System for removing insoluble organic matters in aquatic product processing wastewater and construction method thereof

Abstract

According to the removal system for the insoluble organic matters in the aquatic product processing wastewater and the construction method of the removal system, the removal system comprises the magnetic liquid-solid circulation separator and the magnetic composite particles, and the magnetic composite particles are arranged in the magnetic liquid-solid circulation separator and used for adsorbing the insoluble organic matters in the wastewater; the device structurally comprises a barrel body, a return pipe, an air outlet pipe, an aeration device and a liquid inlet mechanism, according to the magnetic liquid-solid circulation separator matched with the magnetic composite particles, through simulation operation, the operation effect of the magnetic liquid-solid circulation separator under assumed parameters is predicted, the parameter regulation and control work efficiency is improved, it is guaranteed that the magnetic liquid-solid circulation separator maintains a stable solid-liquid-gas fluidization state, and the magnetic composite particles can be recycled. And the magnetic composite particles are matched for use, so that insoluble organic matters such as grease and protein in the aquatic product processing wastewater are efficiently recycled.

Description

Technical Field

[0001] The present invention belongs to the technical field of aquatic product processing wastewater treatment, and specifically relates to a system for removing insoluble organic matter in aquatic product processing wastewater and a construction method thereof. Background Art

[0002] It is reported that for every ton of surimi, squid and chitosan products produced by aquatic product processing enterprises, 20, 25 and 150 tons of wastewater containing high concentrations of organic matter will be generated respectively. Although a few enterprises have begun to recycle organic matter from some processing wastewater, most enterprises still adopt the treatment method of directly discharging after paying treatment fees to sewage treatment plants. This direct discharge method often causes serious impacts on the existing sewage treatment system and even causes the system to collapse. In addition, the high COD value of aquatic product processing wastewater is because it contains a large amount of high-value-added organic matter such as protein, and direct discharge of wastewater will cause huge waste of resources. Therefore, the development of organic matter recovery technology in aquatic product processing wastewater is not only conducive to reducing the discharge of high-concentration organic wastewater and alleviating the operating burden of sewage treatment plants, but more importantly, the efficient recovery of high-value organic matter in it is also of great practical significance for promoting aquatic product processing enterprises to improve quality and efficiency and create considerable additional economic benefits.

[0003] Chinese invention patent CN201610144560.3 discloses a grease separation device for aquatic product processing wastewater, including a grease separation tank and a stirrer. The invention provides a grease separation device for aquatic product processing wastewater, which can stir the wastewater in the grease separation tank both manually and electrically, solving the problem that the existing grease separation equipment can only stir the wastewater electrically. However, the invention only targets the grease in the aquatic product processing wastewater, and does not have the function of efficiently enriching and recovering other high-value organic matter such as protein with a higher content. In addition, the invention does not disclose a simulation calculation method for simulating the efficient operation of the equipment, and the system parameter optimization can only be completed through a large number of trial operations.

[0004] Furthermore, Chinese invention patent CN202110518281.X discloses a system and method for treating wastewater from aquatic product processing, which includes: a collection tank, a grid tank, an electric flocculation tank, an anaerobic fermentation tank, a regulating tank, a photobioreactor, a microalgae harvesting tank and a clear water tank connected in sequence. The system and method for treating wastewater from aquatic product processing provided by the invention have the advantages of good treatment effect, low operation cost, high degree of resource utilization, and easy operation and management. However, the invention also cannot achieve the enrichment and recovery of high-value organic matter in wastewater from aquatic product processing. It takes too long due to biological growth, and the treatment efficiency needs to be improved. In addition, the invention does not disclose the calculation method for simulating the efficient operation of the equipment, and the system parameter optimization can only be completed through a large number of trial operations. Summary of the invention

[0005] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a system for removing insoluble organic matter from aquatic product processing wastewater and a construction method thereof. The system includes composite particles with lipophilic functional groups and magnetic properties, which can effectively enrich the insoluble organic matter in aquatic product processing wastewater. The system also includes a device capable of efficiently separating the enriched organic matter from the wastewater, and is equipped with an operation method for simulating the operation of the device, which can quickly optimize the system operation parameters according to different enriched particle sizes, and is specifically realized through the following technical solutions:

[0006] A system for removing insoluble organic matter from aquatic product processing wastewater, the removal system includes a magnetic liquid-solid circulation separator and magnetic composite particles used in conjunction with the magnetic liquid-solid circulation separator. The magnetic composite particles are placed in the magnetic liquid-solid circulation separator for adsorbing insoluble organic matter in the wastewater. The magnetic liquid-solid circulation separator includes:

[0007] Barrel body: A circular baffle extends from the upper part of its inner wall towards the center. A through hole is provided in the center of the baffle, and a hollow tube extends upward at the through hole. The baffle divides the barrel body into a lower organic matter adsorption area and an upper organic matter collection area;

[0008] Return pipe: A U-shaped pipe with both ends open and connected to the upper organic matter collection area and the lower organic matter adsorption area respectively;

[0009] Outlet pipe: One end of it is connected to the lower part of the barrel body, and the other end is an air outlet. A bubble removal device is placed in the outlet pipe;

[0010] Aeration device: It includes an aeration plate and a blower, and the aeration plate is arranged at the bottom of the barrel body;

[0011] Liquid inlet mechanism: It includes a wastewater pump and a wastewater feed pipe, and the wastewater feed pipe extends into the barrel body from the bottom of the barrel body.

[0012] Furthermore, a barrel cover is provided at the top of the barrel body, and support legs are provided at the bottom of the barrel body.

[0013] Furthermore, the magnetic adsorption particles contain components that form flocs with insoluble organic matter. These components include chitosan with a nano-size and lipophilic modification, and the magnetism is realized by zinc ferrite particles with a nano-size and citric acid modification.

[0014] The magnetic composite particles are specifically prepared through the following steps:

[0015] 1) Add silicate minerals to the NaOH solution, stir magnetically, centrifuge, remove the supernatant, transfer the precipitate to the HCl solution, stir magnetically, centrifuge to remove the supernatant, collect the precipitate and freeze-dry it for later use.

[0016] 2) Chitosan was dispersed in NaOH / urea / deionized water, stirred, freeze-thawed, melted by stirring at room temperature, and the freeze-thawing - stirring process was repeated three times. An equal volume of absolute ethanol was added to the final solution, and it was magnetically stirred. The supernatant was removed by centrifugation, the precipitate was transferred into a dialysis bag, dialyzed with deionized water, the supernatant was removed by centrifugation, and the precipitate was freeze-dried to obtain chitosan nanocrystalline whiskers.

[0017] 3) Chitosan nanocrystalline whiskers were dispersed in NaOH / urea / deionized water (11 / 4 / 85, w / w / w), stirred, freeze-thawed, melted by stirring at room temperature, and the process was repeated three times. Pretreated silicate, sodium tripolyphosphate (TPP), and Ci-ZnFe2O4 were added to the solution, stirred, the supernatant was removed by centrifugation, the precipitate was transferred into a dialysis bag, dialyzed with deionized water, and the precipitate was freeze-dried to obtain magnetic particles before lipophilic modification.

[0018] 4) The magnetic particles before lipophilic modification were ultrasonically dispersed in methoxypolyethylene glycol silane, cross-linked at a constant temperature, the supernatant was removed by centrifugation, and the precipitate was freeze-dried to obtain lipophilic modified magnetic composite particles.

[0019] The magnetic composite particles prepared by this preparation method have amphoteric characteristics, namely hydrophilicity and hydrophobicity. Hydrophilicity enables them to be well dispersed in water, and hydrophobicity (more precisely, lipophilicity) enables them to automatically combine with lipid substances in water. The prepared particles can combine with proteins and lipids in aquatic product processing wastewater to form large particles, increasing the density, and then settling to the bottom of the container. After simple filtration, the efficient recovery of organic matters such as proteins and lipids in aquatic product processing wastewater can be achieved.

[0020] A construction method for removing insoluble organic matters in aquatic product processing wastewater in a removal system. The specific construction method is as follows: Through simulation calculations, the operating effects of the magnetic liquid-solid circulation separator under specific parameters are predicted to ensure that the separator maintains a stable solid-liquid-gas fluidized state, enabling the magnetic composite particles to fully contact the insoluble organic matters in aquatic product processing wastewater and separate from the wastewater under the action of the gas-liquid two-phase, and gather in the upper organic matter collection area for easy recovery.

[0021] Through numerical simulation calculations, the main operating parameters of the magnetic liquid-solid circulation separator are accurately predicted to ensure that the separator maintains a stable solid-liquid-gas fluidized state. The relative flow rate, particle size, and phase viscosity are the main factors affecting the drag force. The k-ε model is selected for the turbulence model. The gidaspow model is selected for the drag force models of air and particles, and water and particles in the three-Euler model.

[0022] Furthermore, the three-Euler model in the multiphase flow heterogeneous model is selected for the simulation calculation. The continuity equation and momentum equation of the nth phase in the Euler model are shown as follows:

[0023]

[0024] Where s, g, and l represent the solid phase, gas phase, and liquid phase respectively, and satisfy: ε s + ε g + ε l = 1;

[0025] The physical model of the discrete phase selects erosion / accumulation, and the drag force model of air and water selects the Schiller-Naumann model. The specific equations are as follows:

[0026]

[0027] Re is the relative Reynolds number, vn and vm are the velocities of the nth and mth phases respectively, μn is the dynamic viscosity of the nth phase, and dm is the particle diameter of the mth phase.

[0028] The magnetic composite particles in the system of the present invention can significantly improve the affinity for water-insoluble lipophilic organic matter, thereby improving the efficiency of separating insoluble organic matter from aquatic product processing wastewater by the magnetic composite particles. By cooperating with the magnetic liquid-solid circulation separator, the particles can combine with proteins and lipids in the aquatic product processing wastewater to form large particles, increasing the density and then settling to the bottom of the container. After simple filtration, the efficient recovery of organic matter such as proteins and lipids in the aquatic product processing wastewater can be achieved. Description of the Drawings

[0029] Figure 1 It is the transmission electron microscope image of the particles prepared by the present invention;

[0030] Figure 2 It is the Fourier transform infrared spectrum of the particles prepared by the present invention;

[0031] Figure 3 It is the water contact angle test result image of the particles prepared by the present invention;

[0032] Figure 4 It is the comparison chart of the difference in oil absorption performance of the particles prepared by the present invention before and after modification;

[0033] Figure 5 It is the comparison chart of the adsorption and flocculation effects of the particles prepared by the present invention and ordinary chitosan on insoluble organic matter in squid processing wastewater (a is ordinary chitosan, b is the particles prepared by the present invention);

[0034] Figure 6 It is the structural schematic diagram of the magnetic liquid-solid circulation separator of the present invention;

[0035] Figure 7 It is the predicted diagram of the distribution of the particles prepared by the present invention with different particle sizes in the separator;

[0036] Figure 8 Prediction diagram of the distribution of the particles prepared by the present invention in the separator under different densities;

[0037] In the figure, 1 - barrel body, 101 - lower organic matter adsorption area, 102 - upper organic matter collection area, 2 - baffle, 3 - hollow tube, 4 - return pipe, 5 - air outlet pipe, 501 - air outlet, 6 - bubble removal device, 7 - aeration device, 701 - aeration plate, 702 - blower, 8 - liquid inlet mechanism, 801 - waste water pump, 802 - waste water feed pipe, 9 - barrel cover, 10 - support leg. Specific embodiments

[0038] The present invention will be further described below in conjunction with the accompanying drawings of the specification to better understand the technical solution.

[0039] Preparation of magnetic composite particles:

[0040] Step 1): Add 10 g of silicate mineral (molecular formula: Al2[Si2O5](OH)4·2H2O) to 100 mL of 4% (w / v) NaOH solution, stir at 200 rpm for 1 min, centrifuge at 8000 rpm to remove the supernatant, transfer the precipitate to 100 mL of 2% (v / v) HCl solution, stir at 200 rpm for 1 min, centrifuge at 8000 rpm to remove the supernatant, collect the precipitate, and freeze-dry for later use.

[0041] Step 2): Take 2 g of chitosan and disperse it in 100 g of NaOH / urea / deionized water (11 / 4 / 85, w / w / w), stir at 200 rpm for 5 min, freeze-thaw at -80 °C for 4 h, stir and melt at room temperature, repeat three times, add an equal volume of absolute ethanol to the solution, stir at 200 rpm for 10 min, centrifuge at 8000 rpm to remove the supernatant, transfer the precipitate to a dialysis bag, dialyze with deionized water for 3 d, centrifuge at 8000 rpm to remove the supernatant, and freeze-dry the precipitate to obtain chitosan nanowhiskers.

[0042] Step 3): Take 2 g of chitosan nanowhiskers and disperse it in 100 g of NaOH / urea / deionized water (11 / 4 / 85, w / w / w), stir at 200 rpm for 5 min, freeze-thaw at -80 °C for 4 h, stir and melt at room temperature, repeat three times, add 10 g of Al2[Si2O5](OH)4·2H2O, 2 g of sodium tripolyphosphate (TPP), and 5 g of Ci-ZnFe2O4 to the solution, stir at 200 rpm for 2 h, centrifuge at 8000 rpm to remove the supernatant, transfer the precipitate to a dialysis bag, dialyze with deionized water for 3 d, and freeze-dry the precipitate to obtain magnetic particles before lipophilic modification.

[0043] Step 4): Ultrasonically disperse the magnetic particles before lipophilic modification in methoxypolyethylene glycol silane (10 g / 100 mL), carry out constant-temperature crosslinking at 60 °C for 2 h, centrifuge at 8000 rpm to remove the supernatant, and freeze-dry the precipitate to obtain lipophilic modified magnetic composite particles.

[0044] The magnetic composite particles prepared above have a core-shell structure. Its core is a magnetic Ci-ZnFe2O4 particle, and the periphery includes nano-chitosan whiskers. Its microscopic morphology is as Figure 1 shown. It can be seen from Figure 1 that the magnetic composite particles are circular and the diameter is between 100 - 200 nm. It can be seen from the Fourier transform infrared spectrum diagram of Figure 2 that a large number of Si-O bonds and Si-O-Si bonds are added after the lipophilic modification of the particles. These chemical bonds have good lipophilicity, so the affinity of the particles for water-insoluble lipophilic organic matter can be significantly improved, thereby improving the efficiency of the particles to separate insoluble organic matter from aquatic product processing wastewater.

[0045] From Figure 3 the water contact angle test result diagram of the magnetic composite particles, it can be seen that after the lipophilic modification, the water contact angle of the particles increases from 60° to 120°, indicating that the hydrophobicity is significantly enhanced after the modification. From Figure 4 the difference comparison diagram of the oil absorption performance of the particles before and after modification, it can be seen from the appearance that the color of the composite particles after lipophilic modification is black with obvious oil luster, indicating that a large amount of oily substances are absorbed. The color of the composite particles before modification is light gray without obvious oil luster, indicating that its adsorption capacity for oily substances is insufficient. In addition, when the magnetic composite particles prepared by the present invention and ordinary chitosan are used to treat squid cooking wastewater respectively, the results are as Figure 5 shown. Compared with ordinary chitosan, the particles of the present invention have a more ideal flocculation separation effect on the organic matter in squid cooking wastewater.

[0046] The structure of the magnetic liquid-solid circulation separator used in the removal system of the present invention is as Figure 6As shown in the figure, it includes: a barrel body 1, a reflux pipe 4, an air outlet pipe 5, an aeration device 7, a liquid inlet mechanism 8, a barrel cover 9 and support legs 10. Among them, an annular baffle 2 extends from the upper part of the inner wall of the barrel body 1 towards the central part. A through hole is provided at the center of the baffle 2, and a hollow pipe 3 extends upwards at the through hole. The baffle 2 divides the barrel body 1 into a lower organic matter adsorption area 101 and an upper organic matter collection area 102; the reflux pipe 4 is a U-shaped pipe, and the two ends are respectively connected to the upper organic matter collection area 102 and the lower organic matter adsorption area 101; one end of the air outlet pipe 5 is connected to the lower part of the barrel body 1, and the other end is an air outlet 501. A bubble removal device 6 is placed in the air outlet pipe 5; the aeration device 7 includes an aeration plate 701 and a blower 702, and the aeration plate 701 is arranged at the bottom of the barrel body 1; the liquid inlet mechanism 8 includes a wastewater pump 801 and a wastewater feed pipe 802. The wastewater feed pipe 802 extends into the barrel body 1 from the bottom of the barrel body 1. The barrel cover 9 is arranged on the top of the barrel body 1, and the support legs 10 are arranged at the bottom of the barrel body 1. When using this equipment, first use the wastewater pump 801 to pump the aquatic product processing wastewater into the lower organic matter adsorption area 101 of the barrel body 1 through the wastewater feed pipe 802, and then add the prepared microparticles into the barrel body 1 containing the aquatic product processing wastewater. Organic matter-microparticle aggregates are formed by the physicochemical action between the functional groups on the microparticles and the organic matter in the wastewater. Use the blower 702 and the aeration plate 701 to aerate the wastewater, improve the contact probability between the microparticles and the organic matter, and at the same time blow the aggregates to the upper organic matter collection area 102. The arranged barrel cover 9 prevents the aggregates from overflowing. Use the reflux pipe 4 to reflux the wastewater in the upper organic matter collection area 102 to the lower organic matter adsorption area 101 to cyclically remove the organic matter in the wastewater. In addition, use the bubble removal device 6 to eliminate a large number of bubbles formed in the barrel body, avoid the large amount of space occupied by the bubbles in the barrel body, and prevent the bubbles from reducing the organic matter collection efficiency. This bubble removal device uses the existing technology and will not be described in detail. Furthermore, the microparticles prepared by the present invention have magnetism, and the magnetic force of the magnet can be used to enrich the unused and excessive microparticles, which can be reused subsequently, improve the utilization efficiency of the microparticles, and avoid environmental residues.

[0047] The present invention uses numerical simulation operations to accurately predict the main operating parameters of the magnetic liquid-solid circulation separator, ensuring that the separator maintains a stable solid-liquid-gas fluidized state. The relative flow velocity, particle size, and phase viscosity are the main factors affecting the drag force. The k-ε model is selected for the turbulence model. The drag force models for air and particles, and water and particles in the three-Euler model are selected as the gidaspow model. Specifically:

[0048] The three-Euler model in the multiphase flow heterogeneous model is selected for the simulation operation. The continuity equation and momentum equation of the nth phase in the Euler model are shown as follows:

[0049]

[0050] where s, g, and l represent the solid phase, gas phase, and liquid phase respectively, and satisfy: ε s + ε g + ε l = 1;

[0051] The physical model of the discrete phase is selected as erosion / deposition, and the drag model of air and water is selected as the Schiller-Naumann model. The specific equations are as follows:

[0052]

[0053] Re is the relative Reynolds number, vn and vm are the velocities of the nth and mth phases respectively, μn is the dynamic viscosity of the nth phase, and dm is the particle diameter of the mth phase

[0054] Using the above simulation method, the optimal particle size and loading density of the composite particles in the magnetic liquid-solid circulating fluidized bed are optimized. Figure 7 The figure shows the particle distribution diagrams of particles with diameters of 0.5 mm, 1 mm, 1.5 mm, and 2 mm respectively when they are running in the simulated fluidized bed. It can be found from the figure that the finer the particles, the better the fluidization state. The particles with a diameter of 0.5 mm are more evenly distributed in the reactor, and have excellent axial and radial diffusion capabilities. It can be observed that the particles rise from the bottom to the top and then return to the bottom clockwise. Compared with the former, although the particles with a diameter of 1 mm also have good circulation performance, a large number of particles adhere to the tube wall during the rising process, and the radial diffusion is weak, resulting in a lower particle density near the inlet, which affects the reaction efficiency. At the same time, it can be observed that the coarser the particle size, the worse the diffusion ability of the bed layer. The height at which the particles can be evenly distributed in the simulated reactor decreases as the particle size increases. When the particle size reaches 2 mm, the particles can hardly reach the top of the reactor, which will cause the particles to be unable to actively adsorb the oil onto the surface. Only relying on the diffusion of oil in water, the reaction will be greatly hindered. The group with a particle size of 0.5 mm shows a dispersed fluidization state (Fr < 1), and the other groups show a aggregative fluidization state. Therefore, according to the conclusion, the smallest possible particle size should be selected during actual operation.

[0055] In addition, the predicted diagram of the distribution of the prepared particles in the separator under different densities is shown by the particle trajectories Figure 8 It can be seen that when the gravity and atmospheric pressure are set to 9.8 m / s 2 and 101325 Pa, and the particle density is controlled at 1100 - 1200 g / m 3 , the particles can be evenly distributed in the separator. At this time, the contact between the particles and the insoluble proteins is the most sufficient, and the particles can be effectively collected from the top of the separator, realizing the effective separation of the solid-liquid-gas three phases and completing the recovery of proteins.

[0056] Select composite particles with a particle size as the simulation result, and transfer the particles to the magnetic liquid-solid circulation separator constructed by the present invention at the particle inoculation density shown by the simulation result. Open the waste water pump valve, and pump the waste water from hairtail surimi processing or the waste water from squid cooking into the lower organic matter adsorption area of the magnetic liquid-solid circulation separator. After completion, close the corresponding valve to recover the oil in the waste water from hairtail surimi processing and the protein in the waste water from squid cooking.

[0057] After measurement, the adsorption capacity of the lipophilic modified magnetic composite particles in the present invention for oily organic matter can reach 96.70%, while the material before modification is only 66.39%, which proves that the lipophilic modification in the present invention can indeed greatly improve the adsorption capacity of the particles for insoluble organic matter. In addition, when using common chitosan as a filler to flocculate and recover the protein in the waste water from squid cooking, the recovery rate is only 19.96%; but when using the particles of the present invention in combination with the separator of the present invention, the recovery rate is as high as 86.67%, and the effect increase is very significant. The results are shown in Table 1 and Table 2.

[0058] Table 1 Difference in the recovery rate of oil in waste water with or without lipophilic modification of the particles of the present invention

[0059]

[0060] Table 2 Difference in the recovery rate of protein in the waste water from squid cooking between common chitosan and the particles of the present invention

[0061]

Claims

1. A system for removing insoluble organic matter from aquatic product processing wastewater, characterized in that The removal system includes a magnetic liquid-solid circulation separator and magnetic composite particles used in conjunction with the magnetic liquid-solid circulation separator. The magnetic composite particles are placed in the magnetic liquid-solid circulation separator to adsorb insoluble organic matter in wastewater. The magnetic liquid-solid circulation separator includes: The barrel body (1) has an annular baffle (2) extending from the upper part of the inner wall thereof to the center, a through hole is provided at the center of the baffle (2), a hollow tube (3) extends upward from the through hole, and the baffle (2) divides the barrel body (1) into a lower organic matter adsorption area (101) and an upper organic matter collection area (102); Reflux pipe (4): a U-shaped pipe, with openings at both ends respectively connected to the upper organic matter collection area (102) and the lower organic matter adsorption area (101); An air outlet pipe (5): one end of which is connected to the lower part of the barrel body (1), and the other end of which is an air outlet (501). A bubble removal device (6) is placed in the air outlet pipe (5); An aeration device (7): comprising an aeration plate (701) and a blower (702), wherein the aeration plate (701) is arranged at the bottom of the barrel (1); The liquid inlet mechanism (8) comprises a wastewater pump (801) and a wastewater inlet pipe (802), wherein the wastewater inlet pipe (802) extends from the bottom of the barrel body (1) into the barrel body (1).

2. A system for removing insoluble organic matter from aquatic product processing wastewater as claimed in claim 1, characterized in that A barrel cover (9) is arranged on the top of the barrel body (1), and supporting legs (10) are arranged on the bottom of the barrel body (1).

3. A system for removing insoluble organic matter from aquatic product processing wastewater as claimed in claim 1, characterized in that The magnetic adsorption particles contain components that form floccules with insoluble organic matter, and the components include chitosan that is nano-sized and lipophilically modified. The magnetism is achieved by zinc ferrite particles that are nano-sized and modified by citric acid.

4. A method for removing insoluble organic matter from aquatic product processing wastewater using the removal system according to claim 1, characterized in that: The construction method is specifically as follows: through simulation calculations, the operating effect of the magnetic liquid-solid circulation separator under specific parameters is predicted to ensure that the separator maintains a stable solid-liquid-gasification state, so that the magnetic composite particles can fully contact with the insoluble organic matter in the aquatic product processing wastewater, and are separated from the wastewater under the action of the gas-liquid two-phase, and gathered in the upper organic matter collection area for easy recovery.

5. The method for removing insoluble organic matter from aquatic product processing wastewater by the removal system according to claim 4 is characterized in that: The simulation operation selects the three-Eulerian model in the multiphase flow heterogeneous model. The continuity equation and momentum equation of the nth phase of the Euler model are shown as follows: Where s, g, and l represent the solid phase, gas phase, and liquid phase, respectively, satisfying: ε s +ε g +ε l =1; The discrete phase physical model is erosion / deposition, and the drag model of air and water is the Schiller-Naumann model. The specific equation is as follows: Re is the relative Reynolds number, vn and vm are the velocities of the nth and mth phases respectively, μn is the dynamic viscosity of the nth phase, and dm is the particle diameter of the mth phase.

Images