A fly ash water washing device and a water washing tank contained therein

Abstract

The utility model discloses a fly ash's water washing equipment, including the water washing jar of multiple water washing jar, microbubble generator and solid -liquid separation device that connect gradually, solid -liquid separation device is connected in the water washing jar back for to the slurry in the water washing jar carries out solid -liquid separation, and microbubble generator is linked with water washing jar and is used for sending microbubble into the water washing jar, microbubble generator sets up at least two, and multiple microbubble generators are connected with CO2 and O3 gas delivery pipeline respectively, and gas passes through microbubble generator and enters the water washing jar. This fly ash's water washing equipment can remove dioxin in fly ash through the CO2 and ozone that are passed into the water washing liquid.

Description

Technical Field

[0001] This utility model relates to the field of fly ash washing, specifically to a fly ash washing device and its included washing tank. Background Technology

[0002] Fly ash is a fine ash particle emitted during the combustion of waste. Its composition is complex, containing large amounts of dioxins, soluble salts, and heavy metals. Dioxins are a class of highly toxic, highly stable, and difficult-to-degrade organic pollutants that easily accumulate in organisms. They not only cause serious environmental pollution but also pose a great threat to human health, such as causing cancer, damaging the immune system, and affecting reproductive development.

[0003] Currently, fly ash disposal typically requires pretreatment with water washing. The main purpose of this pretreatment is to reduce the chlorine content in the solids by dissolving soluble salts in the fly ash. During the washing process, soluble chlorine is dissolved out. Traditional fly ash pretreatment processes often employ three-stage countercurrent washing, relying primarily on mechanical agitation. Its effectiveness is limited to dissolving soluble salts in the fly ash solids through physical action, and it cannot remove dioxins from the fly ash. Utility Model Content

[0004] The purpose of this invention is to provide a fly ash washing device and its included washing tank. This fly ash washing device can effectively remove dioxins from fly ash by introducing CO2 and ozone into the washing liquid.

[0005] To achieve the above objectives, this utility model provides a fly ash washing device, including multiple washing tanks, a microbubble generator, and a solid-liquid separation device connected in sequence. The solid-liquid separation device is connected to the washing tanks and is used to separate the slurry in the washing tanks. The microbubble generator is connected to the washing tanks and is used to send microbubbles into the washing tanks.

[0006] At least two microbubble generators are provided, and multiple microbubble generators are connected to CO2 and O3 gas delivery pipelines respectively. The gas enters the water washing tank through the microbubble generators.

[0007] Preferably, the liquid outlet of the solid-liquid separation device after the Nth washing tank is connected to the (N-1)th washing tank for replenishing the (N-1)th washing tank with washing liquid, where N is a natural number greater than 1.

[0008] Preferably, the liquid outlet of the solid-liquid separation device after the Nth washing tank is connected to the solid-liquid separation device before the (N-1)th washing tank for rinsing the solid-liquid separation device, where N is a natural number greater than 1.

[0009] Preferably, the liquid outlet of the first solid-liquid separation device is connected to the water purification system.

[0010] Preferably, the last washing tank is connected to a clean water tank, which is used to add washing solution to the last washing tank.

[0011] This utility model also provides a water washing device for fly ash, comprising a water washing tank, including a tank body, a feed inlet, a discharge outlet, and a tubular distributor. The feed inlet is located at the top of the tank body and is connected to the solid outlet of the solid-liquid separation device before the water washing tank. The discharge outlet is located at the bottom of the tank body and is connected to the solid-liquid separation device after the water washing tank. The tubular distributor is located inside the tank body and is connected to a microbubble generator for introducing microbubbles into the tank body.

[0012] Preferably, the tank body is equipped with a stirrer for stirring the slurry.

[0013] Preferably, a slurry discharge port is also provided at the lower part of the tank body.

[0014] Preferably, the tubular distributor is located above the slurry discharge outlet.

[0015] According to the above technical solution, the fly ash washing equipment of this utility model is equipped with at least two washing tanks, a primary washing tank and a secondary washing tank. The primary washing tank is connected to the CO2 gas conveying pipeline through a microbubble generator. The CO2 microbubbles are used to treat the fly ash slurry in the primary washing tank in order to achieve the purpose of reducing the pH value and dechlorinating the fly ash slurry.

[0016] The primary water washing process involves high concentrations of chloride and calcium ions in the washing solution. The main functions of this process include lowering the pH value and dechlorinating the fly ash.

[0017] During the primary washing stage, fly ash slurry typically has an initial pH value greater than 10, indicating strong alkalinity. In this strongly alkaline environment, many metal ions readily combine with hydroxide ions to form insoluble hydroxide precipitates. For example, calcium ions combine with hydroxide ions to form calcium hydroxide, a slightly soluble substance that easily precipitates.

[0018] When CO2 gas is introduced into the washing tank, it dissolves in water to form carbonic acid (H2CO3). Carbonic acid is a weak acid, which lowers the pH of the system. As the system pH decreases, the fly ash slurry in the primary washing tank gradually changes from strongly alkaline to neutral or weakly alkaline.

[0019] Under strongly alkaline conditions, calcium ions readily form precipitates. These precipitates can trap soluble chlorine (such as calcium chloride, CaCl2) in fly ash, hindering its further dissolution. By introducing CO2 gas to lower the pH, these precipitates gradually dissolve as the system pH decreases. This allows calcium ions to exist primarily in a dissolved state, releasing the trapped soluble chlorine and promoting its dissolution. Therefore, introducing CO2 gas lowers the pH, inhibiting the precipitation reaction between calcium ions and hydroxide ions, reducing the formation of precipitates such as Ca(OH)2. This prevents precipitates from trapping soluble chlorine, allowing it to dissolve more fully into the washing solution and improving the efficiency of dechlorination.

[0020] After CO2 is introduced into the primary water wash, CO2 can react with Ca²⁺ in the liquid phase. + The reaction produces CaCO3 precipitate, which prevents soluble chloride salts such as CaCl2 from redepositing due to excessive calcium ion concentration, and also achieves the effect of decalcification of fly ash slurry.

[0021] Introducing CO2 into the primary water wash can also promote the dissolution of sparingly soluble chloride salts, such as CaClOH, Friedel salt, and Ca6(CO3)5(OH)2Cl. CO2 accelerates the decomposition of sparingly soluble chloride salts through acidification. For example, CaClOH is originally sparingly soluble, but under acidic conditions it can be converted into soluble CaCl2 and removed by water washing.

[0022] Therefore, introducing CO2 gas into the primary water washing tank can lower the pH value of the system and improve the chlorine dissolution efficiency, thereby improving the dechlorination effect of water washing.

[0023] The fly ash slurry after primary water washing is pumped to a solid-liquid separation unit for solid-liquid separation. The solids enter a secondary water washing tank for secondary water washing. The washing liquid enters a water purification unit for decalcification, weight removal, and neutralization reactions. Decalcification uses sodium carbonate for precipitation, and neutralization uses hydrochloric acid. By introducing CO2 into the primary water washing process, sodium carbonate consumption can be reduced by 10%, and hydrochloric acid consumption can be reduced by 90%. Therefore, adding CO2 to the primary water washing process can significantly reduce the treatment cost of the water purification unit.

[0024] The secondary washing tank is connected to the O3 gas delivery pipeline via a microbubble generator. O3 microbubbles are used to treat the fly ash slurry within the secondary washing tank. Using ozone microbubbles can increase the peak liquid-phase ozone concentration to more than 1.5 times that of traditional aeration, while simultaneously extending the gas-liquid contact time to tens of seconds or even minutes. Increasing the ozone content in the washing tank effectively improves the degradation efficiency of dioxins by ozone.

[0025] Ozone microbubbles generate localized high temperatures and pressures upon collapse, triggering a chain reaction via the pyrolysis reaction O3→O2+O(¹D): O(¹D)+H2O→2•OH. The resulting hydroxyl radicals (•OH) have an oxidation potential of 2.8V, which is more likely to attack the C-Cl bonds (bond energy 339 kJ / mol) and aromatic ring systems of dioxins than ozone molecules (2.07V). Therefore, adding ozone microbubbles to the secondary water washing process can effectively remove dioxins from fly ash slurry.

[0026] Preferably, the secondary washing tank is connected to a microbubble generator for CO2 and O3. During the secondary washing process, microbubbles containing a mixture of CO2 and ozone are introduced. The localized high temperature and pressure generated when the CO2 microbubbles collapse help ozone oxidize and remove dioxins. Since a potential difference can be generated on the surface of the microbubbles, and potential is an important factor affecting the adsorption performance of the bubble surface, introducing microbubbles containing the two mixed gases allows for the full adsorption of dioxins by utilizing the strong potential difference generated by the CO2 microbubbles. Simultaneously, when the ozone microbubbles contract, the charge density of the double layer increases rapidly. When the bubbles collapse, the drastic change in the gas-liquid interface releases the energy accumulated at the high concentration of positive and negative ions on the interface. This can stimulate the generation of a large number of hydroxyl radicals, which have a strong oxidizing effect and are used to decompose dioxins in the washing solution. Through the adsorption of dioxins by the CO2 microbubbles, the ozone microbubbles surrounding the CO2 microbubbles can act more effectively on the dioxins, thereby achieving efficient degradation of dioxins in the washing solution.

[0027] Meanwhile, introducing CO2 into the washing solution can maintain its pH value at a low level, and a low pH environment is conducive to the generation of hydroxyl radicals (•OH). Therefore, by introducing microbubbles of CO2 and ozone into the secondary washing process, the generation of hydroxyl radicals (•OH) in the washing tank is increased by 40% to 60% compared with traditional aeration, significantly improving the dechlorination and ring-opening efficiency of dioxins.

[0028] Microbubbles form a gas-liquid-solid three-phase mixed layer in the fly ash-washing liquid system. The microjet streams generated by bubble collapse promote the stripping and oxidation of dioxins on the surface of fly ash particles. Simultaneously, in the calcium-containing washing liquid, carbon dioxide and ozone microbubbles can simultaneously induce Ca²⁺… + CaCO3 precipitate is generated, thereby achieving synergistic treatment of dioxin degradation and system decalcification during the secondary water washing stage.

[0029] Therefore, introducing CO2 and ozone microbubbles into the secondary water wash can improve the removal efficiency of dioxins by ozone microbubbles, and at the same time achieve decalcification treatment of the system.

[0030] To improve the removal efficiency of harmful substances in fly ash slurry by fly ash washing equipment, fly ash washing equipment usually also includes a three-stage washing tank.

[0031] The fly ash slurry after secondary washing is pumped to a solid-liquid separation unit for solid-liquid separation. The solids enter the tertiary washing tank 23 for tertiary washing, and the washing liquid is recycled back to the primary washing tank for reuse. The washing liquid obtained from the secondary washing solid-liquid separation is stored in a washing liquid storage tank. When needed, the washing liquid in the washing liquid storage tank can be pumped into the primary washing tank.

[0032] The tertiary washing tank is connected to a microbubble generator for CO2 and O3. During the tertiary washing process, with the assistance of CO2, the hydroxyl groups generated when the ozone microbubbles collapse fully degrade the dioxins in the fly ash slurry. After the tertiary washing, the fly ash slurry is pumped to a solid-liquid separation device for solid-liquid separation. The solids enter the next process. If drying is carried out in the drying device, the washing liquid is returned to the secondary washing tank for reuse.

[0033] Using this fly ash washing equipment, CO2 is introduced into the primary washing tank to adjust the pH value of the fly ash slurry, which also improves the dechlorination effect of the washing. In the secondary and tertiary washing tanks, hydroxyl radicals generated by the collapse of ozone microbubbles are used to remove dioxins from the fly ash slurry. At the same time, the microbubbles of CO2 are used to increase the content of hydroxyl radicals in the system, thereby improving the dioxin removal efficiency of the washing process.

[0034] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is a schematic diagram of a fly ash washing device.

[0037] Figure 2 This is a structural diagram of a water washing tank;

[0038] Figure 3 This is a schematic diagram of the structure of a tubular distributor 31.

[0039] Explanation of reference numerals in the attached figures

[0040] 1 can body 31 tubular distributor

[0041] 14 Slurry discharge port 11 Feed inlet

[0042] 12 Exhaust port 13 Discharge port

[0043] 32 gas interface 15 stirrer

[0044] 21 Primary washing tank 4 Solid-liquid separation unit

[0045] 22 Secondary washing tank 23 Tertiary washing tank

[0046] 41 Primary filtrate tank; 42 Secondary filtrate tank

[0047] 43 Three-stage filtrate tanks 5 Clear water tanks

[0048] 6 Microbubble generator Detailed Implementation

[0049] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0050] In this utility model, unless otherwise stated, directional words such as "top," "bottom," "lower part," and "above" contained in the terminology only represent the orientation of the term in its conventional use or are common terms understood by those skilled in the art, and should not be regarded as limitations on the term.

[0051] See Figure 1 The fly ash washing equipment includes a microbubble generator 6, a solid-liquid separation device 4, and at least two washing tanks connected in sequence. The solid-liquid separation device 4 is connected to the washing tank and is used to separate the solid and liquid in the slurry in the washing tank. The microbubble generator 6 is connected to the washing tank and is used to send microbubbles into the washing tank.

[0052] At least two microbubble generators 6 are provided, and multiple microbubble generators 6 are respectively connected to CO2 and O3 gas delivery pipelines. The gas enters the water washing tank through the microbubble generators 6.

[0053] By implementing the above technical solution, the fly ash washing equipment is equipped with at least two washing tanks, a primary washing tank 21 and a secondary washing tank 22. The primary washing tank 21 is connected to the CO2 gas delivery pipeline through a microbubble generator 6. The fly ash slurry in the primary washing tank 21 is treated by CO2 microbubbles in order to reduce the pH value and dechlorinate the fly ash slurry.

[0054] The primary water washing process involves high concentrations of chloride and calcium ions in the washing solution. The main functions of this process include lowering the pH value and dechlorinating the fly ash.

[0055] During the primary washing stage, fly ash slurry typically has an initial pH value greater than 12, exhibiting strong alkalinity. In this strongly alkaline environment, many metal ions readily combine with hydroxide ions to form insoluble hydroxide precipitates. For example, calcium ions combine with hydroxide ions to form calcium hydroxide, a slightly soluble substance that readily precipitates.

[0056] When CO2 gas is introduced into the water washing tank, it dissolves in water to form carbonic acid (H2CO3). Carbonic acid is a weak acid, which lowers the pH of the system. As the pH of the system decreases, the fly ash slurry in the primary water washing tank 21 gradually changes from strongly alkaline to neutral or weakly alkaline.

[0057] Under strongly alkaline conditions, calcium ions readily form precipitates. These precipitates can trap soluble chlorine (such as calcium chloride, CaCl2) in fly ash, hindering its further dissolution. By introducing CO2 gas to lower the pH, these precipitates gradually dissolve as the system pH decreases. This allows calcium ions to exist primarily in a dissolved state, releasing the trapped soluble chlorine and promoting its dissolution. Therefore, introducing CO2 gas lowers the pH, inhibiting the precipitation reaction between calcium ions and hydroxide ions, reducing the formation of precipitates such as Ca(OH)2. This prevents precipitates from trapping soluble chlorine, allowing it to dissolve more fully into the washing solution and improving the efficiency of dechlorination.

[0058] After CO2 is introduced into the primary water wash, CO2 can react with Ca²⁺ in the liquid phase. + The reaction produces CaCO3 precipitate, which prevents soluble chloride salts such as CaCl2 from redepositing due to excessive calcium ion concentration, and also achieves the effect of decalcification of fly ash slurry.

[0059] Introducing CO2 into the primary water wash can also promote the dissolution of sparingly soluble chloride salts, such as CaClOH, Friedel salt, and Ca6(CO3)5(OH)2Cl. CO2 accelerates the decomposition of sparingly soluble chloride salts through acidification. For example, CaClOH is originally sparingly soluble, but under acidic conditions it can be converted into soluble CaCl2 and removed by water washing.

[0060] Therefore, by introducing CO2 gas into the primary water washing tank 21, the pH value of the system can be reduced, and the chlorine dissolution efficiency can be improved, thereby improving the effect of water washing and dechlorination.

[0061] The fly ash slurry after primary water washing is pumped to solid-liquid separation device 4 for solid-liquid separation. The solids enter secondary water washing tank 22 for secondary water washing. The washing liquid enters the water purification unit for decalcification, weight removal, and neutralization reactions. Decalcification uses sodium carbonate for precipitation, and neutralization uses hydrochloric acid. By introducing CO2 during the primary water washing process, sodium carbonate consumption can be reduced by 10%, and hydrochloric acid consumption can be reduced by 90%. Therefore, adding CO2 to the primary water washing process can significantly reduce the treatment cost of the water purification unit.

[0062] The secondary washing tank 22 is connected to the O3 gas delivery pipeline via a microbubble generator 6. O3 microbubbles are used to treat the fly ash slurry within the secondary washing tank 22. Using ozone microbubbles can increase the peak liquid-phase ozone concentration to more than 1.5 times that of traditional aeration, while simultaneously extending the gas-liquid contact time to tens of seconds or even minutes. Increasing the ozone content in the washing tank effectively improves the degradation efficiency of dioxins by ozone.

[0063] Ozone microbubbles generate localized high temperatures and pressures upon collapse, triggering a chain reaction via the pyrolysis reaction O3→O2+O(¹D): O(¹D)+H2O→2•OH. The resulting hydroxyl radicals (•OH) have an oxidation potential of 2.8V, which is more likely to attack the C-Cl bonds (bond energy 339 kJ / mol) and aromatic ring systems of dioxins than ozone molecules (2.07V). Therefore, adding ozone microbubbles to the secondary water washing process can effectively remove dioxins from fly ash slurry.

[0064] Preferably, the secondary washing tank 22 is connected to the microbubble generator 6 for CO2 and O3. During the secondary washing process, microbubbles of a mixture of CO2 and ozone are introduced. The local high temperature and pressure generated when the CO2 microbubbles collapse can help ozone oxidize and remove dioxins. Since a potential difference can be generated on the surface of the microbubbles, and potential is an important factor affecting the adsorption performance of the bubble surface, the introduction of microbubbles of the two mixed gases can fully adsorb dioxins by utilizing the strong potential difference generated by the CO2 microbubbles. At the same time, when the ozone microbubbles contract, the charge density of the double layer increases rapidly. When the bubbles collapse, the drastic change of the disappearance of the gas-liquid interface releases the energy accumulated by the high concentration of positive and negative ions on the interface. At this time, a large number of hydroxyl radicals can be generated. Hydroxyl radicals have a strong oxidizing effect and are used to decompose dioxins in the washing solution. Through the adsorption of dioxins by CO2 microbubbles, the ozone microbubbles located around the CO2 microbubbles can act more effectively on dioxins, thereby achieving efficient degradation of dioxins in the washing solution.

[0065] Meanwhile, introducing CO2 into the washing solution can maintain its pH value at a low level, and a low pH environment is conducive to the generation of hydroxyl radicals (•OH). Therefore, by introducing microbubbles of CO2 and ozone into the secondary washing process, the generation of hydroxyl radicals (•OH) in the washing tank is increased by 40% to 60% compared with traditional aeration, significantly improving the dechlorination and ring-opening efficiency of dioxins.

[0066] Microbubbles form a gas-liquid-solid three-phase mixed layer in the fly ash-washing liquid system. The microjet streams generated by bubble collapse promote the stripping and oxidation of dioxins on the surface of fly ash particles. Simultaneously, in the calcium-containing washing liquid, carbon dioxide and ozone microbubbles can simultaneously induce Ca²⁺… + CaCO3 precipitate is generated, thereby achieving synergistic treatment of dioxin degradation and system decalcification during the secondary water washing stage.

[0067] Therefore, introducing CO2 and ozone microbubbles into the secondary water wash can improve the removal efficiency of dioxins by ozone microbubbles, and at the same time achieve decalcification treatment of the system.

[0068] In order to improve the removal efficiency of harmful substances in fly ash slurry by fly ash washing equipment, fly ash washing equipment usually also includes a three-stage washing tank 23.

[0069] The fly ash slurry after secondary washing is pumped to the solid-liquid separation device 4 for solid-liquid separation. The solids enter the tertiary washing tank 23 for tertiary washing, and the washing liquid is recycled back to the primary washing tank 21 for reuse. The washing liquid obtained from the secondary washing solid-liquid separation is stored in the washing liquid storage tank. When needed, the washing liquid in the washing liquid storage tank can be pumped into the primary washing tank 21.

[0070] The tertiary washing tank 23 is connected to the microbubble generator 6 for CO2 and O3. During the tertiary washing process, with the assistance of CO2, the hydroxyl groups generated when the ozone microbubbles collapse fully degrade the dioxins in the fly ash slurry. After the tertiary washing, the fly ash slurry is pumped to the solid-liquid separation device 4 for solid-liquid separation. The solid enters the next process. If drying is carried out in the drying device, the washing liquid is returned to the secondary washing tank 22 for reuse.

[0071] Using this fly ash washing equipment, CO2 is introduced into the primary washing tank 21 to adjust the pH value of the fly ash slurry, which also improves the dechlorination effect of the washing. In the secondary washing tank 22 and the tertiary washing tank 23, hydroxyl radicals generated by the collapse of ozone microbubbles are used to remove dioxins from the fly ash slurry. At the same time, the microbubbles of CO2 are used to increase the content of hydroxyl radicals in the system, thereby improving the dioxin removal efficiency of the washing process.

[0072] In this embodiment, preferably, the liquid outlet of the solid-liquid separation device 4 after the Nth washing tank is connected to the (N-1)th washing tank for replenishing the washing liquid to the (N-1)th washing tank, where N is a natural number greater than 1.

[0073] The liquid outlet of the solid-liquid separation device 4 after the Nth washing tank is connected to the (N-1)th washing tank.

[0074] Specifically, the liquid outlet of the solid-liquid separation device 4 after the secondary washing tank 22 is connected to the primary washing tank 21. The washing liquid separated by the solid-liquid separation device 4 after the secondary washing tank 22 can be used to replenish the liquid of the primary washing tank 21, thereby achieving the purpose of saving washing liquid.

[0075] The washing liquid separated by the secondary washing tank 22 still contains unremoved harmful substances and cannot be directly discharged. Adding the washing liquid filtered from the secondary washing tank 22 to the primary washing tank 21 not only replenishes the liquid in the primary washing tank 21 but also achieves the goal of preventing the discharge of system wastewater. Moreover, the harmful substances in the washing liquid separated by the secondary washing tank 22 have been sufficiently removed, so the amount of harmful substances in the washing liquid after the primary washing tank will not significantly increase, and the impact on the water purification system is minimal.

[0076] The liquid outlet of the solid-liquid separation device 4 after the tertiary washing tank 23 is connected to the secondary washing tank 22. The washing liquid separated by the solid-liquid separation device 4 after the tertiary washing tank 23 can be used to replenish the liquid of the secondary washing tank 22, which can also achieve the purpose of saving washing liquid.

[0077] Similarly, the washing liquid obtained from the tertiary washing tank 23 still contains unremoved harmful substances and cannot be directly discharged. Because of the treatment effect of the tertiary washing tank 23, the content of harmful substances in the liquid obtained after solid-liquid separation in the tertiary washing tank 23 is significantly lower than that in the secondary washing tank 22. Therefore, the washing liquid obtained after the tertiary washing tank 23 can be added to the secondary washing tank 22. This not only replenishes the liquid in the secondary washing tank 22, but also ensures that the solid harmful substances in the washing liquid obtained after the tertiary washing tank 23, after entering the secondary washing tank 22, will eventually enter the primary washing tank 21 under the action of the solid-liquid separation device 4 after the secondary washing tank 22, thus achieving the goal of preventing the discharge of system wastewater.

[0078] In this embodiment, preferably, the liquid outlet of the solid-liquid separation device 4 after the Nth washing tank is connected to the solid-liquid separation device 4 before the N-1th washing tank for rinsing the solid-liquid separation device 4, where N is a natural number greater than 1.

[0079] The liquid from the solid-liquid separation device 4 after the tertiary washing tank can also rinse the solid-liquid separation device 4 before the secondary washing tank 22. The fly ash slurry obtained from rinsing enters the secondary washing tank 22.

[0080] Preferably, the fly ash washing equipment also includes a primary filtrate tank 41, a secondary filtrate tank 42, and a tertiary filtrate tank 43.

[0081] The liquid separated by the solid-liquid separation device 4 after the primary water washing tank 22 enters the primary filtrate tank 41 for storage, and the water washing liquid in the primary filtrate tank 41 is pumped into the water purification system.

[0082] The liquid separated by the solid-liquid separation device 4 after the secondary washing tank 22 enters the secondary filtrate tank 42 for storage. A second infusion pump is installed between the secondary filtrate tank 42 and the primary washing tank 21. A liquid level sensor is installed in the primary washing tank 21, which is electrically connected to the second infusion pump and controls the opening and closing of the second infusion pump.

[0083] When the liquid level in the primary washing tank 21 is low, the liquid level sensor controls the second infusion pump to start and replenish the liquid in the primary washing tank 21. When the liquid level in the primary washing tank 21 is high, the liquid level sensor controls the second infusion pump to stop replenishing the liquid in the primary washing tank 21.

[0084] The liquid separated by the solid-liquid separation device 4 after the third-stage washing tank 23 enters the third-stage filtrate tank 43 for storage. A third infusion pump is installed between the third-stage filtrate tank 43 and the second-stage washing tank 22. A liquid level sensor is installed in the second-stage washing tank 22, which is electrically connected to the third infusion pump and controls the opening and closing of the third infusion pump.

[0085] When the liquid level in the secondary washing tank 22 is low, the liquid level sensor controls the third infusion pump to start and replenish the liquid in the secondary washing tank 22. When the liquid level in the secondary washing tank 22 is high, the liquid level sensor controls the third infusion pump to shut down and stop replenishing the liquid in the secondary washing tank 22.

[0086] The third infusion pump is connected to two branch pipelines, which are respectively connected to the secondary washing tank 22 and the solid-liquid separation device 4 in front of the secondary washing tank 22. Valves are installed on both branches. When it is necessary to add washing liquid to the secondary washing tank 22 or the solid-liquid separation device 4 in front of the secondary washing tank 22, it is only necessary to open the valve on the corresponding branch.

[0087] In this embodiment, preferably, the liquid outlet of the first solid-liquid separation device 4 is connected to the water purification system.

[0088] A primary filter tank 41 is provided between the first solid-liquid separation device 4 and the water purification system to buffer the liquid separated by the first solid-liquid separation device 4.

[0089] The washing liquid in the primary filtrate tank 41 enters the water purification unit for decalcification, weight removal, and neutralization reactions. Decalcification uses sodium carbonate for precipitation, and neutralization uses hydrochloric acid. By introducing CO2 into the primary washing process, sodium carbonate consumption can be reduced by 10%, and hydrochloric acid consumption can be reduced by 90%. Therefore, adding CO2 to the primary washing process can significantly reduce the treatment cost of the water purification unit.

[0090] In this embodiment, preferably, the last washing tank is connected to the clean water tank 5, and the clean water tank 5 is used to add washing liquid to the last washing tank.

[0091] The clean water tank 5 replenishes the fly ash washing equipment with washing liquid. Specifically, the clean water tank 5 replenishes clean water to the last washing tank, for example, the last washing tank is the third-stage washing tank 23. The liquid obtained by the solid-liquid separation device 4 from the slurry of the third-stage washing tank 23 will enter the second-stage washing tank 22, and then be separated by the solid-liquid separation device 4 after the second-stage washing tank 22. When needed, it will be added to the first-stage washing tank 21. Therefore, through this reverse addition method, the fly ash washing equipment realizes the step-by-step addition of washing liquid.

[0092] The present invention also provides a fly ash washing equipment including a washing tank, comprising a tank body 1, a feed inlet 11, a washing liquid inlet, a discharge outlet 13, and a tubular distributor 31. The feed inlet 11 is located at the top of the tank body 1 and is connected to the solid outlet of the solid-liquid separation device 4 before the washing tank. The discharge outlet 13 is located at the bottom of the tank body 1 and is connected to the solid-liquid separation device 4 after the washing tank. The tubular distributor 31 is located inside the tank body 1 and is connected to a microbubble generator 6 for inputting microbubbles into the tank body 1.

[0093] The fly ash slurry or the solids separated by the solid-liquid separation device 4 are added into the tank body 1 through the feed inlet 11, and the washing liquid can be added to the washing tank through the washing liquid inlet. The discharge outlet 13 located at the bottom of the washing tank can output the slurry in the washing tank to the next process.

[0094] Microbubbles of the required diameter are generated using a microbubble generator. These microbubbles are then fed into a tubular distributor 31 via a gas interface 32, and discharged into the tank body 11 through the outlet of the tubular distributor 31. These microbubbles entering the tank body 11 will annihilate and dissolve in the solution within the tank body 11, reacting with harmful chemicals in the solution to achieve solution treatment.

[0095] When it is necessary to introduce both CO2 and ozone microbubbles into the washing tank, two microbubble generators are set up to process the CO2 and ozone gases respectively. Microbubbles of both gases are added to the washing tank, and the CO2 microbubbles assist the ozone microbubbles in degrading dioxins. The two microbubble generators can be connected to two gas interfaces 32 respectively, allowing the CO2 and ozone microbubbles to enter the washing tank from opposite ends of the tubular distributor 31. Alternatively, each microbubble generator can have two outlet pipes, each connected to one of the two gas interfaces 32, allowing for more thorough mixing of the CO2 and ozone microbubbles within the tubular distributor 31.

[0096] The tank body 11 is provided with a feed inlet 11. Fly ash slurry or solids obtained from solid-liquid separation after water washing can enter the water washing tank through the feed inlet 11. Undissolved gases in the water washing tank will leave the solution and enter the upper part of the water washing tank, and finally be discharged through the exhaust port 12.

[0097] The bottom of the washing tank is provided with a discharge port 13, which is connected to a pump. The pump pumps the fly ash slurry to the solid-liquid separation device for separation.

[0098] In this embodiment, preferably, a stirrer 15 for stirring the slurry is provided inside the tank body 11.

[0099] To ensure that the solids entering through the feed inlet 11 are evenly distributed in the liquid of the washing tank, an agitator 15 is also installed inside the tank body 11. Under the action of the agitator 15, the fly ash will mix with the washing liquid in the washing tank and be distributed as evenly as possible. This not only facilitates the dissolution of soluble substances, but also helps to improve the working efficiency of CO2 and ozone microbubbles.

[0100] Preferably, the agitator 15 is configured as a multi-layer agitator 15. Due to gravity, the fly ash concentration is higher at the bottom of the washing tank and lower at the top. Moreover, the washing tank has a large capacity and is usually quite tall. By setting up this multi-layer agitator 15, the uniform dispersion of fly ash in the washing tank can be promoted more effectively.

[0101] In this embodiment, preferably, a slurry discharge port 14 is also provided at the lower part of the tank body 11.

[0102] If the discharge port 13 becomes blocked, the slurry in the washing tank can be discharged through the slurry discharge port 14, and the blockage of the discharge port 13 can also be cleared through the slurry discharge port 14.

[0103] In this embodiment, preferably, the tubular distributor 31 is located above the slurry outlet 14.

[0104] The tubular distributor 31 is positioned above the slurry outlet 14 to prevent excessive fly ash concentration from clogging the outlet of the tubular distributor 31.

[0105] Multiple outlets of the tubular distributor 31 are evenly distributed around each pipe of the tubular distributor 31, so that microbubbles can enter the washing tank more evenly. These microbubbles will stir the liquid in the washing tank, promote the uniform distribution of fly ash around the tubular distributor 31, and help improve the working efficiency of ozone microbubbles.

[0106] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0107] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0108] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. An apparatus for washing fly ash with water, characterized by, It includes multiple washing tanks, a microbubble generator (6) and a solid-liquid separation device (4) connected in sequence. The solid-liquid separation device (4) is connected to the washing tank and is used to separate the slurry in the washing tank. The microbubble generator (6) is connected to the washing tank and is used to send microbubbles into the washing tank. At least two microbubble generators (6) are provided. Multiple microbubble generators (6) are connected to CO2 and O3 gas delivery pipelines respectively. The gas enters the water washing tank through the microbubble generators (6).

2. The fly ash water scrubbing apparatus of claim 1, wherein, The liquid outlet of the solid-liquid separation device (4) after the Nth washing tank is connected to the N-1th washing tank to replenish the washing liquid to the N-1th washing tank, where N is a natural number greater than 1.

3. The fly ash water scrubbing apparatus of claim 2, wherein, The liquid outlet of the solid-liquid separation device (4) after the Nth water washing tank is connected to the solid-liquid separation device (4) before the N-1th water washing tank for rinsing the solid-liquid separation device (4).

4. The fly ash water scrubbing apparatus of claim 2, wherein, The liquid outlet of the first solid-liquid separation device (4) is connected to the water purification system.

5. The fly ash water scrubbing apparatus of claim 2, wherein, The last washing tank is connected to the clean water tank (5), which is used to add washing liquid to the last washing tank.

6. A water washing apparatus for fly ash according to any one of claims 1 to 5, comprising a water washing tank, wherein The tank includes a tank body (1), a feed inlet (11), a discharge outlet (13), and a tubular distributor (31). The feed inlet (11) is located at the top of the tank body (1) and is connected to the solid outlet of the solid-liquid separation device (4) before the water washing tank. The discharge outlet (13) is located at the bottom of the tank body (1) and is connected to the solid-liquid separation device (4) after the water washing tank. The tubular distributor (31) is located inside the tank body (1) and is connected to a microbubble generator (6) to input microbubbles into the tank body (1).

7. The wash tank of claim 6, wherein, The tank body (1) is equipped with a stirrer (15) for stirring the slurry.

8. The wash tank of claim 6, wherein, The lower part of the tank body (1) is also provided with a slurry discharge port (14).

9. The wash tank of claim 8, wherein, The tubular distributor (31) is located above the slurry outlet (14).

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