A composite powder carrier process

Abstract

This invention relates to the field of wastewater treatment microbial carrier preparation technology, and particularly to a composite powder carrier process. The process includes the following steps: S1, substrate activation pretreatment; S2, functional powder modification; S3, wet composite crosslinking; S4, low-temperature curing powder production; and S5, sieving and refining. Through the wet crosslinking + low-temperature curing process, multi-component microscopic bonding is achieved, improving the carrier's porosity, biocompatibility, and structural stability.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment microbial carrier preparation technology, and in particular to a composite powder carrier process. Background Technology

[0002] In the biochemical processes of wastewater treatment, microbial powder carriers are the core materials for biological fluidized beds, contact oxidation, and modified activated sludge processes. Their main function is to provide attachment and growth sites for microorganisms, increase the concentration of microorganisms in the system, enhance the degradation and removal of organic pollutants, ammonia nitrogen, and total phosphorus in the water, and at the same time optimize the sludge floc structure and improve the sludge-water separation effect.

[0003] Existing water treatment powder carriers mostly use single mineral powders such as activated carbon, diatomaceous earth, and bentonite, with simple and crude carrier preparation processes. Conventional carrier preparation processes generally lack a systematic set of steps including substrate activation, powder modification, wet crosslinking, low-temperature curing, and sieving and refining. Traditional preparation processes only involve direct mixing without substrate activation treatment, which prevents the opening of closed pores on the surface of the diatomaceous earth substrate, resulting in a small specific surface area of ​​the carrier; the absence of activated carbon alkali modification process leads to a lack of active functional groups on the surface of functional powders; reliance on physical mixing without wet crosslinking results in powder components merely stacked and adhered without microscopic bonding structures; the lack of a low-temperature curing and shaping process results in a loose composite powder structure with extremely poor stability; and the absence of a subsequent sieving and refining step leads to uneven particle size and severe agglomeration in the finished powder. These missing processes and technological defects directly result in a limited number of microbial attachment sites for the finished carrier, poor biofilm formation, easy pulverization and loss in water, rapid degradation of water treatment performance, and inability to stably adapt to wastewater biological treatment.

[0004] Therefore, the present invention provides a composite powder carrier process that achieves microscopic bonding of multiple components through wet crosslinking and low-temperature curing, thereby improving the carrier porosity, biocompatibility and structural stability. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and to propose a composite powder carrier process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A composite powder carrier process for the production of water pollution treatment agents includes the following steps: S1. Substrate activation pretreatment: Grind diatomaceous earth through a 200-300 mesh sieve, add 2%-5% citric acid aqueous solution, stir and activate at 40-50℃ and 300-500rpm for 30-60min, filter, and dry at low temperature to obtain activated diatomaceous earth substrate. S2. Functional powder modification: Powdered activated carbon is passed through a 300-mesh sieve, modified by soaking in a dilute sodium hydroxide solution, washed with deionized water until neutral, and then dried to obtain modified powdered activated carbon. S3. Wet composite crosslinking: The activated diatomaceous earth and modified powdered activated carbon are mixed evenly to prepare a powder suspension with a solid content of 25% to 35%. The mixture is stirred at room temperature for 20 minutes, then chitosan and polyaluminum chloride are added. The mixture is heated to 55 to 65°C and stirred at a constant temperature for 60 to 90 minutes to obtain a composite slurry. S4. Low-temperature curing powder making: The composite slurry is laid flat and cured at a low temperature of 50-60℃ for 4-6 hours to obtain a blocky composite material. S5. Sieving and refining: Grind and crush the blocky composite material and pass it through a 200-mesh standard sieve to obtain a water treatment porous composite powder carrier.

[0007] Preferably, the raw materials for preparation include, by mass parts: 40-60 parts diatomaceous earth, 20-30 parts modified powdered activated carbon, 3-8 parts chitosan, 2-5 parts polyaluminum chloride, 1-3 parts citric acid, and the balance being deionized water.

[0008] Preferably, the raw materials are prepared in the following proportions by weight: 50 parts diatomaceous earth, 25 parts modified powdered activated carbon, 5 parts chitosan, 3 parts polyaluminum chloride, 2 parts citric acid, and the remainder deionized water.

[0009] Preferably, in step S1, the low-temperature drying temperature is 50-60°C, the optimal mass concentration of the citric acid aqueous solution is 3%, the activation temperature is 45°C, the activation stirring speed is 400 rpm, and the activation time is 45 min.

[0010] Preferably, in step S2, the concentration of the dilute sodium hydroxide solution is 0.4–0.6 mol / L, the activated carbon soaking modification time is 2 hours, and the powder drying temperature is 55–65°C.

[0011] Preferably, in step S3, the optimal solid content of the powder suspension is 30%, the crosslinking stirring speed is constant at 400 rpm, the crosslinking temperature is 60℃, and the crosslinking time is 75 min.

[0012] Preferably, in step S4, the optimal curing temperature is 55°C and the optimal curing time is 5 hours.

[0013] Preferably, in step S3, chitosan is used as a crosslinking binder and polyaluminum chloride is used as an inorganic coagulation and crosslinking aid component. The two work together to achieve microscopic covalent crosslinking of powder and modification of floc structure.

[0014] Preferably, the stepwise process of activation pretreatment, wet crosslinking and low-temperature curing is used to regulate the carrier to form a three-dimensional network porous structure, so that the finished carrier has the structural characteristics of high porosity, high biocompatibility and low water loss, which is suitable for microbial attachment and proliferation and sewage flocculation and purification.

[0015] Preferably, the prepared composite powder carrier is used in biological fluidized bed, contact oxidation, and modified activated sludge biochemical treatment processes for domestic sewage and low-concentration industrial organic wastewater.

[0016] Compared with the prior art, the present invention provides a composite powder carrier process with the following advantages: 1. This invention achieves microscopic bonding of multiple components through a wet crosslinking + low-temperature curing process, thereby improving the carrier porosity, biocompatibility and structural stability.

[0017] 2. In this invention, the speed distribution box of the stirred reactor is modified so that the stirring shaft can rotate and revolve synchronously. Compared with the fixed-axis stirring, the stirring range can be expanded and the stirring state can be more varied rather than stable. The varied stirring state can drive the liquid to tumble better, reduce the local aggregation of liquid near the outer layer, enhance the dispersibility of powder in liquid, and thus improve the stirring and mixing effect.

[0018] 3. In this invention, the output shaft of the speed distribution box is modified so that the stirring paddle can float up and down while revolving and rotating, which promotes the intersection and fusion of adjacent interfaces, thereby improving the mixing effect.

[0019] 4. This invention modifies the design of the stirring paddle, incorporating a spiral cylinder on each blade. The lower end of the spiral cylinder faces the lower side of the reactor interior, while the upper end faces upwards, with the lower end pointing in the direction of rotation. As the stirring paddle rotates, the lower layer of liquid flows into the spiral cylinder from its lower end and then flows out through its upper end. This circumferential shearing stirring of the liquid within the reactor is achieved through the paddle's revolution and rotation. Combined with the spiral cylinder's upward movement during stirring, this creates a three-dimensional stirring effect, significantly reducing stratification and improving mixing uniformity.

[0020] 5. In this invention, multiple flow dividers are arranged sequentially along the axis of the spiral cylinder. Each flow divider is a spiral plate that twists at least half a turn, and the spiral plate twists in the same direction as the spiral cylinder. When the liquid enters the spiral cylinder, it is divided into two streams by the flow divider at the first end. Under the action of the spiral plate structure of the flow divider, the liquid mixes by centrifugal surging. When the two streams of liquid reach the end of the next flow divider, they are divided into two streams again. The liquid is then mixed again by centrifugal surging along the flow divider structure of the next spiral plate structure. This process is repeated, and the liquid undergoes multiple splitting and mixing while surging in the spiral cylinder. The liquid itself exhibits self-stirring and mixing during surging, thereby improving the efficiency of mixing equilibrium.

[0021] 6. The present invention provides an adjustable rigid tensioning structure for the transmission between the motor and the gearbox. Compared with elastic tensioning, it retains the adjustable effect without affecting the tensioning effect due to elastic fatigue.

[0022] Other advantages, objectives and features of the invention will be set forth in part in the description which follows; and in part will be apparent to those skilled in the art upon examination of the following description; or may be learned from practice of the invention. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0024] Figure 2 This is a three-dimensional schematic diagram of the mixing device of the present invention.

[0025] Figure 3 This is a schematic diagram of the stirring device screen of the present invention.

[0026] Figure 4 This is a top view of the stirring device of the present invention.

[0027] Figure 5 This is a schematic diagram of the motor mounting structure and tensioning structure of the present invention.

[0028] Figure 6 This is a schematic cross-sectional view of the fit between the threaded sleeve and the stud in the tensioning structure of the present invention.

[0029] Figure 7 For the present invention Figure 2 A three-dimensional diagram after the lid of the vessel has been removed.

[0030] Figure 8 For the present invention Figure 7 A three-dimensional schematic diagram after removing the support frame and reactor.

[0031] Figure 9 For the present invention Figure 8A 3D view after removing the gearbox body and cover.

[0032] Figure 10 For the present invention Figure 3 Schematic diagram of the cross section at point AA.

[0033] Figure 11 For the present invention Figure 10 Diagram showing the connection between the medium-speed distribution box, the reactor, and the agitator.

[0034] Figure 12 For the present invention Figure 11 A cross-sectional view after the reactor has been removed.

[0035] Figure 13 This is a schematic cross-sectional view of the speedbox assembly of the present invention.

[0036] Figure 14 This is a schematic diagram of the cooperation between the spiral cylinder and the flow divider and the connection of the flow divider according to the present invention.

[0037] Figure 15 This is a schematic diagram of the configuration of the lifting shaft and the lifting drive structure of the lifting shaft according to the present invention.

[0038] In the diagram: 1. Frame; 2. Cantilever; 3. Swing arm; 4. Motor; 5. Connecting column; 6. Screw sleeve; 7. Stud; 8. Gearbox; 9. Input shaft; 10. Transition shaft; 11. Output shaft; 12. Input gear; 13. Transition gear; 14. Output gear; 15. Internal gear ring; 16. Agitator; 17. Spiral drum; 18. Diverter; 19. Reactor; 20. Reactor cover; 21. Rotary drum; 22. Lifting shaft; 23. Truss; 24. Slide rail; 25. Bracket; 26. Installation chamber; 27. Mounting buckle. Detailed Implementation

[0039] The following will refer to the appendices in the embodiments of the present invention. Figure 1-15 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0040] Example 1: Existing traditional carrier preparation methods only employ dry powder physical mixing, lacking the core steps of wet crosslinking and curing. Various functional powders are only surface-bonded, lacking microscopic chemical bonding structures, resulting in poor component compatibility, loose structure, easy delamination and detachment in aqueous environments, unstable microbial biofilm formation, and significant carrier loss. To address these shortcomings of traditional processes, this example provides a composite powder carrier process that achieves multi-component microscopic bonding through wet crosslinking and low-temperature curing, thereby improving carrier porosity, biocompatibility, and structural stability.

[0041] The raw materials for preparation, by mass fraction, include: 40-60 parts diatomaceous earth, 20-30 parts modified powdered activated carbon, 3-8 parts chitosan, 2-5 parts polyaluminum chloride, 1-3 parts citric acid, and the remainder deionized water.

[0042] The preparation process of the composite powder carrier according to the above component ratio includes the following steps: First, the raw materials are prepared according to the preferred mass proportions: 50 parts diatomaceous earth, 25 parts modified powdered activated carbon, 5 parts chitosan, 3 parts polyaluminum chloride, 2 parts citric acid, and the remainder deionized water.

[0043] Chitosan is used as a cross-linking binder, and polyaluminum chloride is used as an inorganic coagulation and cross-linking aid. The two work together to achieve microscopic covalent cross-linking of powder and modification of floc structure.

[0044] All powder raw materials are pre-treated to remove impurities such as lumps and large particles, ensuring that the purity of the raw materials meets the requirements for the preparation of water treatment carriers.

[0045] S1. Substrate Activation Pretreatment: 50 parts of purified diatomaceous earth were selected and put into a grinder, and ground continuously for 15 minutes. The ground powder was then sieved through a 200-300 mesh sieve. A 3% (w / w) citric acid aqueous solution was then prepared, and the sieved diatomaceous earth powder was completely immersed in the citric acid solution. The mixture was then placed into a constant-temperature stirred reactor 19. The reactor 19 was set to a stable temperature of 40-50°C and a stirring speed of 300-500 rpm. Activation was carried out under constant temperature and continuous stirring for 30-60 minutes. Through the weak acid corrosion of citric acid, the closed micropores on the surface of the diatomaceous earth powder were opened, generating hydroxyl active sites. After activation, solid-liquid separation was performed by vacuum filtration. The filter cake was then placed in a hot air drying oven and dried at a low temperature of 55°C to constant weight to remove residual surface moisture and acidic waste liquid, ultimately obtaining a porous, surface-activated rigid diatomaceous earth substrate.

[0046] S2. Functional Powder Modification: Commercially available powdered activated carbon is directly selected and sieved through a 300-mesh sieve to remove large particles of carbon residue. Then, a 0.5 mol / L sodium hydroxide dilute solution is prepared, and the activated carbon powder is immersed in the alkaline solution for 2 hours at room temperature. The alkaline solution corrodes the surface pores of the activated carbon, producing carboxyl and hydroxyl oxygen-containing active functional groups, resulting in modified powdered activated carbon with enhanced cross-linking activity and biocompatibility. After modification, the powder is repeatedly rinsed with deionized water until neutral. The washed modified activated carbon powder is placed in a drying oven and dried at a constant temperature of 60℃ to constant weight, yielding highly active modified activated carbon powder, which is then sealed for later use.

[0047] S3. Wet Composite Crosslinking: Pretreated activated diatomaceous earth and modified powdered activated carbon are added to a stirred reactor 19 and mechanically stirred for 20 minutes to ensure uniform mixing of the dry powders. Deionized water is added to the mixed powder to prepare a powder suspension with a solid content of 25%–35% (30% is preferred). The suspension is stirred at 400 rpm at room temperature for 20 minutes to ensure uniform dispersion and no agglomeration or precipitation. Then, chitosan powder and polyaluminum chloride powder are added sequentially and continuously stirred for dispersion. The reactor 19 is then heated to 55–65°C and stirred for crosslinking for 60–90 minutes. During this process, chitosan molecules fully expand in the warm water environment and chemically bond the two inorganic powders through amino and hydroxyl condensation reactions. Polyaluminum chloride hydrolyzes to generate polynuclear hydroxyl complexes, which fill the gaps in the crosslinking network and adsorb and bridge the structure. The two work synergistically to complete the multi-component micro-composite crosslinking, resulting in a uniform and stable composite slurry.

[0048] S4. Low-Temperature Curing Powder Formation: The cross-linked composite slurry is evenly spread on a high-temperature resistant tray, with the slurry thickness controlled at 3-5mm to ensure uniform heating. The tray is then placed in a hot air curing oven and cured at 50-60℃ for 4-6 hours, maintaining a constant low-temperature curing throughout. This process slowly evaporates free moisture from the slurry, solidifies and shapes the chitosan cross-linked network, and completely locks in the microscopic bonding structure of the powder, preventing pore collapse caused by high-temperature sintering. The final product is a dense, well-defined blocky composite material.

[0049] S5. Sieving and Refining: The cured blocky composite material is placed in a dust-free pulverizing device and ground at low speed to avoid violent crushing that could damage the microporous structure. After crushing, it is uniformly passed through a 200-mesh standard sieve to retain and remove large particle agglomerates. The powder passing through the sieve is the finished composite powder carrier with uniform particle size and stable structure.

[0050] The composite powder carrier prepared by this process was added to a sequencing batch reactor (SBR) for wastewater treatment at a standard dosage of 500 mg / L and operated under standardized experimental conditions. The finished carrier exhibited uniform particle size, no agglomeration or clumping, and a stable three-dimensional porous network structure. Testing revealed a carrier porosity of 62.8%, a saturated biofilm formation rate of 336 mg / g, and a steady-state water loss rate of only 2.4%. After 300 hours of continuous operation, the carrier showed no pulverization, stratification, or pore blockage. The system maintained a stable COD removal rate of 86.8% and an ammonia nitrogen removal rate of 80.3%. This effectively addresses the shortcomings of traditional processes, such as missing steps, loose carrier structure, easy loss, poor biofilm formation, and unstable water treatment. The process demonstrates strong controllability and excellent finished product performance.

[0051] Example 2: In this example, a stirring device for mixing materials in steps S1 and S3 of the above-mentioned water treatment composite powder carrier preparation process is specifically described.

[0052] To achieve the stirring and heating functions, the basic components of the stirring equipment include a stirring vessel and a matching vessel cover 20. The vessel cover 20 and the port of the reaction vessel 19 can be detachably connected via bolts arranged in a flange structure. A stirring paddle 16 is rotatably mounted on the vessel cover 20 inside the stirring vessel. The stirring paddle 16 is driven by a motor 4 mounted on the vessel cover 20 to continuously stir the materials inside the reaction vessel 19. The motor 4 is detachably mounted on the vessel cover 20 via bolts and a mounting base. An electric heating element is embedded in the inner wall of the reaction vessel 19. Thus, the motor 4 drives the stirring vessel to rotate, thereby achieving the effect of material stirring and mixing; the electric heating element heats the materials inside the reaction vessel 19.

[0053] Generally, at least one set of feed pipes with valves is installed on the lid 20 for the input of powder and liquid; a set of discharge pipes with valves is also installed at the bottom of the reactor 19 for the discharge of mixed materials.

[0054] However, when the reactor 19 is not in continuous operation or is used for mixing and processing different materials, the inside of the reactor 19 will be cleaned. To clean the inside of the reactor, either an internal rinsing spray structure is required, but this not only increases the equipment cost and design difficulty, but the spray structure, such as the spray head, is suspended inside the reactor 19 and comes into contact with the agitator or the vortex liquid flow driven by the agitator 16. After long-term use, it is easy to wear out and affect the service life; or the reactor cover 20 needs to be removed, which requires removing each bolt fastener one by one, which is time-consuming and laborious.

[0055] Therefore, to facilitate the cleaning of the reactor 19 or to coordinate with other processes, the conventional reactor 19 structure can be adapted and modified: an additional support frame 1 can be added, allowing either the reactor lid 20 or the reactor 19 to slide vertically on the support frame 1. The lid 20 and reactor 19 are no longer connected by bolts, but rather by overlapping. Thus, by moving the lid 20 or reactor 19 closer or further apart, the sealing or opening effect can be achieved. In this design, the attached diagram shows the vertical movement of the reactor 19, specifically: See attached document Figure 3As shown, a cantilever 2 is mounted on the upper end of the support frame 1, and the vessel cover 20 and the corresponding motor 4 are mounted on the cantilever 2. A bracket 25 is provided on the support frame 1, sliding vertically along it. The bracket 25 is driven by a lifting structure that allows it to move vertically back and forth; the lifting structure can be a hydraulic cylinder or similar device. The bracket 25 has an installation chamber 26 for mounting the reactor 19, preventing the reactor 19 from shaking during stirring. Thus, by driving the bracket 25 downwards, the reactor 19 is lowered along with the drive device, separating it from the vessel cover 20 and the stirring paddle 16. At this point, the port of the reactor 19 is open, facilitating cleaning and maintenance. When the reactor 19 is driven upwards by the drive device, upon reaching the end of the reaction, the port of the reactor 19 abuts against the inside of the vessel cover 20, sealing it and preventing material from splashing out during stirring.

[0056] In traditional designs, the motor 4 directly drives the agitator 16, with the motor 4's output shaft 11 directly connected to the end of the agitator 16 via a coupling. This method forces the motor 4 to directly bear the reaction impact resistance of the agitator 16 during the agitation process, without any buffering. Furthermore, motors 4 typically used for agitation have high operating power and high speeds. This design requires speed switching to avoid violent agitation that could damage the microstructure of the unformed material. Therefore, in this design, a speed distribution box 8 is installed between the motor 4's output shaft 11 and the agitator 16. The speed distribution box 8 is bolted to the end of the cantilever 2. The speed distribution box 8 contains a gear transmission mechanism. The input shaft 9 of this gear transmission mechanism is connected to the motor 4's output shaft 11 via chain drive or belt drive (synchronous belt), and the output shaft 11 of the gear transmission mechanism is connected to the end of the agitator 16 via a coupling. In this way, power is transmitted to the speed distribution box 8 via chain drive, and the gear transmission mechanism replaces the motor 4 in directly bearing the transmission resistance impact, reducing the probability of motor 4 wear.

[0057] Generally, belt drives or chain drives require a tensioning mechanism to ensure proper tension of the chain or belt and prevent slippage that could affect transmission stability. Traditional tensioning mechanisms use a tensioning wheel, which adjusts its position based on the elasticity of a component. However, this method relies entirely on the elastic component, and as the component fatigues, its elasticity weakens, affecting the tensioning effect. Referring to Figure 5, a swing arm 3 is rotatably mounted on the cantilever 2. The swing arm 3 has a C-shaped opening for mounting a buckle 27, into which the motor 4 is embedded. Bolts are used to lock the two ends of the mounting buckle 27, thus securing the motor 4 within it. Preferably, the mounting buckle 27 has downward-extending L-shaped claws on its sidewalls. These claws abut against the bottom of the motor 4, supporting it and preventing it from falling. (Refer to Figure 5.) Figure 6As shown, a connecting post 5 is rotatably mounted on the side wall of the mounting buckle 27, and a threaded sleeve 6 is rotatably mounted on the connecting post 5. A stud 7 is screwed onto the inner thread of the threaded sleeve 6, and the end of the stud 7 is rotatably mounted on the cantilever 2. The stud 7 and the rotating parts of the swing arm 3 on the cantilever 2 are staggered. In this way, the swing arm 3, the threaded sleeve 6, and the stud 7, together with the mounting base provided by the cantilever 2, form a rigid motor 4 mounting structure. Furthermore, by screwing the threaded sleeve 6, the extension and retraction state of the stud 7 within the threaded sleeve 6 can be adjusted, thereby controlling the swing angle of the swing arm 3 and achieving a tensioning effect. The threaded engagement between the threaded sleeve 6 and the stud 7 has self-locking properties. After the threaded sleeve 6 stops rotating, the position of the mounting buckle 27 is fixed, resulting in rigid tension and avoiding fatigue relaxation that occurs with elastic tension. Preferably, a set of locking screws can be added between the threaded sleeve 6 and the connecting post 5. The end of the locking screw is spherical. Tightening the locking screw clockwise will make the locking screw press tightly against the outer wall of the connecting post 5, which will have a braking and limiting effect on the threaded sleeve 6. When it is necessary to tighten the threaded sleeve 6, the locking screw is turned counterclockwise, and the end of the locking screw is separated from the threaded sleeve 6. At this time, the threaded sleeve 6 can be rotated to adjust the tension.

[0058] In a traditional gearbox 8, the output shaft 11 is fixed, so the stirring shaft rotates on its own axis for stirring. To improve the stirring effect, this design modifies the output of the gearbox 8: see attached... Figure 12 , 13As shown, the gearbox 8 includes a housing and a cover that can be detachably installed via bolts. An input shaft 9 and a transition shaft 10 are rotatably mounted on the non-axial portion between the housing and the cover. The upper end of the input shaft 9 passes through the cover and connects to a belt drive or chain drive, serving as a power transmission access point. An input gear 12 is integrally mounted on the input shaft 9, and a transition gear 13 meshes with the input gear 12 on the transition shaft 10. The lower end of the transition shaft 10 passes through the bottom wall of the housing and has a rotating cylinder 21. An output shaft 11 is rotatably mounted on the rotating cylinder 21, and an output gear 14 is mounted on the upper end of the output shaft 11. An internal gear ring 15, coaxially arranged with the transition shaft 10, is located on the bottom wall of the housing, and the output gear 14 meshes with the internal gear ring 15. The lower end of the output shaft 11 connects to a stirring paddle 16. Multiple blades are arranged around the lower side of the stirring paddle 16 to expand the stirring range and improve the mixing effect. According to the above technical solution, the motor 4 drives the input shaft 9 to rotate via belt drive / chain drive. The input shaft 9, through the cooperation of the input gear 12 and the transition gear 13, drives the transition shaft 10 to rotate. The transition shaft 10 then drives the rotating drum 21 to rotate. The rotating drum 21 drives the output shaft 11 to revolve around the transition shaft 10, which in turn drives the small-diameter stirring paddle 16 to revolve. Simultaneously, under the cooperation of the output gear 14 and the internal gear ring 15, the output shaft 11 rotates on its own axis, which in turn drives the stirring paddle 16 to rotate on its own axis. The stirring paddle 16 integrates both revolution and rotation. With the cooperation of revolution and rotation on its own axis, compared with the fixed-axis stirring, this stirring method can expand the stirring range and make the stirring state more variable rather than stable. The variable stirring state can lead to better turbulence of the liquid, reduce local aggregation of liquid near the outer layer, enhance the dispersibility of powder in liquid, and thus improve the stirring and mixing effect.

[0059] To further improve the mixing effect, this solution also improves the agitator 16. Traditional agitator structures, including those in this solution, are mostly shear-type agitators. While this method is effective for mixing horizontal layers of liquid, it is less effective for powder settling, i.e., the direction of material mixing between upper and lower layers, potentially leading to uneven concentrations between the layers. Therefore, to reduce the probability of stratification, a bracket is welded to each blade of the agitator 16, and a spiral cylinder 17 is welded to each bracket. The spiral angle of the spiral cylinder 17 does not exceed 20°. The lower port of the spiral cylinder 17 faces the lower inner side of the reactor 19, and the upper port faces upwards, with the lower port facing the direction of rotation. Thus, as the agitator 16 rotates, the lower layer of liquid flows into the spiral cylinder 17 from the lower port and then flows out along the upper port. It is important to note that the upper port of the spiral cylinder is above the liquid surface, so that the liquid flowing upwards along the spiral cylinder 17 is less affected by hydraulic pressure and flows more smoothly. As the stirring paddle 16 revolves and rotates, it achieves circumferential shearing stirring of the liquid in the reactor 19. In addition, the spiral cylinder 17 promotes the upward flow of the lower layer of liquid to the upper layer during the stirring process, thus forming a three-dimensional stirring effect. This greatly reduces the occurrence of stratification and improves the uniformity of mixing.

[0060] And refer to the appendix Figure 14 As shown, multiple flow dividers 18 are arranged sequentially along the cylinder axis inside the spiral cylinder 17. Each flow divider 18 is a spiral plate that has twisted itself at least half a turn. The spiral plate twists in the spiral direction of the spiral cylinder 17. The outer edge of the flow divider 18 is in contact with the inner wall of the spiral cylinder 17. The ends of the flow dividers 18 are connected sequentially, and the connecting ends of adjacent flow dividers 18 are not aligned. The attached figure shows a vertical arrangement. When the liquid enters the spiral drum 17, it is divided into two streams by the diversion section 18 at the beginning. Under the action of the spiral plate structure of the diversion section 18, the liquid mixes by centrifugal surging. When the two streams of liquid reach the end of the next diversion section 18, they are divided into two streams again. It is highly likely that the two streams were almost split in half by the end of the next diversion section 18. The liquid after being divided again is mixed by centrifugal surging of the next diversion section 18 with the spiral plate structure. This process is repeated. While the liquid is surging in the spiral drum 17, it will undergo multiple splitting and mixing. During the surging, it will exhibit a self-stirring and mixing phenomenon, thereby improving the efficiency of mixing equilibrium.

[0061] In summary, compared to the traditional stirring structure of the reactor 19, this solution first sets up a support frame 1 and then adjusts the lifting of the reactor 19 to achieve the opening and closing control of the reactor 19, facilitating cleaning and maintenance of the reactor 19. Then, by modifying the traditional speed distribution box 8, the stirring paddle 16 can achieve both revolution and rotation in parallel, improving the circumferential shear stirring effect. Furthermore, the spiral cylinder 17, while the stirring paddle 16 rotates, causes the lower layer of liquid to surge upwards and randomly spray out with the rotation of the stirring paddle 16, allowing the upper and lower layers to mix and reducing stratification. Moreover, the spiral cylinder 17 is equipped with multiple sets of sequentially connected diversion sections 18. Through the diversion effect of the diversion sections 18, the liquid flowing into the spiral cylinder 17 is continuously divided and mixed, and mixed along the diversion sections 18 of the spiral plate structure. During the surging process, it achieves self-mixing, thus minimizing the problem of local aggregation of the sprayed liquid and ensuring better uniform dispersion.

[0062] In Example 3, further, based on the existing impeller 16 with blades or the impeller 16 with a spiral barrel 17 structure, a method is provided that allows the impeller 16 to rise and fall slightly during its revolution and rotation, thereby promoting the cross-breaking and fusion of adjacent interfaces and improving the mixing effect.

[0063] Specifically: The output shaft 11 is hollow, and a lifting shaft 22 is installed through the central hole of the output shaft 11. The lifting shaft 22 and the output shaft 11 are in an axial sliding fit relationship (for example, the central hole is a rectangular hole, and the corresponding part of the lifting shaft 22 is a rectangular shaft). The lower end of the lifting shaft 22 extends out of the lower end of the output shaft 11 and is inserted into the upper end of the agitator 16 and locked with bolts; the upper end of the lifting shaft 22 extends out of the upper end of the output shaft 11 and is rotatably mounted with a set of struts 23. The bottom end of the gearbox 8 is fixedly mounted with a slide rail 24 inside the internal gear ring 15. Referring to the attached figure 15, the slide rail 24 consists of two sets of vertically spaced corrugated plates, and the ends of the struts 23 are round rods inserted into the two sets of corrugated plates. As the output shaft 11 rotates around the transition shaft 10, the output gear 14 meshes with the internal gear and rotates on its own. At the same time, the truss 23 is guided by the slide rail 24, causing the lifting shaft 22 to rise and fall in response to the undulation of the wave plate, which in turn drives the stirring paddle 16 to rise and fall inside the reactor 19.

[0064] This also includes other types of structures that can drive the lifting shaft 22 to rise and fall. For example, the rotating drum 21 is equipped with a suspension, and an inner screw is located directly above the output gear 14 on the suspension. The upper end of the lifting shaft 22 extends out to the output shaft 11 and is equipped with a reciprocating screw with reciprocating threads. The inner screw is fixed relative to the output gear 14, and when the output gear 14 rotates, the lifting shaft 22 rotates accordingly. Through the engagement of the reciprocating threads on the reciprocating screw, the lifting of the connecting shaft can be achieved.

[0065] The fundamental reason why this solution does not use electronic components such as cylinders or electric rods to drive the lifting shaft 22 is that the lifting shaft 22 revolves around the transition shaft 10 and rotates continuously for a full circle, which is inconvenient for wiring.

[0066] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0068] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A composite powder carrier process, characterized in that, The production of water pollution treatment agents includes the following steps: S1. Substrate activation pretreatment: Grind diatomaceous earth through a 200-300 mesh sieve, add 2%-5% citric acid aqueous solution, stir and activate at 40-50℃ and 300-500rpm for 30-60min, filter, and dry at low temperature to obtain activated diatomaceous earth substrate. S2. Functional powder modification: Powdered activated carbon is passed through a 300-mesh sieve, modified by soaking in a dilute sodium hydroxide solution, washed with deionized water until neutral, and then dried to obtain modified powdered activated carbon. S3. Wet composite crosslinking: The activated diatomaceous earth and modified powdered activated carbon are mixed evenly to prepare a powder suspension with a solid content of 25% to 35%. The mixture is stirred at room temperature for 20 minutes, then chitosan and polyaluminum chloride are added. The mixture is heated to 55 to 65°C and stirred at a constant temperature for 60 to 90 minutes to obtain a composite slurry. S4. Low-temperature curing powder making: The composite slurry is laid flat and cured at a low temperature of 50-60℃ for 4-6 hours to obtain a blocky composite material. S5. Sieving and refining: Grind and crush the blocky composite material and pass it through a 200-mesh standard sieve to obtain a water treatment porous composite powder carrier.

2. The composite powder carrier process according to claim 1, characterized in that, The raw materials for preparation, by mass parts, include: 40-60 parts diatomaceous earth, 20-30 parts modified powdered activated carbon, 3-8 parts chitosan, 2-5 parts polyaluminum chloride, 1-3 parts citric acid, and the balance of deionized water.

3. The composite powder carrier process according to claim 1 or 2, characterized in that, The raw materials used in the preparation are as follows: 50 parts diatomaceous earth, 25 parts modified powdered activated carbon, 5 parts chitosan, 3 parts polyaluminum chloride, 2 parts citric acid, and the remainder deionized water.

4. The composite powder carrier process according to claim 1, characterized in that, In step S1, the low-temperature drying temperature is 50-60℃, the optimal mass concentration of the citric acid aqueous solution is 3%, the activation temperature is 45℃, the activation stirring speed is 400 rpm, and the activation time is 45 min.

5. The composite powder carrier process according to claim 1, characterized in that, In step S2, the concentration of the sodium hydroxide dilute solution is 0.4–0.6 mol / L, the activated carbon soaking modification time is 2 hours, and the powder drying temperature is 55–65℃.

6. The composite powder carrier process according to claim 1, characterized in that, In step S3, the optimal solid content of the powder suspension is 30%, the crosslinking stirring speed is constant at 400 rpm, the crosslinking temperature is 60℃, and the crosslinking time is 75 min.

7. The composite powder carrier process according to claim 4, characterized in that, In step S4, the optimal curing temperature is 55°C and the optimal curing time is 5 hours.

8. The composite powder carrier process according to claim 1, characterized in that, In step S3, chitosan is used as a crosslinking binder and polyaluminum chloride is used as an inorganic coagulation and crosslinking aid. The two work together to achieve microscopic covalent crosslinking of powder and modification of floc structure.

9. The composite powder carrier process according to claim 1, characterized in that, Through the step-by-step process of activation pretreatment, wet crosslinking and low-temperature curing, the carrier is controlled to form a three-dimensional network porous structure, so that the finished carrier has the structural characteristics of high porosity, high biocompatibility and low water loss, which is suitable for microbial attachment and proliferation and sewage flocculation purification.

10. The composite powder carrier process according to any one of claims 1-9, characterized in that, The prepared composite powder carrier is applied to biological fluidized bed, contact oxidation, and modified activated sludge biochemical treatment processes for domestic sewage and low-concentration industrial organic wastewater.

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