Fluorinated high-fluorine and high-sulfur organic waste gas and waste liquid resourceful and environmentally-friendly treatment system and method

Abstract

The application provides a fluorine chemical high-fluorine and high-sulfur organic waste gas and waste liquid resourceization and environmental protection treatment system and method. The treatment system comprises, in sequence, a burning furnace, a graphite quenching tower, an absorption tower, a first-stage water washing tower, a second-stage water washing tower, a first-stage alkali washing tower, a second-stage alkali washing tower and a wet electric dust collector. The bottom outlet of the wet electric dust collector is communicated with the second-stage alkali washing tower, the top outlet of the wet electric dust collector is communicated with the cold medium inlet of a GGH flue gas heat exchanger, the cold medium outlet of the GGH flue gas heat exchanger and the outlet of a hot blast furnace are respectively communicated with the inlet of a flue gas mixer, the outlet of the flue gas mixer is connected with the inlet of an SCR denitration reactor, the outlet of the SCR denitration reactor is communicated with the hot medium inlet of the GGH flue gas heat exchanger, and the hot medium outlet of the GGH flue gas heat exchanger is communicated with a chimney through an induced draft fan. The fluorine chemical high-fluorine and high-sulfur organic waste gas and waste liquid resourceization and environmental protection treatment system can recycle fluorine elements and sulfur elements in waste gas and waste liquid to produce sulfuric acid solution and hydrofluoric acid solution for utilization.

Description

Technical Field

[0001] This invention relates to waste gas and waste liquid treatment technology, and more particularly to a resource-based and environmentally friendly treatment system and method for high-fluorine and high-sulfur organic waste gas and waste liquid from fluorochemical industries. Background Technology

[0002] Currently, high-fluorine and high-sulfur organic waste gases and liquids from the fluorochemical industry can only be treated separately, resulting in complex processes and large equipment investments. Fluorine-containing waste gases are mainly treated using water absorption, alkaline absorption, adsorption, and dilution methods. Each of these methods has its drawbacks, and none can treat the organic components in the waste gas. Water absorption and alkaline absorption towers can only absorb specific components in the waste gas; they cannot treat organic matter that is insoluble in water or does not react with alkali solutions. Furthermore, they consume large amounts of alkali, and the resulting absorbent still requires treatment. Adsorption methods use alumina powder, activated carbon, or other solid adsorbents to adsorb harmful substances in the waste gas, but they are only suitable for low-concentration waste gases, and the solid adsorbent still needs treatment after adsorption. Fluorine-containing waste liquids are mainly treated using precipitation and adsorption methods, both targeting ionic fluorides in the waste liquid. They are ineffective at treating molecular organic matter that is insoluble in water, and both methods generate large amounts of other waste requiring additional treatment. Summary of the Invention

[0003] The purpose of this invention is to address the problems of separate treatment of fluorine-containing waste gas and waste liquid in fluorochemicals, the inability to treat organic matter in the waste gas and waste liquid, the large consumption of adsorbents and chemicals, and the generation of other waste byproducts. This invention proposes a resource-based and environmentally friendly treatment system for high-fluorine and high-sulfur organic waste gas and waste liquid in fluorochemicals. This system can simultaneously treat waste gas and waste liquid for resource recovery. The fluorine and sulfur elements in the waste gas and waste liquid are recovered and utilized through high-temperature incineration followed by water washing, producing hydrofluoric acid and sulfuric acid solutions respectively, which can be used as raw materials for fluorochemicals, generating revenue.

[0004] To achieve the above objectives, the technical solution adopted by this invention is: a resource-based and environmentally friendly treatment system for high-fluorine and high-sulfur organic waste gas and liquid in the fluorochemical industry, comprising an incinerator, a graphite quench tower, an absorption tower, a primary water scrubbing tower, a secondary water scrubbing tower, a primary alkali scrubbing tower, a secondary alkali scrubbing tower, a wet electrostatic precipitator, a GGH flue gas heat exchanger, a flue gas mixer, an SCR denitrification reactor, a hot air furnace, an induced draft fan, and a chimney; wherein the incinerator, graphite quench tower, absorption tower, primary water scrubbing tower, secondary water scrubbing tower, primary alkali scrubbing tower, secondary alkali scrubbing tower, and wet electrostatic precipitator are sequentially connected; the bottom outlet of the wet electrostatic precipitator is connected to the secondary alkali scrubbing tower, the top outlet of the wet electrostatic precipitator is connected to the cold medium inlet of the GGH flue gas heat exchanger, and the cold medium outlet and the hot air furnace outlet of the GGH flue gas heat exchanger are respectively connected to the inlet of the flue gas mixer, and the flue gas from the GGH flue gas heat exchanger and the hot air furnace is mixed in the flue gas mixer to reach the required temperature. The outlet of the flue gas mixer is connected to the inlet of the SCR denitrification reactor, the outlet of the SCR denitrification reactor is connected to the heat medium inlet of the GGH flue gas heat exchanger, and the heat medium outlet of the GGH flue gas heat exchanger is connected to the chimney through an induced draft fan.

[0005] Furthermore, the incinerator 1 has an inverted L-shaped structure, including a horizontal section and a vertical section connected together. A combined burner is installed at the head of the horizontal section. The combined burner is connected to a combustion air duct, a natural gas duct, a waste gas buffer tank, and a waste liquid buffer tank. Specifically, the combustion air duct is connected to the combined burner via an incinerator combustion air fan; the waste liquid buffer tank is connected to the waste liquid spray gun of the combined burner via a waste liquid booster pump.

[0006] Furthermore, the graphite quench tower includes: an upper graphite section and a lower fluoropolymer-lined steel storage tank. The fluoropolymer-lined steel storage tank stores the circulating liquid required for spraying. The lower part of the fluoropolymer-lined steel storage tank is connected to the heat medium inlet of the graphite heat exchanger of the quench tower via a quench tower spray pump. The heat medium outlet of the graphite heat exchanger of the quench tower is connected to the nozzle at the top of the graphite section. The circulating chilled water supply is connected to the cold medium inlet of the graphite heat exchanger of the quench tower. The cold medium outlet of the graphite heat exchanger of the quench tower is connected to the circulating chilled water return, using low-temperature chilled water to remove heat from the circulating liquid of the quench tower.

[0007] Furthermore, the fluorochemical high-fluorine and high-sulfur organic waste gas and waste liquid resource utilization and environmental protection treatment system also includes an elevated water tank. The bottom of the elevated water tank is higher than the top of the graphite quench tower. The graphite section of the graphite quench tower is connected to the elevated water tank. In the event of water or power outage, the water stored in the elevated water tank can enter the graphite quench tower by its own gravity to protect the graphite quench tower.

[0008] Furthermore, the absorption tower is a packed tower, with two layers of packing material inside the upper part of the absorption tower, and a spray layer arranged on each layer of packing material; a storage tank is set in the lower part of the absorption tower to store the circulating liquid required for spraying. The storage tank is connected to the heat medium inlet of the graphite heat exchanger of the absorption tower through the absorption tower spray pump. The heat medium outlet of the graphite heat exchanger of the absorption tower is connected to the spray layer. The circulating chilled water supply is connected to the cold medium inlet of the graphite heat exchanger of the absorption tower. The cold medium outlet of the graphite heat exchanger of the absorption tower is connected to the circulating chilled water return water. The heat of the circulating liquid in the absorption tower is carried away by the low temperature chilled water.

[0009] Furthermore, both the primary and secondary water washing towers are packed towers. The upper part of the water washing tower has two layers of packing to increase the contact area between the flue gas and the circulating liquid. An internal circulation method is adopted, and a spray layer is arranged above each layer of packing. A storage tank is set at the bottom of the water washing tower to store the circulating liquid required for spraying.

[0010] Furthermore, both the primary and secondary alkaline scrubbing towers are packed towers. The upper part of the alkaline scrubbing tower has two layers of packing to increase the contact area between the flue gas and the circulating liquid. An internal circulation method is adopted, and a spray layer is arranged on each layer of packing. A storage tank is set at the bottom of the alkaline scrubbing tower to store the circulating liquid required for spraying.

[0011] Furthermore, a demister is installed at the flue gas outlet at the top of the absorption tower, the primary water washing tower, the secondary water washing tower, the primary alkaline washing tower, and the secondary alkaline washing tower. The demister can collect (capture) large droplets carried in the flue gas, improving the operating conditions of subsequent equipment.

[0012] Furthermore, the head of the hot air furnace is equipped with an integrated natural gas burner, and natural gas is connected to the integrated natural gas burner via a pipeline. The additional combustion air required is provided by the hot air furnace combustion fan.

[0013] Furthermore, urea is used as the denitrification reducing agent. The fluorochemical high-fluorine and high-sulfur waste gas and waste liquid resource utilization and environmental protection treatment system also includes a urea solution preparation tank. The urea solution preparation tank is connected to the urea solution storage tank through a urea solution transfer pump, and then connected to the hot air furnace through a urea solution spray pump.

[0014] Another objective of this invention is to disclose a resource-based and environmentally friendly treatment method for high-fluorine and high-sulfur organic waste gas and liquid in fluorochemicals. The method involves recovering and utilizing the fluorine and sulfur elements in the waste gas and liquid by first incinerating at high temperature and then washing with water, thereby producing hydrofluoric acid and sulfuric acid solutions, which can be used as raw materials for fluorochemicals.

[0015] Specifically, the method for resource-based and environmentally friendly treatment of high-fluorine and high-sulfur organic waste gas and waste liquid in the fluorochemical industry of the present invention includes the following steps: Step 1. Organic waste gas, waste liquid, and natural gas are combusted with air in the incinerator. The amount of natural gas burned or the flow rate of combustion air is controlled to ensure that the temperature of the high-temperature flue gas in the incinerator is 1100~1200℃. At this temperature, all the harmful substances with high fluorine and high sulfur content in the organic waste gas and waste liquid undergo oxidation reaction with oxygen and decompose into carbon dioxide, water, hydrogen fluoride, and sulfur trioxide, etc. Step 2. The flue gas passes through the horizontal section of the incinerator to the vertical section, with a residence time of not less than 2 seconds (preferably 2-3 seconds). It is then drawn out from the top of the vertical section and sent to the graphite quench tower. The circulating liquid in the carbon steel fluoropolymer-lined storage section at the bottom of the graphite quench tower is sent to the graphite heat exchanger of the quench tower by the quench tower spray pump. After being cooled by the circulating chilled water, it is sent to the inlet of the graphite quench tower and sprayed into the flue gas, reducing the flue gas temperature from 1100-1200℃ to 70-80℃ in less than 1 second (preferably 0-1 second). The sulfur trioxide in the flue gas is absorbed. Step 3. The flue gas is drawn out from the middle of the graphite quench tower and enters the absorption tower; the circulating liquid of the absorption tower is sent to the graphite heat exchanger of the absorption tower by the absorption tower spray pump and cooled by the circulating chilled water before being sent to each spray layer. The circulating liquid and the flue gas flow counterclockwise in the absorption tower and come into full contact in the packing layer to continue to absorb sulfur trioxide in the flue gas. Step 4. After exiting the top of the absorption tower, the flue gas enters the primary water scrubbing tower and the secondary water scrubbing tower sequentially through the flue. The circulating liquid of the primary water scrubbing tower is sent to the spray layer by the primary water scrubbing tower spray pump, and the circulating liquid of the secondary water scrubbing tower is sent to the spray layer by the secondary water scrubbing tower spray pump. In the primary and secondary water scrubbing towers, the flue gas and the circulating liquid flow counterclockwise and come into full contact in the packing layer. The hydrogen fluoride in the flue gas is absorbed to produce hydrofluoric acid solution. Step 5. After exiting the top of the secondary water scrubbing tower, the flue gas enters the primary and secondary alkaline scrubbing towers sequentially through the flue. The circulating liquid of the primary alkaline scrubbing tower is sent to the spray layer by the primary alkaline scrubbing tower spray pump, and the circulating liquid of the secondary alkaline scrubbing tower is sent to the spray layer by the secondary alkaline scrubbing tower spray pump. In the primary and secondary alkaline scrubbing towers, the flue gas and the circulating liquid flow in opposite directions, making full contact within the packing layer to remove residual acidic gases from the flue gas. Step 6. After the flue gas is drawn from the top of the secondary alkaline scrubbing tower, it enters the wet electrostatic precipitator. The particulate matter and water droplets in the flue gas fall onto the dust collector and are periodically washed off by backwash water.

[0016] Step 7. After exiting the wet electrostatic precipitator, the flue gas enters the GGH flue gas heat exchanger, where it exchanges heat with the denitrified flue gas to preheat the flue gas temperature to 130~140℃ (preferably 140℃). Then, it enters the flue gas mixer. In the mixer, the flue gas mixes with the high-temperature flue gas from the hot blast stove, resulting in a mixed flue gas temperature of 210~220℃ (preferably 220℃). The hot blast stove uses natural gas to generate hot air. The urea solution in the urea solution preparation tank is pumped to the urea solution storage tank, and then pumped to the hot blast stove via a urea solution spray pump. After being injected, the urea solution is decomposed by the high-temperature flue gas in the hot air furnace, producing ammonia. The 210-220°C flue gas mixed in the flue gas mixer enters the SCR denitrification reactor, where denitrification is achieved under the action of the catalyst. The denitrified 210-220°C flue gas returns to the GGH flue gas heat exchanger, where it is used as a heat medium to heat the low-temperature flue gas from the wet electrostatic precipitator, while simultaneously reducing its own temperature from 210-220°C to 140-150°C. The flue gas is then sent to the chimney by the induced draft fan for discharge. At this point, all pollutants in the flue gas meet the emission standards, and there is no white smoke coming out of the chimney.

[0017] Furthermore, the organic waste gas and waste liquid are high-fluorine and high-sulfur organic waste gas and waste liquid from fluorochemical industries, and the organic waste gas and waste liquid mainly contain one or more of hydrogen fluoride, fluoroethylene, fluorosulfonic acid, fluoroethylene polymer, difluoroethane, trifluoromethane, tetrafluoroethylene and hexafluoropropylene.

[0018] Further, in step 1, the waste liquid is first temporarily stored in a waste liquid buffer tank to stabilize its flow and pressure. Then, it is pressurized by a waste liquid booster pump and sent to the waste liquid spray gun of the combined burner. After being atomized by compressed air, it is sprayed into the horizontal section of the incinerator. Simultaneously, the waste gas is sent to the waste gas buffer tank through a pipeline. The waste gas buffer tank adopts a water seal method. After passing through the water seal, the waste gas is sent to the combined burner through a pipeline. Natural gas is sent to the combined burner through a pipeline. The air required for combustion is sent to the combined burner by a combustion air blower. The waste gas, waste liquid, and natural gas burn with air in the incinerator, releasing heat. The combustion rate of natural gas or the flow rate of combustion air is controlled according to the actual situation to ensure that the flue gas temperature in the incinerator is not lower than 1100℃ (1100~1200℃). At this temperature, all the harmful substances with high fluorine and high sulfur content in the waste gas and waste liquid undergo oxidation reaction with oxygen, decomposing into carbon dioxide, water, hydrogen fluoride, and sulfur trioxide, etc.

[0019] Further, in step 2, the flue gas flows from the horizontal section to the vertical section of the incinerator, with a residence time of not less than 2 seconds (2-3 seconds). It is then drawn from the top of the vertical section and sent to the graphite quench tower. The graphite quench tower consists of an upper graphite quench section and a lower carbon steel fluoropolymer-lined liquid storage section. The quench section is made of impregnated graphite and has an external water-cooled jacket, using circulating water for cooling and protection. The lower carbon steel fluoropolymer-lined liquid storage section stores circulating liquid, which is pumped to the graphite heat exchanger of the quench tower by a spray pump. After being cooled by the circulating chilled water, the liquid is injected into the flue gas at the inlet of the graphite quench tower, reducing the flue gas temperature from 1100℃ (1100-1200℃) to 70-80℃ in less than 1 second (0-1 second). Utilizing the property that sulfur trioxide in the flue gas can react with water to form sulfuric acid, the sulfur trioxide in the flue gas is absorbed.

[0020] Further, in step 3, the flue gas is drawn from the middle of the graphite quench tower and enters the absorption tower. The absorption tower adopts a packed tower type, with two layers of packing inside. Each layer of packing has a spray layer, and a liquid storage section is set at the bottom. The circulating liquid is sent to the graphite heat exchanger of the absorption tower by the absorption tower spray pump, where it is cooled by the circulating chilled water and then sent to each spray layer. The circulating liquid and flue gas in the absorption tower flow counterclockwise, making full contact within the packing layer to continue absorbing sulfur trioxide in the flue gas. After passing through the graphite quench tower and the absorption tower, almost all the sulfur trioxide in the flue gas is absorbed, producing sulfuric acid solution, which is discharged from the bottom of the graphite quench tower. Makeup water enters through the absorption tower and is supplied to the graphite quench tower through the overflow pipe between the absorption tower and the graphite quench tower. At the graphite quench tower and the absorption tower, due to the high temperature of the flue gas, the solubility of hydrogen fluoride gas in the flue gas is very low. At this time, most of the recovered circulating liquid is sulfur trioxide, which reacts with water to produce sulfuric acid, and hydrogen fluoride gas enters the subsequent equipment.

[0021] Further, in step 4, after the flue gas exits from the top of the absorption tower, it sequentially enters the primary and secondary water scrubbing towers via a flue. The primary and secondary water scrubbing towers are arranged in series, both using a packed tower type with two layers of packing. Each layer has a spray layer, and a liquid storage section at the bottom. The circulating liquid from the primary water scrubbing tower is pumped to the spray layer via a primary water scrubbing tower spray pump, and the circulating liquid from the secondary water scrubbing tower is pumped to the spray layer via a secondary water scrubbing tower spray pump. Inside the primary and secondary water scrubbing towers, the flue gas and circulating liquid flow counter-currently, making full contact within the packing layers. As the flue gas temperature decreases, the solubility of hydrogen fluoride increases significantly, absorbing the hydrogen fluoride in the flue gas to produce a hydrofluoric acid solution. The generated hydrofluoric acid solution is discharged from the bottom of the primary water scrubbing tower. Makeup water enters through the secondary water scrubbing tower and is supplied to the primary absorption tower via an overflow pipe between the primary and secondary water scrubbing towers. Demisters are installed at the top of the primary and secondary water scrubbing towers to prevent large water droplets carried by the flue gas from entering subsequent equipment.

[0022] Further, in step 5, after exiting the top of the secondary water scrubbing tower, the flue gas sequentially enters the primary and secondary alkaline scrubbing towers via a flue. The primary and secondary alkaline scrubbing towers are arranged in series, both using a packed tower type with two layers of packing. Each packing layer has a spray layer, and a storage section is located at the bottom. The circulating liquid from the primary alkaline scrubbing tower is pumped to the spray layer, and the circulating liquid from the secondary alkaline scrubbing tower is pumped to the spray layer. Inside the primary and secondary alkaline scrubbing towers, the flue gas and circulating liquid flow counter-currently, making full contact within the packing layers. The alkali in the circulating liquid reacts with the acidic gases in the flue gas, efficiently removing the acidic gases. Industrial water and alkali solution are respectively piped to the storage sections of the primary and secondary alkaline scrubbing towers to prepare circulating liquids of appropriate concentrations. After a period of operation, the circulating liquid is discharged, and fresh circulating liquid is prepared. Two layers of demisters are installed at the top of the primary and secondary alkaline scrubbing towers to prevent large water droplets carried by the flue gas from entering subsequent equipment.

[0023] Further, in step 6, the flue gas is drawn from the top of the secondary alkaline scrubbing tower and enters the wet electrostatic precipitator. High-voltage discharge is used at the inlet of the wet electrostatic precipitator to charge the water droplets and particulate matter carried in the flue gas and then they enter the anode tube. Under the action of the electric field in the anode tube, the particulate matter and water droplets in the flue gas fall onto the dust collector and are periodically washed off by backwash water.

[0024] Further, in step 7, after exiting the wet electrostatic precipitator, the flue gas enters the GGH flue gas heat exchanger, where it exchanges heat with the denitrified flue gas to preheat its temperature to approximately 140°C (130~140°C), and then enters the flue gas mixer. In the mixer, the flue gas mixes with the high-temperature flue gas from the hot blast stove, resulting in a mixed flue gas temperature of approximately 220°C (210~220°C). The hot blast stove uses natural gas to generate hot air, which is piped to the burner. The required air is supplied by the hot blast stove's combustion fan. Solid urea is added to the urea solution preparation tank, dissolved in water to prepare a urea solution of appropriate concentration, pumped to the urea solution storage tank, and then sprayed into the hot blast stove via a urea solution spray pump. After atomization, the urea solution is sprayed into the hot blast stove, where the high-temperature flue gas decomposes it, producing ammonia. The 220℃ (210~220℃) flue gas, mixed in the flue gas mixer, enters the SCR denitrification reactor. Under the action of the catalyst, the nitrogen oxides in the flue gas undergo a reduction reaction with ammonia, reducing the nitrogen oxides to nitrogen and water, thus achieving denitrification. After denitrification, the 220℃ (210~220℃) flue gas returns to the GGH flue gas heat exchanger, where it serves as a heat medium to heat the low-temperature flue gas exiting the wet electrostatic precipitator. Simultaneously, it lowers its own temperature from 220℃ (210~220℃) to 140~150℃, and is then sent to the chimney for emission by the induced draft fan. At this point, all pollutants in the flue gas meet emission standards, and no white smoke is emitted from the chimney.

[0025] The present invention provides a resource-based and environmentally friendly treatment system and method for high-fluorine and high-sulfur waste gas and waste liquid in the fluorochemical industry, which has the following advantages compared with the prior art: 1) This invention enables resource recovery. In the incinerator, fluorine and sulfur elements in the waste gas and waste liquid are converted into hydrogen fluoride and sulfur trioxide respectively through oxidation reaction. Then, sulfur trioxide is absorbed in the quench tower and absorption tower to produce sulfuric acid solution. Hydrogen fluoride is absorbed in the primary water washing tower and secondary water washing tower to produce hydrofluoric acid solution for recycling.

[0026] 2) This invention utilizes the different solubilities of sulfur trioxide and hydrogen fluoride at different temperatures to achieve staged recovery of sulfur trioxide and hydrogen fluoride from flue gas, enabling preliminary separation of the recovered sulfuric acid and hydrofluoric acid solutions. The quench tower and absorption tower operate at 70-80℃. At this temperature, the solubility of hydrofluoric acid is very low, while the reaction of sulfur trioxide with water to form sulfuric acid is independent of temperature. Sulfur trioxide is largely absorbed in the quench tower and absorption tower, producing a sulfuric acid solution. The primary and secondary water washing towers operate at 40-50℃. At this temperature, the solubility of hydrogen fluoride is significantly increased. After passing through the primary and secondary water washing towers, the hydrogen fluoride is almost completely absorbed, producing a hydrofluoric acid solution.

[0027] 3) This invention utilizes recycled sulfuric acid and hydrofluoric acid solutions for production use, significantly reducing the amount of alkali required for tail gas neutralization and thus greatly reducing operating costs. Furthermore, the inorganic salts produced during neutralization are not only inexpensive but also require investment in equipment for separation and purification.

[0028] 4) The present invention is equipped with a GGH flue gas heat exchanger, which can use the high temperature flue gas after denitrification to preheat the low temperature flue gas after the wet electrostatic precipitator, thereby reducing the fuel consumption of the hot blast stove and lowering the operating costs.

[0029] 5) This invention does not generate wastewater during operation, and can achieve zero wastewater discharge. Attached Figure Description

[0030] Figure 1 A schematic diagram of a resource-based and environmentally friendly treatment system for high-fluorine and high-sulfur organic waste gas and waste liquid in the fluorochemical industry. Figure 2 This is a flowchart of a resource-based and environmentally friendly treatment system for high-fluorine and high-sulfur organic waste gas and liquid in the fluorochemical industry.

[0031] Serial number and name: 1. Incinerator; 2. Graphite quench tower; 3. Absorption tower; 4. Primary water scrubbing tower; 5. Secondary water scrubbing tower; 6. Primary alkaline scrubbing tower; 7. Secondary alkaline scrubbing tower; 8. Wet electrostatic precipitator; 9. GGH flue gas heat exchanger; 10. Flue gas mixer; 11. SCR denitrification reactor; 12. Hot air furnace; 13. Exhaust fan; 14. Chimney; 15. Waste liquid buffer tank; 16. Waste gas buffer tank; 17. Urea solution preparation tank; 18. Urea solution storage tank; 9. High-level water tank; 20. Combustion fan for incinerator; 21. Combustion fan for hot air furnace; 22. Waste liquid booster pump; 23. Quenching tower spray pump; 24. Absorption tower spray pump; 25. Primary water washing tower spray pump; 26. Secondary water washing tower spray pump; 27. Primary alkali washing tower spray pump; 28. Secondary alkali washing tower spray pump; 29. ​​Urea solution transfer pump; 30. Urea solution spray pump; 31. Quenching tower graphite heat exchanger; 32. Absorption tower graphite heat exchanger. Detailed Implementation

[0032] The present invention will be further described below with reference to the embodiments: Example 1

[0033] This embodiment discloses a resource-based and environmentally friendly treatment system for high-fluorine and high-sulfur organic waste gas and waste liquid in the fluorochemical industry, such as... Figure 1-2 As shown, the system includes: an incinerator 1, a graphite quench tower 2, an absorption tower 3, a primary water scrubbing tower 4, a secondary water scrubbing tower 5, a primary alkali scrubbing tower 6, a secondary alkali scrubbing tower 7, a wet electrostatic precipitator 8, a GGH flue gas heat exchanger 9, a flue gas mixer 10, an SCR denitrification reactor 11, a hot air furnace 12, an induced draft fan 13, and a chimney 14; wherein the incinerator 1, graphite quench tower 2, absorption tower 3, primary water scrubbing tower 4, secondary water scrubbing tower 5, primary alkali scrubbing tower 6, secondary alkali scrubbing tower 7, and wet electrostatic precipitator 8 are connected sequentially; the bottom outlet of the wet electrostatic precipitator 8 is connected to... The lower storage tank of the secondary alkaline scrubbing tower 7 is connected. The top outlet of the wet electrostatic precipitator 8 is connected to the cold medium inlet of the GGH flue gas heat exchanger 9. The cold medium outlet of the GGH flue gas heat exchanger 9 and the outlet of the hot air furnace 12 are respectively connected to the inlet of the flue gas mixer 10. The outlet of the flue gas mixer 10 is connected to the inlet of the SCR denitrification reactor 11. The outlet of the SCR denitrification reactor 11 is connected to the hot medium inlet of the GGH flue gas heat exchanger 9. The hot medium outlet of the GGH flue gas heat exchanger 9 is connected to the chimney 14 through the induced draft fan 13.

[0034] The incinerator 1 has an insulated furnace wall structure. The shell is made of carbon steel, and the inner lining of the furnace wall consists of refractory castable, insulating castable, and aluminosilicate fiber felt, in sequence. A suitable refractory castable is selected to prevent hydrogen fluoride in the flue gas from reacting with the substances in the castable and damaging the furnace wall. The incinerator 1 has an inverted L-shaped structure, divided into a horizontal section and a vertical section. A combined burner is installed at the head of the horizontal section for easy operation. The combined burner is connected to the combustion air duct, natural gas duct, waste liquid buffer tank 15, and waste gas buffer tank 16. Specifically, the combustion air duct is connected to the combined burner via a combustion air fan 20; the waste liquid buffer tank 15 is connected to the waste liquid spray gun of the combined burner via a waste liquid booster pump 22.

[0035] The graphite quench tower 2 is divided into two parts: the upper part is a graphite section, and the lower part is a steel-lined fluorine storage tank. The steel-lined fluorine storage tank stores the circulating liquid required for spraying. The lower part of the steel-lined fluorine storage tank is connected to the heat medium inlet of the graphite heat exchanger 31 of the quench tower through the quench tower spray pump 23. The heat medium outlet of the graphite heat exchanger 31 of the quench tower is connected to the top nozzle of the graphite section. The circulating chilled water supply is connected to the cold medium inlet of the graphite heat exchanger 31 of the quench tower. The cold medium outlet of the graphite heat exchanger 31 of the quench tower is connected to the circulating chilled water return. The low-temperature chilled water carries away the heat of the circulating liquid in the quench tower. The fluorochemical high-fluorine and high-sulfur organic waste gas and waste liquid resource utilization and environmental protection treatment system also includes an elevated water tank 19. The bottom of the elevated water tank 19 is higher than the top of the graphite quench tower 2. The graphite section of the graphite quench tower 2 is connected to the elevated water tank 19. In the event of water or power outage, the water stored in the elevated water tank 19 can enter the graphite quench tower 2 by its own gravity to protect the graphite quench tower 2.

[0036] The absorption tower 3 is a packed tower with two layers of packing, each layer of which is covered with a spray layer. A storage tank is provided at the bottom of the absorption tower to store the circulating liquid required for spraying. The storage tank is connected to the absorption tower spray pump 24 and the absorption tower graphite heat exchanger 32, and the heat of the circulating liquid in the absorption tower is removed by low-temperature chilled water.

[0037] Both the primary water washing tower 4 and the secondary water washing tower 5 are packed towers, with two layers of packing inside, and a spray layer arranged on each layer of packing. A storage tank is set at the bottom of the water washing tower to store the circulating liquid required for spraying.

[0038] Both the primary alkaline scrubbing tower 6 and the secondary alkaline scrubbing tower 7 are packed towers, with two layers of packing inside, and a spray layer arranged on each layer of packing. A storage tank is provided at the bottom of the alkaline scrubbing tower to store the circulating liquid required for spraying.

[0039] Demisting devices are installed at the top flue gas outlets of the absorption tower 3, primary water washing tower 4, secondary water washing tower 5, primary alkaline washing tower 6, and secondary alkaline washing tower 7. These devices can collect large droplets carried in the flue gas, improving the operating conditions of downstream equipment. The demisting devices include, but are not limited to, baffle demisters and wire mesh demisters.

[0040] The cold medium of the GGH flue gas heat exchanger 9 is the low-temperature flue gas after passing through the wet electrostatic precipitator 8, and the hot medium is the high-temperature flue gas after passing through the SCR denitrification reactor 11. Heat is exchanged in the GGH flue gas heat exchanger 9 to preheat the low-temperature flue gas and reduce the fuel consumption of the hot blast stove 12.

[0041] The flue gas mixer 10 is connected to the GGH flue gas heat exchanger 9 and the hot air furnace 12 respectively. The flue gas from the GGH flue gas heat exchanger 9 and the hot air furnace 12 is mixed in the flue gas mixer 10 to reach the required temperature.

[0042] The head of the hot air furnace 12 is equipped with an integrated natural gas burner. Natural gas is connected to the integrated natural gas burner via a pipeline. Additional combustion air is provided by the hot air furnace combustion fan 21.

[0043] The denitrification reducing agent is urea. The fluorochemical high-fluorine and high-sulfur organic waste gas and waste liquid resource utilization environmental protection treatment system also includes a urea solution preparation tank 17. The urea solution preparation tank 17 is connected to the urea solution storage tank 18 through the urea solution transfer pump 29, and then connected to the hot air furnace (12) through the urea solution spray pump 30. The urea solution decomposes in the hot air furnace 12 to produce ammonia.

[0044] Example 2 This invention discloses a resource-based and environmentally friendly treatment method for high-fluorine and high-sulfur organic waste gas and liquid in the fluorochemical industry. The method utilizes the system described in Example 1, and the specific steps are as follows: The waste liquid is first temporarily stored in the waste liquid buffer tank 15 to stabilize its flow and pressure. Then, it is pressurized by the waste liquid booster pump 22 and sent to the waste liquid spray gun of the combined burner. After being atomized by compressed air, it is sprayed into the horizontal section of the incinerator 1. At the same time, the waste gas is sent to the waste gas buffer tank 16 through a pipeline. The waste gas buffer tank 16 adopts a water seal. After passing through the water seal, the waste gas is sent to the combined burner through a pipeline. Natural gas is sent to the combined burner through a pipeline. The air required for combustion is sent to the combined burner by the combustion air fan 20. The waste gas, waste liquid, and natural gas are combusted with air in the incinerator 1, releasing heat. The amount of natural gas burned or the flow rate of the combustion air is controlled according to the actual situation to ensure that the flue gas temperature in the incinerator is 1100~1200℃. At this temperature, all the harmful substances with high fluorine and high sulfur content in the waste gas and waste liquid undergo oxidation reaction with oxygen, decomposing into carbon dioxide, water, hydrogen fluoride, and sulfur trioxide, etc.

[0045] High-temperature flue gas flows from the horizontal section of incinerator 1 to the vertical section, with a residence time of 2-3 seconds. It is then drawn from the top of the vertical section and sent to the graphite quench tower 2. The graphite quench tower 2 consists of an upper graphite quench section and a lower carbon steel fluoropolymer-lined liquid storage section. The quench section is made of impregnated graphite and has an external water-cooled jacket, using circulating water for cooling and protection. The lower carbon steel fluoropolymer-lined liquid storage section stores circulating liquid, which is sent to the graphite heat exchanger 31 of the quench tower by the quench tower spray pump 23. After being cooled by the circulating chilled water, the liquid is injected into the flue gas at the inlet of the graphite quench tower 2, reducing the flue gas temperature from 1100-1200℃ to 70-80℃ within 0-1 seconds. Utilizing the property that sulfur trioxide in the flue gas can react with water to form sulfuric acid, the sulfur trioxide in the flue gas is absorbed. The flue gas is then drawn from the middle of the graphite quench tower 2 and enters the absorption tower 3.

[0046] Absorber 3 is a packed tower type with two layers of packing inside. Each layer has a spray layer, and a liquid storage section is located at the bottom. The circulating liquid is sent to the graphite heat exchanger 32 of the absorber tower by the absorber tower spray pump 24, where it is cooled by the circulating chilled water before being sent to each spray layer. The circulating liquid and flue gas flow counterclockwise in absorber 3, making full contact within the packing layer to continue absorbing sulfur trioxide in the flue gas. After passing through graphite quench tower 2 and absorber 3, almost all the sulfur trioxide in the flue gas is absorbed, producing sulfuric acid solution, which is discharged from the bottom of graphite quench tower 2. Makeup water enters through absorber 3 and is supplied to graphite quench tower 2 through the overflow pipe between absorber 3 and graphite quench tower 2. At graphite quench tower 2 and absorber 3, due to the high temperature of the flue gas, the solubility of hydrogen fluoride gas in the flue gas is very low. At this time, most of the recovered circulating liquid is sulfur trioxide, which reacts with water to produce sulfuric acid, and hydrogen fluoride gas enters the subsequent equipment.

[0047] After exiting the top of the absorption tower 3, the flue gas is introduced into the primary water scrubbing tower 4 and the secondary water scrubbing tower 5 via a flue. The primary and secondary water scrubbing towers 4 and 5 are arranged in series, both using a packed tower type with two layers of packing. Each layer has a spray layer on top and a liquid storage section at the bottom. The circulating liquid from the primary water scrubbing tower 4 is sent to the spray layer via the primary water scrubbing tower spray pump 25, and the circulating liquid from the secondary water scrubbing tower 5 is sent to the spray layer via the secondary water scrubbing tower spray pump 26. Inside the primary and secondary water scrubbing towers 4 and 5, the flue gas and circulating liquid flow counter-currently, making full contact within the packing layers. As the flue gas temperature decreases, the solubility of hydrogen fluoride increases significantly, absorbing the hydrogen fluoride in the flue gas to produce a hydrofluoric acid solution. The generated hydrofluoric acid solution is discharged from the bottom of the primary water scrubbing tower 4. Makeup water enters through the secondary water scrubbing tower 5 and is supplied to the primary absorption tower 4 via an overflow pipe between the primary and secondary water scrubbing towers 4 and 5. Demisters are installed at the top of the primary water scrubbing tower 4 and the secondary water scrubbing tower 5 to prevent flue gas from carrying larger water droplets into subsequent equipment.

[0048] After exiting the top of the secondary water scrubbing tower 5, the flue gas is introduced into the primary alkaline scrubbing tower 6 and the secondary alkaline scrubbing tower 7 via a flue. The primary and secondary alkaline scrubbing towers 6 and 7 are arranged in series, both using a packed tower type with two layers of packing. Each layer has a spray layer on top and a liquid storage section at the bottom. The circulating liquid from the primary alkaline scrubbing tower 6 is sent to the spray layer via the primary alkaline scrubbing tower spray pump 27, and the circulating liquid from the secondary alkaline scrubbing tower 7 is sent to the spray layer via the secondary alkaline scrubbing tower spray pump 28. Inside the primary and secondary alkaline scrubbing towers 6 and 7, the flue gas and circulating liquid flow counter-currently, making full contact within the packing layers. The alkali in the circulating liquid reacts with the acidic gases in the flue gas, efficiently removing residual acidic gases. Industrial water and alkaline solution are respectively piped to the liquid storage sections of the primary and secondary alkaline scrubbing towers 6 and 7 to prepare circulating liquids of appropriate concentrations. After a period of operation, the circulating liquid is discharged and freshly prepared. Two layers of demisters are installed at the top of the primary alkaline scrubbing tower 6 and the secondary alkaline scrubbing tower 7 to prevent the flue gas from carrying larger water droplets into subsequent equipment.

[0049] After the flue gas is drawn from the top of the secondary alkaline scrubbing tower 7, it enters the wet electrostatic precipitator 8. At the inlet of the wet electrostatic precipitator 8, high voltage discharge is used to charge the water droplets and particulate matter carried in the flue gas and then enter the anode tube. Under the action of the electric field in the anode tube, the particulate matter and water droplets in the flue gas fall onto the dust collector and are periodically washed off by backwash water.

[0050] After exiting the wet electrostatic precipitator 8, the flue gas enters the GGH flue gas heat exchanger 9, where it exchanges heat with the denitrified flue gas to preheat its temperature to 130-140℃. Then, it enters the flue gas mixer 10. In the mixer 10, the flue gas mixes with the high-temperature flue gas from the hot blast stove 12, resulting in a mixed flue gas temperature of 210-220℃. The hot blast stove 12 uses natural gas to generate hot air, which is piped to the burner. The required air is supplied by the hot blast stove combustion fan 21. Solid urea is added to the urea solution preparation tank 17, dissolved in water to prepare a urea solution of appropriate concentration, and then pumped to the urea solution storage tank 18 via the urea solution delivery pump 29. From there, it is sent to the hot blast stove 12 via the urea solution spray pump 30, atomized, and sprayed into the hot blast stove 12. The high-temperature flue gas in the hot blast stove 12 decomposes the urea solution, producing ammonia. The mixed flue gas at 210-220℃ enters the SCR denitrification reactor 11. Under the action of the catalyst, the nitrogen oxides in the flue gas undergo a reduction reaction with ammonia, reducing the nitrogen oxides to nitrogen and water, thus achieving the purpose of denitrification. After denitrification, the 210-220℃ flue gas returns to the GGH flue gas heat exchanger 9, where it serves as a heat medium to heat the low-temperature flue gas exiting the wet electrostatic precipitator 8. At the same time, it lowers its own temperature from 210-220℃ to 140-150℃ and is then sent to the chimney 14 for discharge by the induced draft fan 13. At this point, all pollutants in the flue gas meet the emission standards, and there is no white smoke coming out of the chimney.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for the resource-based and environmentally friendly treatment of high-fluorine and high-sulfur organic waste gas and liquid in the fluorochemical industry, characterized in that, Includes the following steps: Step 1. Organic waste gas, waste liquid and natural gas are burned with air in the incinerator (1). The amount of natural gas burned or the flow rate of combustion air is controlled to ensure that the temperature of the high-temperature flue gas in the incinerator is 1100~1200℃. At this temperature, all the high-fluorine and high-sulfur harmful substances in the organic waste gas and waste liquid are oxidized with oxygen and decomposed into carbon dioxide, water, hydrogen fluoride and sulfur trioxide. Step 2. The flue gas passes through the horizontal section of the incinerator (1) to the vertical section. The flue gas residence time is not less than 2 seconds. It is drawn out from the top of the vertical section and sent to the graphite quench tower (2). The circulating liquid in the carbon steel fluorine-lined storage section at the bottom of the graphite quench tower (2) is sent to the graphite heat exchanger (31) of the quench tower by the quench tower spray pump (23). After being cooled by the circulating chilled water, it is sent to the inlet of the graphite quench tower (2) and sprayed into the flue gas, reducing the flue gas temperature from 1100~1200℃ to 70~80℃ in less than 1 second. The sulfur trioxide in the flue gas is absorbed. Step 3. The flue gas is drawn out from the middle of the graphite quench tower (2) and enters the absorption tower (3); the circulating liquid of the absorption tower (3) is sent to the graphite heat exchanger (32) of the absorption tower by the absorption tower spray pump (24) and cooled by the circulating chilled water before being sent to each spray layer. The circulating liquid and the flue gas flow counterclockwise in the absorption tower (3) and come into full contact in the packing layer to continue to absorb sulfur trioxide in the flue gas. Step 4. After the flue gas exits from the top of the absorption tower (3), it enters the primary water scrubbing tower (4) and the secondary water scrubbing tower (5) in sequence through the flue. The circulating liquid of the primary water scrubbing tower (4) is sent to the spray layer by the primary water scrubbing tower spray pump (25), and the circulating liquid of the secondary water scrubbing tower (5) is sent to the spray layer by the secondary water scrubbing tower spray pump (26). In the primary water scrubbing tower (4) and the secondary water scrubbing tower (5), the flue gas and the circulating liquid flow in opposite directions and come into full contact in the packing layer. The hydrogen fluoride in the flue gas is absorbed to produce hydrofluoric acid solution. The operating temperature of the primary water scrubbing tower and the secondary water scrubbing tower is 40~50℃. Step 5. After the flue gas exits from the top of the secondary water scrubbing tower (5), it enters the primary alkaline scrubbing tower (6) and the secondary alkaline scrubbing tower (7) in sequence through the flue. The circulating liquid of the primary alkaline scrubbing tower (6) is sent to the spray layer by the primary alkaline scrubbing tower spray pump (27), and the circulating liquid of the secondary alkaline scrubbing tower (7) is sent to the spray layer by the secondary alkaline scrubbing tower spray pump (28). In the primary alkaline scrubbing tower (6) and the secondary alkaline scrubbing tower (7), the flue gas and the circulating liquid flow in opposite directions and come into full contact in the packing layer to remove the residual acidic gas in the flue gas. Step 6. After the flue gas is drawn out from the top of the secondary alkaline scrubbing tower (7), it enters the wet electrostatic precipitator (8). The particulate matter and water droplets in the flue gas fall onto the dust collector and are periodically washed off by backwash water. Step 7. After exiting the wet electrostatic precipitator (8), the flue gas enters the GGH flue gas heat exchanger (9), where it exchanges heat with the denitrified flue gas to preheat the flue gas temperature to 130~140℃, and then enters the flue gas mixer (10); in the flue gas mixer (10), the flue gas mixes with the high-temperature flue gas from the hot blast stove (12) to make the temperature of the mixed flue gas 210~220℃; the hot blast stove (12) uses natural gas to generate hot air; The urea solution in the urea solution preparation tank (17) is sent to the urea solution storage tank (18) by the urea solution transfer pump (29), and then sent to the hot air furnace (12) by the urea solution spray pump (30). After atomization, it is sprayed in and the high temperature flue gas in the hot air furnace (12) is used to decompose the urea solution and produce ammonia. The flue gas mixed in the flue gas mixer (10) at 210~220℃ enters the SCR denitrification reactor (11) and achieves the purpose of denitrification under the action of the catalyst. The flue gas at 210~220℃ after denitrification returns to the GGH flue gas heat exchanger (9) and is used as a heat medium to heat the low temperature flue gas from the wet electrostatic precipitator (8). At the same time, it reduces its own temperature from 210~220℃ to 140~150℃ and is sent to the chimney (14) by the induced draft fan (13) for discharge. At this time, all pollutants in the flue gas meet the emission standards and there is no white smoke from the chimney. The environmentally friendly treatment system for high-fluorine and high-sulfur organic waste gas and liquid in the fluorochemical industry includes an incinerator (1), a graphite quench tower (2), an absorption tower (3), a primary water scrubbing tower (4), a secondary water scrubbing tower (5), a primary alkali scrubbing tower (6), a secondary alkali scrubbing tower (7), a wet electrostatic precipitator (8), a GGH flue gas heat exchanger (9), a flue gas mixer (10), an SCR denitrification reactor (11), a hot air furnace (12), an induced draft fan (13), and a chimney (14); wherein the incinerator (1), graphite quench tower (2), absorption tower (3), primary water scrubbing tower (4), secondary water scrubbing tower (5), primary alkali scrubbing tower (6), and secondary alkali scrubbing tower (7) are all environmentally friendly treatment methods for high-fluorine and high-sulfur organic waste gas and liquid in the fluorochemical industry. The washing tower (7) and the wet electrostatic precipitator (8) are connected in sequence; the bottom outlet of the wet electrostatic precipitator (8) is connected to the secondary alkaline washing tower (7), the top outlet of the wet electrostatic precipitator (8) is connected to the cold medium inlet of the GGH flue gas heat exchanger (9), the cold medium outlet of the GGH flue gas heat exchanger (9) and the outlet of the hot air furnace (12) are respectively connected to the inlet of the flue gas mixer (10), the outlet of the flue gas mixer (10) is connected to the inlet of the SCR denitrification reactor (11), the outlet of the SCR denitrification reactor (11) is connected to the hot medium inlet of the GGH flue gas heat exchanger (9), and the hot medium outlet of the GGH flue gas heat exchanger (9) is connected to the chimney (14) through the induced draft fan (13). The fluorochemical high-fluorine and high-sulfur organic waste gas and waste liquid resource utilization and environmental protection treatment system also includes a high-level water tank (19). The bottom of the high-level water tank (19) is higher than the top of the graphite quench tower (2). The graphite section of the graphite quench tower (2) is connected to the high-level water tank (19). In the emergency of water and power outage, the water stored in the high-level water tank (19) can enter the graphite quench tower (2) by its own gravity to protect the graphite quench tower (2). The absorption tower (3) is a packed tower. The upper part of the absorption tower has two layers of packing, and a spray layer is arranged on each layer of packing. The lower part of the absorption tower is equipped with a storage tank to store the circulating liquid required for spraying. The storage tank is connected to the heat medium inlet of the graphite heat exchanger (32) of the absorption tower through the absorption tower spray pump (24). The heat medium outlet of the graphite heat exchanger (32) of the absorption tower is connected to the spray layer. The circulating chilled water is connected to the cold medium inlet of the graphite heat exchanger (32) of the absorption tower. The cold medium outlet of the graphite heat exchanger (32) of the absorption tower is connected to the circulating chilled water return water. The heat of the circulating liquid in the absorption tower is carried away by the low temperature chilled water. Both the primary water washing tower (4) and the secondary water washing tower (5) are packed towers. The upper part of the water washing tower has two layers of packing to increase the contact area between the flue gas and the circulating liquid. The tower adopts an internal circulation method, and a spray layer is arranged above each layer of packing. The lower part of the water washing tower is equipped with a storage tank to store the circulating liquid required for spraying. Both the primary alkaline scrubbing tower (6) and the secondary alkaline scrubbing tower (7) are packed towers. The upper part of the alkaline scrubbing tower has two layers of packing to increase the contact area between the flue gas and the circulating liquid. The tower adopts an internal circulation method, and a spray layer is arranged on each layer of packing. A storage tank is set at the bottom of the alkaline scrubbing tower to store the circulating liquid required for spraying. Demisting devices are installed at the top flue gas outlets of the absorption tower (3), primary water washing tower (4), secondary water washing tower (5), primary alkaline washing tower (6) and secondary alkaline washing tower (7). The demisting devices can collect large droplets carried in the flue gas and improve the operating conditions of the subsequent equipment. The head of the hot air furnace (12) is equipped with an integrated natural gas burner. Natural gas is connected to the integrated natural gas burner via a pipeline. Additional combustion air is provided by the hot air furnace combustion fan (21). The denitrification reducing agent is urea. The fluorochemical high-fluorine and high-sulfur organic waste gas and waste liquid resource utilization environmental protection treatment system also includes a urea solution preparation tank (17). The urea solution preparation tank (17) is connected to the urea solution storage tank (18) through the urea solution transfer pump (29), and then connected to the hot air furnace (12) through the urea solution spray pump (30).

2. The method for resource-based and environmentally friendly treatment of high-fluorine and high-sulfur organic waste gas and liquid in fluorochemical industry according to claim 1, characterized in that, The incinerator includes a horizontal section and a vertical section connected together. A combined burner is provided at the head of the horizontal section. The combined burner is connected to the combustion air pipeline, the natural gas pipeline, the waste gas buffer tank (16), and the waste liquid buffer tank (15), respectively.

3. The method for resource-based and environmentally friendly treatment of high-fluorine and high-sulfur organic waste gas and liquid in fluorochemical industry according to claim 1, characterized in that, The graphite quench tower (2) includes an upper graphite section and a lower fluoropolymer-lined steel storage tank. The fluoropolymer-lined steel storage tank stores the circulating liquid required for spraying. The lower part of the fluoropolymer-lined steel storage tank is connected to the heat medium inlet of the graphite heat exchanger (31) of the quench tower through the quench tower spray pump (23). The heat medium outlet of the graphite heat exchanger (31) of the quench tower is connected to the top nozzle of the graphite section. The circulating chilled water supply is connected to the cold medium inlet of the graphite heat exchanger (31) of the quench tower. The cold medium outlet of the graphite heat exchanger (31) of the quench tower is connected to the circulating chilled water return water. The heat of the circulating liquid in the quench tower is carried away by the low-temperature chilled water.

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