electrode is ionized to produce positive ions and free electrons. Under the action of high electric field, the movement speed of these free electrons is accelerated. When they collide with neutral gas molecules, their energy is enough to release other free electrons, thereby generating new positive ions and free electrons. New free electrons and ions will occur continuously like an avalanche, which is usually called electron avalanche. In the process of electron avalanche, strong corona discharge will occur near the corona electrode, and an "ionized gas area" will be formed near it. At this time, a large number of free electrons and negative ions escape from the corona area and fly to the anode. When the gas carrying acid mist passes through the demister, the negatively charged particles will constantly collide and be adsorbed onto the acid mist particles during movement, thereby charging the acid mist. Under the action of the electric field force, the charged acid mist reaches the anode one after another within a few seconds and releases negative charges, causing the acid mist itself to gather on the anode and condense into larger droplets under the action of gravity. They flow down the pipe wall and are discharged into the black acid storage tank through the acid discharge port at the bottom of the ESP, and are discharged and treated regularly.

[0004] Wet electrostatic precipitators have been used for many years in the chemical and metallurgical fields, but the flue gas treatment capacity is relatively small, and the gas velocity is generally around 1 m / s. In order to improve the treatment efficiency, the air intake speed is usually increased. When the gas velocity increases, the residence time becomes shorter. To ensure a certain demisting efficiency, it is necessary to increase the specific current of the corona electrode line. At the same time, the increase in gas velocity will cause the corona electrode line to swing to a large extent, thereby affecting the demisting efficiency; in addition, more water vapor in the exhaust gas will affect the effect of electrostatic demisting in the electrostatic area. If the acidic exhaust gas contains tetrahydrosilicon, it is very easy to spontaneously combust under the action of static electricity in the electric field and high temperature conditions, leading to accidents. Therefore, the development of a high-gas-speed, efficient and safe electrostatic demisting system is the most urgent problem to be solved. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a modified perlite filler for a horizontal wet electric power washing tower and an application system thereof.

[0006] A modified perlite filler. The raw materials for preparing the modified perlite filler include expanded perlite and unsaturated fatty primary amine.

[0007] In some embodiments of the present invention, the preparation method of the modified perlite is as follows: S1: Weigh a certain amount of expanded perlite, dry it at 100-120°C, evenly disperse it in an ether organic solvent, and stir it evenly; S2: Mix unsaturated fatty primary amine and di-tert-butyl dicarbonate in an alcohol solvent, remove the alcohol solvent after 2-3 hours, and wash the product with n-hexane; S3: adding the product obtained in step S2 to the mixed system of step S1, adding a solid acid catalyst thereto, raising the temperature and pressurizing to a certain condition, reacting for 3-8 hours, cooling to room temperature, filtering the obtained precipitate, washing with anhydrous ethanol and then drying to obtain the modified perlite filler.

[0008] In some embodiments of the present invention, in step S1, the particle size of the expanded perlite used is 2-4 mm; in step S2, the molar ratio of unsaturated fatty primary amine to di-tert-butyl dicarbonate is 1:1.5-2, and the alcohol solvent is at least one of methanol and ethanol. In step S1, if the particle size of the expanded perlite is too large or too small, the unsaturated fatty primary amine cannot be fully combined with the expanded perlite, resulting in incomplete modification of the expanded perlite and inability to achieve effective absorption. In addition, too small a particle size can easily cause clogging of the filler. Since the amino group reacts with the hydroxyl group in the protic solvent (alcohols, amines), the tert-butyloxycarbonyl group in di-tert-butyl dicarbonate is used to protect the amino group in step S2.

[0009] In some embodiments of the present invention, the mass ratio of expanded perlite to unsaturated fatty primary amine in the reaction system in step S3 is 10-15:3-5; the carbon chain of the unsaturated fatty primary amine is an alkenyl group with 6-18 carbon atoms, and the specific selection can be pentylamine, hexylamine, decylamine, octadecylamine, eicosylamine, and more preferably one of hexylamine, decylamine and octadecylamine.

[0010] The surface of expanded perlite contains hydrophilic groups and is polar, and it is very easy to absorb water. When it is used in the pretreatment area of ​​a horizontal wet power scrubber, the water content of the exhaust gas entering the electrostatic area can be reduced, but the expanded perlite that absorbs too much water needs to be replaced frequently. In the present invention, the inventors found that by controlling the amount of unsaturated fatty primary amine and its fatty chain length, the modified expanded perlite can have a certain degree of hydrophobicity. The expanded perlite modified by unsaturated fatty primary amine absorbs water in the pretreatment area, and its surface is alkaline. The exhaust gas passes through the modified perlite filler, and the silicon hydride contained in it can be absorbed and hydrolyzed to form silicic acid precipitation, and hydrofluoric acid is also absorbed at the same time.

[0011] In some embodiments of the present invention, in step S3, the solid acid catalyst used is at least one of aluminum oxide, titanium oxide, and zirconium oxide, and the added amount is 0.15-0.3% of the mass of the modified perlite; the reaction conditions are 0.1-0.5 MPa and 60-100°C.

[0012] The present invention also provides an application system of the modified perlite filler - a horizontal wet electric power washing tower, wherein the horizontal wet electric power washing tower comprises a box, wherein air inlets and air outlets are respectively arranged on both sides of the box, and a pretreatment zone, a demisting zone and an electrostatic adsorption zone are arranged in the box. The pretreatment zone is close to the air inlet and is filled with the modified perlite filler. In this zone, the flow rate of the exhaust gas is generally controlled at 0.75-1.0 m / s, and the retention time is 1.0-1.5 s, which is used to remove acidic gases such as hydrofluoric acid and silicon tetrahydride in the exhaust gas, and can also intercept some large-particle pollutants; the demisting zone is close to the outlet and is used to perform demisting operations on the exhaust gas; two electrostatic adsorption zones are arranged between the pretreatment zone and the demisting zone, and the electrostatic adsorption zone is used to release electric charges to make the pollutants negatively charged and adsorb them by electrostatic adsorption.

[0013] In some embodiments of the present invention, an anode plate and a discharge electrode are provided in the electrostatic adsorption zone of the horizontal wet electric washing tower.

[0014] In some embodiments of the present invention, an insulating chamber is further provided above the electrostatic adsorption area, an electrode suspension is provided in the insulating chamber, the upper part of the discharge electrode is suspended on the electrode suspension, and the lower part is fixed by a tooth rod; insulators are further provided on both sides of the interior of the insulating chamber, and a high-frequency power supply is provided on the external side, the high-frequency power supply is connected to the discharge electrode through a high-voltage voltage line, and provides high voltage electricity to the discharge electrode; the anode plate is connected to the plate fixing frame in the box body by bolts; a glass fiber reinforced plastic (FRP) grid is further provided at the lower part of the interior of the box body, and the FRP grid is used to support the plate fixing frame.

[0015] In some embodiments of the present invention, the discharge electrodes are vertically arranged with uniform spacing.

[0016] In some embodiments of the present invention, the pretreatment zone, electrostatic adsorption zone and demisting zone are all provided with a spray system, and the spray medium of the spray system is an alkaline solution, preferably a 0.5-1.0 mol / L ammonia solution, sodium hydroxide solution or potassium hydroxide solution.

[0017] The operation sequence of the horizontal wet electric washing tower is as follows: 1 hour after the hot air blowing and spraying are turned on at the same time, the first electrostatic adsorption zone is turned on, and the first electrostatic adsorption zone first works at 50% of the working voltage for 5 minutes, and then the second electrostatic adsorption zone is turned on at the same time. At this time, the voltage of the first electrostatic adsorption zone is increased to 100% of the working voltage and works for 1 hour, and the second electrostatic adsorption zone works at 50% of the working voltage for 1 hour; thereafter, the voltage of the first electrostatic adsorption zone is reduced to 50% of the working voltage again and works for 6 minutes, and the voltage of the second electrostatic adsorption zone is increased to 100% of the working voltage and continues to work for 1h6min; the voltage of the first electrostatic adsorption zone is After the voltage has been working at 50% for 6 minutes, it is adjusted to 100% and continues to work for 2h5min; after the voltage in the second electrostatic adsorption zone has been working at 100% for 1h6min, its voltage is reduced to 50% and worked for 5min, and then it works at 100% for 2h6min until the end of the program; on the other hand, after the first horizontal wet electric washing tower has been working at 100% for 2h5min, its voltage is reduced to 50% again, and after working for 6min, it runs at 100% for 1h until the end of the program.

[0018] While the two electrostatic adsorption zones are discharging, it is necessary to start the cleaning procedure to clean the particles adsorbed on the anode plate. The first electrostatic adsorption zone is cleaned twice during the entire discharge process, once starting 2h5min after the discharge, and once starting 3h16min after the discharge. Both cleanings only take 2min; the second electrostatic adsorption zone only needs to be cleaned once during the entire operation process, that is, 3h11min after the second electrostatic adsorption zone starts working, and it also only takes 2min.

[0019] In some embodiments of the present invention, a water tank for collecting sewage is provided at the bottom of the box body, and a circulating water pump is provided in the water tank. The collected sewage undergoes simple treatment and then enters the cleaning process through the circulating water pump, thereby reducing treatment costs.

[0020] In some embodiments of the present invention, a plurality of box reinforcement members are disposed outside the box, and the box reinforcement members are used to reinforce the box.

[0021] Beneficial effects: 1. Compared with the prior art, the modified perlite filler provided by the present invention uses unsaturated fatty primary amine as a modifier, and adds and grafts amino groups and fatty alkyl chains on the surface of expanded perlite. By controlling the length of the unsaturated fatty primary amine carbon chain, part of the surface of the expanded perlite is made hydrophobic, and the water absorption of the perlite is reduced. While improving the expanded perlite's ability to treat hydrofluoric acid and silicon tetrahydride in acidic waste gas, the modified perlite filler will not be unusable due to excessive water absorption; 2. The modified perlite filler of the present invention can be recycled as a building material to prepare cement slurry after use, thus realizing resource utilization and greatly reducing damage to the environment; 3. Compared with the prior art, the horizontal wet electric washing tower provided by the present invention is also provided with a pretreatment zone, which is filled with the modified perlite filler. The content of acidic gas, water vapor and some suspended particulate matter in the pretreated exhaust gas will be greatly reduced, and the working pressure of the subsequent electrostatic adsorption zone and the demisting zone will be greatly reduced, thereby reducing the working cost of the horizontal wet electric washing tower. The setting of the two electrostatic adsorption zones can further improve the overall purification efficiency and can effectively and thoroughly clean pollutants with different particle sizes in industrial exhaust gas. Moreover, the structure of the horizontal wet electric washing tower is horizontal, which can be set in an area with limited height space, and is also convenient for daily inspection and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a horizontal wet electric washing tower in one embodiment of the present invention; In the figure: 1. box body; 2. box body reinforcement; 3. air inlet; 4. air outlet; 5. modified perlite filler; 6. anode plate; 7. discharge electrode; 8. tooth rod; 9. plate fixing frame; 10. demister; 11. spray system; 12. insulation chamber; 13. insulator; 14. electrode suspension; 15. circulating water pump; 16. FRP grille; 17. high-frequency power supply; 18. water tank. DETAILED DESCRIPTION

[0023] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0024] In the following embodiments and comparative examples, the electrical control parameters of the horizontal wet electric washing tower are: AC voltage 380V; DC voltage 20KV; average electric field strength 2.5KV / cm.

[0025] Example 1 S1: Weigh 2 kg of expanded perlite with a particle size of 2 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 700 g of hexyl primary amine and 11 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 3g of zinc oxide thereto, raise the temperature and pressure to 0.1MPa and 95°C, react for 6h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-1.

[0026] Example 2 S1: Weigh 5 kg of expanded perlite with a particle size of 3 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 1550 g of decene primary amine and 18 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 15g of titanium oxide thereto, raise the temperature and pressure to 0.3MPa and 60°C, react for 8h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-2.

[0027] Example 3 S1: Weigh 7 kg of expanded perlite with a particle size of 4 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 2100 g of octadecene primary amine and 16 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 14g of zinc oxide thereto, raise the temperature and pressure to 0.5MPa and 75°C, react for 3h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-3.

[0028] Example 4 S1: Weigh 7 kg of expanded perlite with a particle size of 4 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 1700 g of pentyl primary amine and 30 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 14g of zinc oxide thereto, raise the temperature and pressure to 0.5MPa and 75°C, react for 3h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-4.

[0029] Example 5 S1: Weigh 7 kg of expanded perlite with a particle size of 4 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 2100 g of primary eicosene amine and 13 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 14g of zinc oxide thereto, raise the temperature and pressure to 0.5MPa and 75°C, react for 3h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-5.

[0030] Example 6 S1: Weigh 7 kg of expanded perlite with a particle size of 1 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 2100 g of octadecene primary amine and 16 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 14g of zinc oxide thereto, raise the temperature and pressure to 0.5MPa and 75°C, react for 3h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-6.

[0031] Example 7 S1: Weigh 7 kg of expanded perlite with a particle size of 5 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 2100 g of octadecene primary amine and 16 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 14g of zinc oxide thereto, raise the temperature and pressure to 0.5MPa and 75°C, react for 3h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-7.

[0032] Comparative Example 1 S1: Weigh 7 kg of expanded perlite with a particle size of 4 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 2100 g of dioctadecene secondary amine and 8 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 14g of zinc oxide thereto, raise the temperature and pressure to 0.5MPa and 75°C, react for 3h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-8.

[0033] Comparative Example 2 S1: Weigh 7 kg of expanded perlite with a particle size of 4 mm, dry it at 100-120°C, put it in ether, and stir it evenly; S2: 1500 g of octadecene dimethyl tertiary amine and 7.5 mol of di-tert-butyl dicarbonate were mixed evenly in methanol, the methanol was removed after 2 hours, and the product was washed with n-hexane; S3: Add the product obtained in step S2 into the mixed system of step S1, add 14g of zinc oxide thereto, raise the temperature and pressure to 0.5MPa and 75°C, react for 3h, cool to room temperature, filter the obtained precipitate, wash with anhydrous ethanol and then dry to obtain the modified perlite filler-9.

[0034] Comparative Example 3 Granular activated carbon (particle size 4-8 mesh) was purchased from Henan Runwang Environmental Protection Materials Co., Ltd.

[0035] Furthermore, the present invention utilizes Figure 1 The horizontal wet power scrubber shown in the figure is tested. The demister includes a box body 1, and a box body reinforcement 2 for reinforcing the box body 1 is provided on the outside of the box body 1. An air inlet 3 and an air outlet 4 are provided on both sides of the box body 1. The air inlet 3 is used to input industrial waste gas, and the air outlet 4 is used to discharge gas that meets the standards after treatment. Since the demister is horizontal, the air inlet 3 and the air outlet 4 are arranged on both sides of the box body 1, rather than at the upper and lower ends, so it is more suitable to be set in an area with limited height space. At the same time, because the air intake height is reduced, the air intake operation is also convenient.

[0036] From the air inlet 3 to the air outlet 4, the interior of the box 1 is provided with a pretreatment area, two electrostatic adsorption areas and a demisting area in sequence. Among them, the pretreatment area is used to remove pollutants with larger particle sizes in industrial waste gas, and the electrostatic adsorption area can release the charge to make the pollutants negatively charged and move them under the action of static electricity, so that the pollutants and gas are separated. The demisting area can remove the water mist in the gas. After being treated in the three areas, the industrial waste gas can meet the emission standards and can be discharged.

[0037] The pretreatment area is provided with a packing area 5, and the packing in the packing area 5 can remove pollutants with larger particle sizes to reduce the load of the electrostatic field behind. The pretreated gas enters the electrostatic adsorption area, which includes an anode plate 6 and a discharge electrode 7. An insulating chamber 12 is provided on the box 1 located in the electrostatic adsorption area, and a high-frequency power supply 17 is provided on one side of the insulating chamber 12. The high-frequency power supply 17 is connected to the discharge electrode 7 through a high-voltage voltage line, and is used to provide high voltage electricity to the discharge electrode 7.

[0038] An electrode suspension 14 is provided in the insulating chamber 12, and the upper part of the discharge electrode 7 is suspended on the electrode suspension 14, and the lower part is fixed by a tooth rod 8, so that the discharge electrode 7 can be arranged vertically and the intervals are kept consistent. The discharge electrode 7 can release the charge to make the pollutant negatively charged and move under the action of electrostatic force.

[0039] A plate fixing frame 9 is provided in the box 1, and an FRP grid 16 is provided at the lower part of the box 1. The FRP grid 16 is used to support the plate fixing frame 9. The plate fixing frame 9 is connected to the anode plate 6 by bolts. The anode plate 6 is placed vertically, and the number of the anode plates 6 can be two, which are respectively located on both sides of the discharge electrode 7. When the pollutants are separated from the gas, they will gather on the anode plate 6.

[0040] The demisting area is provided with a demisting device 10, and the gas can meet the emission standards after the demisting device 10 removes water and mist from the exhaust gas. The pretreatment area, the electrostatic adsorption area and the demisting area are all provided with a spraying system 11. The spraying medium used by the spraying system 11 is an alkaline liquid, which can neutralize the acidic pollutants in the exhaust gas to generate stable salts. The pretreatment area uses a dual-fluid spray technology to wet the acid mist and ammonium salt and make them condense and enlarge, which can improve the treatment efficiency of the subsequent electrostatic adsorption area.

[0041] A water tank 18 for collecting sewage is provided at the bottom of the box body 1. The water tank 18 is also equipped with a circulating water pump 15. The spray system 11 in the electrostatic adsorption area can wash the pollutants accumulated on the anode plate 6 into the water tank 18. In the process of removing the water mist, a small amount of solid particles will remain in the demister 10. After a period of time, the pressure loss of the equipment will increase. Therefore, the spray system needs to be cleaned regularly to flush the particles into the water tank 18.

[0042] Insulators 13 are provided on both sides of the insulating chamber 12. The insulators 13 can keep the anode plate 6 dry during the process of the spray system 11 cleaning the anode plate 6, provide a favorable environment for high-voltage discharge, and play a role in safety protection.

[0043] Application: The modified perlite filler and granular activated carbon obtained in the above-mentioned Examples 1-7 and Comparative Examples 1-3 are respectively used in the packing area 5 of the above-mentioned horizontal wet power scrubber, and the exhaust gas discharged from a factory is treated by the following operation method, and the gas is collected at the air inlet 3 and the air outlet 4 for detection: After the hot air blowing and spraying are turned on for 1 hour, the first electrostatic adsorption zone is turned on. The first electrostatic adsorption zone works at 50% of the working voltage for 5 minutes. Then the second electrostatic adsorption zone is turned on at the same time. At this time, the voltage of the first electrostatic adsorption zone is increased to 100% of the working voltage and works for 1 hour. The second electrostatic adsorption zone works at 50% of the working voltage for 1 hour. After that, the voltage of the first electrostatic adsorption zone is reduced to 50% of the working voltage again and works for 6 minutes. The voltage of the second electrostatic adsorption zone is increased to 100% of the working voltage and continues to work for 1h6min. The voltage of the first electrostatic adsorption zone is increased to 100% of the working voltage and works for 1h6min. After the working voltage lasts for 6 minutes, it is adjusted to 100% of the working voltage and continues to work for 2h5min; after the voltage in the second electrostatic adsorption zone works at 100% of the working voltage for 1h6min, its voltage is reduced to 50% and works for 5min, and then it works at 100% of the working voltage for 2h6min until the end of the program; on the other hand, after the first horizontal wet electric washing tower works at 100% of the working voltage for 2h5min, its voltage is reduced to 50% of the working voltage again, and after continuing for 6min, it runs at 100% of the working voltage for 1h until the end of the program.

[0044] Performance testing: Hydrogen fluoride content: Use a hydrogen fluoride gas detector to detect the concentration of hydrogen fluoride in the waste gas before and after treatment; Silicon tetrahydride content: Silicon tetrahydride in the exhaust gas before and after treatment is collected with an alkaline resin-based spherical activated carbon sampling tube, desorbed with hot water, and converted into sodium metasilicate. In a 50% hydrochloric acid solution, sodium metasilicate is converted into metasilicic acid and reacts with ammonium molybdate to produce silicomolybdenum heteropoly acid, which is then reduced to silicomolybdenum blue with 1,2,4-aminonaphthol sulfonic acid solution, and the absorbance is measured at a wavelength of 680nm for quantification. The standard solution of silicon is a 10μg / mL silicon dioxide standard solution, which is equivalent to a 5.34μg / mL silicon tetrahydride standard solution, and the detection limit is 1.2 mg / m 3 ; PM2.5 content: According to the national standard "Technical requirements and detection methods for continuous automatic monitoring system of ambient air particulate matter (PM10 and PM2.5)" (HJ 653-2013), the particulate matter in the exhaust gas before and after treatment is detected; Use time limit: When the hydrogen fluoride content, silicon tetrahydride content and PM2.5 content contained in the treated exhaust gas are all higher than 80% of the concentration before treatment, the use time of the modified expanded perlite is recorded.

[0045] The performance index changes before and after the exhaust gas treatment using the modified perlite and granular activated carbon described in each embodiment and comparative example and starting the horizontal wet power scrubber are shown in Table 1: Table 1 Test results of the modified perlite and activated carbon in the horizontal wet power scrubber for treating waste gas in Examples 1-7 and Comparative Examples 1-3

[0046] It can be seen from the test data in Table 1 that the modified perlite filler provided by the present invention is used in conjunction with the horizontal wet power washing tower, and has an excellent removal effect on hydrogen fluoride, silicon tetrahydride and particulate matter in the exhaust gas, and the concentrations after treatment meet the exhaust gas emission standards of the environmental protection industry. The modified perlite in Examples 4-5 is obtained by modifying expanded perlite with primary amine pentanoic acid and primary amine eicosanoic acid. Although the concentration of the waste gas after treatment also meets the emission standard, the water absorption of the modified perlite is not suitable for the application scenario of the horizontal wet power washing tower compared with Examples 1-3 due to the short or long aliphatic carbon chain, resulting in the removal effect of the modified perlite being inferior to that of Examples 1-3, and it needs to be replaced frequently to achieve better treatment efficiency; the particle size of the modified perlite used in Example 6 is 1 mm, and the removal effect of hydrogen fluoride and silicon tetrahydride is almost the same as that of Examples 1-3, and it has no great effect on the removal of particulate matter, but it is very easy to be blocked during the application process, affecting the smoothness and efficiency of operation; although the particle size of the modified perlite in Example 7 is larger, 5 mm, the capture efficiency of particulate matter is insufficient, and particulate matter is easier to escape from the surface. Comparative Example 1-2, in which the expanded perlite is modified by unsaturated fatty secondary amine or tertiary amine, has a treatment effect far inferior to that of the embodiment.

[0047] The treatment results of Comparative Examples 1-2 compared with those of Example 3 show the superiority of primary amine in absorbing silicon hydride and hydrogen fluoride.

[0048] The results of Comparative Example 3 show that the modified perlite of the present invention is better than common activated carbon in treating acidic waste gas.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although detailed description is given with reference to the embodiments of the present invention, those skilled in the art should understand that modifications or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be included in the protection scope of the claims of the present invention.

Claims

1. A modified perlite filler for a horizontal wet power scrubber, characterized in that: The raw materials for preparing the modified perlite filler include: expanded perlite and unsaturated fatty primary amine.

2. The modified perlite filler for a horizontal wet power washing tower according to claim 1, characterized in that: The preparation method of the modified perlite filler comprises the following steps: S1: Weigh a certain amount of expanded perlite, dry it at 100-120°C, and evenly disperse it in an ether organic solvent; S2: Mix unsaturated fatty primary amine and di-tert-butyl dicarbonate in an alcohol solvent, remove the alcohol solvent after 2-3 hours, and wash the product with n-hexane; S3: adding the product obtained in step S2 to the mixed system of step S1, adding a solid acid catalyst thereto, raising the temperature and pressurizing to a certain condition, reacting for 3-8 hours, cooling to room temperature, filtering the obtained precipitate, washing with anhydrous ethanol and then drying to obtain the modified perlite filler.

3. The modified perlite filler for a horizontal wet power washing tower according to claim 2, characterized in that: In the step S1, the particle size of the expanded perlite used is 2-4 mm; in the step S2, the molar ratio of the unsaturated fatty primary amine to di-tert-butyl dicarbonate is 1:1.5-2, and the alcohol solvent is at least one of methanol and ethanol.

4. The modified perlite filler for a horizontal wet power washing tower according to claim 2, characterized in that: In the step S3, the mass ratio of expanded perlite to unsaturated fatty primary amine in the reaction system is 10-15:3-5; the carbon chain on the unsaturated fatty primary amine is an olefin group with 6-18 carbon atoms.

5. The modified perlite filler for a horizontal wet power washing tower according to claim 2, characterized in that: In the step S3, the solid acid catalyst used is at least one of aluminum oxide, titanium oxide and zirconium oxide, and the added amount is 0.15-0.3% of the mass of the modified perlite; the reaction conditions are 0.1-0.5 MPa and 60-100°C.

6. A horizontal wet electric washing tower using the modified perlite for a horizontal wet electric washing tower according to any one of claims 1 to 5 as filler, characterized in that: The invention comprises a box body, wherein a pretreatment area, a demisting area and an electrostatic adsorption area are arranged in the box body.

7. The horizontal wet electric washing tower according to claim 6, characterized in that: The pretreatment area is close to one side of the air inlet, the demisting area is close to one side of the air outlet, and the electrostatic adsorption area is located between the pretreatment area and the demisting area.

8. The horizontal wet electric washing tower according to claim 7, characterized in that: The pretreatment zone is filled with modified perlite prepared by the preparation method according to any one of claims 1 to 5; the electrostatic adsorption zone is provided with an anode plate and a discharge electrode; and the demisting zone is provided with a demister.

9. The horizontal wet electric washing tower according to claim 8, characterized in that: An insulating chamber is also provided above the electrostatic adsorption area, and an electrode suspension is provided in the insulating chamber. The upper part of the discharge electrode is suspended on the electrode suspension, and the lower part is fixed by a tooth rod; insulators are also provided on both sides of the interior of the insulating chamber, and a high-frequency power supply is provided on the external side, and the high-frequency power supply is connected to the discharge electrode through a high-voltage voltage line; the anode plate is connected to the plate fixing frame in the box body by bolts; a fiberglass grille is also provided at the lower part of the interior of the box body.

10. The horizontal wet electric washing tower according to any one of claims 6 to 9, characterized in that: The pretreatment area, the electrostatic adsorption area and the demisting area are all provided with a spraying system, and the spraying medium of the spraying system is an alkaline solution.

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