Solid-liquid mixed heterogeneous Fenton-like reaction device

Abstract

The invention discloses a solid-liquid mixed heterogeneous Fenton-like reaction device which comprises a reaction tank, a stainless steel bracket is arranged at the top of the reaction tank, and a porous water distributor is arranged at the lower part of the reaction tank; a water inlet pipe and an emptying pipe are respectively arranged on two sides of the bottom end of the reaction tank, a water inlet pump is arranged on the water inlet pipe, and an emptying valve is arranged on the emptying pipe; a two-stage stirring structure composed of the push type three-blade paddle stirrer and the flat and straight blade disc turbine stirrer is provided, the flat and straight blade disc turbine stirrer on the lower layer provides large plane shearing force and can roll up deposited solid powder, and the push type three-blade paddle stirrer on the upper layer provides large axial circulation amount and can roll up the deposited solid powder. The rolled powder catalyst is circulated to the upper part of the reaction tank, so that the solid powder catalyst is sufficiently and uniformly mixed in the reaction container in the axial direction and the radial direction, and the technical problem that a heterogeneous Fenton reaction device in the prior art cannot meet the requirement on sufficient mixing of the catalyst and a mixed solution is solved.

Description

Technical Field

[0001] The invention belongs to the field of heterogeneous Fenton-like reactors, in particular to a solid-liquid mixed heterogeneous Fenton-like reaction device. Background Art

[0002] Advanced oxidation processes are often used to treat recalcitrant organic matter in industrial wastewater that cannot be removed by conventional biochemical processes. Fenton advanced oxidation technology uses strong acidic conditions where Fe₂+ reacts with H₂O₂ to produce hydroxyl radicals, which mineralize or decompose organic pollutants into small molecules, thereby removing recalcitrant organic matter. However, traditional Fenton processes have drawbacks such as a narrow pH operating range (pH = 2-4), high continuous Fe₂+ consumption, and high iron sludge production.

[0003] The heterogeneous Fenton-like process utilizes a solid catalyst powder to catalyze a liquid oxidant, generating strong oxidizing radicals that subsequently oxidize and degrade organic pollutants. This process addresses shortcomings of the traditional Fenton process, offering a wide pH operating range, high recyclability of the solid catalyst, and minimal precipitation.

[0004] The commonly used heterogeneous Fenton-type reaction device is a tower or tank fluidized bed reactor, which uses the mixing effect of the agitator and the uniform water distribution effect of the water distributor to effectively promote the contact between the catalyst and the mixed liquid. However, the existing agitators mostly use a single-stage agitator, and the single stirring blade cannot achieve sufficient contact between the catalyst and the mixed liquid, especially in the height direction, where the catalyst powder sedimentation is serious. At the same time, the existing water distributors mostly use fixed water distributors, which are easily clogged by catalyst powder and the ineffective catalyst powder is easily deposited in the dead corners of the water distributor, making it difficult to clean. The defects of the heterogeneous Fenton-type reaction device limit the development and application of this process in the field of wastewater treatment. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a heterogeneous Fenton-type reaction device for solid-liquid mixing to solve the technical problem that the heterogeneous Fenton-type reaction device in the existing technology cannot meet the technical problem of sufficient mixing of the catalyst and the mixed liquid.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device comprises a reaction tank, a stainless steel bracket is provided on the top of the reaction tank, and a porous water distributor is provided at the bottom of the reaction tank;

[0008] A water inlet pipe and an exhaust pipe are respectively provided on both sides of the bottom end of the reaction tank, the water inlet pipe is provided with a water inlet pump, and the exhaust pipe is provided with an exhaust valve;

[0009] A reflux pipe is provided on the outside of the reaction tank, the top and bottom of the reflux pipe are respectively connected to the top and bottom of the reaction tank, a reflux pipe valve and a centrifugal pump are provided on the reflux pipe, and the bottom end of the reflux pipe is below the porous water distributor;

[0010] The stainless steel bracket is provided with a dosing system, and the dosing system includes a first metering pump, a second metering pump and a screw pump which are respectively connected to the reaction tank through pipelines;

[0011] A rotating shaft is provided in the center of the reaction tank, the top end of which extends out of the stainless steel bracket and is provided with a stirring motor; the bottom end of the rotating shaft passes through the porous water distributor and is rotatably provided at the bottom of the reaction tank; a propulsion-type three-blade paddle stirrer and a straight-blade disc turbine stirrer are provided in sequence from top to bottom in the vertical middle portion of the rotating shaft;

[0012] A supporting disc is fixed on the rotating shaft below the porous water distributor, and a water outlet pipe is provided on the outer wall of the reaction tank above the porous water distributor, and the water outlet pipe is sequentially provided with a pH detector, a COD detector and a water outlet pump.

[0013] The present invention also includes the following technical features:

[0014] The bottom of the reaction tank is provided with a central hole groove, a bearing is provided in the central hole groove, the bottom end of the rotating shaft is provided in the bearing, and a bearing is provided between the rotating shaft and the stainless steel bracket.

[0015] A supporting ring is provided on the side wall of the reaction tank, and the porous water distributor is provided on the supporting ring.

[0016] The porous water distributor has a first truncated cone and a second truncated cone with a diameter that decreases from top to bottom, and a plurality of grooves and a plurality of chutes are provided on the outer wall of the second truncated cone at equal intervals, and the grooves are connected to the chutes;

[0017] A plurality of protrusions are arranged at equal intervals on the inner wall of the support ring. The protrusions have the same depth and width as the sliding grooves, and the protrusions have the same depth and length as the grooves.

[0018] A flange hand hole is provided on the outer wall of the reaction tank above the porous water distributor.

[0019] The ratio of the bottom diameter D of the reaction tank to the total height H is 1:3 to 1:2.

[0020] The ratio of the diameter of the propulsion type three-blade agitator to the diameter of the reaction tank is 1:4 to 1:3, and the distance between the propulsion type three-blade agitator and the straight blade disc turbine agitator is 0.3 to 0.4D.

[0021] The straight-blade disc turbine agitator is a six-blade type, and the ratio of its outer diameter to the diameter of the reaction tank is 1:3 to 1:2; the distance between the straight-blade disc turbine agitator and the porous water distributor is 0.3 to 0.4D.

[0022] The porous water distributor is provided with a plurality of holes, which are evenly spaced and distributed on three concentric circles. The ratio of the radii of the three concentric circles, R1:R2:R3, is 1:2:3. The diameter of each hole is d.

[0023] The calculation formula of the hole number n is as follows:

[0024]

[0025] in:

[0026] v represents the water flow velocity through the holes on the porous water distributor, m / s;

[0027] h represents the jet height, that is, the distance between the height that the water flow can finally reach and the water distributor, in m;

[0028] η represents the empirical correction coefficient, which is set to 0.3 to 0.5 according to the magnitude of the water flow resistance;

[0029] Q represents the total flow rate of the water inlet below the return pipe, m 3 / s;

[0030] g represents the acceleration due to gravity, m / s 2 .

[0031] Compared with the prior art, the present invention has the following beneficial technical effects:

[0032] (I) The present invention provides a two-stage stirring structure consisting of a propulsion-type three-blade agitator and a straight-blade disc turbine agitator. The straight-blade disc turbine agitator in the lower layer provides a large planar shear force, which can roll up the deposited solid powder. The propulsion-type three-blade agitator in the upper layer provides a large axial circulation volume, so that the rolled-up powder catalyst circulates to the upper part of the reaction tank, thereby fully and evenly mixing the solid powder catalyst in the axial and radial directions within the reaction vessel, thereby solving the technical problem in the prior art that the heterogeneous Fenton-type reaction device cannot meet the requirement of sufficient mixing of the catalyst and the mixed liquid.

[0033] (II) The present invention proposes to achieve the jet effect of the porous water distributor through the relationship between the number of holes and the aperture on the porous water distributor. At the same time, by setting the jet height, the catalyst deposited on the porous water distributor can be further rolled up so that it can be evenly mixed in the axial direction within the reaction tank.

[0034] (III) The porous water distributor of the present invention can be removed from the reaction tank by rotating, which facilitates the cleaning of spent powder deposited on the porous water distributor, thereby effectively preventing blockage and extending the service life of the heterogeneous Fenton-like reaction device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the present invention;

[0036] Figure 2 yes Figure 1 A bottom-up schematic diagram of a medium porous water distributor;

[0037] Figure 3 yes Figure 1 3D schematic diagram of the medium porous water distributor;

[0038] Figure 4 yes Figure 1 3D schematic diagram of the support ring.

[0039] The meanings of the various numbers in the figure are as follows: 1-water inlet pump; 2-water inlet pipe; 3-support ring; 4-porous water distributor; 5-straight blade disc turbine agitator; 6-reaction tank; 7-propelling three-blade agitator; 8-top stainless steel bracket; 9-first metering pump; 10-second metering pump; 11-stirring motor; 12-screw pump; 13-reflux pipe valve; 14-reflux pipe; 15-centrifugal pump; 16-pH tester; 17-COD tester; 18-water outlet pump; 19-water outlet pipe; 20-drain pipe; 21-drain valve; 22-support disc; 23-flange hand hole; 24-rotating shaft; 25-center hole groove; 26-groove; 27-chute; 28-protrusion;

[0040] 401-first frustum, 402-second frustum.

[0041] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0042] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0043] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0044] The present invention provides a high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device, comprising a reaction tank 6, a stainless steel bracket 8 is provided on the top of the reaction tank 6, and a porous water distributor 4 is provided at the bottom of the reaction tank 6;

[0045] A water inlet pipe 2 and an exhaust pipe 20 are respectively provided on both sides of the bottom end of the reaction tank 6. The water inlet pipe 2 is provided with a water inlet pump 1, and the exhaust pipe 20 is provided with an exhaust valve 21;

[0046] A reflux pipe 14 is provided outside the reaction tank 6. The top and bottom of the reflux pipe 14 are respectively connected to the top and bottom of the reaction tank 6. A reflux pipe valve 13 and a centrifugal pump 15 are provided on the reflux pipe 14. The bottom end of the reflux pipe 14 is below the porous water distributor 4.

[0047] The stainless steel bracket 8 is provided with a dosing system, which includes a first metering pump 9, a second metering pump 10 and a screw pump 12 respectively connected to the reaction tank 6 through pipelines;

[0048] A rotating shaft 24 is provided in the center of the reaction tank 6. The top end of the rotating shaft 24 extends out of a stainless steel bracket 8 and is provided with a stirring motor 11. The bottom end of the rotating shaft 24 passes through a porous water distributor 4 and is rotatably disposed at the bottom of the reaction tank 6. A propulsion-type three-blade paddle stirrer 7 and a straight-blade disc turbine stirrer 5 are provided in the vertical middle of the rotating shaft 24 in order from top to bottom.

[0049] A support disc 22 is fixed on the rotating shaft 24 below the porous water distributor 4, and a water outlet pipe 19 is provided on the outer wall of the reaction tank 6 above the porous water distributor 4, and the water outlet pipe 19 is provided with a pH detector 16, a COD detector 17 and a water outlet pump 18 in sequence.

[0050] The water inlet of the return pipe 14 is on the top outer wall of the reaction tank 6, and the water outlet is on the outer wall of the reaction tank 6 below the porous water distributor 4, so as to return the upper layer of unreacted sewage to the water distribution area for re-distribution.

[0051] The above technical solution is used as follows:

[0052] First, close the drain valve 21 and the reflux pipe valve 13, the porous water distributor 4 is in a tightened state, and the industrial wastewater is pumped in by the water inlet pump 1 through the water inlet pipe 2. Then, turn on the screw pump 12 to start adding the solid powder catalyst, and then turn on the first metering pump 9 and the second metering pump 10 to start adding the liquid oxidant. Finally, turn on the stirring motor 11, so that the propulsion three-blade propeller agitator 7 and the straight-blade disc turbine agitator 5 are in working state, so as to achieve all-round stirring and mixing of the wastewater, liquid oxidant and solid catalyst powder.

[0053] After stirring for a period of time, the reflux pipe valve 13 is opened, and the centrifugal pump 15 is used to allow the upper layer of wastewater that has not fully reacted to re-enter the water distribution area (i.e., the area formed between the porous water distributor 4 and the bottom of the reaction tank 6). At the same time, the porous water distributor 4 starts to work, and the powder entrained in the jet formed after the wastewater passes through the porous water distributor 4 reaches the expected height. At this time, the jet will entrain part of the solid catalyst powder that has settled to the bottom to a certain axial height, so that the solid catalyst powder is more evenly distributed in the axial direction, and it also facilitates the stirring action of the propulsion three-blade agitator 7 on more solid catalyst powder, thereby ensuring sufficient reaction.

[0054] After the reaction is completed, the stirring motor 11 is turned on, and the pH value and COD value of the effluent are monitored in real time using the pH detector 16 and the COD detector 17 on the effluent pipe 19. Whether the pH value and the COD value meet the standards is determined based on the pH value and the COD value. If the standards are met, the treated water is discharged through the effluent pipe 19 using the effluent pump 18. A portion of the solid catalyst powder is discharged from the reaction tank 6 along with the treated water, and the rest is deposited at the bottom of the reaction tank 6 to participate in the reaction during the next water treatment.

[0055] After multiple reaction treatments, the solid catalyst powder becomes ineffective. The ineffective solid catalyst powder is deposited and causes the porous water distributor 4 to be blocked. After the treated water is drained, the porous water distributor 4 is taken out and cleaned in all directions.

[0056] A central hole groove 25 is provided at the bottom of the reaction tank 6 , a bearing is provided in the central hole groove 25 , the bottom end of the rotating shaft 24 is provided in the bearing, and a bearing is provided between the rotating shaft and the stainless steel bracket 8 .

[0057] In the above technical solution, the rotating shaft 24 is rotatable by providing a bearing.

[0058] A supporting ring 3 is provided on the side wall of the reaction tank 6 , and a porous water distributor 4 is provided on the supporting ring 3 .

[0059] In the above technical solution, the installation of the porous water distributor 4 on the side wall of the reaction tank 6 is achieved by providing the support ring 3 .

[0060] The porous water distributor 4 has a first truncated cone 401 and a second truncated cone 402 with decreasing diameters from top to bottom. A plurality of grooves 26 and a plurality of chutes 27 are provided on the outer wall of the second truncated cone 402 at equal intervals. The grooves 26 are connected to the chutes 27.

[0061] A plurality of protrusions 28 are provided at equal intervals on the inner wall of the support ring 3 . The protrusions 28 have the same depth and width as the slide grooves 27 , and the protrusions 28 have the same depth and length as the grooves 26 .

[0062] In the above technical solution, the three chutes are all arc-shaped, and the corresponding angles are all 30 degrees. When the protrusion 28 is screwed into the chute 27, the porous water distributor 4 is in a fastened state. When the protrusion 28 is screwed out of the chute 27, the porous water distributor 4 is in an active state.

[0063] After multiple reaction treatments, the solid catalyst powder becomes ineffective, and the deposition of the ineffective solid catalyst powder causes the porous water distributor 4 to become clogged. After the treated water is drained, the porous water distributor 4 is rotated so that the protrusion 28 on the support ring 3 is disengaged from the slide 27 and withdrawn from the groove 26, and then the porous water distributor 4 is taken out and cleaned.

[0064] A flange hand hole 23 is provided on the outer wall of the reaction tank 6 located above the porous water distributor 4 .

[0065] In the above technical solution, the flange hand hole is provided to facilitate the rotation and disassembly of the porous water distributor.

[0066] Preferably, the ratio of the bottom diameter D of the reaction tank 6 to the total height H is 1:3 to 1:2.

[0067] In the above technical solution, such an arrangement saves floor space.

[0068] Preferably, the ratio of the diameter of the propulsion type three-blade agitator 7 to the diameter of the reaction tank 6 is 1:4 to 1:3, and the distance between the propulsion type three-blade agitator 7 and the straight blade disc turbine agitator 5 is 0.3 to 0.4D.

[0069] In the above technical solution, the propulsion three-blade agitator 7 can provide a large amount of axial flow, pushing the fluid to circulate up and down along the agitation axis, forming a strong overall mixing, so that the catalyst powder is more evenly distributed in the axial direction. The above size setting makes the catalyst powder more evenly distributed in the axial direction.

[0070] Preferably, the straight-blade disc turbine agitator 5 is a six-blade type, and the ratio of its outer diameter to the diameter of the reaction tank 6 is 1:3 to 1:2; the distance between the straight-blade disc turbine agitator 5 and the porous water distributor 4 is 0.3 to 0.4D.

[0071] In the above technical solution, the straight-bladed disc turbine agitator 5 generates high shear forces beneath the disc, sweeping up catalyst powder deposited on the surface of the porous water distributor 4. The solid-liquid mixture is then ejected from the impeller at high speed, impacting the container wall to form a vertical vortex, effectively preventing powder agglomeration. The above-mentioned dimensional configuration further enhances this effect.

[0072] The porous water distributor 4 is provided with a plurality of holes, which are evenly spaced and distributed on three concentric circles. The ratio of the radii of the three concentric circles, R1:R2:R3, is 1:2:3. The diameter of each hole is d.

[0073] In the above technical solution, by opening holes at equal intervals, it is possible to avoid the water flow in local areas being too strong or too weak, which is conducive to forming a stable laminar flow or uniform turbulence, reducing eddies and pressure fluctuations, and thus improving the water distribution effect.

[0074] The calculation formula for the number of holes n is as follows:

[0075]

[0076] in:

[0077] v represents the water flow velocity through the holes on the porous water distributor 4, m / s;

[0078] h represents the jet height, that is, the distance between the height that the water flow can finally reach and the water distributor, in m;

[0079] η represents the empirical correction coefficient, which is set to 0.3 to 0.5 according to the magnitude of the water flow resistance;

[0080] Q represents the total flow rate of the water inlet below the return pipe 14, m 3 / s;

[0081] g represents the acceleration due to gravity, m / s 2 .

Claims

1. A high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device, comprising a reaction tank (6), the top of which is provided with a stainless steel bracket (8), characterized in that: A porous water distributor (4) is provided at the lower part of the reaction tank (6); A water inlet pipe (2) and an exhaust pipe (20) are respectively provided on both sides of the bottom end of the reaction tank (6); a water inlet pump (1) is provided on the water inlet pipe (2), and an exhaust valve (21) is provided on the exhaust pipe (20); A reflux pipe (14) is provided outside the reaction tank (6), the top and bottom of the reflux pipe (14) are respectively connected to the top and bottom of the reaction tank (6), a reflux pipe valve (13) and a centrifugal pump (15) are provided on the reflux pipe (14), and the bottom end of the reflux pipe (14) is below the porous water distributor (4); The stainless steel bracket (8) is provided with a dosing system, and the dosing system includes a first metering pump (9), a second metering pump (10) and a screw pump (12) which are respectively connected to the reaction tank (6) through pipelines; A rotating shaft (24) is provided at the center of the reaction tank (6), the top end of the rotating shaft (24) extends out of the stainless steel bracket (8) and is provided with a stirring motor (11); the bottom end of the rotating shaft (24) passes through the porous water distributor (4) and is rotatably provided at the bottom of the reaction tank (6); a propulsion type three-blade agitator (7) and a straight blade disc turbine agitator (5) are provided in sequence from top to bottom at the vertical middle portion of the rotating shaft (24); A supporting disc (22) is fixed on a rotating shaft (24) passing through the porous water distributor (4), and a water outlet pipe (19) is provided on the outer wall of the reaction tank (6) above the porous water distributor (4). The water outlet pipe (19) is provided with a pH detector (16), a COD detector (17) and a water outlet pump (18) in sequence.

2. The heterogeneous Fenton-like reaction device for efficient solid-liquid mixing according to claim 1, characterized in that: The bottom of the reaction tank (6) is provided with a central hole groove (25), a bearing is provided in the central hole groove (25), the bottom end of the rotating shaft (24) is provided in the bearing, and a bearing is provided between the rotating shaft and the stainless steel bracket (8).

3. The high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device according to claim 1, characterized in that: A supporting ring (3) is provided on the side wall of the reaction tank (6), and the porous water distributor (4) is provided on the supporting ring (3).

4. The high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device according to claim 3, characterized in that: The porous water distributor (4) has a first truncated cone (401) and a second truncated cone (402) with decreasing diameters from top to bottom, and a plurality of grooves (26) and a plurality of chutes (27) are provided on the outer wall of the second truncated cone (402) at equal intervals, and the grooves (26) are connected to the chutes (27); A plurality of protrusions (28) are arranged at equal intervals on the inner wall of the support ring (3); the protrusions (28) have the same depth and width as the slide groove (27); and the protrusions (28) have the same depth and length as the groove (26).

5. The high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device according to claim 1, characterized in that: A flange hand hole (23) is provided on the outer wall of the reaction tank (6) above the porous water distributor (4).

6. The high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device according to claim 1, characterized in that: The ratio of the bottom diameter D of the reaction tank (6) to the total height H is 1:3 to 1:

2.

7. The heterogeneous Fenton-like reaction device for efficient solid-liquid mixing according to claim 1, characterized in that: The ratio of the diameter of the propulsion type three-blade stirrer (7) to the diameter of the reaction tank (6) is 1:4 to 1:3, and the distance between the propulsion type three-blade stirrer (7) and the straight blade disc turbine stirrer (5) is 0.3 to 0.4D.

8. The high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device according to claim 1, characterized in that: The straight blade disc turbine agitator (5) is a six-blade type, and the ratio of its outer diameter to the diameter of the reaction tank (6) is 1:3 to 1:2; the distance between the straight blade disc turbine agitator (5) and the porous water distributor (4) is 0.3 to 0.4D.

9. The high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device according to claim 1, characterized in that: The porous water distributor (4) is provided with a plurality of holes, and the holes are distributed at equal intervals on three concentric circles, and the ratio of the radii of the three concentric circles R1:R2:R3 is 1:2:3; the diameter of each hole is d.

10. The high-efficiency solid-liquid mixing heterogeneous Fenton-like reaction device according to claim 9, characterized in that: The calculation formula of the hole number n is as follows: in: v represents the water flow velocity through the holes of the porous water distributor (4), m / s; h represents the jet height, that is, the distance between the height that the water flow can finally reach and the water distributor, in m; η represents the empirical correction coefficient, which is set to 0.3 to 0.5 according to the magnitude of the water flow resistance; Q represents the total flow rate of the water inlet below the return pipe (14), m 3 / s; g represents the acceleration due to gravity, m / s 2 .

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