Rapid crystallization device of Fenton fluidized bed

Abstract

The utility model discloses a Fenton fluidized bed rapid crystallization device which comprises a reaction tower, a raw water adjusting assembly, a crystal filtering assembly, a crystal separation box, a reflux tank assembly, a sulfuric acid liquid storage barrel, a ferrous sulfate liquid storage barrel, a hydrogen peroxide liquid storage barrel, a raw water rapid mixer, a reflux rapid mixer I and a reflux rapid mixer II, the reaction tower comprises a downstream assembly, a countercurrent assembly, a steady flow layer I, a steady flow layer II, a crystallization layer, a baffling layer, a solid crystal assembly and a feeding assembly which are sequentially arranged from bottom to top; through control of the raw water quick mixer, the first backflow quick mixer and the second backflow quick mixer on reaction water flow and synergistic reaction between the upper layer and the lower layer, quick crystallization is realized. The device is fast in crystallization and low in reagent consumption.

Description

Technical Field

[0001] The utility model relates to a Fenton fluidized bed rapid crystallization device, belonging to the technical field of organic wastewater treatment. Background Art

[0002] Advanced oxidation is a commonly used treatment technology for organic wastewater, especially for difficult-to-degrade industrial organic wastewater. As a pioneer of advanced oxidation technology, Fenton is a homogeneous chemical oxidation water treatment technology. Its reaction conditions are easy to obtain, and it does not require high temperature and high pressure. It has the advantages of simple equipment and rapid reaction. At present, Fenton has been widely used in the treatment of industrial wastewater such as petroleum industry, textile industry, paper industry, wood processing industry, brewing industry, and landfill leachate. The traditionally recognized Fenton chain reaction mechanism: Fenton reagent Fe 2+ The ·OH generated by the reaction with H2O2 utilizes the strong oxidizing hydroxyl free radicals to oxidize and decompose organic pollutants. The relevant reaction formula and its reaction rate constant are as follows:

[0003] Fe 2+ +H2O2→Fe 3+ +OH - +·OH; k1=40~80(L·mol -1 ·s -1 ) (1)

[0004] Fe 3+ +H2O2→Fe 2+ +·O2H+H + ; k2 = 0.001 ~ 0.02 (L·mol -1 ·s -1 ) (2)

[0005] In the Fenton reaction, Fe 3+ Return to Fe 2+ is the rate-limiting step, and the rate constant k2 of this reaction is much lower than that of Fe 2+ Fe 3+ The conversion rate k1 will cause Fe 3+ Accumulation makes chain reaction difficult to achieve, which ultimately leads to a decrease in the degradation rate of organic matter. 2+ and H2O2 dosage, thereby increasing the hydroxyl radical generation concentration to improve the degradation rate of organic matter, but the amount of Fenton reagent and the amount of sludge produced will be greatly increased. 2+ Both H2O2 and ·OH can act as hydroxyl radical scavengers to consume ·OH and produce less active HO2·, which can also lead to ineffective decomposition of H2O2, thereby reducing the utilization rate of Fenton's reagent and increasing the cost of wastewater treatment.

[0006] The Fenton fluidized bed system is a widely used reaction system in the Fenton oxidation process. It is a process that combines the traditional Fenton process with a fluidized bed crystallizer. The conventional fluidized bed crystallizer is a columnar reactor. Water is generally introduced from the bottom. The reactor is filled with seed material. The seed material is expanded and fluidized through internal circulation. The seed support undergoes heterogeneous crystallization during full contact with the solution, achieving the effect of removing the target substance from the wastewater. Compared with the traditional precipitation method, the crystallization product obtained by the crystallization method has a low water content, which is beneficial to the subsequent sludge treatment.

[0007] Compared with traditional Fenton, Fenton fluidized bed has obvious advantages in organic matter removal rate and Fenton reagent utilization rate. However, since the iron crystallization process is easily disturbed, such as reaction pH, iron ion concentration, hydraulic conditions, organic intermediates, complex interfering ions, etc., the reactor crystallization debugging time is very long, often requiring 3-6 months or even longer. How to reduce the rate-limiting effect of the fluidized bed, reduce the amount of Fenton reagent and improve the reagent utilization rate is an urgent problem to be solved in the industrial refractory organic wastewater treatment industry. Utility Model Content

[0008] Purpose of the utility model: In order to solve the problem of long crystallization time in Fenton fluidized bed, the utility model provides a Fenton fluidized bed rapid crystallization device, which improves the conversion rate of iron ions and organic matter in the chain reaction through multi-flow hydraulic mixing and upper and lower multi-layer multi-effect rapid crystallization, thereby realizing the improvement of the overall organic matter oxidation capacity of the Fenton system.

[0009] Technical solution: To achieve the above purpose, the technical solution adopted by the utility model is:

[0010] A Fenton fluidized bed rapid crystallization device comprises a reaction tower, a raw water adjustment component, a crystal filtering component, a crystal separation box, a reflux tank component, a sulfuric acid storage tank, a ferrous sulfate storage tank, and a hydrogen peroxide storage tank, wherein:

[0011] The reaction tower comprises a downstream component, a countercurrent component, a first stabilizing layer, a second stabilizing layer, a crystallization layer, a baffle layer, a crystal fixing component and a feeding component which are sequentially arranged from bottom to top.

[0012] The outlet of the hydrogen peroxide storage tank is connected to the top suction port of the reflux fast mixer 1, and the inlet of the reflux fast mixer 1 is connected to the reflux tank assembly through the reflux pipe 1 33. The outlet end of the reflux fast mixer 1 is connected to the inlet of the countercurrent assembly, the inlet of the stabilizing layer 1, the inlet of the stabilizing layer 2, and the raw water fast mixer.

[0013] The outlet of the ferrous sulfate storage barrel is connected to the top suction port of the second reflux fast mixer, and the inlet of the second reflux fast mixer is connected to the reflux tank assembly through the second reflux pipe.

[0014] The raw water adjustment component includes a raw water adjustment tank and a raw water fast mixer. The sulfuric acid storage tank, the raw water adjustment tank and the raw water fast mixer are connected in sequence. The outlet of the raw water fast mixer is connected to the inlet of the downstream component, the top suction port 1 of the raw water fast mixer is connected to the outlet end of the reflux fast mixer 1, and the top suction port 2 of the raw water fast mixer is connected to the outlet end of the reflux fast mixer 2.

[0015] The inlet of the crystal filtering assembly is connected to the crystal liquid outlet of the crystal layer, and the crystal filtering assembly is located at the center of the upper part of the crystal separation box.

[0016] Preferably, it comprises a water outlet degassing tank and a water outlet tank, wherein the water outlet degassing tank is located on the left outer side of the upper part of the reaction tower, a degassing pipe is arranged in the water outlet degassing tank, and the water outlet of the reaction tower enters the water outlet degassing tank through the water outlet hole 1. The water outlet tank is located at the rear end of the water outlet degassing tank, and the water outlet tank and the water outlet degassing tank are provided with a water outlet hole 2 for communication.

[0017] Preferably: the reflux trough assembly includes reflux trough 1 and reflux trough 2, wherein the reflux trough 1 and reflux trough 2 are located on the right outer side of the upper part of the reaction tower and are connected to the reaction tower through water outlet 3 respectively, the bottom of reflux trough 1 is connected to reflux pipe 1, and the bottom of reflux trough 2 is connected to reflux pipe 2.

[0018] Preferably: a multi-parameter flow analysis pool is arranged outside the reaction tower, the top interface of the multi-parameter flow analysis pool is connected to the baffle layer and the reflux tank one through pipelines respectively, the bottom interface one of the multi-parameter flow analysis pool is connected to the steady flow layer two pipeline, and the interface two is connected to the waste liquid discharge pipeline.

[0019] Preferably, the raw water adjustment component includes a raw water adjustment tank, a raw water pump, a raw water flow meter, and a raw water fast mixer connected in sequence. The sulfuric acid storage tank is connected to the raw water adjustment tank through a pressurized pipe, and a dosing pump 3 is provided on the pressurized pipe. A pH online detector is provided in the raw water adjustment tank.

[0020] Preferably: the outlet of the reflux quick mixer 1 is provided with a reflux mixing pump 1 and a reflux flow meter 1. A reflux mixing pump 2 and a reflux flow meter 2 are provided between the raw water quick mixer and the reflux quick mixer 2.

[0021] Preferably, the feeding assembly comprises a feeder and a vibrating membrane cloth, the feeder is arranged at the top of the reaction tower, and the vibrating membrane cloth is laid on the bottom of the feeder.

[0022] Preferably, an open 3.5 mm nylon mesh bag is placed on the crystal separation box, the outlet of the crystal separation box is connected to the water inlet on the top of the crystal fixing assembly through a filtrate reflux pipe, and a filtrate reflux pump is provided on the filtrate reflux pipe 22 .

[0023] Preferably, the first stabilizing layer is filled with 25 mm coarse glass beads, the second stabilizing layer is filled with 16 mm fine glass beads, and the crystallization layer is composed of 0.4-0.6 mm complex crystal seeds.

[0024] Preferably: the baffle layer includes a small baffle assembly and a large baffle assembly, the small baffle assembly is arranged inside the large baffle assembly, the small baffle assembly is welded by more than two PP plates, and the angle between the welded plates is 20°-30°. The large baffle assembly is welded by 4 PP plates, and the welding angle between adjacent plates is 105°-155°. A PP inclined plate is fixedly installed below the solid crystal assembly, and the installation angle is 55°.

[0025] Compared with the prior art, the utility model has the following beneficial effects:

[0026] Through the control of the reaction water flow by the raw water fast mixer, the reflux fast mixer 1, and the reflux fast mixer 2, as well as the coordinated reaction between the upper and lower layers, on the one hand, the water flow rate can be increased by mixing with the raw water through the fast mixing reflux device, the fluidization state of the water body can be increased, and the hydraulic mixing component increases the contact area of ​​the Fenton reagent mixing reaction, the reaction effect is increased, and the conversion rate of iron ions and organic matter in the chain reaction can be increased, so as to realize the improvement of the overall organic matter oxidation capacity of the Fenton system. On the other hand, the non-directional turbulence effect between the multiple layers in the reaction tower makes the reagent mixing speed fast and the mixing more sufficient. Therefore, the utility model not only crystallizes quickly, but also consumes less reagents. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 : Schematic diagram of the Fenton fluidized bed crystallization control system flow chart.

[0028] Figure 2 : Schematic diagram of the top plan structure of the fluidized bed.

[0029] Figure 3 : Schematic diagram of the hydraulic mixing components at the bottom of the fluidized bed.

[0030] In the figure: 1, reaction tower, 2, countercurrent component, 3, downstream component, 4, raw water adjustment tank, 41, online pH meter, 42, raw water COD meter, 5, raw water pump, 6, raw water flow meter, 7, sulfuric acid storage tank, 8, ferrous sulfate storage tank, 9, hydrogen peroxide storage tank, 91, dosing pump 1, 81, dosing pump 2, 71, dosing pump 3, 101, raw water fast mixer, 102, reflux fast mixer 1, 103, reflux fast mixer 2, 11, reflux mixing pump 1, 12, reflux flow meter 1, 13, reflux mixing pump 2, 14, reflux flow meter 2, 15, stabilizing layer 1, 16, stabilizing layer 2, 17, crystallization layer, 18, baffle layer, 191, small baffle component, 192. Large baffle assembly, 20. Multi-parameter flow analysis pool, 21. Solid crystal assembly, 22. Filtrate reflux pipe, 23. Crystal separation box, 24. Filter crystal assembly, 25. Filtrate reflux pump, 251. Filtrate level meter, 26. Feeder, 27. Vibrating membrane cloth, 281. Water outlet hole one, 282. Water outlet hole two, 283. Water outlet hole three, 29. Water outlet degassing tank, 30. Degassing pipe, 31. Water outlet tank, 321. Reflux tank one, 322. Reflux tank two, 33. Reflux pipe one, 34. Reflux pipe two, 35. Sampling valve, 36. COD online instrument, 37. Electrical control assembly V21. Lower layer dosing valve, V22. Middle layer dosing valve, V23. Upper layer dosing valve. DETAILED DESCRIPTION

[0031] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0032] Example

[0033] A Fenton fluidized bed rapid crystallization device, such as Figure 1-3 As shown: it includes a reaction tower 1, a raw water adjustment component, a crystal filter component 24, a crystal separation box 23, a reflux tank component, a sulfuric acid storage tank 7, a ferrous sulfate storage tank 8, and a hydrogen peroxide storage tank 9, wherein:

[0034] The reaction tower 1 comprises a downstream component 3, a countercurrent component 2, a first stabilizing layer 15, a second stabilizing layer 16, a crystallization layer 17, a baffle layer 18, a crystal fixing component 21, and a feeding component, which are arranged in sequence from bottom to top.

[0035] A hydraulic mixing assembly is provided at the bottom of the reaction tower 1, including a countercurrent assembly 2 and a downstream assembly 3. The inlet of the downstream assembly 3 is connected to the outlet end of the raw water fast mixer 101. The countercurrent assembly 2 is located at the upper end of the downstream assembly 3. The inlet of the countercurrent assembly 2 is connected to the outlet end of the reflux flow meter 12 and is connected to the top suction port of the raw water fast mixer 101; the other top suction port of the raw water fast mixer 101 is connected to the outlet of the reflux flow meter 2 14; the upper part of the countercurrent assembly 2 is arranged in sequence along the reaction tower 1 from bottom to top with a stabilizing layer 1 (15), a stabilizing layer 2 (16) and a crystallization layer 17. In another embodiment, the stabilizing layer 1 15 is filled with 25 mm coarse glass beads, the stabilizing layer 2 16 is filled with 16 mm fine glass beads, and the crystallization layer 17 is composed of 0.4-0.6 mm complex crystal seeds.

[0036] In another embodiment, the baffle layer 18 is on the upper part of the crystallization layer 17, and the baffle layer 18 includes a small baffle assembly 191 and a large baffle assembly 192. The small baffle assembly 191 is arranged inside the large baffle assembly 192, and the small baffle assembly 191 is welded by more than two PP plates, and the angle between the welded plates is 20°-30°. The large baffle assembly 192 is welded by 4 PP plates, and the welding angle of adjacent plates is 105°-155°. The solid crystal assembly 21 is located between the baffle layer 18 and the feeder 26. A PP inclined plate is fixedly installed below the solid crystal assembly 21, and the installation angle is 55°. The upper end of the inclined plate is connected to the filtrate reflux pipe 22, and the filtrate reflux pipe 22 is provided with a water outlet undercut.

[0037] The concentration of hydrogen peroxide in the hydrogen peroxide storage tank 9 is 27.5%. The outlet of the hydrogen peroxide storage tank 9 is connected to the top suction port of the reflux fast mixer 102, and the inlet of the reflux fast mixer 102 is connected to the reflux tank assembly through the reflux pipe 1 33. The outlet end of the reflux fast mixer 102 is connected to the inlet of the countercurrent assembly 2, the inlet of the stabilizing layer 15, the inlet of the stabilizing layer 2 16, and the raw water fast mixer 101.

[0038] The concentration of ferrous sulfate in the ferrous sulfate storage tank 8 is 8%. The outlet of the ferrous sulfate storage tank 8 is connected to the top suction port of the second reflux mixer 103, and the inlet of the second reflux mixer 103 is connected to the reflux tank assembly through the second reflux pipe 34.

[0039] The raw water adjustment component includes a raw water adjustment tank 4 and a raw water fast mixer 101. The solution in the sulfuric acid storage tank 7 is 98% sulfuric acid. The sulfuric acid storage tank 7, the raw water adjustment tank 4, and the raw water fast mixer 101 are connected in sequence. The outlet of the raw water fast mixer 101 is connected to the inlet of the downstream component 3, the top suction port 1 of the raw water fast mixer 101 is connected to the outlet end of the reflux fast mixer 1 102, and the top suction port 2 of the raw water fast mixer 101 is connected to the outlet end of the reflux fast mixer 2 103.

[0040] In another embodiment, the outlet of the reflux fast mixer 102 is provided with a reflux mixing pump 11 and a reflux flow meter 12. A reflux mixing pump 2 13 and a reflux flow meter 2 14 are provided between the raw water fast mixer 101 and the reflux fast mixer 2 103.

[0041] In another embodiment, the raw water adjustment tank 4 is connected to the raw water pump 5, the raw water flow meter 6, and the raw water fast mixer 101 in sequence to form a raw water adjustment component, and the sulfuric acid storage tank 7 is connected to the raw water adjustment tank 4 through the dosing pump 3 71 and the pressure pipe, and the raw water adjustment tank 4 is provided with a pH online detector.

[0042] The inlet of the crystal filtering assembly 24 is connected to the crystal liquid outlet of the crystal layer 17 , and the crystal filtering assembly 24 is located at the center of the upper part of the crystal separation box 23 .

[0043] The crystal filtering assembly 24 is located at the center of the upper part of the crystal separation box 23 , and is covered with an open 3.5 mm nylon mesh bag; the crystal separation box 23 is connected to the filtrate reflux pump 25 , and the outlet of the filtrate reflux pump 25 is connected to the filtrate reflux pipe 22 .

[0044] In another embodiment, a water outlet degassing tank 29 and a water outlet tank 31 are further provided. The water outlet degassing tank 29 is located on the left outer side of the upper part of the reaction tower 1. A degassing pipe 30 is provided in the water outlet degassing tank 29. The water outlet of the reaction tower 1 enters the water outlet degassing tank 29 through the water outlet hole 1 281. The water outlet tank 31 is located at the rear end of the water outlet degassing tank 29. The water outlet tank 31 and the water outlet degassing tank 29 are provided with a water outlet hole 282 for communication.

[0045] In another embodiment, the reflux trough assembly includes a reflux trough 1 321 and a reflux trough 2 322, wherein the reflux trough 1 321 and the reflux trough 2 322 are located on the right outer side of the upper part of the reaction tower 1, and are connected to the reaction tower 1 through the water outlet 3 283 respectively, and the bottom of the reflux trough 1 321 is connected to the reflux pipe 1 33, and the bottom of the reflux trough 2 322 is connected to the reflux pipe 2 34.

[0046] The outlet of the reflux pipe 33 is connected to a reflux mixer 102, a reflux mixing pump 11 and a reflux flowmeter 12 in sequence from top to bottom, the top suction port of the reflux mixer 102 is connected to the outlet of a dosing pump 91, and the outlet of the hydrogen peroxide storage tank 9 is connected to the inlet of a dosing pump 91.

[0047] The outlet of the reflux pipe 34 is connected to the reflux mixer 103, the reflux mixing pump 13 and the reflux flowmeter 14 in sequence from top to bottom. The top suction port of the reflux mixer 103 is connected to the outlet of the dosing pump 81, and the outlet of the ferrous sulfate storage tank 8 is connected to the inlet of the dosing pump 81.

[0048] In another embodiment, a multi-parameter flow analysis pool 20 is arranged outside the reaction tower, and the multi-parameter flow analysis pool 20 is suspended and installed outside the crystal layer 17 of the reaction tower. The top interface of the multi-parameter flow analysis pool 20 is connected to the baffle layer 18 and the reflux tank 1 321 through pipelines, respectively. The bottom interface 1 of the multi-parameter flow analysis pool 20 is connected to the steady flow layer 2 16 pipeline, and the interface 2 is connected to the waste liquid discharge pipeline. The multi-parameter flow pool can analyze and obtain pH / ORP and Fe 2+ / Fe 3+ value.

[0049] In another embodiment, a feeding assembly is provided on the top of the reaction tower 1 , and the feeding assembly includes a feeder 26 and a vibration membrane cloth 27 . The feeder 26 is provided on the top of the reaction tower 1 , and the vibration membrane cloth 27 is laid on the bottom of the feeder 26 .

[0050] In another embodiment, the crystal separation box 23 is covered with an open 3.5 mm nylon mesh bag, and the outlet of the crystal separation box 23 is connected to the water inlet at the top of the crystal fixing assembly 21 through a filtrate reflux pipe 22, and a filtrate reflux pump 25 is provided on the filtrate reflux pipe 22.

[0051] The electrical control component 37 is connected to all motors and control valves through power control lines, and is connected to all detection instruments through signal control lines. The electrical control component 37 receives data obtained from online instruments and flow analysis pool detection through input circuit signal transmission. The PLC of the electrical control component 37 outputs corresponding control signals to the associated execution components (pumps and valves) according to the associated parameters set by the program.

[0052] The initial mass ratio of COD amount per unit time of reaction water inflow to hydrogen peroxide dosage and ferrous sulfate dosage is 1:2:4.

[0053] This embodiment uses a special multi-flow hydraulic mixing component to ensure rapid and stable heterogeneous crystallization. To make the reaction undergo heterogeneous crystallization and prevent the occurrence of homogeneous precipitation, shorten the growth time of iron crystals, and allow the entire reactor to quickly enter a stable operating state, the key lies in the hydraulic conditions of the mixed contact reaction of the Fenton reagent, wastewater, and crystallization carrier. In order to limit the occurrence of homogeneous precipitation and meet the conditions for heterogeneous crystallization, it is necessary to control special hydraulic flow states so that the seed crystals form non-directional turbulence under the action of hydraulic pressure, so that the Fenton reaction as a whole is in a fluidized state that generates tiny solid precipitates. The present invention realizes the control of multi-layer non-directional turbulence:

[0054] The water flow formed by the downstream component 3 in the lower layer is a clockwise upward swirl with large head, large flow rate and fast flow rate; the water flow formed by the upstream component 2 in the upper layer is a counterclockwise downward swirl. Compared with the lower layer, the pressure, flow rate and flow rate are reduced to 1 / 3-1 / 4. The first layer of micro-resistance non-directional turbulence is formed at the bottom of the reaction tower, and the reagents and raw water are fully and quickly mixed;

[0055] The first stabilizing layer 15 is filled with 25mm glass beads, and the second stabilizing layer 16 is filled with 16mm glass beads. The gaps between the glass beads form many small Fenton reaction units. The glass beads are extremely hydrophobic, and each small unit forms many microscopic water flow disturbance effects. The contact probability and contact area of ​​·OH produced by the Fenton reaction with the organic pollutants in the wastewater are increased; and the small reaction units of the upper and lower stabilizing layers are reduced from large to small. The H2O2 dosing pipes are arranged at the lower part of the two stabilizing layers respectively. The dosing pipes are provided with a plurality of φ3mm small holes for discharging drugs. The drug discharging time is controlled by the electrical control component 37. The drug discharging fast-rush mode of segmented and timed drug discharging is formed, forming the second and third layers of large resistance non-directional turbulence, the Reynolds number of the upper and lower mixed liquids is increased, the turbulent state is deepened, the reaction is more intense, and at the same time, the ineffective decomposition caused by excessive H2O2 dosing is avoided, and the overall efficiency of Fenton oxidation of organic matter is improved;

[0056] After the first, second and third layers of non-directional turbulent reaction, the mixed solution undergoes rapid and stable heterogeneous precipitation crystallization in the crystallization layer 17. First, the iron ion concentration is controlled by a multi-parameter flow analysis cell and an electrical control component, so that the mixed solution is supersaturated and prone to solid precipitation. At the same time, a heterogeneous particle SiO-Fe complex with a structure similar to that of the precipitate is provided as a crystal nucleus. The surface free energy of the crystal nucleus is small, and the driving force for heterogeneous precipitation is smaller, thereby forming FeOOH crystals on the surface of the crystal nucleus. The tiny precipitates in the fluidized mixed solution quickly aggregate and grow at the crystal surface crystallization sites, achieving rapid and stable crystallization.

[0057] After the crystals stabilize, in addition to homogeneous Fenton oxidation of organic matter, reduction dissolution of the crystals and heterogeneous Fenton oxidation also occur. FeOOH will produce Fe 2+ , Fe(OH)2 and ·OH, thereby reducing the homogeneous Fenton reagent and improving the utilization rate of ·OH oxidized organic matter; a baffle layer 18 is provided on the crystallization layer 17, and the mixed liquid rises and passes through the small baffle component 191 and the large baffle component 192 in turn. The baffle component can change the flow direction and state of the mixed liquid, increase the turbulent state, and extend the residence time of the iron oxide; the solid crystal component 21 can prevent the iron ion precipitate from escaping the reaction tower due to the high fluidization velocity, thereby ensuring the concentration of the mixed solid matter in the reaction and maintaining the optimal conditions for crystallization.

[0058] In addition, separate control is adopted, and the reflux mixing pump 1 and the reflux mixing pump 2 13 are in a normally open state (except when discharging crystals). When starting up, the raw water pump 5 is turned on and the dosing pump 2 81 is turned on at the same time. After 30 seconds, the dosing pump 2 91 is turned on again, which can further solve the speed limit problem of the Fenton reaction, and at the same time, the reflux flow rate is used to control the reaction fluidization rising speed.

[0059] A Fenton fluidized bed rapid crystallization method comprises the following control steps:

[0060] Step 1, wastewater enters the raw water adjustment tank 4, adjusts the pH value of the wastewater, the online pH meter 41 is linked with the dosing pump 3 71, the electrical control component 37 associates the parameter pH value in the range of 3.3 to 3.5, and the dosing pump 3 71 stops running.

[0061] Step 2, the COD concentration of the raw water adjustment tank 4 is obtained in real time through the raw water COD meter 42, the electrical control component 37 inputs the raw water COD concentration, and according to the set H2O2:COD mass ratio initial value M=2, the H2O2 dosage is obtained by feedback, and the execution action is output to open the dosing pump 91 and the lower dosing valve V21, and according to the timer set time interval of 8-10min, the middle dosing valve V22 and the upper dosing valve V23 are opened and closed alternately in batches, and V22 and V23 are set to an interlocking relationship, that is, when V23 is opened, V22 is closed, and V21 is normally open; when the M value is adjusted, the frequency of the dosing pump 91 is automatically adjusted, thereby intelligently adjusting the pump outflow.

[0062] Step 3, the electrical control component 37 sets H2O2:Fe 2+ The initial value of the molar ratio is L = 5, combined with the H2O2 dosage obtained in step 2, the feedback output Fe 2+ The quality is obtained, and then the dosage of FeSO4 is obtained, and the dosing pump 81 is turned on; when the L value is adjusted, the frequency of the dosing pump 81 is automatically adjusted, thereby intelligently adjusting the outflow rate of the pump.

[0063] Step 4: the electrical control component 37 regularly discharges the crystal particles at the bottom of the crystal layer 17 according to the crystal discharge cycle T.

[0064] When crystals are discharged, the electrical control component 37 is set to shut down the raw water pump, reflux pump and outlet valve 60 seconds before the crystals are discharged, and restore the normal water inlet and outlet 15 to 20 seconds after the crystals are discharged, that is, open the raw water pump, reflux pump and outlet valve. The optimal crystal discharge point of the control system can maintain the normal growth metabolism system of the crystals, which is conducive to the rapid and stable growth of the crystals.

[0065] The crystal filter assembly 24 intercepts most of the crystal particles. The filtrate in the lower part of the crystal separation box is set according to the high and low liquid levels, which are related to the opening and closing of the filtrate reflux pump. The high liquid level opens the filtrate reflux pump 25 to pump the filtrate back to the upper part of the reaction tower 1; when the filtrate pump is running, the filtrate rushes out from the downward holes of the filtrate reflux pipe 22, and the sludge and accumulated iron powder on the lower inclined plate can be quickly and regularly washed to prevent the sludge from caking and accumulating on the inclined plate due to long-term operation, causing the reactor to stop operating.

[0066] Step 5: At the initial start-up, the electrical control component 37 controls the Fe 2+The initial iron powder dosage F value (mg / L) is set at 1 / 2 to 1 / 3 of the dosage. The vibration motor starts, and the vibration membrane cloth at the bottom of the feeder vibrates with a certain amplitude. The iron powder quickly passes through the baffle layer 18 and returns to the crystal layer, where a reduction reaction occurs. Fe+2Fe 3+ =3Fe 2+ , adjust the ferrous ion concentration of the crystallization system to prevent the reaction system Fe 3+ Accumulation; electrical control component 37 reads the multi-parameter flow cell 20 to detect and analyze Fe 2+ and Fe 3+ The concentration data of Fe 2+ :Fe 3+ The molar ratio N = 5-6:1, the output iron powder is adjusted to the dosage, the output cycle is 60min, that is, the iron powder dosage is adjusted every hour until the accumulated Fe 3+ is restored so that the target N value meets the interval requirements; the control logic of the electrical control component 37 for adjusting the amount of iron powder added:

[0067] When the reaction Fe 3+ When the temperature rises and N value is less than 5, the dosage of iron powder is adjusted. On the basis of the initial value F, it is increased in stages. The staged increase value ΔF1 is 10 mg / L. After 1 hour of reaction, the new N value is detected and analyzed. When the N value is close to the range of 3.6 to 4.4, the staged increase value ΔF2 is 5 mg / L. The ΔF value can be set to an open value in the debugging mode. After manually inputting ΔF, the appropriate iron powder dosage can be controlled.

[0068] Step 6, the electrical control component 37 controls the output flow of the reflux mixing pump 11 and the reflux mixing pump 2 12. The electrical control component 37 controls the output frequency change of the frequency converter and the pump, so as to meet the requirements of different flow values ​​of the output flow of the reflux mixing pump 11 and the reflux mixing pump 2 12; further, the initial rising flow rate of the reaction tower crystallization is controlled to be above 32m / h, and the crystal maturity period is controlled to be within 65m / h, so as to accelerate the crystallization growth rate and improve the crystal stability of the system.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A Fenton fluidized bed rapid crystallization device, characterized in that: It comprises a reaction tower (1), a raw water adjustment component, a crystal filtering component (24), a crystal separation box (23), a reflux tank component, a sulfuric acid storage tank (7), a ferrous sulfate storage tank (8), and a hydrogen peroxide storage tank (9), wherein: The reaction tower (1) comprises, arranged in order from bottom to top, a downstream component (3), a upstream component (2), a first stabilizing layer (15), a second stabilizing layer (16), a crystallization layer (17), a baffle layer (18), a crystal fixing component (21), and a feeding component; The outlet of the hydrogen peroxide storage barrel (9) is connected to the top suction port of the reflux quick mixer (102), and the inlet of the reflux quick mixer (102) is connected to the reflux tank assembly through the reflux pipe (33); the outlet end of the reflux quick mixer (102) is respectively connected to the inlet of the countercurrent assembly (2), the inlet of the stabilizing layer (15), the inlet of the stabilizing layer (16), and the raw water quick mixer (101); The outlet of the ferrous sulfate storage tank (8) is connected to the top suction port of the second reflux mixer (103), and the inlet of the second reflux mixer (103) is connected to the reflux tank assembly through the second reflux pipe (34); The raw water adjustment component comprises a raw water adjustment tank (4) and a raw water quick mixer (101); the sulfuric acid storage tank (7), the raw water adjustment tank (4) and the raw water quick mixer (101) are connected in sequence; the outlet of the raw water quick mixer (101) is connected to the inlet of the downstream component (3); the top suction port 1 of the raw water quick mixer (101) is connected to the outlet end of the reflux quick mixer 1 (102); the top suction port 2 of the raw water quick mixer (101) is connected to the outlet end of the reflux quick mixer 2 (103); The inlet of the crystal filtering component (24) is connected to the crystal liquid outlet of the crystal layer (17), and the crystal filtering component (24) is located at the center of the upper part of the crystal separation box (23).

2. The Fenton fluidized bed rapid crystallization device according to claim 1, characterized in that: The invention comprises a water outlet degassing groove (29) and a water outlet groove (31), wherein the water outlet degassing groove (29) is located on the left outer side of the upper part of the reaction tower (1), a degassing pipe (30) is arranged in the water outlet degassing groove (29), and the water outlet of the reaction tower (1) enters the water outlet degassing groove (29) through a water outlet hole 1 (281); the water outlet groove (31) is located at the rear end of the water outlet degassing groove (29), and a water outlet hole 2 (282) for communication is arranged between the water outlet groove (31) and the water outlet degassing groove (29).

3. The Fenton fluidized bed rapid crystallization device according to claim 2, characterized in that: The reflux trough assembly comprises a reflux trough 1 (321) and a reflux trough 2 (322). The reflux trough 1 (321) and the reflux trough 2 (322) are located on the right outer side of the upper part of the reaction tower (1), and are respectively connected to the reaction tower (1) through a water outlet 3 (283). The bottom of the reflux trough 1 (321) is connected to a reflux pipe 1 (33), and the bottom of the reflux trough 2 (322) is connected to a reflux pipe 2 (34).

4. The Fenton fluidized bed rapid crystallization device according to claim 3, characterized in that: A multi-parameter flow analysis pool (20) is arranged outside the reaction tower, and the top interface of the multi-parameter flow analysis pool (20) is connected to the baffle layer (18) and the reflux tank one (321) through pipelines respectively, the bottom interface one of the multi-parameter flow analysis pool (20) is connected to the stabilizing layer two (16) through a pipeline, and the interface two is connected to the waste liquid discharge pipeline.

5. The Fenton fluidized bed rapid crystallization device according to claim 4, characterized in that: The raw water adjustment component comprises a raw water adjustment tank (4), a raw water pump (5), a raw water flow meter (6), and a raw water quick mixer (101) which are connected in sequence; a sulfuric acid storage tank (7) is connected to the raw water adjustment tank (4) via a pressurizing pipe, and a dosing pump (71) is provided on the pressurizing pipe; and a pH online detector is provided in the raw water adjustment tank (4).

6. The Fenton fluidized bed rapid crystallization device according to claim 5, characterized in that: The outlet of the reflux quick mixer 1 (102) is provided with a reflux mixing pump 1 (11) and a reflux flow meter 1 (12); and a reflux mixing pump 2 (13) and a reflux flow meter 2 (14) are provided between the raw water quick mixer (101) and the reflux quick mixer 2 (103).

7. The Fenton fluidized bed rapid crystallization device according to claim 6, characterized in that: The feeding assembly comprises a feeder (26) and a vibrating membrane cloth (27); the feeder (26) is arranged at the top of the reaction tower (1), and the vibrating membrane cloth (27) is laid on the bottom layer of the feeder (26).

8. The Fenton fluidized bed rapid crystallization device according to claim 7, characterized in that: The crystal separation box (23) is covered with an open 3.5 mm nylon mesh bag. The outlet of the crystal separation box (23) is connected to the water inlet at the top of the crystal fixing assembly (21) through a filtrate reflux pipe (22). A filtrate reflux pump (25) is provided on the filtrate reflux pipe (22).

9. The Fenton fluidized bed rapid crystallization device according to claim 8, characterized in that: The first stabilizing layer (15) is filled with 25 mm coarse glass beads, the second stabilizing layer (16) is filled with 16 mm fine glass beads, and the crystallization layer (17) is composed of 0.4-0.6 mm complex crystal seeds.

10. The Fenton fluidized bed rapid crystallization device according to claim 9, characterized in that: The baffle layer (18) includes a small baffle component (191) and a large baffle component (192). The small baffle component (191) is arranged inside the large baffle component (192). The small baffle component (191) is welded from more than two PP plates, and the angle between the welded plates is 20°-30°; the large baffle component (192) is welded from four PP plates, and the welding angle between adjacent plates is 105°-155°; a PP inclined plate is fixedly installed below the solid crystal component (21), and the installation angle is 55°.

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