Pressure-variable cavitation high-speed triple vortex-microwave composite super-nano grinding device for obtaining plant fiber powder

Abstract

A pressure-variable cavitation high-speed triple vortex-microwave composite super-nano grinding device for obtaining plant fiber powder, comprising a pretreatment system (1), a pressure-variable cavitation high-speed triple vortex-microwave composite super-nano grinding system (2), a multifunctional integrated selective nanofiltration solid-liquid separation system (3), and a two-stage composite drying system (4). A plant fiber material enters the pretreatment system (1) to be primarily ground to a micron-scale material, the micron-scale material passes through a negative pressure pipes and enters the pressure-variable cavitation high-speed triple vortex-microwave composite super-nano grinding system (2) to be ground to a nanoscale material, and after separation by the multifunctional integrated selective nanofiltration solid-liquid separation system (3), the nanoscale material enters the two-stage composite drying system (4) for drying, thereby finally obtaining nanoscale plant fiber powder of which the D50 is less than or equal to 0.316 µm.

Description

A device for high-speed three-vortex pressure-variable cavitation-microwave composite ultra-nano grinding of plant fiber powder Technical Field

[0001] The invention relates to a plant fiber crushing and grinding production device, belongs to the field of plant fiber powder grinding production, and specifically relates to a device for crushing and grinding plant fiber powder by using pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding. Background Art

[0002] There are several prominent problems with common plant fiber crushing and grinding devices currently on the market:

[0003] ⑴ Crushing and grinding equipment is not fine, energy consumption is high, production cost is high, production efficiency is low, equipment wear is serious, and it is difficult to achieve nano-level crushing

[0004] In the prior art, common processing equipment for the crushing or grinding process of plant fiber powder includes: steam explosion device, hammer mill, screw extrusion mill, air flow mill, colloid mill, freezing mill, etc.

[0005] For example, patent document CN107553656 A discloses a bamboo crushing and grinding processing device. The device uses carbide materials to directly crush and grind bamboo into powder, and has a simple structure. However, the crushing and grinding efficiency of the processing device is low, the strength and hardness are low, the blades are easily worn, and complete crushing and grinding cannot be performed. The device also has a single function, poor separation and screening, and requires a large investment in equipment and high production costs.

[0006] Taking the patent document CN104473187B, which discloses a whole giant fungus grass peptide nutritional product and its preparation method, as an example, it mentions that "the giant fungus grass is crushed and water is added to make pulp, and the pulp is placed in a multi-stage colloid mill system in series and ground for 3 to 4 times to make it reach a fineness of 80 to 120 meshes." It can be seen that even after repeated grinding, the maximum fineness that can be achieved is about 100 meshes;

[0007] The particle size d50 obtained in "Study on the Effect of Starch Particle Size on the Properties of Thermoplastic Starch" by Wu Jun, Xie Bijun, and Xiong Hanguo is ≈4.23μm; the particle size d50 obtained by air milling, ball milling, stone milling, etc. in "The Effect of Grinding Technology on Matcha Quality" by Lv Pin, Gong Shuying, Xu Yongquan, etc. is all in the range of 4-10μm; Ding Jinlong, Sun Yuanming, Yang Youhui, etc. "The Effect of Vibration Grinding on the Physical and Chemical Properties of Konjac Flour" uses a BFM-6 Bailey micronizer to vibrate and grind for 60 minutes, and the 180 mesh screening rate is 65%, which shows that its fineness is still not enough for some material extraction scenarios;

[0008] According to reports, the lowest particle size of plant fiber powder currently sold on the market is D50 = 19μm for German technology and D50 = 10μm for Chinese technology, both of which are at the micron level. There are mainly the following problems:

[0009] ①Steam explosion device is mainly used in pulping, feed starter, lignocellulose raw material pretreatment and other fields. After steam explosion, the relative density of the raw material decreases and the volume increases, and the fermentation inhibitors produced need to be washed away;

[0010] ② Hammer mills, spiral extrusion mills, air flow mills, frozen mills, etc. do not grind finely, consume a lot of energy, have high production costs, and cause serious wear and tear on the equipment, making it difficult to achieve nano-level grinding;

[0011] ③ In the field of grinding research, ultrasonic assistance has been mentioned many times, and the technology of using ultrasonic assisted grinding has emerged. Ultrasonic waves can generate a large number of bubbles in the entire grinding process to form a cavitation effect, accelerate the collision and friction between the medium and plant fiber particles, and facilitate better crushing and grinding. In reality, laboratory equipment uses low-intensity ultrasonic waves, which has a certain effect in the field of scientific research experiments, but

[0012] (1) Ultrasonic equipment is expensive, has high production costs, consumes high power, and is difficult to control;

[0013] (2) The aging time of the ultrasonic probe is very short, which seriously affects the extraction and grinding effect and efficiency;

[0014] 3. Ultrasonic waves have an extremely short wavelength, so they scatter severely and have poor penetration. To produce cavitation, the intensity of ultrasound waves must be increased, and high-intensity ultrasound waves are harmful to the human body. Long-term exposure to ultrasound waves may cause deformities and cancer. Contact with the eye area or skin may cause eye congestion and edema, and even cataracts and conjunctivitis, and produce local inflammatory reactions in the skin; leading to cell necrosis and vascular paralysis, and in severe cases, numbness of the limbs; causing vasoconstriction and even motor nerve paralysis, resulting in slow blood flow, increased blood viscosity, and even the occurrence of thrombosis;

[0015] ㈣ There are high requirements for the thickness of the container wall and the placement of the container, otherwise it will affect the grinding effect;

[0016] ㈤ The ultrasonic generator has a relatively high working noise, so its industrial application is somewhat difficult;

[0017] Therefore, the technology of ultrasonic-assisted grinding is not easy to use in industrial production and is not suitable for large-scale industrial production;

[0018] ⑵The filter membrane of the filtration device is easily clogged, the filtration is not thorough, and the production efficiency is low

[0019] The most common filtration methods in the current market are centrifuge filtration and ceramic membrane filtration. A centrifuge is a machine that uses centrifugal force to separate liquids from solid particles or components in a liquid-liquid mixture. It is mainly used to separate solid particles from liquids in suspensions or to separate two immiscible liquids of different densities in emulsions. Ceramic membrane filters are a set of precision super-filtration and purification equipment that can be widely used in various fields. Their core component, the inorganic ceramic membrane, has excellent thermal and pore stability, and the dual advantages of high-efficiency and precision filtration. However, these two filtration methods have the following problems in actual production processes:

[0020] ① The centrifuge does not filter thoroughly, the concentration cannot be increased, the filtration efficiency is low, and the production cost is high;

[0021] ② The flux of the ceramic membrane will continue to decrease during use, which may cause the membrane to become clogged easily;

[0022] ③The solid content of the ceramic membrane cannot be concentrated;

[0023] ④ The ceramic membrane has a short service life, is easily blocked, and requires frequent cleaning;

[0024] ⑶ Drying equipment, large one-time investment, uneven drying, low drying efficiency, and very high energy consumption

[0025] The common drying equipment in the current market include fluidized bed drying equipment, spray drying equipment, air flow drying equipment, drum drying equipment and belt drying equipment, among which

[0026] ① Fluidized bed drying equipment is commonly used for drying granular materials. It has certain restrictions on the particle size of the drying material. The material is mixed more violently, resulting in uneven residence time of some materials. The material is not fully dried due to short residence time or over-dried due to long residence time, resulting in very high energy consumption.

[0027] ② Spray drying equipment is often used to dry materials with high initial moisture content. The drying chamber is relatively large. The exhaust gas contains a certain amount of fine powder, which requires a set of high-efficiency separation devices. The equipment has low thermal efficiency and high power consumption. The equipment is relatively complex and requires a large one-time investment.

[0028] ③ Airflow drying equipment is often used to dry various powdery, granular, and muddy materials. It has a certain degree of wear on the materials and requires a high-efficiency dust collection device. For materials that are agglomerated or difficult to disperse, a high-performance feeding device is required. It has high power consumption and a large one-time investment.

[0029] ④Drum drying equipment is often used to dry fluid materials such as suspensions and colloidal solutions. It has a complex structure and a small heat transfer area.

[0030] 5. Belt dryers are often used to dry flake, strip, and granular materials with good air permeability. Paste materials such as filter cakes can also be dried after being formed by a granulator or extruder. The inlet and outlet of the equipment are not tightly sealed, which is prone to air leakage, resulting in low production capacity and low thermal efficiency.

[0031] The advantages and disadvantages of existing production equipment are listed as follows:

[0032] In summary, the processing equipment currently used in the market for preparing plant fiber powder has low cost-effectiveness and insufficient mechanical properties due to reasons such as poor grinding, high energy consumption, high production cost, severe wear of the crushing and grinding device, etc., and cannot solve the problems of small particle size of plant fiber powder, high production energy consumption, low equipment production efficiency and insufficient performance. It cannot simultaneously meet the requirements of equipment safety, hygiene, environmental protection and process stability, and cannot produce plant fiber powder products with higher mesh counts. According to reports, the lowest particle size of plant fiber powder currently sold on the market is D50=19μm for German technology, which is about 800 mesh, and D50=10μm for Chinese technology, which is about 1600 mesh. However, in the existing technology, due to insufficient attention to grinding and refinement, some experiments have been done in the direction of plant fiber refinement, but nano-level grinding has not yet been achieved. The research on high-mesh plant fiber powder materials is still in its infancy, and the complex production process and high preparation cost have restricted its further promotion and use. So far, it has hardly been widely industrialized and applied in actual business.

[0033] The high mesh number of plant fiber powder has an important influence on the microstructure, flow properties and mechanical properties of composite materials. According to the principle of fiber reinforcement, the larger the mesh number of plant fiber powder and the smaller the particle size, the more uniform its dispersion in the polymer matrix and the better the mechanical properties of the composite material; the smaller the particle size, the more difficult it is to disperse evenly, the more additives and better processing equipment are needed, and the higher the processing cost.

[0034] Summary of the Invention

[0035] In response to the above problems, the present invention proposes a device for ultra-nano grinding of plant fiber powder using pressure-variable cavitation high-speed three-vortex-microwave composites, providing a complete set of production equipment for plant fiber from crushing, grinding, filtering to drying to nano-scale plant fiber powder, which can continuously input materials and continuously industrialize production. The grinding particle size of the plant fiber powder reaches the nanometer level with D50 ≤ 0.316 μm. The ground plant fiber powder is a very good material whether used as an extraction, additive or any other purpose. This aspect has not been reported before, and it is the world's first case before the present application. In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0036] A device for ultra-nano grinding of plant fiber powder using a pressure-variable cavitation high-speed three-vortex-microwave composite method comprises a pretreatment system, a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system, a multifunctional integrated selective nanofiltration solid-liquid separation system, and a two-stage composite drying system. The process is as follows:

[0037] ① Plant fiber segment (such as sugarcane segment, bamboo stem segment, bamboo leaf, etc.) → feeding device 1 → first negative pressure pipeline → vacuum feeder → buffer chamber → grinding device → second negative pressure pipeline → grinding storage mixing tank → relevant solution is added to the grinding storage mixing tank in a certain proportion to obtain a uniform slurry → third negative pressure pipeline → micron grinder → multiple cycles of grinding between the micron grinder and the micron circulation mixing tank to achieve ultra-nano grinding requirements → fifth negative pressure pipeline → micron storage mixing tank → sixth negative pressure pipeline → enter the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system for grinding → The grinding process is repeated between the pressure-variable cavitation high-speed three-vortex-microwave composite nano-grinding machine and the nano-circulation stirring tank to achieve a grinding particle size of 10 to 800 nanometers → the eighth negative pressure pipeline → the nano-storage stirring tank → the ninth negative pressure pipeline → the safety filter of the multifunctional integrated selective nanofiltration solid-liquid separation system → the material pump → the material enters the rotating swash plate type axial piston type selective nanofiltration device for material filtration → the tenth negative pressure pipeline → the solid-liquid separation device for solid-liquid separation → the eleventh negative pressure pipeline → the storage stirring tank → the twelfth negative pressure pipeline → the secondary composite drying system → the finished plant fiber powder with D50 ≤ 0.316 μm;

[0038] ② The large foreign matter particles in the liquid filtered out by the safety filter of the multifunctional integrated selective nanofiltration solid-liquid separation system → the first reflux pipe of the reflux device → return to the ultra-nano circulation stirring tank of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system;

[0039] ③ The liquid with particles larger than the required nanoparticles is filtered and retained by the rotating swash plate axial plunger selective nanofiltration device of the multifunctional integrated selective nanofiltration solid-liquid separation system → the first reflux pipe of the reflux device → returns to the ultra-nano circulation stirring tank of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system;

[0040] ④ The filtrate separated by the separation membrane of the separation membrane disk of the multifunctional integrated selective nanofiltration solid-liquid separation system → the hollow flow area of ​​the separation rotating shaft → the second reflux pipe of the reflux device → returns to the ultra-nano circulation stirring tank of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system;

[0041] The pretreatment system is composed of a feeding device 1, a vacuum loader, a buffer chamber, a grinding device, a grinding storage stirring tank, a micron grinder, a micron circulation stirring tank, a micron storage stirring tank, a first negative pressure pipeline, a second negative pressure pipeline 1, a third negative pressure pipeline, a fourth negative pressure pipeline, a fifth negative pressure pipeline, a sixth negative pressure pipeline and a constant temperature device; the feeding device 1 is connected to the vacuum loader through the first negative pressure pipeline, the vacuum loader is connected to the buffer chamber, the buffer chamber is connected to the grinding device, the grinding device is connected to the grinding storage stirring tank through the second negative pressure pipeline, the grinding storage stirring tank is connected to the micron grinder through the third negative pressure pipeline, the micron grinder is connected to the micron circulation stirring tank through the fourth negative pressure pipeline, the micron grinder is respectively connected to the micron circulation stirring tank and the micron storage stirring tank through the fifth negative pressure pipeline, the micron grinder and the micron circulation stirring tank are subjected to multiple cycles of grinding through the fourth negative pressure pipeline and the fifth negative pressure pipeline until the required requirements are met, and the micron storage stirring tank is connected to the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system through the sixth negative pressure pipeline;

[0042] The grinding device, the grinding storage stirring tank, the micron grinder, the micron circulation stirring tank, the micron storage stirring tank, the first negative pressure pipeline, the second negative pressure pipeline, the third negative pressure pipeline, the fourth negative pressure pipeline, the fifth negative pressure pipeline and the sixth negative pressure pipeline are all connected to the constant temperature device by a constant temperature pipeline;

[0043] The constant temperature device is mainly used for low temperature cooling and protecting the effective components in the plant fiber during the overall powder preparation process;

[0044] The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system is composed of a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine, an ultra-nano circulation stirring tank, an ultra-nano storage stirring tank, a seventh negative pressure pipeline, an eighth negative pressure pipeline and a ninth negative pressure pipeline;

[0045] The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder is connected to the ultra-nano circulation stirring tank through the seventh negative pressure pipeline, and the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder is respectively connected to the ultra-nano circulation stirring tank and the ultra-nano storage stirring tank through the eighth negative pressure pipeline. The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder and the ultra-nano circulation stirring tank are subjected to multiple cycles of grinding through the seventh negative pressure pipeline and the eighth negative pressure pipeline until the required requirements are met. The ultra-nano storage stirring tank is connected to the multifunctional integrated selective nanofiltration solid-liquid separation system through the ninth negative pressure pipeline;

[0046] The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine consists of a body, a motor, a grinding cavity, a high-speed discrete device, a cavitation device, a grinding medium, a microwave device, a spindle constant temperature device and a cavity constant temperature device;

[0047] The motor drives the high-speed dispersing device to rotate at high speed in the grinding chamber, driving the material slurry and the grinding media in the cylinder to move at high speed, generating a swirling flow. The swirling of the flow causes a pressure drop, causing the local slurry to undergo a phase transition from liquid to gas phase, generating a large number of bubbles. While the high-speed dispersing device rotates at high speed, it also drives the surrounding slurry to flow rapidly, thereby forming turbulence and countercurrent.

[0048] The cavitation device, when the material slurry enters the grinding chamber of the pressure-changing cavitation high-speed three-vortex-microwave composite nano-grinding machine through the cavitation device, the flow surface area suddenly decreases, the flow velocity increases sharply, and the pressure change occurs. The pressure in the flow channel is lower than the saturated vapor pressure, causing cavitation in the liquid, forming a cavitation effect;

[0049] The grinding medium is L65 zirconium silicate balls, L80 stabilized zirconia balls, or L95 yttrium stabilized zirconia balls, with a particle size of 0.1 mm to 0.8 mm;

[0050] The microwave device directly acts on the material slurry in the grinding chamber of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder, thereby increasing the number of cavitation bubbles in the grinding chamber, increasing the kinetic energy of the material particles, accelerating the friction and collision between particles and between particles and grinding media, and improving the pulverization fineness and grinding efficiency of the nanoparticle powder;

[0051] The spindle constant temperature device and the cavity constant temperature device are mainly used to maintain the low temperature operation of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine, protecting the effective components of the plant fiber in the material slurry during the overall powder preparation process;

[0052] The multifunctional integrated selective nanofiltration solid-liquid separation system includes a safety filter, a material pump, a swash plate type axial piston type selective nanofiltration device, a solid-liquid separation device, a reflux device, an intelligent high-pressure backwash circulation cleaning device, a storage mixing tank, a tenth negative pressure pipeline, an eleventh negative pressure pipeline and a twelfth negative pressure pipeline;

[0053] The swash plate type axial plunger type selective nanofiltration device is composed of a selective nanofiltration membrane and a filter chamber, wherein the selective nanofiltration membrane is an asymmetric microporous nanofiltration separation membrane;

[0054] The solid-liquid separation device consists of a separation rotating shaft, a separation membrane disc and a separation chamber; the separation rotating shaft is a hollow structure, the hollow portion is the filtrate flow area, and 2 to 100 separation membrane discs are installed on the outside of the separation rotating shaft through a sealing ring, and the whole rotates at high speed in the separation chamber; the feed liquid filtered by the rotating inclined plate type axial piston type selective nanofiltration device enters the separation chamber, and under the action of centrifugation, the filtrate enters the hollow flow area of ​​the separation rotating shaft through the separation membrane of the separation membrane disc and flows out, and returns to the ultra-nano circulation stirring tank through the eleventh negative pressure pipeline. The concentrate leaves the separation membrane of the separation membrane disc through the high-speed centrifugation, so that the separation membrane always maintains normal filtration, and the concentrate enters the storage stirring tank and enters the secondary composite drying system through the tenth negative pressure pipeline;

[0055] The separation membrane disk adopts double-sided filtration and contains membranes with various filtration pore sizes of 5 nanometers, 7 nanometers, 30 nanometers, 50 nanometers, 80 nanometers, 200 nanometers, 500 nanometers, and 2 microns.

[0056] The reflux device consists of a first reflux pipe and a second reflux pipe;

[0057] The intelligent high-pressure backwash circulation cleaning device is connected to the interior of the selective nanofiltration membrane of the rotating swash plate type axial piston type selective nanofiltration device, and by timing the intelligent high-pressure backwash circulation mode, the cleaning solution is instantly sprayed out at high pressure to impact the attached particles on the surface of the selective nanofiltration membrane from the inside out. At the same time, the attached particles impacted by the rotating swash plate type axial piston type selective nanofiltration device are flushed by continuous feeding, so that the particles flow out of the rotating swash plate type axial piston type selective nanofiltration device and return to the ultra-nano circulation stirring tank, thereby ensuring that the selective nanofiltration membrane continues to work normally;

[0058] The two-stage composite drying system is a hollow blade drying assisted rotary flash drying two-stage composite drying system, which consists of a primary drying system and a secondary drying system;

[0059] The first-level drying is a hollow paddle dryer, which consists of a heating device, a dust removal device, a drying device and a conveyor. The material moisture can be dried from 60% to 30% by heating and drying.

[0060] The secondary drying is a rotary flash dryer, which consists of a second heating device, a second feeding device, a second drying device, a second dust removal device, a separation device and a collection device. By heating and drying, the moisture content of the material can be dried from 30% to 5%.

[0061] The plant fiber material of the present invention is crushed, ground, filtered, separated and dried to become nano-scale plant fiber powder, and its D50 is ≤ 0.316 μm;

[0062] The present invention keeps pace with social development and transforms plant fiber materials into nano-scale plant fiber powder through crushing, grinding, filtering, solid-liquid separation and drying, making it possible for high-mesh plant fiber powder materials to replace traditional low-mesh plant fiber powder material products. The complete set of equipment is energy-saving, environmentally friendly and low-carbon, and the production process is continuous and stable, safe and pollution-free. It is suitable for industrial large-scale production and can be widely used in high-value-added products in the fields of composite materials, bioplastics, daily necessities, motor vehicle shells and interiors, coatings and inks, biomedicine, beauty cosmetics, health products, food, water purification, bioethanol, petrochemicals, tobacco, explosives, xylitol and nanocellulose. Beneficial effects:

[0063] 1. This invention pioneered the use of a pressure-variable cavitation high-speed three-vortex-microwave composite nano-grinding system to nano-grind plant fiber powder to a D50 of ≤ 0.316 μm and ≥ 50,000 mesh. This technology has not been reported before and is the first of its kind in the world before this application. The results of third-party testing of the median particle size of bamboo leaf powder are shown in Figure 8.

[0064] In the prior art, common processing equipment for the crushing or grinding process of plant fiber powder includes: steam explosion device, hammer mill, screw extrusion mill, air flow mill, colloid mill, freezing mill, etc.

[0065] ①Steam explosion devices are mainly used in pulping, feed starter, lignocellulose raw material pretreatment and other fields. However, after steam explosion, the relative density of the raw materials decreases and the volume increases, and the fermentation inhibitors produced need to be washed away;

[0066] ② Hammer mills, spiral extrusion mills, air flow mills, frozen mills, etc. have coarse grinding particle size, high energy consumption, high production costs, and severe device wear, making it difficult to achieve nano-level grinding;

[0067] ③ In the field of crushing and grinding research, the technology of using ultrasonic assisted grinding has emerged. Ultrasonic waves can generate a large number of bubbles to form a cavitation effect during the entire grinding process, accelerate the collision and friction between the medium and plant fiber particles, and facilitate better crushing and grinding. In reality, laboratory equipment uses low-intensity ultrasonic waves, which have certain effects in the field of scientific research experiments. However, ultrasonic equipment is expensive, has high production costs, high power consumption, and is difficult to control. The wavelength of ultrasonic waves is extremely short, so the scattering is very serious and the penetration is poor. In order to produce cavitation, the intensity of ultrasonic waves must be increased, and high-intensity ultrasonic waves can be harmful to the human body. Therefore, ultrasonic assisted grinding technology is not easy to use in large-scale industrial production and is not suitable for large-scale industrial production.

[0068] At present, the more prominent problems of the common plant fiber crushing and grinding devices available on the market are that the crushing and grinding equipment have poor grinding particle size, high energy consumption, high production cost, low production efficiency, serious device wear, and difficulty in achieving nano-level crushing; according to reports, the lowest particle size of plant fiber powder currently sold on the market is D50=19μm for German technology, which is about 800 mesh, and D50=10μm for Chinese technology, which is about 1600 mesh. China only has laboratory-scale technology with D50=6.5μm (it usually takes 240 minutes to produce 5 kilograms); currently, the research on high-mesh plant fiber powder materials is still in its infancy, due to shortcomings such as poor performance, insufficient mechanical strength, high cost, poor experience, serious operation pollution, or other other reasons, it cannot meet the requirements of safety, hygiene, environmental protection, low cost, and high mesh at the same time. The complex production process and high preparation cost have restricted its further promotion and use; so far, it has hardly been widely industrialized and applied in actual business.

[0069] Plant fiber powder is the most commonly used material in plant fiber molding composites. The mesh size of the plant fiber powder used as a filler has a significant impact on the mechanical properties, flow properties, and microstructure of the composite material. The particle size of the plant fiber significantly affects the plant fiber molding composite effect. The particle size of the plant fiber powder determines the degree of dispersion of the plant fiber in the matrix, ultimately affecting the material properties. According to the principle of fiber reinforcement, the larger the mesh size of the plant fiber powder and the smaller the particle size, the more uniform its dispersion in the polymer matrix and the better the mechanical properties of the composite material. This is related to the different interface bonding between the plant fiber powder and the matrix plastic, the fiber morphology, the surface roughness, and the internal void conditions. Therefore, the mesh size of the plant fiber powder is an important parameter to consider in the preparation of plant fiber molding composites.

[0070] To address the above problems, the present invention pioneered the technology of ultra-nano grinding plant fiber powder to D50≤0.316μm, ≥50000 mesh by using a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system. Its advanced features are as follows:

[0071] ⑴ Pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system Pressure-variable cavitation high-speed three-vortex

[0072] ① The high-speed rotation of the high-speed discrete device drives the grinding media to achieve grinding, with a linear speed of up to 8-20m / s. The high-speed rotation drives the grinding media and the material particles to move at high speed, causing the grinding media and the material particles to rub, collide and shear with each other, ultimately breaking, dispersing and deagglomerating the material particles into nano-scale fine particles;

[0073] ② The improved feeding mechanism forms fluid pressure change, thereby forming a cavitation effect and enhancing particle crushing. When the material slurry enters the grinding chamber through the improved flow channel, the flow surface area suddenly decreases and the flow velocity increases sharply, causing the pressure in the flow channel to be lower than the saturated vapor pressure, resulting in the generation of a large number of cavitation bubbles and cavitation. The cavitation bubbles undergo a process of generation, development and final explosion. When the bubbles explode, high-speed shock waves and microjets are generated, which accelerate the movement of material particles, making them have a higher speed, intensifying friction and collision, improving the efficiency of crushing fine particles, and improving the fineness of nanoparticle crushing. At the same time, due to the mutual friction, collision and shear between the grinding media and the material particles, microcracks are generated in the material particles themselves, and cavitation bubbles are also generated in the microcracks of the material particles themselves. When the cavitation bubbles collapse, high-speed shock waves and microjets are generated, which can cause the microcracks to continue to expand, explode the material particles, and realize the crushing of the material particles. At the same time, it has a dispersion effect on the material and prevents the crushed material particles from re-aggregating.

[0074] ③ The high-speed rotation of the high-speed discrete device is used to generate a swirling flow, and a turbulent device is set at the feed end to form three vortexes, which accelerate and enhance the cavitation effect; the vortex flow that appears at the beginning instantly becomes three, and three vortex flows appear to perform a swirling motion together, which drives more material slurry in the grinding chamber to participate in the swirling motion more comprehensively. The swirling of the flow causes the pressure to drop. When the liquid pressure is lower than the saturated vapor pressure, a phase change process from liquid phase to gas phase occurs, resulting in the emergence of cavitation and generating a large number of bubbles. The bursting of cavitation bubbles drives the surrounding slurry to generate turbulence, forming a turbulent flow, which increases the collision, shear and friction of the material particles per unit time, achieving the purpose of repeated grinding, accelerated crushing and dispersed aggregation, greatly shortening the grinding time, and improving the grinding efficiency. It has the advantages of low energy consumption, high production efficiency and strong continuity.

[0075] ⑵ Microwave of pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system

[0076] Microwaves are used to strongly assist the cavitation effect, increasing the number of cavitation bubbles and the kinetic energy of material particles. Microwaves have heating and absorption properties. Microwave heating turns fine particles and water molecules into heating elements. Fine particles and water molecules can absorb microwaves, generating heat, increasing molecular activity, giving microparticles and water molecules greater kinetic energy, accelerating more friction and collisions, and at the same time generating more cavitation bubbles. These tiny bubbles are constantly moving, growing, and suddenly collapsing. When collapsing, they generate instantaneous local high temperatures and high pressures, as well as strong shock waves and high-speed microjets, which can cause microcracks in particles to continue to expand and explode material particles. They also accelerate the movement of material particles, giving them a very high initial velocity, resulting in intense friction and collisions between particles, and thus causing particle crushing. Microwaves also have the characteristics of low-temperature sterilization and no pollution. Microwave energy itself will not contaminate the product, and the dual sterilization effect of microwave thermal effects can kill bacteria at lower temperatures. During microwave heating, no wastewater, exhaust gas, or waste is generated, and no radiation residues are left.

[0077] (3) Under the action of pressure-variable cavitation high-speed three-vortex assisted microwave, the material particles increase the collision, shear and friction between particles and between particles and medium in unit time, achieving the purpose of repeated grinding, accelerating the crushing of fine particles and dispersing aggregates, greatly shortening the grinding time and improving the grinding efficiency. The final ground plant fiber powder has uniform particle fineness, good quality and high product dispersion. The whole process is protected by negative pressure and constant temperature, and the material quality is extremely high.

[0078] (4) This method solves the problem that the particle size of materials in existing technologies, whether in laboratory processes or industrial equipment, remains at the micron level. Plant fiber powder can be ground to a D50 of ≤ 0.316 μm and ≥ 50,000 mesh, increasing the particle fineness by nearly 30 to 250 times. The production time of 1,000 kg only takes about 120 minutes.

[0079] 5. It has the advantages of low energy consumption, low cost and strong continuity, realizing the industrialized, continuous and automated production of plant fiber powder, greatly improving production efficiency;

[0080] ⑹ It is a very safe and harmless high-tech that can meet the subsequent further processing needs of materials and is suitable for large-scale industrial production. It can be widely used in high-value-added fine products such as composite materials, bioplastics, daily necessities, aerospace, automobiles, ships, high-speed railways, coatings and inks, biomedicine, beauty cosmetics, medical protective products, food, water purification, bioethanol, petrochemical tobacco, explosives, xylitol and nanocellulose.

[0081] 2. This invention is the first multifunctional integrated selective nanofiltration solid-liquid separation system, which effectively combines the filtering principles and characteristics of various traditional equipment. It is equivalent to an all-in-one device, continuously filtering high-mesh plant fibers to ensure product quality.

[0082] At present, the filtration equipment on the market mainly includes cartridge filtration equipment, centrifuge filtration equipment, tubular ceramic membrane filtration equipment and hollow fiber membrane filtration equipment. However, these traditional filtration equipment have more or less corresponding disadvantages, such as long filtration process, high energy consumption, high material loss, large equipment, low efficiency and complicated operation.

[0083] ⑴The filtering principle of the filter element is mainly dead-end filtration, which is the most traditional filtering and solid-liquid separation method. But its disadvantages are:

[0084] ① Solid residue impurities easily accumulate, causing blockage. This results in low filtration efficiency, or even clogging, preventing filtration from proceeding.

[0085] ② The filtration accuracy of the filter element and filter bag is too poor, which makes it easy to penetrate and cause turbidity of the permeate;

[0086] ③Filter elements and filter bags are consumables and need to be replaced constantly;

[0087] ④The material to be filtered needs to be pre-processed by other coarse filters, which is more troublesome to apply;

[0088] ⑤ If solids need to be collected, they cannot be collected;

[0089] ⑵ Centrifuge filtration is a machine that uses centrifugal force to separate liquid and solid particles or components in a mixture of liquid and liquid. It is mainly used to separate solid particles from liquid in a suspension, but its disadvantages are:

[0090] ① The separation and filtration is not thorough, the filtration efficiency is low, the clear liquid still contains certain solids, the turbidity of the clear liquid is higher than 100ntu, and the turbidity cannot be reduced;

[0091] ② The concentration cannot be further increased. If the solid concentrate is collected, the loss will be large, the concentrated solid content will be low, and the overall production cost will be high;

[0092] ③ The operation is complicated, unloading is troublesome, and maintenance is frequent;

[0093] ⑶ The filtration principle of tubular ceramic membrane is cross-flow filtration, which effectively solves the problem of dead-end filtration. Its core component, inorganic ceramic membrane, has excellent thermal stability and pore stability, but its disadvantages are:

[0094] ① Its membrane flux is only 50% to 60%. The first problem is that as the solid content of the material increases, the accumulation on the membrane surface becomes more and more serious, which makes it easy to block the membrane. The flux will continue to decrease and the efficiency will decrease.

[0095] ② The solid content of the concentrated solution cannot be concentrated to a high level, which is neither high nor low, and the yield is low;

[0096] ③ Frequent cleaning requires continuous backwashing, which consumes a lot of water and produces a large amount of sewage, greatly reducing the filtration efficiency of the membrane tube;

[0097] ④High energy consumption and relatively short service life;

[0098] ⑷The disadvantages of hollow fiber membrane filtration are:

[0099] The biggest problem with filtration is that over time, the efficiency becomes lower and lower, the membrane becomes clogged, and the flux decreases; it is difficult to clean and the flux is not easy to recover; it is too easy to be contaminated; the yield is low and the concentration content does not increase;

[0100] To address the above problems, the multifunctional integrated selective nanofiltration solid-liquid separation system of the present invention integrates the functions of a swash plate type axial plunger type selective nanofiltration device, a solid-liquid separation device, a reflux mechanism, and an intelligent high-pressure backwash circulation cleaning device. It integrates nanofiltration with solid-liquid separation, reflux, and high-pressure backwash circulation cleaning, and has the following advantages:

[0101] ⑴ Rotating swash plate type axial plunger type selective nanofiltration device of multifunctional integrated selective nanofiltration solid-liquid separation system

[0102] The nanofiltration separation membrane has a pore size of 0.001 to 0.01 mm and can separate mixtures of different particle sizes. The semi-permeable membrane with an asymmetric microporous structure uses an intelligent hydraulic constant pressure variable pump as a power source to provide pressure and flow, causing the material to rotate and flow at high speed on the surface of the nanofiltration separation membrane, ensuring the membrane surface flow rate required for filtration, and performing dynamic filtration on the surface of the nanofiltration separation membrane to achieve selective separation and screening:

[0103] ① The nanoparticle liquid that passes through the nanofiltration separation membrane layer enters the solid-liquid separation device through the tenth negative pressure pipe 301;

[0104] ② The material liquid with a larger mesh size than the required size retained by the nanofiltration separation membrane is returned to the pressure-variable cavitation high-speed three-vortex cavitation-microwave composite ultra-nano grinding system through the first reflux pipe 351 of the reflux device for another round of cyclic grinding;

[0105] ③ The material liquid forms turbulence due to high-speed rotation, which continuously washes the membrane surface and prevents solid matter from staying on the membrane disc surface, thereby effectively preventing the membrane surface from being blocked and ensuring normal filtration and accurate filtration;

[0106] ⑵Solid-liquid separation device of multifunctional integrated selective nanofiltration solid-liquid separation system

[0107] It effectively combines the principles of centrifuge and dynamic filtration, setting the separation rotating shaft as a hollow structure, with the hollow space as the filtrate flow area. 2 to 100 separation membrane discs are installed on the outside of the separation rotating shaft through a sealing ring, and the whole rotates at high speed in the separation chamber. The material and liquid enter the separation chamber of the solid-liquid separation device, and the separation grinding disc rotates at high speed under the power to produce centrifugal effect, which can dehydrate a large amount of water, reducing the unbound water content of the material from 70% to 15%, and finally quickly performing solid-liquid separation:

[0108] ① The nano-particle liquid passing through the nanofiltration separation membrane layer rotates at high speed under the action of centrifugation to form turbulence, which continuously washes the surface of the separation membrane, effectively preventing the pollution and blockage of the separation membrane surface. After separation by the separation membrane of the separation membrane disc, a large amount of water is dehydrated to form a solid concentrate. Under the action of the pump and 2-4Kgf / cm2 pressure, the high-viscosity and high-concentration material is pumped into the composite drying system;

[0109] ② Under the action of fluid pressure, most of the water molecules and other filtrate pass through the membrane pores of the enhanced separation membrane, enter the hollow filtrate flow area, and then flow out. They are returned to the pressure-variable cavitation high-speed three-vortex cavitation-microwave composite nano-grinding system through the negative pressure pipeline for reuse;

[0110] ③ The separation membrane of the solid-liquid separation device adopts double-sided filtration, with a pass rate of ≥95%. The separation and filtration is continuous and stable, without membrane clogging and flux reduction;

[0111] ⑶ Reflux device of multifunctional integrated selective nanofiltration solid-liquid separation system

[0112] ① Large-mesh particles larger than the desired nanoparticles that cannot pass through the membrane are retained by the membrane through the asymmetric microporous membrane layer, flow out of the rotating swash plate type axial piston type selective nanofiltration device, reflux through the first reflux pipe 351 of the reflux device, and return to the pressure-variable cavitation high-speed three-vortex cavitation-assisted microwave composite ultra-nano grinding system for another cycle grinding, thereby ensuring the continuous and normal filtration of the rotating swash plate type axial piston type selective nanofiltration device;

[0113] ② The water feed liquid is collected through the permeate pipeline, and the direction of the permeate can be controlled by opening and closing the valve; it is returned to the material tank through the second reflux pipe 352 of the reflux device to maintain the stability of the material level in the circulation tank and balance the material concentration in the membrane group and the circulation tank, reducing the frequency and amount of continuous feed liquid replenishment during production, preventing the material from being too concentrated and causing a rapid drop in flux or rapid contamination of the membrane surface, so as to achieve continuous circulation filtration and meet process requirements.

[0114] ⑷ Intelligent high-pressure backwash circulation cleaning device for multifunctional integrated selective nanofiltration solid-liquid separation system

[0115] During the production process of the selective nanofiltration device and the solid-liquid separation device, the intelligent high-pressure backwash circulation mode is started regularly to use the continuously entering high-speed flow of material slurry to instantly perform secondary cleaning on the nanofiltration separation membrane, flushing the large-mesh materials attached to the outside of the nanofiltration separation membrane that are retained by the nanofiltration separation membrane and are larger than the required size, so that they leave the outer surface of the nanofiltration separation membrane, keep the nanofiltration separation membrane clean, restore the membrane flux, prevent membrane pollution, and ensure normal production at the same time;

[0116] ⑸ The invention is the first multifunctional integrated selective nanofiltration solid-liquid separation system

[0117] ① Because it uses a rotating swash plate axial plunger filtration process, the membrane flux is not affected by the solid content of the feed, the flux does not decrease, and it is less affected by the feed concentration. The continuous and stable filtration time is long, which means high efficiency and high yield. At the same time, because the membrane has multiple working surfaces above and below, the effective filtration area is increased within the equivalent volume, thereby playing a concentrating role, achieving clarification, filtration, and impurity removal of the feed, and increasing the solid content of the concentrate to ≥85%; the cream-like state and lack of fluidity further reduce subsequent evaporation investment and energy consumption.

[0118] ② Its dynamic high-speed rotating operation process continuously flushes the membrane surface to prevent solid matter from staying on the membrane disc surface, thereby effectively preventing fouling on the membrane surface and clogging of the filter membrane;

[0119] ③Perfectly solve the drawbacks of traditional equipment and effectively solve the following problems currently existing in enterprises:

[0120] The centrifuge does not completely separate the material, the clear liquid after separation has high turbidity, there is still precipitation when it is left standing, and the product yield is low;

[0121] Cross-flow filtration tubular ceramic membranes clog, resulting in reduced flux and inability to concentrate solids; hollow fiber membrane clogging is inefficient; ceramic membrane concentrates require multiple filtration and concentration; filter paper and plate and frame leakage lead to incomplete filtration and low efficiency;

[0122] ④Multi-face filtration and multi-faceted secondary cleaning ensure high cleaning efficiency; recycled water uses only 1 / 10 of the ceramic membrane, which is superior to ceramic membrane cleaning;

[0123] ⑤ Low energy consumption, the power consumption is 1 / 5 of the tubular ceramic membrane, easy to save energy;

[0124] ⑥ Suitable for solid-liquid separation and clarification filtration of high viscosity and high concentration materials;

[0125] ⑦The turbidity is below 1ntu;

[0126] ⑧The yield is increased several times;

[0127] ⑨Fully enclosed equipment, effectively preventing oxygen from entering;

[0128] ⑩ It is an enhanced membrane separation technology. Replacing certain traditional technologies with this technology can achieve significant economic benefits.

[0129] 3. This invention pioneers a two-stage composite drying system, which is a hollow paddle drying and auxiliary rotary flash drying two-stage composite drying system. It effectively combines the advantages of paddle dryers and flash dryers to quickly and efficiently dry material particles and maintain the material in nano-scale particle state.

[0130] The common drying equipment in the current market include fluidized bed drying equipment, spray drying equipment, air flow drying equipment, drum drying equipment and belt drying equipment. In the whole process of industrial drying of materials, the industry generally adopts a single drying equipment to dry the materials:

[0131] (1) Fluidized bed drying equipment is often used to dry bulk granular materials, but it has strict restrictions on the particle size of the drying material. The back mixing of the material is relatively intense, which may cause uneven residence time of some materials. The material may not be fully dried due to a short residence time, or it may be over-dried due to a long residence time, causing the material to sinter. During the drying process, channeling, large bubbles, and surges are prone to occur, which reduce the drying qualification rate of the material and the terminal performance of the material, and the one-time investment is large;

[0132] ⑵Spray drying equipment is often used to dry materials with high initial moisture content, but the equipment has low thermal efficiency, high power consumption, and the drying chamber is larger than

[0133] The machine is large in size and has many complicated auxiliary equipment. During the drying process, wet powder is easily adhered to the inner wall of the dryer main tower and powder leakage is serious. The product recovery rate is very low and the pulse bag dust collector has poor dust removal effect. This reduces the drying qualification rate of the material and the terminal performance of the material, resulting in a large one-time investment.

[0134] ⑶ Airflow drying equipment is often used to dry various powdery, granular, and muddy materials, but it has a certain degree of wear on the materials and consumes a lot of power. It requires a high-efficiency dust collection device. For materials that are agglomerated or difficult to disperse, a high-performance feeding device is required, and the one-time investment is large.

[0135] (4) Drum drying equipment is often used for drying fluid materials such as solutions, suspensions, and colloidal solutions, but it has a complex structure and a small heat transfer area;

[0136] 5. Belt dryers are often used to dry flake, strip, and granular materials with good air permeability. Paste materials such as filter cakes can also be dried after being formed by a granulator or extruder. However, the inlet and outlet of the equipment are not tightly sealed, which can easily cause air leakage, resulting in low production capacity and low thermal efficiency.

[0137] The present invention is the first to create a two-stage composite drying system, which is a hollow blade drying assisted rotary flash drying two-stage composite drying system, which has the following advantages:

[0138] (1) The present invention pioneered the first-stage drying of the two-stage composite drying system - hollow blade dryer

[0139] It adopts indirect heating, and its rotating shaft adopts a hollow and wedge-shaped hollow blade structure. The heat medium flows through the blade through the hollow shaft, and the heat is indirectly conducted. The heat is used to heat the material. The heat loss is only the heat dissipation to the environment through the outer wall insulation layer, and the heat loss is relatively small. It has a huge heat transfer surface within the unit effective volume, which shortens the processing time, reduces the equipment size, and reduces the floor space. By using different heat media, it can process both heat-sensitive materials and materials that require high-temperature treatment. The dispersion force generated by the combined movement of the inclined surface of the rotating blade and the plant fiber particles causes the attached particles attached to the heating inclined surface to automatically fall off, so that the blade maintains an efficient heat transfer function. The blade rotates in the opposite direction, alternating the segmented compression and expansion stirring functions to make the heat transfer uniform and improve the heat transfer effect. The moisture content (including bound moisture) of the material can be dried from 60% to 30% in 30 to 60 minutes.

[0140] ⑵The present invention is the first two-stage composite drying system - two-stage drying - rotary flash drying machine

[0141] It is an organic combination of swirl, fluidization and crushing and grading technologies. After being heated, the air enters the secondary drying device tangentially through the air inlet, forming a high-speed rotating airflow in the secondary drying device. The material enters the secondary drying device directly through the secondary feeding device. Under the impact and drive of the high-speed airflow, it is quickly dispersed and rotates at high speed with the airflow. A crushing device is installed at the bottom of the secondary drying device to forcibly crush and micronize relatively large and moist particle clusters, and then they rise again with the high-speed airflow to complete the drying process. In order to make the final moisture content of the material extremely low while not affecting the product quality due to fluctuations in the initial moisture content, swirl plates are installed in the drying tower to form a relatively stable fluidized bed. At the same time, the swirl plates also play a role in ensuring the residence time and classification required for drying. The moisture content of the material (including bound moisture) can be dried from 30% to 5% within 10 to 15 seconds.

[0142] ③ The invention is the first to create a two-stage composite drying system

[0143] The invention pioneers a two-stage composite drying system that uses a paddle dryer to quickly dry materials with high moisture content, significantly improving the drying efficiency per unit time. A flash dryer is then used to quickly remove the remaining moisture and crush large particles in the dried material to ensure the material is micronized.

[0144] ① A return device is added to the feed end to prevent the material from running into the packing seal, thus extending the service life;

[0145] ②The main unit cover adds hot air supplement to speed up the drying process;

[0146] ③Negative pressure or micro-negative pressure operation, good sealing, high efficiency, and elimination of environmental pollution;

[0147] ④The material residence time is short and the finished product quality is good;

[0148] ⑤Wide range of materials to be processed:

[0149] Using different heat media, it can process both heat-sensitive materials and materials that require high temperature treatment;

[0150] ⑥High drying intensity:

[0151] The unit effective volume has a huge heat transfer surface, which shortens the processing time. The equipment size is reduced, reducing the floor space;

[0152] ⑦ Small environmental pollution:

[0153] The amount of air carried is very small, and the dust and material are rarely entrained;

[0154] ⑧Low energy consumption:

[0155] Due to indirect heating, there is no large amount of air carried away to take away the heat, so the heat loss is very small and the thermal efficiency is high;

[0156] ⑨Stable operation:

[0157] Due to the special compression-expansion stirring action of the wedge-shaped blades, the material particles are fully in contact with the heat transfer area. In the axial range, the temperature, humidity, mixing temperature and gradient of the material are very small, thus ensuring the stability of the process.

[0158] ⑩The equipment is compact, small in size, high in production efficiency and can produce continuously, realizing “small equipment, large production”;

[0159] In summary, the present invention provides a whole production line for grinding plant fiber powder, which can continuously input materials and continuously industrialize production. The production process is highly continuous and stable, the production process is safe and has no environmental pollution, and is suitable for industrial-scale production. It is energy-saving and environmentally friendly. The ground material particles reach the nanometer level, with both excellent comprehensive performance and green environmental protection characteristics. The high-mesh plant fiber powder material composite technology is a comprehensive technology that crosses multiple disciplines. The design and development involve professional knowledge of multiple disciplines such as mechanical engineering, electronics, fluid mechanics, materials technology, and control theory. In-depth research and heavy investment will promote the development of my country's high-mesh plant fiber powder material composite technology, which undoubtedly has far-reaching economic and social significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0160] The following is a further description of a device for high-speed three-vortex pressure-induced cavitation-microwave composite ultra-nano grinding of plant fiber powder according to the present invention in conjunction with the accompanying drawings and specific embodiments:

[0161] Figure 1 is a schematic diagram of the process of pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding of plant fiber powder;

[0162] Figure 2 is a schematic diagram of the pretreatment system flow chart;

[0163] FIG3 is a schematic diagram of the process flow of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system;

[0164] FIG4 is a schematic diagram of a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine;

[0165] FIG5 is a schematic diagram of the collision between the grinding medium and the particles and the growth and collapse of the cavitation bubbles;

[0166] Figure 6 is a schematic diagram of a multifunctional integrated selective nanofiltration solid-liquid separation system;

[0167] Figure 7 is a schematic diagram of a two-stage composite drying system;

[0168] FIG8 is a test report of high-mesh bamboo powder produced industrially according to the present invention;

[0169] FIG9 shows the industrial production of high-mesh bamboo flour according to the present invention;

[0170] FIG10 is a multifunctional integrated selective nanofiltration solid-liquid separation diagram of the present invention;

[0171] Pretreatment system 1, pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2, multifunctional integrated selective nanofiltration solid-liquid separation system 3, two-stage composite drying system 4;

[0172] Feeding device 11, vacuum loader 12, buffer chamber 13, grinding device 14, grinding storage mixing tank 15, micron grinder 16, micron circulation mixing tank 17, micron storage mixing tank 18, first negative pressure pipeline 101, second negative pressure pipeline 102, third negative pressure pipeline 102, fourth negative pressure pipeline 104, fifth negative pressure pipeline 105, sixth negative pressure pipeline 106, constant temperature device 107;

[0173] Pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine 21, ultra-nano circulation stirring tank 22, ultra-nano storage stirring tank 23, seventh negative pressure pipeline 201, eighth negative pressure pipeline 202, ninth negative pressure pipeline 203;

[0174] Body 210, motor 211, grinding chamber 212, high-speed discrete device 213, cavitation device 214, grinding medium 215, microwave device 216, spindle constant temperature device 217, chamber constant temperature device 218;

[0175] Safety filter 31, material pump 32, swash plate type axial piston type selective nanofiltration device 33, solid-liquid separator 34, reflux device 35, intelligent high-pressure backwash circulation cleaning device 36, storage mixing tank 37, tenth negative pressure pipeline 301, eleventh negative pressure pipeline 302, twelfth negative pressure pipeline 303, selective nanofiltration membrane 331, filter chamber 332, separation rotating shaft 341, separation membrane disk 342, separation chamber 343, first reflux pipeline 351, second reflux pipeline 352;

[0176] Primary drying 40, secondary drying 41, heating device 1 401, dust removal device 1 402, drying device 1 403, conveyor 404, heating device 2 411, feeding device 2 412, drying device 2 413, dust removal device 2 414, separation device 415, collection device 416. DETAILED DESCRIPTION

[0177] The following is a detailed description of the production device for preparing plant fiber powder through specific implementation methods.

[0178] As shown in Figure 1, a device for ultra-nano grinding of plant fiber powder using a pressure-variable cavitation high-speed three-vortex-microwave composite is characterized by comprising a pretreatment system 1, a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2, a multifunctional integrated selective nanofiltration solid-liquid separation system 3, and a two-stage composite drying system 4. The process is as follows:

[0179] ① Plant fiber segment (such as sugarcane segment, bamboo stem segment, bamboo leaf, etc.) → feeding device 11 → first negative pressure pipeline 101 → vacuum feeder 12 → buffer chamber 13 → grinding device 14 → second negative pressure pipeline 102 → grinding storage stirring tank 15 → relevant solution is added to the grinding storage stirring tank 15 in a certain proportion to obtain a uniform slurry → third negative pressure pipeline 102 → micron grinder 16 → multiple cycles of grinding between the micron grinder 16 and the micron circulation stirring tank 17 to achieve ultra-nano grinding requirements → fifth negative pressure pipeline 105 → micron storage stirring tank 18 → sixth negative pressure pipeline 106 → enter the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine 21 for Grinding → Multiple cycles of grinding between the pressure-variable cavitation high-speed three-vortex-microwave composite nano-grinding machine 21 and the nano-circulation stirring tank 22 to achieve a grinding particle size of 10 to 800 nanometers → eighth negative pressure pipeline 202 → nano-storage stirring tank 23 → ninth negative pressure pipeline 203 → safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → material pump 32 → enter the rotating swash plate type axial piston type selective nanofiltration device 33 for material filtration → tenth negative pressure pipeline 301 → enter the solid-liquid separation device 34 for solid-liquid separation → eleventh negative pressure pipeline 302 → storage stirring tank 37 → twelfth negative pressure pipeline 303 → secondary composite drying system 4 → D50 ≤ 0.316 μm plant fiber powder finished product;

[0180] ② The large foreign matter particles in the liquid filtered out by the safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → return to the first reflux pipe 351 of the reflux device 35 → return to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0181] ③ The liquid with particles larger than the desired nanoparticles is filtered and retained by the rotating swash plate axial piston selective nanofiltration device 33 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the first reflux pipe 351 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0182] ④ The filtrate separated by the separation membrane of the separation membrane disk 342 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the hollow flow area of ​​the separation rotating shaft 341 → the second reflux pipe 352 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0183] As shown in Figure 2, the pretreatment system 1 consists of a feeding device 11, a vacuum loader 12, a buffer chamber 13, a grinding device 14, a grinding storage stirring tank 15, a micron grinder 16, a micron circulation stirring tank 17, a micron storage stirring tank 18, a first negative pressure pipeline 101, a second negative pressure pipeline 102, a third negative pressure pipeline 102, a fourth negative pressure pipeline 104, a fifth negative pressure pipeline 105, a sixth negative pressure pipeline 106 and a constant temperature device 107; the feeding device 11 is connected to the vacuum loader 12 through the first negative pressure pipeline 101, the vacuum loader 12 is connected to the buffer chamber 13, the buffer chamber 13 is connected to the grinding device 14, the grinding device 14 is connected to the grinding storage stirring tank 15 through the second negative pressure pipeline 102, the grinding storage stirring tank 15 is connected to the micron grinder 16 through the third negative pressure pipeline 102, and the micron grinder 16 is connected to the Four negative pressure pipes 104 are connected to the micron circulation stirring tank 17, and the micron grinder 16 is respectively connected to the micron circulation stirring tank 17 and the micron storage stirring tank 18 through the fifth negative pressure pipe 105. The micron grinder 16 and the micron circulation stirring tank 17 are subjected to multiple cycles of grinding through the fourth negative pressure pipe 104 and the fifth negative pressure pipe 105 until the required requirements are met. The micron storage stirring tank 18 is connected to the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2 through the sixth negative pressure pipe 106; the grinding device 14, the grinding storage stirring tank 15, the micron grinder 16, the micron circulation stirring tank 17, the micron storage stirring tank 18, the first negative pressure pipe 101, the second negative pressure pipe 102, the third negative pressure pipe 102, the fourth negative pressure pipe 104, the fifth negative pressure pipe 105 and the sixth negative pressure pipe 106 are all connected to the constant temperature device 107 by a constant temperature pipe;

[0184] The constant temperature device 107 is mainly used for low temperature cooling to protect the effective components in the plant fiber of the material slurry during the overall powder preparation process;

[0185] As shown in FIG3 , the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2 is composed of a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine 21, an ultra-nano circulation stirring tank 22, an ultra-nano storage stirring tank 23, a seventh negative pressure pipe 201, an eighth negative pressure pipe 202 and a ninth negative pressure pipe 203;

[0186] The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder 21 is connected to the ultra-nano circulation stirring tank 22 through the seventh negative pressure pipe 201, and the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder 21 is respectively connected to the ultra-nano circulation stirring tank 22 and the ultra-nano storage stirring tank 23 through the eighth negative pressure pipe 202. The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder 21 and the ultra-nano circulation stirring tank 22 are subjected to multiple cycles of grinding through the seventh negative pressure pipe 201 and the eighth negative pressure pipe 202 until the required requirements are met. The ultra-nano storage stirring tank 23 is connected to the multifunctional integrated selective nanofiltration solid-liquid separation system 3 through the ninth negative pressure pipe 203;

[0187] As shown in Figures 4 and 5, the pressure-variable cavitation high-speed three-vortex-microwave composite nano-grinding machine 21 consists of a body 210, a motor 211, a grinding cavity 212, a high-speed discrete device 213, a cavitation device 214, a grinding medium 215, a microwave device 216, a spindle constant temperature device 217 and a cavity constant temperature device 218;

[0188] The motor 211 drives the high-speed dispersing device 213 to rotate at high speed in the grinding chamber 212, driving the material slurry and the grinding media 215 in the cylinder to move at high speed, generating a swirling flow. The swirling flow causes a pressure drop, causing the local slurry to undergo a phase transition from liquid to gas, generating a large number of bubbles. While the high-speed dispersing device 213 rotates at high speed, it also drives the surrounding slurry to flow rapidly, thus forming turbulent flow and countercurrent.

[0189] Cavitation device 214. When the material slurry enters the grinding chamber 212 of the double vortex countercurrent enhanced ultra-nano grinder 21 through the back pressure cavitation device 214, the flow surface area suddenly decreases, the flow velocity increases sharply, the pressure in the flow channel is lower than the saturated vapor pressure, and cavitation occurs in the liquid, forming a cavitation effect.

[0190] The grinding medium 215 is L65 zirconium silicate balls, L80 stabilized zirconia balls, or L95 yttrium stabilized zirconia balls, with a particle size of 0.1 mm to 0.8 mm;

[0191] The microwave device 216 directly acts on the material slurry in the grinding chamber 212 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder 21, increasing the number of cavitation bubbles in the grinding chamber 212, increasing the kinetic energy of the material particles, accelerating the friction and collision between particles and between particles and the grinding medium 215, and improving the pulverization fineness and grinding efficiency of the nanoparticle powder;

[0192] The spindle constant temperature device 217 and the cavity constant temperature device 218 are mainly used to maintain the low temperature operation of the double vortex countercurrent back pressure cavitation-microwave ultra-nano grinding machine 21, protecting the effective components in the plant fiber of the material slurry during the overall powder preparation process;

[0193] As shown in FIG6 , the multifunctional integrated selective nanofiltration solid-liquid separation system 3 includes a safety filter 31, a material pump 32, a swash plate type axial piston type selective nanofiltration device 33, a solid-liquid separation device 34, a reflux device 35, an intelligent high-pressure backwash circulation cleaning device 36, a storage mixing tank 37, a tenth negative pressure pipeline 301, an eleventh negative pressure pipeline 302 and a twelfth negative pressure pipeline 303;

[0194] The swash plate type axial piston type selective nanofiltration device 33 is composed of a selective nanofiltration membrane 331 and a filter chamber 332. The selective nanofiltration membrane 331 is an asymmetric microporous nanofiltration separation membrane.

[0195] The solid-liquid separation device 34 consists of a separation rotating shaft 341, a separation membrane disc 342 and a separation chamber 343; the separation rotating shaft 341 is a hollow structure, and the hollow part is the filtrate flow area. 2 to 100 separation membrane discs 342 are installed on the outside of the separation rotating shaft 341 through a sealing ring, and the whole rotates at high speed in the separation chamber 343; the feed liquid filtered by the rotating inclined plate type axial piston type selective nanofiltration device 33 enters the separation chamber 343, and under the action of centrifugation, the filtrate passes through the separation membrane of the separation membrane disc 342 into the hollow flow area of ​​the separation rotating shaft 341 and flows out, and returns to the ultra-nano circulation stirring tank 22 through the eleventh negative pressure pipeline 302. The concentrate leaves the separation membrane of the separation membrane disc 342 through high-speed centrifugation, so that the separation membrane maintains normal filtration. The concentrate enters the storage stirring tank 36 and enters the secondary composite drying system 4 through the tenth negative pressure pipeline 301;

[0196] The separation membrane disk 342 adopts double-sided filtration and contains membranes with various filtration pore sizes of 5 nanometers, 7 nanometers, 30 nanometers, 50 nanometers, 80 nanometers, 200 nanometers, 500 nanometers, and 2 microns.

[0197] The reflux device 35 is composed of a negative pressure pipe 351 and a negative pressure pipe 352;

[0198] The intelligent high-pressure backwash circulation cleaning device 36 is connected to the interior of the selective nanofiltration membrane 331 of the rotating swash plate type axial piston type selective nanofiltration device 33. By timing the intelligent high-pressure backwash circulation mode, the cleaning solution is instantly sprayed out at high pressure to impact the attached particles on the surface of the selective nanofiltration membrane 331 from the inside out. At the same time, the attached particles are flushed away by the continuous feeding of the rotating swash plate type axial piston type selective nanofiltration device 33, so that they flow out of the rotating swash plate type axial piston type selective nanofiltration device 33 and return to the ultra-nano circulation stirring tank 22, thereby ensuring that the selective nanofiltration membrane 331 continues to work normally.

[0199] As shown in FIG7 , the two-stage composite drying system 4 is a hollow blade drying assisted flash drying two-stage composite drying system, which consists of a primary drying 40 and a secondary drying 41 ;

[0200] The first-stage drying 40 is a paddle dryer, which consists of a heating device 401, a dust removal device 402, a drying device 403 and a conveyor 404. The material moisture content can be dried from 60% to 30% by heating and drying.

[0201] The secondary drying 41 is a flash dryer, which consists of a second heating device 411, a second feeding device 412, a second drying device 413, a second dust removal device 414, a separation device 415 and a collection device 416. By heating and drying, the moisture content of the material can be dried from 30% to 5%.

[0202] As shown in FIG8 , this is a test report of the industrialized production of high-mesh bamboo powder according to the present invention;

[0203] As shown in FIG9 , the present invention is industrialized to produce high-mesh bamboo powder;

[0204] As shown in FIG10 , the multifunctional integrated selective nanofiltration solid-liquid separation of the present invention is shown;

[0205] The following are specific embodiments:

[0206] Example 1. A device for high-speed three-vortex pressure-induced cavitation-microwave composite ultra-nano grinding of plant fiber powder, the process of which is as follows:

[0207] ① Bamboo pole section → feeding device 11 → first negative pressure pipe 101 → vacuum feeder 12 → buffer chamber 13 → grinding device 14 → second negative pressure pipe 102 → grinding storage stirring tank 15 → relevant solution is added to the grinding storage stirring tank 15 in a certain proportion to obtain a uniform slurry → third negative pressure pipe 102 → micron grinder 16 → multiple cycles of grinding between the micron grinder 16 and the micron circulation stirring tank 17 to achieve ultra-nano grinding requirements → fifth negative pressure pipe 105 → micron storage stirring tank 18 → sixth negative pressure pipe 106 → enter the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine 21 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2 for grinding → in the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2 The high-speed three-vortex-microwave composite nano-grinding machine 21 and the nano-circulation stirring tank 22 are repeatedly circulated to grind to a grinding particle size of 10 to 800 nanometers → the eighth negative pressure pipeline 202 → the nano-storage stirring tank 23 → the ninth negative pressure pipeline 203 → the safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the material pump 32 → enter the rotating swash plate type axial piston type selective nanofiltration device 33 for material filtration → the tenth negative pressure pipeline 301 → enter the solid-liquid separation device 34 for solid-liquid separation → the eleventh negative pressure pipeline 302 → the storage stirring tank 37 → the twelfth negative pressure pipeline 303 → the secondary composite drying system 4 → the nano-grade bamboo powder with a D50 of ≤ 0.316 μm;

[0208] ② The large foreign matter particles in the liquid filtered out by the safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → return to the first reflux pipe 351 of the reflux device 35 → return to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0209] ③ The liquid with particles larger than the desired nanoparticles is filtered and retained by the rotating swash plate axial piston selective nanofiltration device 33 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the first reflux pipe 351 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0210] ④ The filtrate separated by the separation membrane of the separation membrane disk 342 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the hollow flow area of ​​the separation rotating shaft 341 → the second reflux pipe 352 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0211] The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder 21 grinds the bamboo powder to a D50 of ≤ 0.316 μm, which is about 50,000 mesh;

[0212] The multifunctional integrated selective nanofiltration solid-liquid separation system 3 integrates filtration and solid-liquid separation. Its safety filter 31 uses a 1-micron filter membrane; the rotating swash plate type axial plunger type selective nanofiltration device 33 uses an 800 nm filter membrane; the solid-liquid separation device 34 uses a 50 nm filter membrane. Multi-face filtration is used, and the concentrate retention rate is about 80%.

[0213] The two-stage composite drying system 4 is a two-stage composite drying system of hollow paddle drying and auxiliary rotary flash drying, wherein the hollow paddle dryer can dry the material moisture from 60% to 30% within 30 to 60 minutes, and the rotary flash dryer can dry the material moisture from 30% to 5% within 10 to 15 seconds;

[0214] The filter membranes of the safety filter 31, the swash plate type axial piston type selective nanofiltration device 33 and the solid-liquid separation device 34 are replaced as needed to make the material particles reach a grinding particle size of 5 to 500 nanometers, which can meet the subsequent further processing requirements of the material, is suitable for industrial large-scale production, and can be widely used in high value-added fine products such as composite materials, bioplastics, daily necessities, aerospace, automobiles, ships, high-speed railways, coatings and inks, biomedicine, beauty cosmetics, medical protective products, food, water purification, bioethanol, petrochemical tobacco, explosives, xylitol and nanocellulose.

[0215] Example 2. A device for high-speed three-vortex pressure-variable cavitation-microwave composite ultra-nano grinding of plant fiber powder, the process of which is as follows:

[0216] ① Sugarcane segment → feeding device 11 → first negative pressure pipe 101 → vacuum feeder 12 → buffer chamber 13 → grinding device 14 → second negative pressure pipe 102 → grinding storage stirring tank 15 → relevant solution is added to the grinding storage stirring tank 15 in a certain proportion to obtain a uniform slurry → third negative pressure pipe 102 → micron grinder 16 → multiple cycles of grinding between micron grinder 16 and micron circulation stirring tank 17 to achieve ultra-nano grinding requirements → fifth negative pressure pipe 105 → micron storage stirring tank 18 → sixth negative pressure pipe 106 → enter the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine 21 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system for grinding → in the pressure-variable cavitation The high-speed three-vortex-microwave composite nano-grinding machine 21 and the nano-circulation stirring tank 22 are repeatedly circulated to achieve a grinding particle size of 10 to 800 nanometers → the eighth negative pressure pipeline 202 → the nano-storage stirring tank 23 → the ninth negative pressure pipeline 203 → the safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the material pump 32 → enter the rotating swash plate type axial piston type selective nanofiltration device 33 for material filtration → the tenth negative pressure pipeline 301 → enter the solid-liquid separation device 34 for solid-liquid separation → the eleventh negative pressure pipeline 302 → the storage stirring tank 37 → the twelfth negative pressure pipeline 303 → the secondary composite drying system 4 → the nano-scale sugarcane powder with a D50 of ≤ 0.316 μm;

[0217] ② The large foreign matter particles in the liquid filtered out by the safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → return to the first reflux pipe 351 of the reflux device 35 → return to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0218] ③ The liquid with particles larger than the desired nanoparticles is filtered and retained by the rotating swash plate axial piston selective nanofiltration device 33 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the first reflux pipe 351 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0219] ④ The filtrate separated by the separation membrane of the separation membrane disk 342 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the hollow flow area of ​​the separation rotating shaft 341 → the second reflux pipe 352 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0220] The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinder 21 grinds the bamboo powder to a D50 of ≤ 0.316 μm, which is about 50,000 mesh;

[0221] The multifunctional integrated selective nanofiltration solid-liquid separation system 3 integrates filtration and solid-liquid separation. Its safety filter 31 uses a 2-micron filter membrane; the rotating swash plate type axial plunger type selective nanofiltration device 33 uses a 1-micron filter membrane; the solid-liquid separation device 34 uses a 100 nm filter membrane and adopts double-sided filtration, with a concentrate retention rate of approximately 80%.

[0222] The two-stage composite drying system 4 is a two-stage composite drying system of hollow paddle drying and auxiliary rotary flash drying, wherein the hollow paddle dryer can dry the material moisture from 60% to 30% within 30 to 60 minutes, and the rotary flash dryer can dry the material moisture from 30% to 5% within 10 to 15 seconds;

[0223] The filter membranes of the safety filter 31, the swash plate type axial piston type selective nanofiltration device 33 and the solid-liquid separation device 34 are replaced as needed to make the material particles reach a grinding particle size of 5 to 500 nanometers, which can meet the subsequent further processing requirements of the material, is suitable for industrial large-scale production, and can be widely used in high value-added fine products such as composite materials, bioplastics, daily necessities, aerospace, automobiles, ships, high-speed railways, coatings and inks, biomedicine, beauty cosmetics, medical protective products, food, water purification, bioethanol, petrochemical tobacco, explosives, xylitol and nanocellulose.

[0224] Example 3. A device for high-speed three-vortex pressure-induced cavitation-microwave composite ultra-nano grinding of plant fiber powder, the process of which is as follows:

[0225] ① Bamboo leaves → feeding device 11 → first negative pressure pipe 101 → vacuum feeder 12 → buffer chamber 13 → grinding device 14 → second negative pressure pipe 102 → grinding storage stirring tank 15 → relevant solution is added to the grinding storage stirring tank 15 in a certain proportion to obtain a uniform slurry → third negative pressure pipe 102 → micron grinder 16 → multiple cycles of grinding between micron grinder 16 and micron circulation stirring tank 17 to achieve ultra-nano grinding requirements → fifth negative pressure pipe 105 → micron storage stirring tank 18 → sixth negative pressure pipe 106 → enter the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine 21 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system for grinding → in the pressure-variable cavitation high The three-speed eddy current assisted-microwave composite nano-grinding machine 21 and the nano-circulation stirring tank 22 are repeatedly circulated to achieve a grinding particle size of 10 to 800 nanometers → the eighth negative pressure pipeline 202 → the nano-storage stirring tank 23 → the ninth negative pressure pipeline 203 → the safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the material pump 32 → enter the rotating swash plate type axial piston type selective nanofiltration device 33 for material filtration → the tenth negative pressure pipeline 301 → enter the solid-liquid separation device 34 for solid-liquid separation → the eleventh negative pressure pipeline 302 → the storage stirring tank 37 → the twelfth negative pressure pipeline 303 → the secondary composite drying system 4 → the nano-grade bamboo powder with a D50 of ≤ 0.316 μm;

[0226] ② The large foreign matter particles in the liquid filtered out by the safety filter 31 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → return to the first reflux pipe 351 of the reflux device 35 → return to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0227] ③ The liquid with particles larger than the desired nanoparticles is filtered and retained by the rotating swash plate axial piston selective nanofiltration device 33 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the first reflux pipe 351 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0228] ④ The filtrate separated by the separation membrane of the separation membrane disk 342 of the multifunctional integrated selective nanofiltration solid-liquid separation system 3 → the hollow flow area of ​​the separation rotating shaft 341 → the second reflux pipe 352 of the reflux device 35 → returns to the ultra-nano circulation stirring tank 22 of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system 2;

[0229] The pressure-variable cavitation high-speed three-vortex assisted-microwave composite ultra-nano grinder 21 grinds the bamboo powder to a D50 of ≤ 0.316 μm, which is about 50,000 mesh;

[0230] The multifunctional integrated selective nanofiltration solid-liquid separation system 3 integrates filtration and solid-liquid separation. Its safety filter 31 uses a 1-micron filter membrane; the rotating swash plate axial plunger type selective nanofiltration device 33 uses a 500-nm filter membrane; the solid-liquid separation device 34 uses a 10-nm filter membrane and adopts double-sided filtration, with a concentrate retention rate of approximately 80%.

[0231] The two-stage composite drying system 4 is a two-stage composite drying system of hollow paddle drying and auxiliary rotary flash drying, wherein the hollow paddle dryer can dry the material moisture from 60% to 30% within 30 to 60 minutes, and the rotary flash dryer can dry the material moisture from 30% to 5% within 10 to 15 seconds;

[0232] The filter membranes of the safety filter 31, the swash plate type axial piston type selective nanofiltration device 33 and the solid-liquid separation device 34 are replaced as needed to make the material particles reach a grinding particle size of 5 to 500 nanometers, which can meet the subsequent further processing requirements of the material, is suitable for industrial large-scale production, and can be widely used in high value-added fine products such as composite materials, bioplastics, daily necessities, aerospace, automobiles, ships, high-speed railways, coatings and inks, biomedicine, beauty cosmetics, medical protective products, food, water purification, bioethanol, petrochemical tobacco, explosives, xylitol and nanocellulose.

[0233] It should be noted that the above-described embodiments merely represent several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the appended claims.

[0234] It should be noted that the above-described embodiments merely represent several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the appended claims.

Claims

1. A device for high-speed three-vortex pressure-variable cavitation-microwave composite ultra-nano grinding of plant fiber powder, characterized in that: It comprises, in sequence, a pretreatment system (1), a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system (2), a multifunctional integrated selective nanofiltration solid-liquid separation system (3), and a two-stage composite drying system (4); The pretreatment system (1) pretreats the plant fibers to be ground, the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system (2) grinds the pretreated plant fibers, the multifunctional integrated selective nanofiltration solid-liquid separation system (3) filters and separates the ground plant fibers, and the secondary composite drying system (4) dries the filtered plant fiber particles; The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system (2) is composed of a pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine (21), an ultra-nano circulation stirring tank (22), an ultra-nano storage stirring tank (23), a seventh negative pressure pipeline (201), an eighth negative pressure pipeline (202) and a ninth negative pressure pipeline (203); The pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine (21) is connected to the ultra-nano circulation stirring tank (22) via the seventh negative pressure pipeline (201); the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine (21) is respectively connected to the ultra-nano circulation stirring tank (22) and the ultra-nano storage stirring tank (23) via the eighth negative pressure pipeline (202); the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine (21) and the ultra-nano circulation stirring tank (22) are subjected to multiple cycles of grinding through the seventh negative pressure pipeline (201) and the eighth negative pressure pipeline (202) until the required requirements are met; the ultra-nano storage stirring tank (23) is connected to the multifunctional integrated selective nanofiltration solid-liquid separation system (3) via the ninth negative pressure pipeline (203); The pressure-variable cavitation high-speed three-vortex-microwave composite nano-grinding machine (21) is composed of a body (210), a motor (211), a grinding cavity (212), a high-speed discrete device (213), a cavitation device (214), a grinding medium (215), a microwave device (216), a spindle constant temperature device (217) and a cavity constant temperature device (218); The grinding medium (215) is L65 zirconium silicate balls, L80 stabilized zirconium oxide balls, or L95 yttrium stabilized zirconium oxide balls, and has a particle size of 0.1 mm to 0.8 mm; The microwave device (216) is connected to the grinding cavity (212) of the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding machine (21) to act on the material slurry in the grinding cavity (212); The multifunctional integrated selective nanofiltration solid-liquid separation system (3) comprises a safety filter (31), a material pump (32), a swash plate type axial piston type selective nanofiltration device (33), a solid-liquid separation device (34), a reflux device (35), an intelligent high-pressure backwashing circulation cleaning device (36), a storage mixing tank (37), a tenth negative pressure pipeline (301), an eleventh negative pressure pipeline (302) and a twelfth negative pressure pipeline (303); The swash plate type axial plunger type selective nanofiltration device (33) is composed of a selective nanofiltration membrane (331) and a filter chamber (332), wherein the selective nanofiltration membrane (331) is an asymmetric microporous nanofiltration separation membrane; The solid-liquid separation device (34) is composed of a separation rotating shaft (341), a separation membrane disc (342) and a separation chamber (343); the separation rotating shaft (341) is a hollow structure; 2 to 100 separation membrane discs (342) are installed on the outside of the separation rotating shaft (341) through a sealing ring, and the whole rotates at a high speed in the separation chamber (343); The separation membrane disk (342) adopts double-sided filtration and contains membranes with various filtration pore sizes of 5 nanometers, 7 nanometers, 30 nanometers, 50 nanometers, 80 nanometers, 200 nanometers, 500 nanometers, and 2 micrometers; The reflux device (35) is composed of a first reflux pipeline (351) and a second reflux pipeline (352); The intelligent high-pressure backwash circulation cleaning device (36) is connected to the swash plate type axial piston type selective nanofiltration device (33) and the separation membrane disk (342), and the intelligent high-pressure backwash circulation cleaning mode is started at a fixed time.

2. The device for high-speed three-vortex pressure-induced cavitation-microwave composite ultra-nano grinding of plant fiber powder according to claim 1, characterized in that: The pretreatment system (1) is composed of a feeding device (11), a vacuum feeder (12), a buffer chamber (13), a grinding device (14), a grinding storage stirring tank (15), a micron grinder (16), a micron circulation stirring tank (17), a micron storage stirring tank (18), a first negative pressure pipeline (101), a second negative pressure pipeline (102), a third negative pressure pipeline (103), a fourth negative pressure pipeline (104), a fifth negative pressure pipeline (105), a sixth negative pressure pipeline (106) and a constant temperature device (107); the feeding device (11) is connected to the vacuum feeder (12) via the first negative pressure pipeline (101), the vacuum feeder (12) is connected to the buffer chamber (13), the buffer chamber (13) is connected to the grinding device (14), and the grinding device (14) is connected to the grinding storage stirring tank (106) via the second negative pressure pipeline (102). 5), the powder grinding storage stirring tank (15) is connected to the micron grinder (16) through the third negative pressure pipeline (103), the micron grinder (16) is connected to the micron circulation stirring tank (17) through the fourth negative pressure pipeline (104), the micron grinder (16) is respectively connected to the micron circulation stirring tank (17) and the micron storage stirring tank (18) through the fifth negative pressure pipeline (105), the micron grinder (16) and the micron circulation stirring tank (17) perform multiple cycles of grinding on the material through the fourth negative pressure pipeline (104) and the fifth negative pressure pipeline (105) until the required requirements are met, and the micron storage stirring tank (18) is connected to the pressure-variable cavitation high-speed three-vortex-microwave composite ultra-nano grinding system (2) through the sixth negative pressure pipeline (106); The grinding device (14), the grinding storage stirring tank (15), the micron grinder (16), the micron circulation stirring tank (17), the micron storage stirring tank (18), the first negative pressure pipeline (101), the second negative pressure pipeline (102), the third negative pressure pipeline (103), the fourth negative pressure pipeline (104), the fifth negative pressure pipeline (105) and the sixth negative pressure pipeline (106) are all connected to the constant temperature pipeline by a constant temperature device (107).

3. The device for high-speed three-vortex pressure-induced cavitation-microwave composite ultra-nano grinding of plant fiber powder according to claim 1, characterized in that: The two-stage composite drying system (4) is a two-stage composite drying system of hollow blade drying assisted by rotary flash drying, and is composed of a primary drying system (40) and a secondary drying system (41); The primary drying (40) is a hollow paddle type drying machine, which is composed of a heating device (401), a dust removal device (402), a drying device (403) and a conveyor (404); The secondary drying (41) is a rotary flash drying machine, which is composed of a second heating device (411), a second feeding device (412), a second drying device (413), a second dust removal device (414), a separation device (415) and a collection device (416).

4. The device for high-speed three-vortex pressure-induced cavitation-microwave composite ultra-nano grinding of plant fiber powder according to claim 1, characterized in that: The plant fiber material is crushed, ground, filtered, solid-liquid separated and dried to become nano-scale plant fiber powder, and its D50 is ≤ 0.316 μm.

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