Energy-saving and efficient fly ash washing dechlorination system

Abstract

The utility model relates to the technical field of fly ash water washing dechlorination, and discloses an energy-saving and efficient fly ash water washing dechlorination system, which comprises a fly ash slurrying unit, a fly ash water washing dechlorination unit, a fly ash water washing dechlorination unit, a fly ash water washing dechlorination unit, a fly ash water washing dechlorination unit, a fly ash water washing dechlorination unit and a fly ash water washing dechlorination unit, the multi-stage washing unit is used for carrying out multi-stage washing on the pre-dissolved raw fly ash primary slurry, and the multi-stage washing unit is composed of a plurality of top driving stirring washing devices; the multi-stage vortex separation unit is used for carrying out multi-stage three-phase separation on the washed primary slurry; the multi-stage eddy current separation unit is composed of a plurality of integrated eddy current three-phase separation devices. According to the utility model, the fly ash pulping unit, the multi-stage washing unit, the multi-stage vortex separation unit, the mechanical solid-liquid separation unit, the weight removal unit, the evaporative crystallization unit and the waste gas and waste water treatment unit are organically combined, so that the backflow mechanism of fly ash washing is optimized, the water consumption is greatly reduced, high efficiency and energy conservation are realized, and the'zero emission 'of waste water is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of fly ash water washing and dechlorination, in particular to a system for energy-saving and efficient fly ash water washing and dechlorination. Background Technique

[0002] The fly ash water washing technology is a method for treating fly ash generated during the garbage incineration process. Fly ash is classified as hazardous waste due to its containing various harmful substances such as heavy metals, benzene series, and dioxins, and its hazardous waste code is HW18. Among traditional hazardous waste treatment methods, co-disposal in a cement kiln is a relatively thorough and effective way. However, due to the excessively high chlorine element content in fly ash, it is difficult to directly enter the kiln only through formulation. And the "Technical Specification for Pollution Control of Municipal Solid Waste Incineration Fly Ash (Trial)" (HJ 1134-2020) stipulates that "the soluble chlorine content in the fly ash treatment product should be controlled, and high-temperature processes, water washing processes, etc. can be used to remove soluble chlorine. The soluble chlorine content in the treatment product (high-temperature treatment product, fly ash after water washing, etc.) should not exceed 2%", and it is preferably not higher than 1%. Therefore, pre-treatment for dechlorination of fly ash is required. Water washing pre-treatment is currently a relatively mainstream and effective method for removing chloride ions in fly ash.

[0003] In the prior art, CN117600206A discloses a fly ash resource treatment system and process, including a low-temperature detoxification unit to remove dioxin substances from incinerated fly ash; a water washing unit to perform countercurrent water washing on the detoxified fly ash; a heavy metal stabilization unit to solidify heavy metals in the washing liquid; a water washing and detoxification unit to capture heavy metals in the washing liquid to generate heavy metal precipitates; a softening unit to soften the detoxified washing liquid to reduce hardness; a membrane treatment unit to separate monovalent salts and divalent salts; a salt production unit to perform evaporation crystallization on the water produced by the membrane treatment unit to produce salt, and recycle the condensed water to the water washing unit. CN202410219764 discloses a method for resource utilization of municipal solid waste incineration fly ash. By adopting a method of three-stage countercurrent circulation ultrasonic enhanced water washing, under stirring conditions, with the combined effect of ultrasonic enhancement, chloride ions can be quickly eluted with less water consumption. Although the one-time water washing time only needs 5 - 10 minutes, reducing the elution time, in its three-stage countercurrent circulation ultrasonic enhanced water washing, the solid-liquid ratio used in each stage still reaches 1:3 - 4. In addition, CN212039181U discloses a circulating gradient fly ash water washing system, including a clean water tank and a premixing tank. The premixing tank is connected to the first pulping tank, and the clean water tank is connected to the second pulping tank. The liquid outlet end of the first pulping tank is connected to the first pressure filtration device; the first pressure filtration device includes multiple filtrate outlets and a filter cake outlet, which are respectively connected to corresponding liquid storage devices and subsequent water treatment systems, and the filter cake outlet is connected to the second pulping tank. The outlet of the second pulping tank is connected to the second pressure filtration device, and the filter cake outlet of the second pressure filtration device is connected to a drying system; through the effective cooperation between equipment systems, after repeated water washing processes, the filtrates with different concentrations after single water washing are respectively retained and washed cyclically to reduce water consumption and obtain washing liquids with different concentrations respectively.

[0004] It can be seen that in the aspect of fly ash water washing and dechlorination pretreatment, there are generally problems such as large water consumption (the total ash-water ratio in the whole water washing process is generally greater than 1:3), high cost of subsequent washing liquid treatment (whether directly evaporating and crystallizing or membrane concentrating and then evaporating and crystallizing, the energy consumption itself is high, and the water used in the water washing link is directly related to the evaporation amount. The larger the water consumption, the higher the operating cost); the solid matter separated by plate and frame or centrifugation after water washing needs to be pulped again, resulting in energy waste; there are too many equipment in the water washing system, the operation is complex, and the accessories need to be replaced frequently. Utility Model Content

[0005] To make up for the above deficiencies, the present utility model provides an energy-saving and efficient fly ash water washing and dechlorination system, aiming to improve the problems of large water consumption, high cost of subsequent washing liquid treatment and energy waste in the prior art.

[0006] To achieve the above object, the present utility model adopts the following technical solution: An energy-saving and efficient fly ash water washing and dechlorination system, including:

[0007] The fly ash pulping unit is used to pre-dissolve and weigh the original fly ash, and it includes a precise control pre-dissolving device and a primary pulp buffer tank;

[0008] The multi-stage water washing unit is used to perform multi-stage water washing on the primary pulp of the pre-dissolved original fly ash. This multi-stage water washing unit is composed of multiple top-driven stirring water washing devices;

[0009] The multi-stage eddy current separation unit is used to perform multi-stage three-phase separation on the washed primary pulp; this multi-stage eddy current separation unit is composed of multiple integrated eddy current three-phase separation devices;

[0010] The wastewater treatment unit is used for wastewater treatment, and it includes a wastewater treatment module and a reclaimed water tank. Among them, the wastewater treatment module includes but is not limited to a multi-stage physical and chemical precipitation system, an MBR system, and a constructed wastewater combination module.

[0011] As a further description of the above technical solution:

[0012] The precise control pre-dissolving device includes a pulping tank, a top-driven variable-frequency stirrer, and a liquid level controller 1. The top of the pulping tank is successively provided with a fly ash inlet, a water inlet 1, a water inlet 2, a maintenance manhole 1, and an exhaust gas outlet 1 from left to right. The side of the pulping tank is successively provided with an overflow interface 1 and a slurry discharge port 1 from top to bottom. The bottom of the pulping tank is provided with an emptying interface 1; the top of the water inlet 2 is connected to a pipeline flowmeter 1 for measuring the water inflow, and a solenoid valve 1 for controlling the water inflow is installed at the top of the pipeline flowmeter 1. The top of the water inlet 1 is equipped with a pipeline flowmeter 2 for measuring the water inflow, and the pipeline flowmeter 2 is connected to the water pump in the reclaimed water tank of the wastewater treatment unit to control the total water inflow. The input end of the fly ash inlet is connected to a weighing scale system for controlling the fly ash inflow. The top-driven variable-frequency stirrer is installed on the top of the pulping tank. The liquid level controller 1 is installed inside the pulping tank to read the liquid level signal in the pulping tank. A speed controller is installed on the top of the top-driven variable-frequency stirrer, and the speed controller is electrically connected to the liquid level controller 1 and the top-driven variable-frequency stirrer respectively. One end of the slurry discharge port 1 away from the pulping tank is connected to a primary pulp discharge pipe, and the other end of the primary pulp discharge pipe is connected to the primary pulp buffer tank. A slurry pump is provided in the primary pulp buffer tank for transporting the prepared primary pulp to the subsequent water washing unit.

[0013] As a further description of the above technical solution:

[0014] The top-driven stirring water-washing device includes a water-washing tank, a top-driven stirrer, and a liquid level controller II. The top of the water-washing tank is successively provided with a mortar inlet, a water inlet III, a water inlet IV, a maintenance manhole II, and an exhaust gas outlet II from left to right. The upper and lower ends of the side of the water-washing tank are respectively provided with an overflow interface II and a mortar discharge port II. The bottom of the water-washing tank is provided with an emptying interface II. Pipe flow meters III, IV, and V for measuring water volume are respectively installed at the tops of the mortar inlet, water inlet III, and water inlet IV. One end of the mortar discharge port II away from the water-washing tank is connected, and the other end is connected to the input end of a variable-frequency booster pump for transporting the washed mortar to the subsequent eddy current separation unit. The top-driven stirrer is installed on the top of the water-washing tank, and the liquid level controller II is installed inside the water-washing tank for reading the liquid level signal in the water-washing tank.

[0015] As a further description of the above technical solution:

[0016] The integrated eddy current three-phase separation device includes a washing liquid storage tank, a concentrated mortar storage tank, and multiple groups of eddy current separators connected therebetween. A dust discharge pipe is installed at the central axis between the washing liquid storage tank and the concentrated mortar storage tank, and a solenoid valve II that is intermittently opened is provided on the dust discharge pipe. Exhaust gas outlets III and maintenance manholes III are respectively provided on both sides of the top of the washing liquid storage tank. A washing liquid discharge port is provided in the upper middle part of the washing liquid storage tank, and a washing liquid discharge pipe connected to the washing liquid discharge port. An ash discharge port is provided at the bottom of the washing liquid storage tank. The ash discharge port is connected to the dust discharge pipe, and the bottom of the dust discharge pipe is connected to the concentrated mortar storage tank. A mortar discharge port is provided at the bottom of the concentrated mortar storage tank, and the bottom end of the mortar discharge port is connected to a mortar discharge pipe, and a solenoid valve III for controlling the self-flow of the concentrated mortar to the subsequent receiving unit is installed at the other end of the mortar discharge pipe.

[0017] As a further description of the above technical solution:

[0018] A water-washed mortar access pipe is provided in the upper part of the side of the eddy current separator. A connecting conduit for upward clear liquid and air is provided at the top of the eddy current separator, and the connecting conduit is connected to the washing liquid storage tank. An inverted conical pipe for downward mortar is provided at the bottom of the eddy current separator, and the inverted conical pipe is connected to the concentrated mortar storage tank. The water-washed mortar access pipes of multiple eddy current separators are all connected to an annular access main pipe. A solenoid valve IV and a variable-frequency slurry pump are successively connected to the side end of the annular access main pipe to control the slurry volume from the top-driven stirring water-washing device and the eddy current intensity in the eddy current separator.

[0019] As a further description of the above technical solution:

[0020] The dechlorination system further includes a mechanical solid-liquid separation unit for separating mud and water, which includes a mechanical separation module and a filtrate buffer pool. The mechanical separation module includes but is not limited to a plate-and-frame pressure filtration device and a centrifugal separation device.

[0021] As a further description of the above technical solution:

[0022] The dechlorination system further includes a heavy metal removal unit for removing heavy metals, which includes a reaction module and a heavy metal removal sedimentation tank, and the reaction module includes, but is not limited to, a flocculation sedimentation device and an electrolytic resolution device.

[0023] As a further description of the above technical solution:

[0024] The dechlorination system further includes an evaporation and crystallization unit for evaporation and crystallization, which includes an evaporation and crystallization device and a condensation water tank, and the evaporation and crystallization device includes, but is not limited to, an MVR device, a membrane concentration + MVR device, and a membrane salt separation + membrane concentration + MVR device.

[0025] As a further description of the above technical solution:

[0026] The dechlorination system further includes an exhaust gas treatment unit for exhaust gas treatment, which includes an exhaust gas treatment module and an exhaust gas emission module, and the exhaust gas treatment module includes, but is not limited to, a spray tower and an activated carbon adsorption device.

[0027] The utility model has the following beneficial effects:

[0028] 1. In the utility model, through the organic combination of fly ash pulping, multi-stage water washing, multi-stage eddy current separation, mechanical solid-liquid separation, heavy metal removal, evaporation and crystallization, and exhaust gas and wastewater treatment units, the reflux mechanism of fly ash water washing is optimized, achieving high efficiency and energy conservation while significantly reducing water consumption, and at the same time realizing "zero discharge" of wastewater.

[0029] 2. In the utility model, through the application of the integrated eddy current three-phase separation device, the solid-liquid separation process realizes continuous operation, greatly improving the efficiency of solid-liquid separation of ash slurry.

[0030] 3. In the utility model, the solid-liquid separation device in the fly ash water washing process is improved and the parameters of multi-stage solid-liquid separation are optimized, avoiding the process of repeated dehydration and repeated pulping in traditional fly ash water washing. Under the condition of ensuring the same elution efficiency, the water consumption of fly ash water washing is greatly reduced, the overall volume of the equipment is significantly reduced, and the degree of automation of the equipment is greatly improved, achieving high efficiency and energy conservation. Description of the Drawings

[0031] Figure 1 It is a schematic structural cross-sectional view of the precise control pre-dissolution device of an energy-saving and efficient fly ash water washing and dechlorination system proposed by the utility model;

[0032] Figure 2 It is a schematic structural cross-sectional view of the top-driven stirring water washing device of an energy-saving and efficient fly ash water washing and dechlorination system proposed by the utility model;

[0033] Figure 3 The front structural view of the integrated vortex separation device of an energy-saving and efficient fly ash water washing and dechlorination system proposed by the present utility model;

[0034] Figure 4 The top structural view of the integrated vortex separation device of an energy-saving and efficient fly ash water washing and dechlorination system proposed by the present utility model;

[0035] Figure 5 The working flow chart of an energy-saving and efficient fly ash water washing and dechlorination system proposed by the present utility model.

[0036] Legend description:

[0037] A1, Pulping tank; A2, Top-driven variable-frequency stirrer; A3, Liquid level controller 1; A4, Fly ash inlet; A5, Incoming water inlet 1; A6, Incoming water inlet 2; A7, Maintenance manhole 1; A8, Exhaust gas outlet 1; A9, Overflow interface 1; A10, Slurry discharge port 1; A11, Emptying interface 1; A12, Pipeline flowmeter 1; A13, Solenoid valve 1; A14, Pipeline flowmeter 2; A15, Weighing scale system; A16, Speed controller; A17, Initial slurry discharge pipe; A18, Initial slurry buffer tank; A19, Slurry pump; B1, Water washing tank; B2, Top-driven stirrer; B3, Liquid level controller 2; B4, Slurry inlet; B5, Incoming water inlet 3; B6, Incoming water inlet 4; B7, Maintenance manhole 2; B8, Exhaust gas outlet 2; B9, Overflow interface 2; B10, Slurry discharge port 2; B11, Emptying interface 2; B12, Pipeline flowmeter 3; B13, Pipeline flowmeter 4; B14, Pipeline flowmeter 5; B15, Slurry discharge pipe; B16, Variable-frequency booster pump; C1, Wash liquid storage tank; C2, Concentrated slurry storage tank; C3, Vortex separator; C4, Ash discharge pipe; C5, Exhaust gas outlet 3; C6, Maintenance manhole 3; C7, Wash liquid discharge port; C8, Wash liquid discharge pipe; C9, Ash outlet; C10, Solenoid valve 2; C11, Slurry discharge port; C12, Slurry discharge pipe; C13, Solenoid valve 3; C3-1, Water-washed slurry access pipe; C3-2, Connecting conduit; C3-3, Inverted conical pipe; C3-4, Annular access main pipe; C3-5, Solenoid valve 4; C3-6, Variable-frequency slurry pump. Specific embodiments

[0038] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0039] Refer toFigures 1 - 5 , an embodiment provided by the present utility model: an energy-saving and efficient fly ash washing and dechlorination system, comprising:

[0040] A fly ash pulping unit for pre-dissolving the weighed original fly ash, which comprises a precisely controlled pre-dissolving device and a primary pulp buffer tank;

[0041] A multi-stage water washing unit for performing multi-stage water washing on the pre-dissolved primary fly ash pulp, and the multi-stage water washing unit is composed of a plurality of top-driven stirring water washing devices;

[0042] A multi-stage eddy current separation unit for performing multi-stage three-phase separation on the water-washed primary pulp; the multi-stage eddy current separation unit is composed of a plurality of integrated eddy current three-phase separation devices;

[0043] A wastewater treatment unit for wastewater treatment, which comprises a wastewater treatment module and a reclaimed water tank, wherein the wastewater treatment module includes but is not limited to a multi-stage physical and chemical precipitation system, an MBR system, and a constructed wastewater combination module. The wastewater treatment unit receives the precipitated sludge from the heavy metal removal unit and the wastewater from the waste gas treatment unit, and connects them for treatment together. The treated effluent is used as reclaimed water for the pulping unit, and the dewatered sludge is properly disposed of externally;

[0044] The fly ash washing and dechlorination system further comprises a mechanical solid-liquid separation unit for separating mud and water, which comprises a mechanical separation module and a filtrate buffer tank, wherein the mechanical separation module includes but is not limited to a plate and frame filter press device and a centrifugal separation device. The mechanical solid-liquid separation unit separates the three-stage water-washed ash pulp into filtrate and solid slag. All the filtrate is returned for treatment as the inlet water of the secondary water washing tank, and the solid slag can reach dechlorinated fly ash with a chlorine content ≤2% and a water content of 30% - 50%. Thus, energy-saving and efficient fly ash dechlorination is completed, and it can be externally disposed of for further terminal treatment;

[0045] The fly ash washing and dechlorination system further comprises a heavy metal removal unit for removing heavy metals, which comprises a reaction module and a heavy metal removal sedimentation tank, wherein the reaction module includes but is not limited to a flocculation precipitation device and an electrolytic separation device. The fly ash washing and dechlorination system further comprises an evaporation and crystallization unit for evaporation and crystallization, which comprises an evaporation and crystallization device and a condensate pool, wherein the evaporation and crystallization device includes but is not limited to an MVR device, a membrane concentration + MVR device, and a membrane salt separation + membrane concentration + MVR device. The primary wash liquor prepared in the primary eddy current separation unit is introduced into the heavy metal removal unit for heavy metal removal treatment. The supernatant after heavy metal removal is transported to the evaporation and crystallization unit for treatment. Finally, it is resource-utilized into industrial salt products through the evaporation and crystallization unit, and the condensate water generated by the evaporation and crystallization unit is temporarily stored in the condensate pool as makeup water for the process link. When the makeup water is insufficient, it is supplemented with clean water (including but not limited to tap water, clean surface environmental water, clean groundwater, etc.); the precipitated sludge after heavy metal removal is pumped to the wastewater treatment unit for treatment, and the waste gas generated during the heavy metal removal process is treated by the waste gas treatment system;

[0046] The fly ash water washing and dechlorination system further includes an exhaust gas treatment unit for treating exhaust gas, which includes an exhaust gas treatment module and an exhaust gas discharge module. The exhaust gas treatment module includes, but is not limited to, a spray tower and an activated carbon adsorption device. The exhaust gas treatment unit connects the exhaust gas from the fly ash pulping unit, the exhaust gas from the multi-stage water washing unit, the exhaust gas from the multi-stage eddy current separation unit, the exhaust gas from the heavy metal removal unit, and the exhaust gas from the wastewater treatment unit through the exhaust gas collection main pipe for combined treatment, and connects the wastewater generated by the treatment to the wastewater treatment unit. The treated exhaust gas is discharged at high altitude.

[0047] The precise regulation pre-dissolution device includes a pulping tank A1, a top-driven variable-frequency stirrer A2, and a liquid level controller A3. At the top of the pulping tank A1, there are successively arranged a fly ash inlet A4, a water inlet A5, a water inlet A6, a maintenance manhole A7, and an exhaust gas outlet A8 from left to right. On the side of the pulping tank A1, there are successively arranged an overflow interface A9 and a slurry discharge port A10 from top to bottom. At the bottom of the pulping tank A1, there is a drain interface A11. At the top of the water inlet A6, there is a pipeline flowmeter A12 for measuring the water inflow, and at the top of the pipeline flowmeter A12, there is a solenoid valve A13 for controlling the water inflow in cooperation with it. At the top of the water inlet A5, there is a pipeline flowmeter A14 for measuring the water inflow, and the pipeline flowmeter A14 is connected to the water pump in the reuse water tank of the wastewater treatment unit to control the total water inflow. The input end of the fly ash inlet A4 is connected to a weighing scale system A15 for controlling the fly ash inflow. The top-driven variable-frequency stirrer A2 is installed at the top of the pulping tank A1. The liquid level controller A3 is installed inside the pulping tank A1 to read the liquid level signal in the pulping tank A1. At the top of the top-driven variable-frequency stirrer A2, there is a speed controller A16, and the speed controller A16 is electrically connected to the liquid level controller A3 and the top-driven variable-frequency stirrer A2 respectively. The end of the slurry discharge port A10 far from the pulping tank A1 is connected to a primary slurry discharge pipe A17, and the other end of the primary slurry discharge pipe A17 is connected to a primary slurry buffer tank A18. Inside the primary slurry buffer tank A18, there is a slurry pump A19 for transporting the prepared primary slurry to the subsequent water washing unit.

[0048] Specifically, a certain amount of raw fly ash is weighed by the weighing scale system A15 and fed into the pulping tank A1 through the fly ash inlet A4. At the same time, part of the washing liquid from the secondary eddy current separation unit is introduced into the pulping tank A1 through the incoming water inlet two A6. Through the control of the pipeline flowmeter one A12 and the solenoid valve one A13, the mass ratio of the introduced raw fly ash to the washing liquid is controlled at 0.5 to 1.5. The top drive variable frequency stirrer A2 is started to mix the raw fly ash and the washing liquid. At the same time, the treated reclaimed water from the wastewater treatment unit is continuously injected into the pulping tank A1, and through the control of the pipeline flowmeter two A14 and the water pump in the regeneration water tank, the mass ratio of the raw fly ash to the reclaimed water is controlled at 1.0 to 2.0. By jointly controlling the material inflow of the incoming water inlet one A5, the incoming water inlet two A6 and the fly ash inlet A4, the mass ratio of the total incoming water to the raw fly ash is controlled at 1.5 to 2.5. And the liquid level controller one A3 reads the liquid level change signal in the pulping tank and transmits the signal to the speed control controller A16 to adjust the stirring intensity of the top drive variable frequency stirrer A2 to ensure the pulping effect. During this process, the waste gas in the pulping tank A1 is led out through the waste gas outlet one A8 and enters the waste gas treatment system for treatment. After stirring and pulping for 10 to 30 minutes, a uniformly textured pre-dissolved primary pulp is prepared. The pre-dissolved primary pulp is introduced into the primary pulp buffer tank A18 through the pulp discharge port one A10 and the primary pulp discharge pipe A17, and the slurry pump A19 in it transports the pre-dissolved primary pulp to the subsequent first-stage water washing unit.

[0049] The top drive stirring water washing device includes a water washing tank B1, a top drive stirrer B2 and a liquid level controller two B3. The top of the water washing tank B1 is successively provided with a pulp inlet B4, an incoming water inlet three B5, an incoming water inlet four B6, a maintenance manhole two B7 and a waste gas outlet two B8 from left to right. The upper and lower ends of the side of the water washing tank B1 are respectively provided with an overflow interface two B9 and a pulp discharge port two B10. The bottom of the water washing tank B1 is provided with a drain interface two B11. The tops of the pulp inlet B4, the incoming water inlet three B5 and the incoming water inlet four B6 are respectively installed with a pipeline flowmeter three B12, a pipeline flowmeter four B13 and a pipeline flowmeter five B14 for measuring the water volume. One end of the pulp discharge port two B10 far away from the water washing tank B1 is communicated with B15, and the other end of B15 is connected to the input end of the variable frequency booster pump B16 for transporting the water washed pulp to the subsequent eddy current separation unit. The top drive stirrer B2 is installed on the top of the water washing tank B1, and the liquid level controller two B3 is installed inside the water washing tank B1 for reading the liquid level signal in the water washing tank B1.

[0050] Specifically, the preliminarily dissolved primary pulp prepared in the precise control preliminarily dissolving device is pumped into the water washing tank B1 through the mortar inlet B4, and all the remaining washing liquid of the secondary eddy current separation unit is also introduced into the water washing tank B1 through the incoming water inlet four B6. Start the water pump in the condensate pool of the evaporation crystallization unit, and continuously pump the make-up water into the water washing tank B1 through the incoming water inlet three B5. By jointly reading the data of the pipeline flow meters three B12 and 13 and the pipeline flow meter five B14, and coordinating with the corresponding control valves, the amount of make-up water is precisely controlled, and the mass ratio of the total incoming water to the primary pulp is controlled at 1.0 - 1.5. During this process, the waste gas in the water washing tank B1 is led out through the waste gas outlet two B8 and enters the waste gas treatment system for treatment. After 45 - 90 minutes of stirring and water washing, the first-stage water-washed mortar is prepared. After passing through the mortar discharge ports two B10 and B15, it is transported to the first-stage eddy current separation unit by the variable-frequency booster pump B16. During the process, the internal liquid level controller two B3 is used to monitor the liquid level in the tank in real time and give an alarm when a high liquid level is detected to avoid frequent overflow.

[0051] During the secondary water washing, the first-stage concentrated mortar and the filtrate of the mechanical separation unit are respectively introduced into the water washing tank of the secondary water washing unit, and by controlling the amount of the introduced filtrate, the mass ratio of the total incoming water to the concentrated mortar is controlled at 0.5 - 1.0. After 45 - 90 minutes of stirring and water washing, the secondary water-washed mortar is prepared and transported to the secondary eddy current separation unit by the variable-frequency booster pump B16 in the secondary water washing unit. The waste gas generated during this period is treated by the waste gas treatment system.

[0052] During the tertiary water washing, the secondary concentrated mortar prepared in the secondary eddy current separation unit and the condensate water in the evaporation crystallization unit are respectively introduced into the water washing tank of the tertiary water washing unit as make-up water, and by controlling the amount of the introduced make-up water, the mass ratio of the total incoming water to the secondary concentrated mortar is adjusted to be controlled at 0.5 - 1.0. After 45 - 90 minutes of stirring and water washing, the tertiary water-washed mortar is prepared, and the waste gas generated during this period is treated by the waste gas treatment system.

[0053] The integrated eddy current three-phase separation device includes a washing liquid storage tank C1, a concentrated ash slurry storage tank C2, and multiple groups of eddy current separators C3 connected between them. A dust discharge pipe C4 is installed at the central axis between the washing liquid storage tank C1 and the concentrated ash slurry storage tank C2, and a second solenoid valve C10 that intermittently opens is provided on the dust discharge pipe C4. On both sides of the top of the washing liquid storage tank C1, an exhaust port three C5 and a maintenance manhole three C6 are respectively provided. In the upper middle part of the washing liquid storage tank C1, a washing liquid discharge port C7 and a washing liquid discharge pipe C8 connected to the washing liquid discharge port C7 are provided. At the bottom of the washing liquid storage tank C1, an ash discharge port C9 is provided, and the ash discharge port C9 is connected to the dust discharge pipe C4, and the bottom of the dust discharge pipe C4 is connected to the concentrated ash slurry storage tank C2. At the bottom of the concentrated ash slurry storage tank C2, a ash slurry discharge port C11 is provided, and the bottom end of the ash slurry discharge port C11 is communicated with an ash slurry discharge pipe C12, and a third solenoid valve C13 for controlling the self-flow of the concentrated ash slurry to the subsequent receiving unit is installed at the other end of the ash slurry discharge pipe C12. At the upper side of the eddy current separator C3, a water-washed ash slurry access pipe C3-1 is provided. At the top of the eddy current separator C3, a connecting conduit C3-2 for upward clear liquid and air is provided, and the connecting conduit C3-2 is connected to the washing liquid storage tank C1. At the bottom of the eddy current separator C3, an inverted conical pipe C3-3 for downward ash slurry is provided, and the inverted conical pipe C3-3 is connected to the concentrated ash slurry storage tank C2. The water-washed ash slurry access pipes C3-1 of multiple eddy current separators C3 are all connected to an annular access main pipe C3-4. A fourth solenoid valve C3-5 and a variable-frequency slurry pump C3-6 are sequentially connected to the side end of the annular access main pipe C3-4 to control the slurry volume from the top-driven stirring water-washing device and the eddy current intensity in the eddy current separator C3.

[0054] Specifically, during the primary eddy current separation, the primary water-washed ash slurry prepared by the primary water-washing unit is evenly distributed to several groups of eddy current separators C3 through the annular access main pipe C3-4 for three-phase high-efficiency separation, and the eddy current intensity in the eddy current separator C3 is controlled by adjusting the pressure of the variable-frequency booster pump B16 and the pressure of the fourth solenoid valve C3-5 in the primary water-washing unit connected to the primary eddy current separation; the separated upward clear liquid and air are introduced into the washing liquid storage tank C1 through the connecting conduit C3-2, and the separated downward concentrated ash slurry is introduced into the concentrated ash slurry storage tank C2 through the inverted conical pipe C3-3; during this process, the exhaust gas in the washing liquid storage tank C1 is discharged through the exhaust port three C5 and enters the exhaust gas treatment system for treatment; the separated primary washing liquid flows into the subsequent heavy metal removal unit by self-flow through the washing liquid discharge port C7 and the washing liquid discharge pipe C8; the separated primary concentrated ash slurry flows to the subsequent secondary water-washing unit by self-flow through the ash slurry discharge port C11 and the ash slurry discharge pipe C12, and its flow rate is controlled by the third solenoid valve C13; the ash slurry deposited in the washing liquid storage tank C1 is discharged into the concentrated ash slurry storage tank C2 regularly through the ash discharge port C9 and the dust discharge pipe C4 by the second solenoid valve C10, and the discharge interval time is 6 - 48h;

[0055] During the secondary eddy current separation treatment, the secondary water-washed slurry prepared in the secondary water-washing unit is pumped into the eddy current separator C3 in the secondary eddy current separation unit for efficient three-phase separation. The separated secondary washing liquid flows by gravity to the pulping unit and the primary water-washing unit. The data of the pipeline flow meter A12 in the pulping unit and the pipeline flow meter B12 in the primary water-washing unit are read, and the distribution ratio of the secondary washing liquid reflux to the pulping unit and the primary water-washing unit is adjusted as needed by controlling the solenoid valve A13 in the pulping unit. The waste gas generated during this period is treated by the waste gas treatment system, and the separated secondary concentrated slurry flows into the subsequent tertiary water-washing unit by its own weight.

[0056] Working principle: Pre-dissolution: Weigh a certain amount of fly ash raw ash through the metering scale system A15, and put it into the pulping tank A1 through the fly ash inlet A4, and introduce part of the washing liquid of the secondary eddy current separation unit into the pulping tank A1 through the water inlet A6. Through the control of the pipeline flow meter A12 and the solenoid valve A13, the mass ratio of the introduced fly ash raw ash and the washing liquid is controlled at 0.5-1.5, and the top drive variable frequency agitator A2 is started to mix the fly ash raw ash and the washing liquid. At the same time, the treated reclaimed water of the wastewater treatment unit is continuously injected into the pulping tank A1, and the mass ratio of the fly ash raw ash and the reclaimed water is controlled at 1.0-2.0 through the control of the pipeline flow meter A14 and the water pump in the regeneration water tank; through the linkage control with the water inlet A5 , the material intake of the water inlet A6 and the fly ash inlet A4, and the mass ratio of the total water to the fly ash is controlled at 1.5-2.5; and the liquid level change signal in the pulping tank is read through the liquid level controller A3, and the signal is transmitted to the speed controller A16 to adjust the stirring intensity of the top drive variable frequency agitator A2 to ensure the pulping effect; in this process, the waste gas in the pulping tank A1 is discharged through the waste gas outlet A8 and enters the waste gas treatment system for treatment; after 10-30 minutes of stirring and pulping, a uniform pre-dissolved primary slurry is obtained, and the pre-dissolved primary slurry is introduced into the primary slurry buffer tank A18 through the slurry outlet A10 and the primary slurry discharge pipe A17, and the pre-dissolved primary slurry is transported to the subsequent first-level water washing unit by the slurry pump A19 therein;

[0057] Primary water washing: The pre-dissolved primary pulp prepared above is pumped into the water washing tank B1 through the mortar inlet B4 by the pump. All the remaining washing liquid of the secondary eddy current separation unit is also introduced into the water washing tank B1 through the water inlet four B6. Start the water pump in the condensate pool of the evaporation crystallization unit, and continuously pump the make-up water into the water washing tank B1 through the water inlet three B5. By jointly reading the data of the pipeline flow meters three B12 and 13 and the pipeline flow meter five B14, accurately control the amount of make-up water, and control the mass ratio of the total incoming water to the primary pulp at 1.0 - 1.5; during this process, the waste gas in the water washing tank B1 is discharged through the waste gas outlet two B8 and enters the waste gas treatment system for treatment; after 45 - 90 minutes of stirring and water washing, the primary water-washed mortar is prepared. The water content of the primary water-washed mortar is 60 - 95%, and the chlorine content is 5 - 15%. Subsequently, the primary water-washed mortar passes through the mortar outlet two B10 and B15 and is then transported to the primary eddy current separation unit by the variable frequency booster pump B16;

[0058] Primary eddy current separation: The primary water-washed mortar prepared above is evenly distributed to several groups of eddy current separators C3 through the annular access main pipe C3-4 for three-phase high-efficiency separation, and the eddy current intensity in the eddy current separator C3 is controlled by adjusting the pressure of the variable frequency booster pump B16; the separated upward clear liquid and air are introduced into the washing liquid storage tank C1 through the connecting conduit C3-2, and the separated downward concentrated mortar is introduced into the concentrated mortar storage tank C2 through the inverted conical pipe C3-3; during this process, the waste gas in the washing liquid storage tank C1 is discharged through the waste gas outlet three C5 and enters the waste gas treatment system for treatment; the separated primary washing liquid flows into the subsequent weight removal unit by self-flow through the washing liquid outlet C7 and the washing liquid discharge pipe C8; the separated primary concentrated mortar with a water content of 70 - 90% and a chlorine content of 5 - 15% passes through the mortar outlet C11 and the mortar discharge pipe C12, and flows to the subsequent secondary water washing unit by gravity, and its flow rate is controlled by the solenoid valve three C13; the mortar deposited in the washing liquid storage tank C1 passes through the ash outlet C9 and the ash discharge pipe C4, and is regularly discharged into the concentrated mortar storage tank C2 by the solenoid valve two C10, and the discharge interval time is 6 - 48 hours;

[0059] Primary washing liquid treatment: The above-mentioned primary washing liquid is introduced into the weight removal unit for weight removal treatment. The supernatant after weight removal is transported to the evaporation crystallization unit for treatment, and finally it is resource-utilized into industrial salt products through the evaporation crystallization unit. The condensate water generated by the evaporation crystallization unit is temporarily stored in the condensate pool as the make-up water for the process link. When the make-up water is insufficient, it is supplemented by clean water including but not limited to tap water, clean surface environmental water, clean groundwater, etc.; the precipitated sludge after weight removal is pumped to the wastewater treatment unit for treatment, and the waste gas generated during the weight removal process is treated by the waste gas treatment system;

[0060] Secondary water washing: The above-mentioned primary concentrated ash slurry and the filtrate from the mechanical separation unit are respectively introduced into the water washing tank of the secondary water washing unit. By controlling the amount of the introduced filtrate, the mass ratio of the total incoming water to the concentrated ash slurry is controlled at 0.5 - 1.0. After 45 - 90 minutes of stirring and water washing, the secondary water-washed ash slurry is obtained. The water content of the secondary water-washed ash slurry is 60 - 95%, and the chlorine content is 3 - 10%. It is then transported to the secondary eddy separation unit by a variable-frequency booster pump. The waste gas generated during this period is treated by the waste gas treatment system;

[0061] Secondary eddy separation: The secondary water-washed ash slurry prepared above is pumped into the secondary eddy separation unit for efficient three-phase separation. The separated secondary washing liquid flows by gravity to the pulp-making unit and the primary water washing unit. Read the data of the pipeline flowmeter A12 in the pulp-making unit and the pipeline flowmeter B12 in the primary water washing unit, and by controlling the solenoid valve A13 in the pulp-making unit, adjust the distribution ratio of the secondary washing liquid flowing back to the pulp-making unit and the primary water washing unit as needed. The waste gas generated during this period is treated by the waste gas treatment system. The water content of the separated secondary concentrated ash slurry is 70 - 90%, and the chlorine content is 3 - 10%. Then the secondary concentrated ash slurry flows into the subsequent tertiary water washing unit by its own weight;

[0062] Tertiary water washing: The above-mentioned secondary concentrated ash slurry and the condensate water from the evaporation and crystallization unit are introduced into the water washing tank of the tertiary water washing unit as supplementary water. By controlling the amount of the introduced supplementary water, the mass ratio of the total incoming water to the secondary concentrated ash slurry is adjusted to be controlled at 0.5 - 1.0. After 45 - 90 minutes of stirring and water washing, the tertiary water-washed ash slurry is obtained. The water content of the tertiary water-washed ash slurry is 60 - 95%, and the chlorine content is 1 - 5%. The waste gas generated during this period is treated by the waste gas treatment system;

[0063] Mechanical solid-liquid separation: The mechanical solid-liquid separation unit separates the tertiary water-washed ash slurry into filtrate and solid residue. The filtrate is all used as the inlet water of the secondary water washing tank for reflux treatment. The solid residue can reach dechlorinated fly ash with a chlorine content ≤ 2% and a water content of 30% - 50%. Thus, the energy-saving and efficient fly ash dechlorination is completed, and it can be entrusted for further terminal disposal;

[0064] Waste gas supporting treatment: The waste gas treatment unit connects the waste gas from the fly ash pulping unit, the waste gas from the multi-stage water washing unit, the waste gas from the multi-stage eddy separation unit, the waste gas from the heavy metal removal unit, and the waste gas from the wastewater treatment unit through the waste gas collection main pipe for combined treatment, and connects the wastewater generated by the treatment to the wastewater treatment unit. The treated waste gas is discharged at high altitude;

[0065] Wastewater supporting treatment: The wastewater treatment unit receives the precipitated sludge from the heavy metal removal unit and the wastewater from the waste gas treatment unit for combined treatment. The treated effluent is used as recycled water for the pulp-making unit, and the dewatered sludge is entrusted for proper treatment.

[0066] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An energy-saving and highly efficient system for washing and dechlorinating fly ash, characterized in that, Including: A fly ash pulping unit for pre-dissolving the weighed original fly ash, which includes a precise regulation pre-dissolving device and a primary pulp buffer tank; A multi-stage water washing unit for performing multi-stage water washing on the primary pulp of the pre-dissolved original fly ash. The multi-stage water washing unit is composed of multiple top-driven stirring water washing devices; A multi-stage eddy current separation unit for performing multi-stage three-phase separation on the washed primary pulp; The multi-stage eddy current separation unit is composed of multiple integrated eddy current three-phase separation devices; A wastewater treatment unit for wastewater treatment, which includes a wastewater treatment module and a reclaimed water tank. The wastewater treatment module includes, but is not limited to, a multi-stage physical and chemical precipitation system, an MBR system, and a constructed wastewater combination module.

2. The system for energy-saving and highly efficient washing and dechlorination of fly ash according to claim 1, characterized in that: The precise regulation pre-dissolving device includes a pulping tank (A1), a top-driven variable-frequency stirrer (A2), and a first liquid level controller (A3). The top of the pulping tank (A1) is successively provided with a fly ash inlet (A4), a first water inlet (A5), a second water inlet (A6), a maintenance manhole (A7), and a first exhaust gas outlet (A8) from left to right. The side of the pulping tank (A1) is successively provided with a first overflow interface (A9) and a first ash slurry discharge port (A10) from top to bottom. The bottom of the pulping tank (A1) is provided with a first drain interface (A11); the top of the second water inlet (A6) is connected to a pipeline flowmeter (A12) for measuring the water inflow, and a solenoid valve (A13) for controlling the water inflow in cooperation with it is installed at the top of the pipeline flowmeter (A12). A pipeline flowmeter (A14) for measuring the water inflow is installed at the top of the first water inlet (A5), and the pipeline flowmeter (A14) is connected to a water pump in the reclaimed water tank of the wastewater treatment unit for controlling the total water inflow. The input end of the fly ash inlet (A4) is connected to a weighing scale system (A15) for controlling the ash inflow. The top-driven variable-frequency stirrer (A2) is installed on the top of the pulping tank (A1). The first liquid level controller (A3) is installed inside the pulping tank (A1) for reading the liquid level signal in the pulping tank (A1). A speed controller (A16) is installed on the top of the top-driven variable-frequency stirrer (A2), and the speed controller (A16) is electrically connected to the first liquid level controller (A3) and the top-driven variable-frequency stirrer (A2) respectively. The end of the first ash slurry discharge port (A10) far from the pulping tank (A1) is connected to a primary pulp discharge pipe (A17), and the other end of the primary pulp discharge pipe (A17) is connected to the primary pulp buffer tank (A18). A slurry pump (A19) is provided in the primary pulp buffer tank (A18) for transporting the prepared primary pulp to the subsequent water washing unit.

3. An energy-saving and highly efficient fly ash water washing and dechlorination system according to claim 1, characterized in that: The top-driven stirring and water-washing device includes a water-washing tank (B1), a top-driven stirrer (B2), and a second liquid level controller (B3). The top of the water-washing tank (B1) is successively provided with a mortar inlet (B4), a third water inlet (B5), a fourth water inlet (B6), a second maintenance manhole (B7), and a second waste gas discharge port (B8) from left to right. The upper and lower ends of the side of the water-washing tank (B1) are respectively provided with a second overflow interface (B9) and a second mortar discharge port (B10). The bottom of the water-washing tank (B1) is provided with a second emptying interface (B11). At the top of the mortar inlet (B4), the third water inlet (B5), and the fourth water inlet (B6), a third pipeline flowmeter (B12), a fourth pipeline flowmeter (B13), and a fifth pipeline flowmeter (B14) for measuring the water volume are respectively installed. One end of the second mortar discharge port (B10) far from the water-washing tank (B1) is communicated with (B15), and the other end of the (B15) is connected to the input end of a variable-frequency booster pump (B16) for conveying the water-washed mortar to the subsequent eddy current separation unit. The top-driven stirrer (B2) is installed on the top of the water-washing tank (B1), and the second liquid level controller (B3) is installed inside the water-washing tank (B1) for reading the liquid level signal in the water-washing tank (B1).

4. An energy-saving and highly efficient fly ash water washing and dechlorination system according to claim 1, characterized in that: The integrated eddy current three-phase separation device includes a washing liquid storage tank (C1), a concentrated mortar storage tank (C2), and multiple groups of eddy current separators (C3) connected therebetween. A dust discharge pipe (C4) is installed at the central axis between the washing liquid storage tank (C1) and the concentrated mortar storage tank (C2), and a second solenoid valve (C10) with intermittent opening is provided on the dust discharge pipe (C4). On both sides of the top of the washing liquid storage tank (C1), a third waste gas discharge port (C5) and a third maintenance manhole (C6) are respectively provided. In the upper middle part of the washing liquid storage tank (C1), a washing liquid discharge port (C7) and a washing liquid discharge pipe (C8) connected to the washing liquid discharge port (C7) are provided. At the bottom of the washing liquid storage tank (C1), a dust outlet (C9) is provided, and the dust outlet (C9) is connected to the dust discharge pipe (C4), and the bottom of the dust discharge pipe (C4) is connected to the concentrated mortar storage tank (C2). At the bottom of the concentrated mortar storage tank (C2), a mortar discharge port (C11) is provided, and the bottom end of the mortar discharge port (C11) is communicated with a mortar discharge pipe (C12), and a third solenoid valve (C13) for controlling the self-flow of the concentrated mortar to the subsequent receiving unit is installed at the other end of the mortar discharge pipe (C12).

5. An energy-saving and highly efficient fly ash washing and dechlorination system according to claim 4, characterized in that: The upper side of the eddy current separator (C3) is provided with a water-washed ash slurry access pipe (C3-1), the top of the eddy current separator (C3) is provided with a connecting conduit (C3-2) for upward clear liquid and air, and the connecting conduit (C3-2) is connected to the washing liquid storage tank (C1). The bottom of the eddy current separator (C3) is provided with an inverted conical pipe (C3-3) for downward ash slurry, and the inverted conical pipe (C3-3) is connected to the concentrated ash slurry storage tank (C2). The water-washed ash slurry access pipes (C3-1) of multiple eddy current separators (C3) are all connected to a circular access main pipe (C3-4). The side end of the circular access main pipe (C3-4) is sequentially connected with a solenoid valve four (C3-5) and a variable-frequency slurry pump (C3-6) to control the slurry amount from the top-driven stirring water-washing device and the eddy current intensity in the eddy current separator (C3).

6. The system for energy-saving and efficient washing and dechlorination of fly ash according to claim 1, characterized in that: The dechlorination system further includes a mechanical solid-liquid separation unit for separating mud and water, which includes a mechanical separation module and a filtrate buffer tank. The mechanical separation module includes, but is not limited to, a plate and frame filter press device and a centrifugal separation device.

7. An energy-saving and highly efficient fly ash water washing and dechlorination system according to claim 1, characterized in that: The dechlorination system further includes a heavy metal removal unit for removing heavy metals, which includes a reaction module and a heavy metal removal sedimentation tank. The reaction module includes, but is not limited to, a flocculation sedimentation device and an electrolytic resolution device.

8. An energy-saving and highly efficient fly ash water washing and dechlorination system according to claim 1, characterized in that: The dechlorination system further includes an evaporation and crystallization unit for evaporation and crystallization, which includes an evaporation and crystallization device and a condensation water tank. The evaporation and crystallization device includes, but is not limited to, an MVR device, a membrane concentration + MVR device, and a membrane salt separation + membrane concentration + MVR device.

9. The system for energy-saving and efficient washing and dechlorination of fly ash according to claim 1, characterized in that: The dechlorination system further includes an exhaust gas treatment unit for exhaust gas treatment, which includes an exhaust gas treatment module and an exhaust gas emission module. The exhaust gas treatment module includes, but is not limited to, a spray tower and an activated carbon adsorption device.

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