Energy-saving polychlorinated dibenzo-p-dioxin multistage control integrated device and method

Abstract

The application discloses an energy-saving polychlorinated dibenzo-p-dioxin multistage control integrated device and method. A spraying system (1), an inlet horn flue (2), an intelligent dynamic adjusting device (3), a plasma generator (4), a bag filter (5) and a return bin pump (6) are combined into an integrated device; the spraying system (1) is installed at the front end of the inlet horn flue (2), the inlet horn flue (2) is installed with the plasma generator (4), and the bag filter (5) is arranged at the rear part of the plasma generator (4); and the intelligent dynamic adjusting device (3) is installed in a centralized control room. The multistage control method of adsorption removal, plasma decomposition and high-efficiency filtration is adopted, and comprehensive control of two forms of polychlorinated dibenzo-p-dioxin in flue gas is realized. The device has the characteristics of small land occupation, 100% polychlorinated dibenzo-p-dioxin purification and removal, low investment and low operation cost, and is suitable for new construction or reconstruction projects of industrial flue gas polychlorinated dibenzo-p-dioxin efficient purification, such as waste steel smelting and waste incineration.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection technology for industrial flue gas pollution control, and specifically relates to an integrated device and method for multi-stage dioxin control in flue gas from energy-saving scrap steel smelting electric furnaces and waste incineration flue gas. Background Technology

[0002] Dioxins are harmful gaseous pollutants produced during the production processes of electric arc furnace steelmaking, iron ore sintering, and waste incineration. They are composed of chlorinated tricyclic aromatic compounds, are physically and chemically stable, and are biologically toxic, carcinogenic, and difficult to degrade. They are an important pollutant that urgently needs to be controlled.

[0003] Dioxins exist in two forms in industrial flue gas: one is as a gaseous substance uniformly mixed in the flue gas, and the other is as an adsorbent on the surface of particulate matter, which then becomes a carrier for dioxin accumulation. Therefore, to achieve dioxin pollution control standards, comprehensive treatment technologies must be adopted to purify both forms of dioxins.

[0004] There are numerous existing end-of-pipe treatment technologies for dioxins, each with its own advantages and disadvantages. The main end-of-pipe control technologies include adsorption technology, catalytic decomposition technology, plasma technology, and bag filtration technology.

[0005] Adsorption technology is prohibitively expensive for enterprises in Yuncheng. Catalytic decomposition technology has limited industrial applications due to the high cost of catalysts, susceptibility to poisoning, and the requirement for reaction temperatures above 300°C.

[0006] Plasma technology has high decomposition efficiency, but it consumes a lot of energy and has limited processing capacity. Bag filter technology can filter more than 99% of particulate matter in flue gas and can effectively control particulate dioxins, but it cannot treat gaseous dioxins.

[0007] The dioxins produced by electric arc furnaces are related to the scrap steel smelting load. During a smelting cycle, the concentration of dioxins produced by oxygen blowing is the highest, while the concentration of dioxins produced by charging, slag making, and tapping is relatively low.

[0008] In response to the characteristics of this process, it is necessary to develop an intelligent dynamic adjustment device to dynamically match the dioxin treatment generator with the dioxin concentration, thereby reducing the energy consumption and cost of the device and achieving green, energy-saving, and environmentally friendly treatment.

[0009] Therefore, existing dioxin purification technologies have limited and singular treatment effects. No single technology can simultaneously address both forms of dioxins, and the technologies lack interrelationships and fail to achieve synergistic effects. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides an energy-saving integrated device and method for multi-level dioxin control.

[0011] One aspect of the present invention provides an energy-saving integrated dioxin multi-stage control device, comprising an injection system, an inlet horn flue, an intelligent dynamic adjustment device, a plasma generator, a bag filter, and a return silo pump, all integrated into a single unit. The injection system is installed at the front end of the inlet horn flue, the plasma generator is installed in the inlet horn flue, and a bag filter is installed behind the plasma generator. The intelligent dynamic adjustment device is installed in the central control room. The injection system consists of an adsorbent silo, a variable frequency feeder, an injector, and a conveying fan. The plasma generator consists of a linear or needle-shaped discharge electrode and a plate, and a high-frequency high-voltage power supply. The intelligent dynamic adjustment device connects signals to the electric furnace outlet flue gas temperature, the variable frequency feeder, the high-frequency high-voltage power supply, and the return silo pump.

[0012] According to an embodiment of the present invention, a variable frequency feeder is provided below the adsorbent silo; the injector is connected to the conveying fan and the variable frequency feeder; the adsorbent in the adsorbent silo is a porous material rich in micropores, which is carbon-based, zeolite or polymer material; the pore size of the porous material is distributed between 1 and 20 nm.

[0013] According to an embodiment of the present invention, the inlet horn flue consists of an inlet horn housing and an internal airflow rectifier; the rectifier is a perforated plate, louvers, or a grille; the rectifier is provided in one or two layers; the inlet horn housing is installed on the air inlet side of the plasma generator.

[0014] According to an embodiment of the present invention, the bag filter includes an upper box, a middle box, an ash hopper, filter bags, bag cages, a dust removal device, and an outlet flue. The middle box is installed at the lower part of the upper box, the filter bags are suspended on the tube sheet of the middle box, the bag cages are inserted inside the filter bags, the dust removal device is provided in the upper box, the outlet flue is provided at the rear of the upper box, and the ash hopper is installed at the bottom of the middle box. The filter bags are PM2.5 ultrafine surface layer filter bags.

[0015] According to an embodiment of the present invention, the plasma generator is installed on the air inlet side of the middle housing; that is, the discharge electrode and electrode plate are installed, and a high-frequency high-voltage power supply is installed on the top.

[0016] According to an embodiment of the present invention, the intelligent dynamic adjustment device is equipped with pre-integrated function calculation model software that mimics a neural network.

[0017] According to an embodiment of the present invention, the return silo pump uses a positive pressure pneumatic conveying method to transport materials.

[0018] Another aspect of the present invention provides a dioxin multi-stage control method for an energy-saving integrated dioxin multi-stage control device. Dioxin-containing flue gas passes sequentially through an adsorbent injection system, a plasma generator, and a bag filter via a flue. First, the injection system injects adsorbent into the flue, where it mixes and contacts the flue gas uniformly. At this point, over 90% of the gaseous dioxins in the flue gas are adsorbed and removed by the adsorbent. Then, the flue gas is rectified by a rectifier in the inlet horn flue and enters the plasma generator. The plasma generator utilizes a high-voltage electric field to generate highly chemically active high-energy electrons and free radicals, which can decompose the remaining 10% of gaseous dioxins in the flue gas into water and carbon dioxide. Finally, the flue gas enters the bag filter, where the adsorbent enriched with dioxins and dust are efficiently filtered and separated. An intelligent dynamic adjustment device dynamically adjusts the adsorbent injection volume, plasma generation frequency, and return material load intensity according to the electric furnace smelting load. The return material hopper pump returns the adsorbent from the ash hopper back into the flue gas, allowing for secondary adsorption and utilization of the adsorbent.

[0019] This invention employs a multi-stage control method involving adsorption removal, plasma decomposition, and high-efficiency filtration to achieve comprehensive control of two forms of dioxins in flue gas.

[0020] The adsorbent is a porous material rich in micropores, which can effectively adsorb dioxin molecules, with an adsorption efficiency of over 90% for gaseous dioxins.

[0021] The variable frequency feeder can automatically adjust according to the electric furnace smelting load to quantitatively transport the adsorbent material into the flue; the injector can increase the material conveying speed, so that the material can be quickly and fully mixed with the flue gas after entering the flue.

[0022] The function of the rectifier is to reduce high-speed flue gas and make the airflow distribution more uniform after the flue gas passes through the rectifier.

[0023] The plasma generator applies high-voltage pulses to the discharge electrodes via a high-frequency, high-voltage power supply at the top, causing the electrodes to continuously release high-density plasma, which can further decompose gaseous dioxins. Because the electrodes are relatively short, they do not accumulate dust, resulting in significant electrophoresis efficiency.

[0024] The main function of bag filters is to use PM2.5 ultrafine surface filter bags, which can filter and separate adsorbents and dust containing dioxins with a filtration efficiency of over 99.99%, achieving highly efficient separation of solid dioxins.

[0025] The intelligent dynamic adjustment device is equipped with pre-integrated function calculation model software that mimics neural networks. It can quickly respond to signals and feed them back to the control device. It can dynamically adjust the operating intensity such as adsorbent injection volume, plasma generation frequency, and return material load according to the electric furnace smelting load, thereby achieving green, energy-saving and environmentally friendly operation.

[0026] The return hopper pump uses positive pressure pneumatic conveying to transport materials, which can return the adsorbent in the ash hopper back into the flue, allowing the adsorbent to be used for secondary adsorption and saving the amount of adsorbent consumed.

[0027] The working principle of the energy-saving type described in this invention is as follows: Industrial flue gas enters the flue, and the injection system injects adsorbent into the flue. At this time, the adsorbent comes into contact with the gaseous dioxins in the flue gas and adsorbs and removes them. Then, the flue gas is rectified by the rectifier and the airflow enters the plasma generator evenly. Here, the gaseous dioxins in the flue gas are further decomposed to generate CO2 and H2O. Then the flue gas enters the bag filter, where the adsorbent containing dioxins and dust particles are filtered and separated, achieving complete removal of solid dioxins. The comprehensive treatment effect is achieved by using adsorption, plasma decomposition and high-efficiency filtration. The purified flue gas is collected in the upper box and discharged from its tail outlet.

[0028] A high-frequency, high-voltage power supply applies high-voltage pulses to the discharge electrode, causing continuous corona discharge to generate high-density plasma, which decomposes dioxins. When the thickness of the powder cake adhering to the filter bag surface exceeds the limit, the automatic control system issues a cleaning command, and the detached adsorbent and dust fall into the ash hopper. When the flue gas temperature at the electric furnace outlet is high, the intelligent dynamic adjustment device transmits a signal to the frequency converter feeder and the high-frequency, high-voltage power supply to enhance the amount of adsorbent injected and the amount of plasma generated, thereby improving the dioxin treatment efficiency. At the same time, the return material pump accelerates the return flow rate to improve the secondary utilization rate of the adsorbent. Finally, the dioxin-containing adsorbent and dust are transported through the ash hopper to the ash silo for subsequent environmental protection treatment.

[0029] The beneficial technical effects of this invention are as follows: it organically combines adsorption technology, plasma decomposition technology, and high-efficiency filtration technology into a single device. First, gaseous dioxins are adsorbed and removed, supplemented by plasma discharge decomposition. Then, the adsorbent rich in solid dioxins and dust are subjected to high-efficiency filtration. This technology completely separates dioxins from the flue gas, achieving comprehensive treatment of both forms of dioxins. Simultaneously, the intelligent dynamic adjustment device can dynamically adjust the adsorbent injection volume, plasma generation frequency, and return material load according to the electric furnace smelting load, thereby achieving green, energy-saving, and environmentally friendly operation. It solves the problems of traditional technologies, such as limited dioxin treatment capacity, low purification efficiency, small treatment volume, high operating costs, and high energy consumption. This device is highly intelligent, highly integrated, occupies little space, achieves 100% dioxin purification and removal, has low investment, and low operating costs, making it suitable for new or retrofit projects for high-efficiency dioxin purification in industrial flue gas from scrap steel smelting and waste incineration. Attached Figure Description

[0030] Figure 1 This is an elevation view of an energy-saving dioxin multi-level control integrated device.

[0031] In the diagram: 1—Injection system; 2—Inlet horn flue; 3—Intelligent dynamic adjustment device; 4—Plasma generator; 5—Bag filter; 6—Return hopper pump; 11—Adsorbent hopper; 12—Variable frequency feeder; 13—Injector; 14—Conveying fan; 21—Shell; 22—Airflow rectifier; 41—Discharge electrode; 42—Electrode plate; 43—High frequency high voltage power supply; 51—Upper box; 52—Outlet flue; 53—Filter bag; 54—Bag cage; 55—Middle box; 56—Ash hopper; 57—Dust removal device. Detailed Implementation

[0032] As attached Figure 1 As shown, the present invention provides an energy-saving dioxin multi-stage control integrated device, which is composed of a jetting system 1, an inlet horn flue 2, an intelligent dynamic adjustment device 3, a plasma generator 4, a bag filter 5, and a return silo pump 6, forming an integrated device. The specific implementation scheme is as follows.

[0033] First, install a bag filter 5, that is, install a dust hopper 56 at the bottom of the middle box 55, install an upper box 51 at the top, install filter bags 53 and bag cages 54 on the inner tube sheet of the middle box 55, install a dust removal device 57 on the tube sheet, and install a dust collector outlet flue 52 at the tail of the upper box 51.

[0034] Second, a plasma generator 4 is installed on the air inlet side of the middle housing 55, consisting of a discharge electrode 41 and an electrode plate 42, with a high-frequency high-voltage power supply 43 installed on top. The high-frequency high-voltage power supply 43 applies high-voltage pulses to the discharge electrode 41, causing it to continuously release high-density plasma, which can further decompose gaseous dioxins. Because the electrode plate 42 is relatively short and does not accumulate dust, the electrostatic collection effect is significant.

[0035] Third, install the imported horn flue 2, and install the imported horn housing 21 on the air intake side of the plasma generator 4, with the airflow rectifier 22 installed inside.

[0036] Fourth, install the adsorbent injection system 1. A variable frequency feeder is installed under the adsorbent silo, and an injector 13 is installed under the feeder. The injector 13 is connected to the conveying fan 14 and the injection pipe. The injection pipe is built into the flue, and the injection port is in the same direction as the flue gas.

[0037] Fifth, install the return material hopper pump 6, which is connected to the ash hopper 56 at one end and to the flue at the other end.

[0038] Sixth, install the intelligent dynamic adjustment device 3. The intelligent dynamic adjustment device 3 is installed in the central control room. The electric furnace outlet flue gas temperature signal, the variable frequency feeder 12 signal, the high frequency high voltage power supply 43 signal, and the return silo pump 6 signal are connected to the intelligent dynamic adjustment device 3 through cables. The function calculation model software that imitates the neural network is pre-set, and the relevant parameters of the signals are input into the model for later use.

[0039] Seventh, start the injection system 1, conveyor fan 13, and variable frequency feed valve to deliver the adsorbent into the flue. Turn on the high-frequency high-voltage power supply 43 to supply power to the discharge electrode 41, establish a high-voltage electric field, and generate plasma through discharge. Connect the flue gas, and the device will be put into operation.

[0040] Eighth, after the resistance of the bag filter 5 reaches the upper limit, the automatic control system issues a command, and the dust removal device 57 starts to work. The dust that is removed during dust removal falls into the dust hopper 56 and is periodically discharged.

[0041] Ninth, when the electric furnace enters the oxygen blowing period, the flue gas temperature at the furnace outlet increases, and the concentration of dioxins in the flue gas increases. At this time, the intelligent dynamic adjustment device 3 sends a signal to the variable frequency feeder 12 and the high-frequency high-voltage power supply 43 to increase the adsorbent injection volume and plasma release volume, thereby improving the dioxin control effect. At this time, the return material hopper pump 6 receives the signal and increases the conveying flow rate to improve the secondary utilization rate of the adsorbent. When the electric furnace enters the slag forming, steel tapping, and charging stages, the smelting load decreases, and the flue gas temperature at the furnace outlet decreases. At this time, the intelligent dynamic adjustment device receives the signal to reduce the operating load of the dioxin control device, achieving energy-saving and environmentally friendly operation.

[0042] Tenth, when the ash content in ash hopper 56 exceeds the limit value, the adsorbent and dust particles in ash hopper 56 are discharged into the ash bin for subsequent environmental protection treatment.

[0043] The above implementation schemes are merely preferred embodiments of the present invention, but the present invention is not limited to the specific implementation details in the above schemes. Any modifications or substitutions made within the spirit and principles of the present invention shall fall within the protection scope of the present invention.

Claims

1. An energy-saving polychlorinated dibenzo-p-dioxin multistage control integrated device, characterized by The injection system (1), the inlet horn flue (2), the intelligent dynamic adjustment device (3), the plasma generator (4), the bag filter (5), and the return silo pump (6) are combined into an integrated device; the injection system (1) is installed at the front end of the inlet horn flue (2), the plasma generator (4) is installed in the inlet horn flue (2), and the bag filter (5) is installed at the rear of the plasma generator (4); the intelligent dynamic adjustment device (3) is installed in the central control room; the injection system (1) consists of an adsorbent silo (11), a frequency converter feeder (12), an injector (13), and a conveying fan (14); the plasma generator (4) consists of a linear or needle-shaped discharge electrode (41) and an electrode plate (42), and a high-frequency high-voltage power supply (43); the intelligent dynamic adjustment device (3) connects the signal to the electric furnace outlet flue gas temperature, the frequency converter feeder (12), the high-frequency high-voltage power supply (43), and the return silo pump (6).

2. The energy-saving dioxin multi-level control integrated device according to claim 1, characterized in that: A variable frequency feeder (12) is installed below the adsorbent silo (11); the ejector (13) is connected to the conveying fan (14) and the variable frequency feeder (12); the adsorbent in the adsorbent silo (11) is a porous material with abundant micropores, which is carbon-based, zeolite or polymer material; the pore size of the porous material is distributed between 1 and 20 nm.

3. The energy-saving dioxin multi-level control integrated device according to claim 1, characterized in that: The inlet horn flue (2) consists of an inlet horn housing (21) and its internal airflow rectifier (22); the rectifier (22) is a perforated plate, louver or grille; the rectifier (22) is provided in one or two layers; the inlet horn housing (21) is installed on the air intake side of the plasma generator (4).

4. The energy-saving dioxin multi-level control integrated device according to claim 1, characterized in that: The bag filter (5) includes an upper box (51), a middle box (55), an ash hopper (56), filter bags (53), bag cages (54), a dust removal device (57), and an outlet flue (52). The middle box (55) is installed at the lower part of the upper box (51), the filter bags (53) are suspended on the tube sheet of the middle box (55), the bag cages (54) are inserted into the filter bags (53), the dust removal device (57) is installed in the upper box (51), the outlet flue (52) is provided at the tail of the upper box (51), and the ash hopper (56) is installed below the middle box (55). The filter bags (53) are PM2.5 ultrafine surface layer filter bags.

5. The energy-saving dioxin multi-level control integrated device according to claim 4, characterized in that: The plasma generator (4) is installed on the air inlet side of the middle box (55); that is, the discharge electrode (41) and the electrode plate (42) are installed, and the high-frequency high-voltage power supply (43) is installed on the top.

6. The energy-saving dioxin multi-level control integrated device according to claim 1, characterized in that: The intelligent dynamic adjustment device (3) is equipped with a pre-integrated function calculation model software that mimics a neural network.

7. The energy-saving dioxin multi-level control integrated device according to claim 1, characterized in that: The return material silo pump (6) uses positive pressure pneumatic conveying to transport materials.

8. A dioxin multi-stage control method using the apparatus described in any one of claims 1-7, characterized in that: The dioxin-containing flue gas passes through the flue in sequence through the adsorbent injection system (1), plasma generator (4), and bag filter (5). First, the injection system (1) injects the adsorbent into the flue and mixes it evenly with the flue gas. At this time, more than 90% of the gaseous dioxins in the flue gas are adsorbed and removed by the adsorbent. Then, the flue gas is rectified by the rectifier (22) of the inlet horn flue (2) and enters the plasma generator (4). The plasma generator (4) uses the high voltage electric field to generate high-energy electrons and free radicals with strong chemical activity, which can decompose the remaining 10% of the gaseous dioxins in the flue gas into water and carbon dioxide. Finally, the flue gas enters the bag filter, which efficiently filters and separates the adsorbent and dust enriched with dioxins. The intelligent dynamic adjustment device (3) dynamically adjusts the adsorbent injection amount, plasma generation frequency, and return material load operation intensity according to the electric furnace smelting load. The return material hopper pump (6) returns the adsorbent in the ash hopper (56) back into the flue, so that the adsorbent can be adsorbed and utilized for secondary adsorption.

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