A device and method for enhanced removal of pollutants by cyclone

Abstract

The application discloses a kind of pollutant cyclone reinforced removal device and method, including reactor, overflow weir, water inlet pipe, dosing pipe and flocculation sludge discharge pipe;Overflow weir is arranged in the inside of reactor, and overflow weir divides the inside cavity of reactor into flocculation zone and secondary sedimentation zone;Wherein, flocculation zone is located at the bottom of the inner chamber of reactor, and secondary sedimentation zone is located at the top of flocculation zone around, and flocculation zone and secondary sedimentation zone are communicated by overflow weir;One side of flocculation zone is provided with water inlet pipe, and the other side of flocculation zone is provided with dosing pipe, and the bottom center of flocculation zone is provided with flocculation sludge discharge pipe;The bottom of secondary sedimentation zone is evenly provided with sediment sludge discharge port around, and the top of secondary sedimentation zone is evenly provided with water outlet around;The application can greatly improve the collision probability between flocculation particles under the condition of lower flocculant dosage, greenly treat wastewater, greatly reduce the treatment burden caused by excessive dosage, and reduce the processing cost.

Description

Technical Field

[0001] This invention belongs to the field of coal chemical wastewater pretreatment technology, and specifically relates to a pollutant cyclone enhanced removal device and method. Background Technology

[0002] Coal chemical wastewater is a typical multi-component, difficult-to-treat industrial wastewater. This type of wastewater contains large amounts of oil, tar-like sludge and suspended solids, phenols, and COD, among other typical pollutants. Oil, in particular, exists primarily in emulsified and dissolved forms, characterized by high concentrations, significant hazard, and difficulty in effective separation and recovery. High-oil-content sludge and suspended solids, if not effectively pretreated, will not only clog pipelines but also severely impact the normal operation of all subsequent processes. High concentrations of COD and phenol not only inhibit microbial activity but also severely affect bioavailability. Therefore, effectively reducing these typical pollutants is the primary problem to be solved in the pretreatment process of coal chemical wastewater.

[0003] Coagulation can effectively promote the agglomeration and separation of oil, dust and sludge in wastewater and has certain applications in some wastewater treatment. However, existing coagulation processes have problems such as large flocculant dosage and high operating costs. Moreover, the addition of large amounts of flocculant will pose new threats to subsequent water treatment processes. Therefore, it is urgent to develop a new low-hazard, low-energy-consumption pretreatment process for coal chemical wastewater. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention provides a pollutant cyclone enhanced removal device and method to solve the technical problems of large flocculant dosage and high operating costs in the existing coagulation process.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention provides a pollutant cyclone-enhanced removal device, including a reactor, an overflow weir, an inlet pipe, a dosing pipe, and a flocculation sludge discharge pipe; the overflow weir is disposed inside the reactor, and the overflow weir divides the internal cavity of the reactor into a flocculation zone and a secondary sedimentation zone;

[0007] The flocculation zone is located at the bottom of the reactor cavity, the secondary sedimentation zone is located above and around the flocculation zone, and the flocculation zone and the secondary sedimentation zone are connected by the overflow weir.

[0008] A water inlet pipe is provided on one side of the flocculation zone, a chemical dosing pipe is provided on the other side of the flocculation zone, and a flocculation sludge discharge pipe is provided at the center of the bottom of the flocculation zone; sedimentation sludge discharge ports are evenly provided around the bottom of the secondary sedimentation zone, and water outlets are evenly provided around the top of the secondary sedimentation zone.

[0009] Furthermore, one end of the inlet pipe is connected to the sewage source, and the other end of the inlet pipe extends into the interior of the flocculation zone; wherein, the extended end of the inlet pipe is inclined toward the bottom center of the flocculation zone.

[0010] Furthermore, the angle between the inlet end of the water inlet pipe and the horizontal plane is 15°-30°.

[0011] Furthermore, the height-to-diameter ratio of the flocculation zone is 8:(4-6).

[0012] Furthermore, the height-to-diameter ratio of the flocculation zone is 8:5.

[0013] Furthermore, it also includes a stirring paddle, which is vertically arranged at the center of the reactor interior; the stirring paddle is located within the flocculation zone and includes a stirring rod and stirring blades arranged on the stirring rod.

[0014] Furthermore, the distance between the stirring blade and the bottom of the reactor is 2 / 10 to 4 / 10 of the height of the reactor.

[0015] Furthermore, the distance between the stirring blade and the bottom of the reactor is 3 / 10 of the reactor height; the stirring speed of the stirring blade is 180 r / min, and it adopts an intermittent stirring mode.

[0016] Furthermore, a flocculant is added to the flocculation zone; wherein the flocculant is an inorganic-organic composite flocculant.

[0017] The present invention also provides a pollutant cyclone enhanced removal method, which uses the pollutant cyclone enhanced removal device to remove oil, sludge suspended solids, COD and phenol from coal chemical wastewater;

[0018] The pollutant cyclone-enhanced removal method is specifically as follows:

[0019] The coal chemical wastewater to be treated is introduced into the flocculation zone through the inlet pipe. After the coal chemical wastewater undergoes a flocculation reaction in the flocculation zone, it forms flocculated wastewater and flocculated sludge. The flocculated sludge is discharged from the flocculation sludge discharge pipe.

[0020] The flocculated wastewater, which is filled with flocculation zone, flows through the overflow weir into the secondary sedimentation zone. After sedimentation, the treated wastewater is discharged from the outlet, and the treated sludge is discharged from the sedimentation sludge discharge outlet.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] This invention provides a pollutant cyclone-enhanced removal device and method. By setting an overflow weir within the reactor, the internal cavity of the reactor is divided into a flocculation zone and a secondary sedimentation zone. The flocculation zone is located at the bottom of the reactor cavity, and the secondary sedimentation zone is located above and around the flocculation zone, connected by the overflow weir. Within the flocculation zone, the cyclone action of the fluid ensures a high flocculation rate and creates conditions for the formation of large-diameter flocs. These large-diameter flocs pass through the overflow weir and enter the secondary sedimentation zone for sedimentation before being discharged. This significantly increases the collision probability between floc particles with a low flocculant dosage, achieving green wastewater treatment and greatly reducing the treatment burden and costs caused by excessive flocculant dosage. Specifically, the internal flow field of the flocculation zone is divided into high-flow... The reactor is divided into high-velocity, low-velocity, and medium-velocity regions to achieve enhanced swirling flow. The high-velocity region is located at the center of the flow field, where flocculants and substances such as oil sludge in the wastewater fully agglomerate to form a large number of flocs. Under the influence of fluid swirling, the flocs are driven to the low-velocity region, which is located between the high-velocity and medium-velocity regions. The low-velocity region has a lower fluid velocity, making it less prone to floc breakage. The floc particles can continuously collide and aggregate, growing and being continuously transported to the reactor wall for more efficient flocculation, providing favorable conditions for further particle growth. The medium-velocity region is located near the reactor wall. In the medium-velocity region, the floc particles and the flocs and the reactor wall continuously and stably expand, resulting in the highest flocculation rate and creating favorable conditions for the production of large-diameter flocs.

[0023] Furthermore, by tilting the inlet end of the water inlet pipe, the coal chemical wastewater to be treated can enter the bottom of the flocculation zone and naturally form a vortex, effectively saving the cost of stirring the wastewater.

[0024] Furthermore, the vortex effect formed when sewage enters is optimal when the angle between the inlet end of the inlet pipe and the horizontal plane is 30°.

[0025] Furthermore, when the height-to-diameter ratio of the flocculation zone is set to 8:(4-6), the flow velocity of the wastewater fluid around the reactor wall is relatively high, which is conducive to the collision of particles with each other at the wall, thereby forming stable flocs and improving the flocculation effect of the wastewater.

[0026] Furthermore, setting the height-to-diameter ratio of the flocculation zone to 8:5 ensures that the high-turbulence kinetic energy region within the reactor is smaller. In most cases, the size of the flocs is inversely proportional to the turbulence intensity, and the growth of the flocs is supported by low turbulence. Lower turbulence energy provides a better environment for particle aggregation. Therefore, a height-to-diameter ratio of 8:5 is most conducive to flocculation.

[0027] Furthermore, when the distance between the bottoms of the stirred blade reactor is set to 2 / 10-4 / 10 of the reactor height, the eddy viscosity is uniform and the high viscosity range is larger. Eddy viscosity essentially represents eddy diffusion. Therefore, higher viscosity helps the diffusion of flocculants and fine particles in the fluid in the reactor, enhancing the surface interaction between flocculants and fine particles as well as the collisions between particles.

[0028] Furthermore, when the distance between the stirring blade and the bottom of the reactor is 3 / 10 of the reactor's height, and the stirring speed of the stirring blade is 180 r / min, the high turbulent kinetic energy region of the device is smaller, and the turbulent kinetic energy is lower. From a hydrodynamic perspective, under the same spatial scale, the greater the turbulent kinetic energy, the wider its range of action and the higher the eddy intensity. Lower turbulent kinetic energy helps to enhance the stability of the formed flocs, and the higher turbulent kinetic energy distribution in the high-density flocculent zone has a certain strengthening effect on improving the working performance of the stirrer. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view of the pollutant cyclone enhanced removal device described in the embodiment;

[0030] Figure 2 This is a top view of the pollutant cyclone enhanced removal device described in the embodiment;

[0031] Figure 3 This is a geometric model and computational fluid dynamics domain mesh diagram of the pollutant cyclone-enhanced removal device described in the embodiment;

[0032] Figure 4 The following are geometric models and X-Y section contour maps of the flow field of the pollutant swirl-enhanced removal device with different aspect ratios, simulated using computational fluid dynamics in the embodiments; wherein, a is the front view and three-dimensional view of the device; b is the fluid velocity contour map of the X-Y section of the device; c is the eddy viscosity contour map of the X-Y section of the device; d is the turbulent kinetic energy contour map of the X-Y section of the device.

[0033] Figure 5 The following are contour maps of the internal flow field of the pollutant cyclone-enhanced removal device under different impeller lengths and stirring speeds, simulated using computational fluid dynamics in this embodiment. Specifically, a is the contour map of fluid velocity at the XY section of the device; b is the contour map of fluid velocity at the ZX section of the device; c is the contour map of eddy current viscosity at the XY section of the device; d is the contour map of eddy current viscosity at the ZX section of the device; e is the contour map of turbulent kinetic energy at the XY section of the device; and f is the contour map of turbulent kinetic energy at the ZX section of the device.

[0034] Figure 6 This is a three-dimensional simulation diagram of the internal fluid velocity of the pollutant cyclone-enhanced removal device in the embodiment;

[0035] Figure 7 The figures shown are the pollutant removal effect curves of the pollutant cyclone enhanced removal device under different operating conditions for actual wastewater in the embodiment; where a is the influent and effluent concentration and removal rate curve of oil in the wastewater; b is the influent and effluent concentration and removal rate curve of sludge in the wastewater; c is the influent and effluent concentration and removal rate curve of COD in the wastewater; and d is the influent and effluent concentration and removal rate curve of phenol in the wastewater.

[0036] The components include: 1. Reactor; 2. Overflow weir; 3. Inlet pipe; 4. Dosing pipe; 5. Flocculation and sludge discharge pipe; 6. Agitator; 7. First water pressure sensor; 8. Second water pressure sensor; 9. Sedimentation and sludge discharge port; 10. Outlet; 101. Flocculation zone; 102. Secondary sedimentation zone; 201. Inner baffle; 202. Outer baffle; 601. Agitator rod; 602. Agitator blade. Detailed Implementation

[0037] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0038] Example

[0039] As attached Figure 1-2 As shown, this embodiment provides a pollutant cyclone-enhanced removal device for the removal of pollutants from coal chemical wastewater; wherein, the pollutants in the coal chemical wastewater include, for example, oil, sludge suspended solids, COD and phenol; the pollutant cyclone-enhanced removal device includes a reactor 1, an overflow weir 2, an inlet pipe 3, a dosing pipe 4, a flocculation and sludge discharge pipe 5, a stirring paddle 6, a first water pressure sensor 7 and a second water pressure sensor 8.

[0040] In this embodiment, the reactor 1 is a hollow cylindrical structure with a conical structure at the bottom. The overflow weir 2 is disposed inside the reactor 1, dividing the internal cavity of the reactor 1 into a flocculation zone 101 and a secondary sedimentation zone 102. The flocculation zone 101 is located at the bottom of the internal cavity of the reactor 1, and the secondary sedimentation zone 102 is located above and around the flocculation zone 101. The flocculation zone 101 and the secondary sedimentation zone 102 are connected by the overflow weir 2. The height-to-diameter ratio of the flocculation zone 101 is 8:(4-6). Preferably, the height-to-diameter ratio of the flocculation zone 101 is 8:5.

[0041] In this embodiment, the overflow weir 2 includes an inner baffle 201 and an outer baffle 202. The inner baffle 201 includes a cylindrical section and a large trumpet section. The cylindrical section is coaxially disposed at the upper end of the interior of the reactor 1, and the large trumpet section is coaxially disposed at the lower end of the cylindrical section. Specifically, the upper end of the cylindrical section extends toward the inner wall of the upper cover of the reactor 1; the lower end of the cylindrical section extends toward the bottom of the reactor 1; the upper end of the large trumpet section is connected to the lower end of the cylindrical section, and the lower end of the large trumpet section is connected to the inner wall of the reactor 1.

[0042] The outer partition 202 is coaxially and spaced out on the outside of the cylindrical section. The outer partition 202 includes an outer cylindrical sleeve section and a small horn section. Specifically, the outer cylindrical sleeve section is spaced out on the outside of the cylindrical section. The upper end of the outer cylindrical section is connected to the inner wall of the upper cover of the reactor 1, and the lower end of the outer cylindrical section extends toward the upper surface of the large horn section. The small horn section is spaced out on the outside of the upper end of the large horn section. The upper end of the small horn section is connected to the lower end of the outer cylindrical section, and the lower end of the small horn section extends downward at an angle.

[0043] It should be noted that a first fluid channel is provided between the upper end of the cylindrical section and the inner wall of the upper cover of the reactor 1, a second fluid channel is provided between the outer cylindrical section and the cylindrical section, and a third fluid channel is provided between the small horn section and the large horn section; wherein, the first fluid channel, the second fluid channel and the third fluid channel are sequentially connected to form an overflow channel, and the flocculated wastewater in the flocculation zone 101 can enter the secondary sedimentation zone 102 through the overflow channel.

[0044] In this embodiment, an inlet pipe 3 is provided on one side of the flocculation zone 101; one end of the inlet pipe 3 is connected to the sewage source, and the other end of the inlet pipe 3 extends into the interior of the flocculation zone 101; wherein, the extended end of the inlet pipe 3 is inclined toward the bottom center of the flocculation zone 101; preferably, the angle between the extended end of the inlet pipe 3 and the horizontal plane is 15°-30°.

[0045] In this embodiment, a dosing pipe 4 is provided on the other side of the flocculation zone 101 for adding flocculant into the flocculation zone 101; one end of the dosing pipe 4 is connected to a flocculant storage device, and the other end of the dosing pipe 4 extends into the interior of the flocculation zone 101; wherein, the flocculant is an inorganic-organic composite flocculant, which is prepared by using aluminum sulfate and polyacrylamide.

[0046] In this embodiment, a flocculation sludge discharge pipe 5 is provided at the bottom center of the flocculation zone 101; specifically, the flocculation exhaust pipe 5 is placed at the bottom center of the reactor 1 and is used to discharge flocculated sludge to the outside of the device.

[0047] In this embodiment, the stirring paddle 6 is vertically positioned at the center of the reactor 1 and located within the flocculation zone 101. The stirring paddle 6 includes a stirring rod 601, stirring blades 602, and a stirring motor. The stirring rod 601 is vertically positioned at the center of the flocculation zone 101, and the stirring blades 602 are mounted on the stirring rod 601. The stirring motor is mounted on the top cover of the reactor 1, and the upper end of the stirring rod 601 is connected to the output end of the stirring motor. The distance between the stirring blades 602 and the bottom of the reactor 1 is 2 / 10 to 4 / 10 of the height of the reactor 1. Preferably, the distance between the stirring blades 602 and the bottom of the reactor 1 is 3 / 10 of the height of the reactor 1. The stirring speed of the stirring blades 602 is 180 r / min, and it operates in an intermittent stirring mode.

[0048] In this embodiment, the first water pressure sensor 7 is symmetrically arranged in the middle of the inner wall of the cylindrical section, and is used to collect water pressure information in the middle section of the cylindrical section; the second water pressure sensor 8 is symmetrically arranged on the inner wall of the reactor 1, and is located near the lower end of the large funnel section; the second water pressure sensor 8 is used to collect water pressure information at the lower end of the large funnel section; both the first water pressure sensor 7 and the second water pressure sensor 8 are connected to the flocculant storage device to realize the automatic dosing function of flocculant.

[0049] In this embodiment, sedimentation sludge discharge ports 9 are evenly provided around the bottom of the secondary sedimentation zone 102. The sedimentation sludge discharge ports 9 are used to discharge the settled sludge to the outside of the device. One end of the sedimentation sludge discharge port 9 is connected to the inner cavity of the secondary sedimentation zone 102, and the other end of the sedimentation sludge discharge port 9 is connected to the outside. Preferably, the sedimentation sludge discharge port 9 is located near the lower end of the large trumpet section.

[0050] In this embodiment, the top of the secondary sedimentation zone 102 is uniformly provided with water outlets 10, which are used to discharge the treated wastewater to the outside of the device; wherein, one end of the water outlet 10 is connected to the upper end of the inner cavity of the secondary sedimentation zone 102, and the other end of the water outlet 10 is connected to the outside.

[0051] This embodiment also provides a cyclone-enhanced removal method for pollutants, used to remove oil, suspended solids in sludge, COD, and phenol from coal chemical wastewater; wherein, the cyclone-enhanced removal method for pollutants is specifically as follows:

[0052] Coal chemical wastewater to be treated is introduced into the flocculation zone 101 through the inlet pipe 3. After flocculation reaction occurs in the flocculation zone 101, flocculated wastewater and flocculated sludge are formed. The flocculated sludge is discharged from the flocculation sludge discharge pipe 5. The flocculated wastewater covering the flocculation zone flows into the secondary sedimentation zone 102 through the overflow weir 2. After sedimentation, the treated wastewater is discharged from the outlet 10, and the treated sludge is discharged from the sedimentation sludge discharge port 9.

[0053] Design principles:

[0054] In the design of the pollutant cyclone-enhanced removal device and method described in this embodiment, to ensure that the overall structure of the device fully considers the internal flow field effect and provides optimal flow field regulation for the flocculation process, this embodiment conducts a simulation study on the height-to-diameter ratio of the flocculation zone; specifically as follows:

[0055] SpaceClaim 2022R1 and ICEM CFD 2022R1 were used as preprocessing tools to create the geometry and mesh of the flocculation zone, as shown in the attached figure. Figure 3 As shown; considering the complex structure of the stirring blades, the geometry of the flocculation zone is divided into two parts: a structured grid and an unstructured grid. The unstructured grid is used to simulate the stirring blades, while the structured grid is used to simulate the fluid velocity, eddy viscosity, and turbulent kinetic energy in other areas of the flocculation zone, thereby determining the height-to-diameter ratio of the flocculation zone of the device.

[0056] As attached Figure 4 As shown, this embodiment uses three different aspect ratios (8:4, 8:5, and 8:6) for simulation studies. Through simulation comparison, the results show that when the aspect ratio of the flocculation zone is 8:5, the fluid velocity around the wall is higher, which is conducive to particle collision and aggregation at the wall to form stable flocs. The average eddy viscosity of the 8:5 model is more uniform compared to 8:4 and 8:6, providing favorable conditions for continuous particle contact. The 8:5 model has a smaller high-turbulence kinetic energy region, and in most cases, the floc size is inversely proportional to the turbulence intensity. The growth of flocs is supported by low turbulence, and the lower turbulence energy provides a better environment for particle aggregation. Therefore, the aspect ratio of 8:5 is most conducive to flocculation.

[0057] In this embodiment, computational fluid dynamics software is used to simulate three types of impeller positions and three types of stirring speeds. The specific process is as follows:

[0058] The stirring blades are positioned at 2 / 10, 3 / 10, and 4 / 10 of the device height, respectively, with stirring speeds set to 60 r / min, 120 r / min, and 180 r / min. Nine operating methods are preset: C1-30 cm, 60 r / min; C2-30 cm, 120 r / min; C3-30 cm, 180 r / min; C4-35 cm, 60 r / min; C5-35 cm, 120 r / min; C6-35 cm, 180 r / min; C7-40 cm, 60 r / min; C8-40 cm, 120 r / min; and C9-40 cm, 180 r / min.

[0059] By drawing cloud maps using two profiles, XY and ZX, a comprehensive analysis of the high-density flocculation zone is conducted, and operational methods are compared and selected, as shown in the attached figure. Figure 5 As shown in the figure, when the stirring blade is located at 3 / 10 of the device and the speed is 180 r / min, the fluid velocity is most uniform and clearly divided into three regions. When the stirring blade is located at 3 / 10 and 4 / 10 of the device and the speed is 180 r / min, the eddy viscosity is uniform and the high viscosity range is larger. Eddy viscosity essentially represents eddy diffusion. Therefore, under the above two operating methods, the higher viscosity helps the flocculant and fine particles in the fluid to diffuse in the reactor, enhancing the surface interaction between the flocculant and fine particles and the collision between particles. When the stirring blade is located at 3 / 10 of the device and the speed is 180 r / min, the high turbulent kinetic energy region of the device is smaller and the turbulent kinetic energy is lower. From a hydrodynamic perspective, under the same spatial scale, the greater the turbulent kinetic energy, the wider its range of action and the higher the eddy intensity. The lower turbulent kinetic energy helps to enhance the stability of the formed flocs. The higher turbulent kinetic energy distribution in the high-density flocculent zone has a certain strengthening effect on improving the working performance of the stirrer.

[0060] Therefore, computational fluid dynamics simulations show that the optimal operating method, with the agitator blade positioned at 3 / 10 of the device and a speed of 180 r / min, is most effective in reducing pollutants in coal chemical wastewater. The agitation method involves intermittent stirring at 180 r / min for one minute, followed by a 20-second settling period to allow sufficient contact between the crystal nuclei and the oil, dust, and sludge, forming denser and larger flocs. This process is repeated with stirring at 180 r / min for one minute, followed by another 20-second settling period, and this cycle is used for the flocculation pretreatment of the device.

[0061] Experimental Results 1

[0062] Taking the removal of oily substances from coal chemical wastewater in actual production as an example; the coal chemical wastewater treatment scale is 0.3t / h, the pollutant influent concentration is shown in Table 1, the hydraulic retention time of the reactor is 2h, the device runs continuously for 300h, and water samples are collected from the outlet every 20h for water quality analysis.

[0063] Table 1 Actual influent water quality of coal chemical wastewater

[0064]

[0065] After treatment by this device, under the operating conditions of intermittent stirring at 180 r / min and the stirring blades being at 3 / 10 of the device position, the highest removal rates of oil, sludge suspended solids, COD, and phenol in coal chemical wastewater were 73.43%, 87.88%, 78.63%, and 65.20%, respectively. Compared with the flocculation experiment alone, the amount of reagent added was reduced by 50%-60%, and the removal rate was increased by 20%-30%. This further verifies the rationality of the design of the cyclone-enhanced removal device for pollutants in coal chemical wastewater, indicating that this device has broad prospects for industrial application in coal chemical wastewater treatment.

[0066] Experimental Results 2

[0067] Taking the removal of oily substances from coal chemical wastewater in actual production as an example; the coal chemical wastewater treatment scale is 2t / h, the pollutant influent concentration is shown in Table 2, the hydraulic retention time of the reactor is 5h, the device runs continuously for 300h, and water samples are collected from the outlet every 20h to analyze the water quality.

[0068] Table 2 Actual influent water quality of coal chemical wastewater

[0069]

[0070] After treatment by this device, under the operating conditions of intermittent stirring at 180 r / min and the stirring blades being at 3 / 10 of the device position, the highest removal rates of oil, suspended solids in sludge, COD, and phenol in coal chemical wastewater were 69.83%, 86.24%, 72.19%, and 63.27%, respectively. Compared with the flocculation experiment alone, the amount of reagent added was reduced by 50%, and the removal rate was increased by 25%. After the cyclone-enhanced removal device for pollutants in coal chemical wastewater was scaled up for production, actual treatment of coal chemical wastewater showed that it can still significantly reduce the addition cost while improving the removal rate. The device utilizes the cyclone effect to treat wastewater efficiently and in a green manner. It can be seen that the device can be scaled up proportionally according to the actual treatment capacity of the water plant and still achieve good treatment results.

[0071] As attached Figure 6 As shown, attached Figure 6The paper presents a three-dimensional simulation diagram of the internal fluid velocity of the pollutant cyclone enhanced removal device, from which... Figure 6 As can be seen, when the height-to-diameter ratio of the flocculation zone is 8:5, and the operation method is that the stirring blade is located at 3 / 10 of the device and the speed is 180 r / min, the fluid inside the device forms a high-speed swirling zone near the stirring blade. In this zone, the pollutants in the wastewater come into full contact with the flocculant and agglomerate to form a large number of floc particles. Under the action of the high-speed fluid swirling, the particles are further driven to the wall of the flocculation zone. The particles collide steadily with each other and with the wall, resulting in the maximum flocculation rate. The particles further undergo agglomeration and finally form dense, large-diameter flocs, completing the "swirling granulation" process. This achieves green and harmless treatment of wastewater and greatly reduces operating costs.

[0072] As attached Figure 7 As shown, attached Figure 7 The paper presents the pollutant removal efficiency of actual wastewater under different operating conditions, from the appendix... Figure 7 The results show that under the operating conditions of a 35cm agitator length and 180r / min, the SFR achieves the highest removal rates of oil, sludge, COD, and phenol, at 73.43%, 87.88%, 78.63%, and 65.2%, respectively. This is consistent with the fluid dynamics simulation results, demonstrating that placing the agitator at 3 / 10 of the SFR height and a stirring speed of 180r / min is more beneficial for the flocculation process and pollutant removal. Compared with traditional processes, this device reduces the dosage of the two flocculants by 50% and 60% respectively during flocculation, while increasing the pollutant removal rate by 20%-30%. This proves that under well-optimized reactor conditions and operation, flocculation can achieve high-efficiency removal of pollutants using relatively low reagent dosages. The flocculation effect of the device on actual coal chemical wastewater proves the rationality of its design, indicating that this reactor has broad industrial application prospects in coal chemical wastewater treatment.

[0073] Working principle:

[0074] In this embodiment, an overflow weir is installed inside the reactor, dividing the internal cavity of the reactor into a flocculation zone and a secondary sedimentation zone. The flocculation zone is thoroughly simulated and compared using fluid dynamics simulation software to determine the optimal height-to-diameter ratio. Under the optimal ratio, the flow field within the flocculation zone is divided into three regions, thus achieving swirling enhancement. The center of the flow field is located in a high-velocity region (v≥0.20m / s), where the flocculant and substances such as oil sludge in the wastewater fully agglomerate, forming a large number of flocs. These flocs are then driven away by the fluid swirling action to reach the second region—a low-velocity region (0.06m / s≥v≥0.04m / s). The lower fluid velocity in this region allows the flocs to... The flocs are not easily broken, and they continuously collide and aggregate, growing and being transported to the reactor wall for more efficient flocculation. This provides favorable conditions for further particle growth. The area near the flocculation zone wall is the third zone – the medium flow velocity zone (0.20 m / s ≥ v ≥ 0.06 m / s). In this zone, particles collide steadily with each other and with the wall, resulting in the highest flocculation rate and creating favorable conditions for the formation of large-diameter flocs. During this process, the swirling effect of the fluid in the flocculation zone is efficiently utilized, significantly increasing the collision probability between floc particles with a low flocculant dosage. This enables green wastewater treatment and greatly reduces the treatment burden caused by excessive dosage, thus lowering treatment costs.

[0075] The pollutant cyclone-enhanced removal device and method described in this invention effectively removes pollutants from coal chemical wastewater, improving the pollutant removal rate while reducing reagent dosage costs. The coal chemical wastewater and flocculant undergo a thorough and efficient physical interaction in the high-density flocculation zone. The sludge return system, on the one hand, transfers some of the flocculant adhering to the flocs back to the flocculation system; on the other hand, the high-density sludge return from the secondary sedimentation zone significantly promotes the flocculation process, thus contributing to reduced pretreatment costs. When determining the operating method, computational fluid dynamics software is used for simulation to understand the fluid movement within the device in advance. The optimal operating conditions are selected by comparing the fluid velocity, eddy viscosity, and turbulent kinetic energy of the water body inside the pollutant cyclone-enhanced removal device for coal chemical wastewater, and determining that the stirring blades are located at 3 / 10 of the device with a speed of 180 r / min.

[0076] The flocculation zone is located inside the overall device. An inlet pipe with a 30° inclination is located on the left side of the flocculation zone, allowing wastewater to naturally form a vortex at the bottom of the flocculation system, saving on stirring costs. A dosing pipe is located on the right side of the flocculation zone, with four hydraulic sensors at both ends. These sensors are connected to an automatic dosing port, automatically identifying the dosing time based on water pressure data. The bottom end is the sludge discharge port for the flocculation zone. An agitator and agitator blades are installed inside the flocculation zone to agitate it. The secondary sedimentation zone is located outside the flocculation zone and connected to it via an overflow weir. The right end of the secondary sedimentation zone is the sludge discharge port for the sedimentation zone, discharging excess low-concentration sludge. The upper end of the secondary sedimentation zone is the outlet. Here, after flocculation and secondary sedimentation, the oil sludge pollutants in the coal chemical wastewater are effectively removed, and the wastewater color changes from dark black to light yellow, which is beneficial for the next step of biological treatment.

[0077] In this embodiment, computational fluid dynamics is used to simulate the internal flow field of the cyclone flocculation enhancement device under different height-to-diameter ratios and different operating methods, thereby obtaining the optimal height-to-diameter ratio and operating method of the device. This significantly reduces the amount of chemicals added while improving the pollutant removal rate, achieving low-cost and high-efficiency green treatment of coal chemical wastewater.

[0078] The pollutant cyclone-enhanced removal device and method of the present invention includes: a sludge discharge port equipped with a sludge discharge pipe for discharging flocculated sludge; a water inlet equipped with a water inlet pipe for introducing wastewater into the high-density flocculation zone; an automatic dosing port for adding flocculant to the high-density flocculation zone; a stirring rod for mixing and coagulating the flocculant with the wastewater in the high-density flocculation zone; and an overflow weir for overflowing wastewater into the secondary sedimentation zone after the flocculated wastewater has filled the high-density flocculation zone. The inlet has an inclination angle of 30°, allowing the wastewater to naturally form a vortex at the bottom of the flocculation system, saving stirring time. The automatic dosing port is electrically connected to a water pressure sensor, which automatically identifies the dosing time based on water pressure data and can adjust the ratio between wastewater and flocculant at any time to determine the optimal mixing ratio for sludge removal. The automatic dosing port of the flocculation system uses an inorganic-organic composite flocculant. The flocculant is aluminum sulfate and polyacrylamide. The flocculation zone was simulated using computational fluid dynamics software, and the final height-to-diameter ratio was determined to be 8:5. The sludge discharge port is equipped with a sludge discharge pipe for secondary sedimentation sludge discharge. The effluent outlet is equipped with an effluent pipe for the overall discharge of wastewater after flocculation and secondary sedimentation treatment.

[0079] The dimensions of the device in this invention were designed using computational fluid dynamics simulation. The simulation analyzed the internal fluid velocity, eddy viscosity, and turbulent kinetic energy, selecting the most suitable aspect ratio, stirring speed, and stirring blade position through comparison. This approach better suits the overall flocculation process and utilizes the internal flow field, allowing flocculated particles to undergo sufficient collision and further flocculation to form larger particles. The flocculant used in this invention is an inorganic-organic composite flocculant. After hydrolysis and polymerization in the high-flocculation zone, crystal nuclei are formed. Then, under the action of swirling shear force, the crystal nuclei further adhere to the oil, dust, and sludge through electrostatic adsorption and netting, forming large aggregated particles. Under gravity, these particles are separated through two sedimentation processes, achieving highly efficient treatment of typical pollutants in wastewater. Intermittent stirring provides the crystal nuclei with more buffer time, allowing for sufficient contact between the oil and sludge, forming larger and denser flocs, which facilitates rapid sedimentation and pollutant removal.

[0080] The device of this invention was used to treat coal chemical wastewater. The results showed that under optimal operating conditions, the highest removal rates of oil, SS, COD, and phenol were 73.43%, 87.88%, 78.63%, and 65.20%, respectively. Compared with the flocculation experiment alone, the amount of reagent added was reduced by 50%-60%, and the removal rate was increased by 20%-30%, which further verified the rationality of the device design. It can be seen that this reactor has broad prospects for industrial application in the treatment of coal chemical wastewater.

[0081] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A device for enhanced removal of pollutants by cyclone, characterized in that, The utility model relates to a kind of sewage treatment equipment, including reactor (1), overflow weir (2), water inlet pipe (3), dosing pipe (4) and flocculation sludge discharge pipe (5);The overflow weir (2) is arranged inside the reactor (1), and the overflow weir (2) divides the internal cavity of the reactor (1) into flocculation zone (101) and secondary precipitation zone (102); Wherein, the flocculation zone (101) is located at the bottom of the inner cavity of the reactor (1), and the secondary precipitation zone (102) is located above the flocculation zone (101) around, and the flocculation zone (101) and the secondary precipitation zone (102) are communicated by the overflow weir (2) between; The one side of the flocculation zone (101) is provided with water inlet pipe (3), and the other side of the flocculation zone (101) is provided with dosing pipe (4), and the bottom center of the flocculation zone (101) is provided with flocculation sludge discharge pipe (5);The bottom of the secondary precipitation zone (102) is evenly provided with sediment sludge discharge port (9) around, and the top of the secondary precipitation zone (102) is evenly provided with water outlet (10) around; The height-diameter ratio of the flocculation zone (101) is 8:5; The flocculation zone (101) is added with flocculant;Wherein, the flocculant is inorganic-organic composite flocculant, and the inorganic-organic composite flocculant is prepared by aluminum sulfate and polyacrylamide; One end of the water inlet pipe (3) is connected with sewage source, and the other end of the water inlet pipe (3) extends into the inside of the flocculation zone (101);Wherein, the extending end of the water inlet pipe (3) is inclinedly arranged towards the bottom center side of the flocculation zone (101); The angle between the extending end of the water inlet pipe (3) and the horizontal plane is 30°; It also includes stirring paddle (6), which is vertically arranged in the inside center of the reactor (1);The stirring paddle (6) is located in the flocculation zone (101), including stirring rod (601) and stirring blade (602) arranged on the stirring rod (601); The distance between the stirring blade (602) and the bottom of the reactor (1) is 3 / 10 of the height dimension of the reactor (1);The stirring rate of the stirring blade (602) is 180r / min, and the working mode is gap stirring; The internal flow field of the flocculation zone is divided into high flow rate area, low flow rate area and medium flow rate area to realize cyclone strengthening effect; The overflow weir (2) includes inner baffle (201) and outer baffle (202), the inner baffle (201) includes circular straight cylinder segment and large horn segment, the circular straight cylinder segment is coaxially arranged at the inside upper end of the reactor (1), and the large horn segment is coaxially arranged at the lower end of the circular straight cylinder segment; The outer baffle (202) is coaxially and spacedly sleeved outside the circular straight cylinder segment, and the outer baffle (202) includes outer circular sleeve segment and small horn segment;The outer circular sleeve segment is spacedly sleeved outside the circular straight cylinder segment, and the upper end of the outer circular sleeve segment is connected with the inner wall of the upper cover of the reactor (1), and the lower end of the outer circular sleeve segment extends towards the upper surface direction of the large horn segment.

2. A method for enhanced removal of pollutants by cyclone, characterized by, The device is used for removing oil, sludge suspended substance, COD and phenol in coal chemical industry wastewater. The pollutant cyclone enhanced removal method is specifically as follows: The coal chemical industry wastewater to be treated is introduced into the flocculation zone (101) through the water inlet pipe (3), and flocculation reaction occurs in the flocculation zone (101), so that flocculation wastewater and flocculation sludge are formed; the flocculation sludge is discharged from the flocculation sludge discharge pipe (5); The flocculation wastewater in the flocculation zone flows into the secondary sedimentation zone (102) through the overflow weir (2), and after sedimentation, the treated wastewater is discharged from the water outlet (10), and the treated sludge is discharged from the sedimentation sludge discharge port (9).

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