Grading screening device and method for continuous multi-stage narrow-particle-size-section micron particles and coarse particles

Abstract

The invention discloses a continuous multi-stage narrow-granularity-section micron particle and coarse particulate matter grading screening device and a continuous multi-stage narrow-granularity-section micron particle and coarse particulate matter grading screening method. The device is formed by connecting a rotational flow grading module, a purification liquid supplementing module and a filtering concentration module in series, the rotational flow grading module and the purification liquid supplementing module are respectively formed by connecting n hydrocyclones with the same structure and different specifications in parallel, the hydrocyclones of the two modules are in one-to-one correspondence, every two hydrocyclones are connected in series to form a hydrocyclone group, then the n hydrocyclone groups are connected in parallel, and n is equal to the number of target particle size sections minus 1. And through a series-parallel connection structure of the multi-stage cyclone, precise stepless regulation and control and circulating purification of size grading are realized. After being stirred, a solid-liquid mixture is sequentially graded and purified by a cyclone group, and then is concentrated by a cloth bag filter of the filtering and concentrating module. The device is automatically controlled through a PLC, can realize high-precision and high-efficiency grading of micron and coarse particles in a narrow particle size section, and has the advantages of high separation precision, energy conservation, high applicability and the like.

Description

Technical Field

[0001] The present invention relates to a device and method for continuous multi-stage narrow-size micron particles and coarse particles grading and screening, and specifically to a device that utilizes a cyclone grading module, a purification and rehydration module, and a filtration and concentration module to grade and screen narrow-size micron particles and coarse particles in a liquid. Background Art

[0002] Particle size classification technology for fine and micron-sized particles involves classifying particles in a mixed system according to their size. This process is crucial for achieving accurate multi-gradient fluidization classification of micron and coarse particles in various fields such as mining, agricultural processing, and fine chemicals, especially in the food and pharmaceutical industries. Currently, the following methods are mainly used for particle size classification:

[0003] Dry classification: This technology directly screens the material through a screen, without the addition of liquid. It maintains the material's original physical and chemical properties, avoiding the loss or dilution of active ingredients caused by the addition of liquids. It offers advantages such as shorter production cycles and lower energy consumption, helping to reduce costs. However, the resulting granules are weak, fragile, and prone to agglomeration. Dry classification also requires high moisture and humidity levels, making it unsuitable for materials prone to agglomeration or caking.

[0004] Semi-dry classification: This technology combines the characteristics of wet and dry methods and is suitable for raw materials with a moisture content of 20% to 30%. Moisture content must be adjusted during processing, resulting in a product with a higher density than wet-processed products, but a rougher surface, not as smooth as dry-processed products. Despite this, semi-dry products surpass wet-processed products in hardness and durability. This technology is characterized by high efficiency, low cost, and environmental friendliness, but its applicability is limited.

[0005] Wet classification: Suitable for materials with a liquid content exceeding 30%, such as slurries and pastes. Wet classification can improve the binding force between particles, enhance particle strength and stability, and reduce breakage and agglomeration during subsequent processing. However, the equipment is relatively complex and the operating cost is high.

[0006] Traditional particle size classification technologies face challenges in achieving high-precision and efficient classification of micron and coarse particles across multiple narrow size ranges. To overcome these challenges, researchers and engineers have conducted extensive research and development, introducing a variety of novel particle size classification technologies. These technologies improve classification efficiency and accuracy while reducing energy consumption through improved equipment design and optimized operating parameters.

[0007] Among existing particle size classification equipment, centrifugal classifiers and gravity classifiers are two commonly used devices. Centrifugal classifiers classify particles of different sizes by taking advantage of the differences in force exerted by particles in a centrifugal field, making them suitable for screening fine particles. Gravity classifiers classify particles of different sizes based on their settling velocities in a gravitational field. Improved designs and optimized operating parameters of these devices have improved classification efficiency and accuracy. However, a single technology is still insufficient to meet the requirements for narrow particle size classification and screening of liquid materials. Therefore, a combination of multiple technologies is needed to achieve more refined and energy-efficient particle size classification.

[0008] Chinese utility model patent CN201910313685.8 discloses a micro-nano powder particle size centrifugal classification device and its use method. The invention aims to solve the problems of complex synthesis devices, high operating requirements, low controllability of particle size classification and low separation efficiency of existing physical methods. The device includes a separation cylinder, a lifting and stirring device and a control panel; the separation cylinder includes a shell and a separation tank; the lifting and stirring device includes stirring blades, a motor and a bracket. The method of use is to first prepare a suspension, fully disperse it through mechanical stirring and ultrasonic vibration, add the suspension to a centrifugal device for centrifugation, take out the separation tank, and add a new separation tank. Under the centrifugal action of different speeds, the powder particles are successively settled in the separation tanks of each level according to their own particle size, and nano powders of various levels can be obtained after drying. This method is suitable for the separation of micro-nano powders of various sizes, but it cannot achieve high-precision and high-efficiency classification of micron particles and coarse particles in multiple narrow particle size segments.

[0009] Chinese utility model patent CN202311259960.5 discloses a fluidized screening device and method for precise particle classification. The device and method utilize wet classification technology and are particularly suitable for occasions requiring high resource consumption and large equipment scale. The device includes a fluidized bed and a screening system, which realizes the preliminary dispersion and classification of particles through the fluidized bed, and then accurately separates the particles through the screening system. This method achieves precise control of particle size by controlling the fluid dynamic conditions in the fluidized bed and the sieve size of the screening system. This technology can effectively improve the classification accuracy and is suitable for precise classification of particles in large-scale industrial production, but it cannot achieve long-term operation and the classification efficiency needs to be further improved.

[0010] Therefore, there is an urgent need in this field to develop a particle size classification device that can simultaneously achieve high-precision classification of narrow particle size range micron particles and coarse particles, with low resource consumption, energy saving and environmental protection. Summary of the Invention

[0011] Micron particles refer to particles with a particle size between 1 micron and 100 microns, coarse particles refer to particles with a particle size between 100 microns and 1000 microns, and narrow particle size segments refer to particles with a concentrated particle size distribution within a single particle size segment, with the interval frequency distribution curve being a narrow single peak, indicating that the particle size is uniform and there are no extreme sizes. The present invention belongs to the field of particle size classification technology, and specifically provides a device and method for grading and screening micron particles and coarse particles in a continuous narrow particle size segment. The device includes a cyclone classification module, a purification and rehydration module, and a filtration and concentration module connected in series. The cyclone classification module is composed of multiple groups of cyclones of different specifications connected in parallel, and is used to achieve continuous particle classification of any multiple narrow particle size segments. The purification and rehydration module is composed of cyclones of different specifications connected in parallel with the same number of cyclone groups as the cyclone classification module, and is used to achieve purification of the pre-classified material and system rehydration. The filtration and concentration module is composed of multiple groups of bag filters matched with the classified particle size segments connected in parallel, and is used to achieve concentration of the target classified material. The device has the characteristics of high separation accuracy and high separation efficiency, and PLC automatic control can realize human-machine isolation operation.

[0012] The concept of the present invention is as follows:

[0013] Traditional cyclone classification processes mostly achieve multi-size segment classification by connecting the overflow port of the preceding cyclone and the feed port of the subsequent cyclone in series, but this classification method has two defects. First, the multi-stage cyclones have a great influence on each other. The traditional multi-stage cyclone series connection method has high requirements on the cyclone size parameters and process parameters. If it is not properly regulated, it is difficult to achieve accurate classification of micron particles and coarse particles in a narrow particle size segment. Second, the traditional cyclone separation technology has a large split ratio and high continuous phase consumption, and it is often difficult for the device to achieve long-term high-efficiency and energy-saving operation. In response to these two defects, the present invention proposes a multi-stage cyclone series-parallel structure. By connecting the cyclone used for particle size classification in the cyclone classification module and the cyclone used for solid-liquid separation in the purification and rehydration module in series and parallel, precise stepless control of particle size classification and a green process route of cyclic purification are achieved. The series connection of a cyclone for particle size classification and a cyclone for solid-liquid separation realizes the preliminary classification, enhanced classification and solid-liquid separation of particles. The parallel connection between each series cyclone group realizes precise stepless control within the controllable particle size range of the series cyclone group. Based on the above basic ideas, a device and method for grading and screening micron particles and coarse particles in a continuous multi-stage narrow particle size segment was developed. A preceding cyclone for particle size classification and a subsequent cyclone for solid-liquid separation are connected in series to form a group of series cyclone groups for purifying a single target particle size segment. Multiple series cyclone groups are connected in parallel to form the core components of the grading and screening device. Since the overflow of the cyclone can only guarantee the upper limit of the dispersed phase particle size of the two-phase flow, the order of grading the raw materials is to classify smaller particles first and then larger particles. Each set of cyclones in series for particle size classification and solid-liquid separation completes the classification and screening of a target particle size segment. After the cyclic purification efficiency decreases, the online particle size detector determines that the classification and screening of the target particle size segment is completed. After the product in the temporary storage tank is pumped out by diaphragm pump II and enters the bag filter to reduce the continuous specific gravity, it switches to the next set of cyclone passages in series and repeats the cyclic purification process. After the cyclic purification is completed, the particles of the largest particle size segment remaining in the mixing tank are extracted, and the classification and screening of all target particle size segments is completed.

[0014] In summary, the combined effect of the cyclone classification module, the purification and rehydration module, and the filtration and concentration module can achieve particle size classification in a stable, accurate, and energy-saving manner, thereby improving production efficiency.

[0015] The present invention is achieved through the following technical solutions:

[0016] A device for continuous multi-stage narrow particle size segment micron particle and coarse particle classification and screening, characterized in that the device comprises a cyclone classification module, a purification and rehydration module and a filtration and concentration module connected in series in sequence, the cyclone classification module and the purification and rehydration module are respectively composed of n cyclones with the same structure and different specifications, the cyclones of the cyclone classification module and the purification and rehydration module correspond to each other one by one, two of them are connected in series to form a cyclone group, n cyclone groups are connected in parallel, the number n of cyclones is equal to the number m-1 of target particle size segments, the diameter of the straight pipe section of the cyclone in the cyclone classification module is larger than the diameter of the straight pipe section of the cyclone in the corresponding purification and rehydration module connected in series, in each of the above modules, the cyclones are arranged in parallel from small to large in size according to the material flow direction; the cyclone classification module is installed above the stirring tank, the bottom outlet of the stirring tank is connected to the inlet of the first diaphragm pump, and An online particle size detector is installed on the pipeline. In the cyclone classification module, the feed port of the cyclone is connected to the outlet of the first diaphragm pump, the underflow port of the cyclone is connected to the top of the stirring tank, and the overflow port of the cyclone is connected to the feed port of the cyclone in the purification and replenishment module. The purification and replenishment module is installed above the temporary storage tank. In the purification and replenishment module, the underflow port of the cyclone is connected to the top of the temporary storage tank, and the overflow port of the cyclone is connected to the top of the stirring tank. The bottom outlet of the temporary storage tank is connected to the inlet of the second diaphragm pump, and the outlet of the second diaphragm pump is connected to the filter inlet of the filtration and concentration module. The bottom outlet of a liquid storage tank is connected to the inlet of the centrifugal pump, and the outlet of the centrifugal pump is connected to the top of the stirring tank and the temporary storage tank respectively. A PLC control cabinet is connected to and controls electronic equipment including valves, flow meters, liquid level gauges, stirring motors, online particle size detectors, and water pump motors via power supply lines and signal lines.

[0017] Preferably, in each cyclone group, the diameter of the straight pipe section of the cyclone used for particle size classification in the cyclone classification module is 25-50 μm larger than the diameter of the straight pipe section of the cyclone used for solid-liquid separation in the purification and rehydration module.

[0018] Preferably, the length L of the straight pipe section of the cyclone is 1-2 times the diameter D, and the feed port diameter d i The size is 0.13-0.2 times the diameter D, the overflow port diameter d o The size is 0.2-0.3 times the diameter D, the depth h0 of the overflow port inserted into the cyclone is 0.2-0.35 times the diameter D, the cone angle θ ranges from 8-30°, and the bottom flow port diameter d s The size is 0.07-0.1 times the diameter D.

[0019] Preferably, the diameter D of the straight pipe section of the cyclone in the cyclone classification module is in the range of 35-550 mm, and the diameter D of the straight pipe section of the cyclone in the purification and rehydration module is in the range of 10-500 mm.

[0020] Preferably, the filtration and concentration module is composed of a plurality of bag filters connected in parallel that match the graded particle size segments, and the pore size range of the bag filters is 0.5 μm-1000 μm.

[0021] The present invention also provides a method for continuous multi-stage narrow particle size segment micron particles and coarse particles classification screening:

[0022] A method for continuous multi-stage narrow particle size segment micron particle and coarse particle classification and screening, characterized in that the method comprises the following steps: a solid-liquid mixture is uniformly mixed in a stirring tank, discharged from the bottom outlet of the stirring tank, and pumped into a cyclone for particle size classification in a cyclone classification module of a first cyclone group by a diaphragm pump; the bottom flow port of the cyclone discharges particles larger than the target particle size back into the stirring tank; the overflow port of the cyclone discharges the target particles into the feed port of the cyclone for solid-liquid separation in the purification and rehydration module; the bottom flow port of the cyclone in the purification and rehydration module discharges the target particles into a temporary storage tank; the overflow port of the cyclone in the purification and rehydration module discharges the separated clarified liquid phase back to the stirring tank for rehydration to complete liquid phase recovery, until the online particle size detector determines that the particles in the particle size segment have been separated, and the classification work is ended, and the target particles in the temporary storage tank are discharged from the bottom of the temporary storage tank. The diaphragm pump draws water into the filter in the filtration and concentration module, which is equipped with a filter bag with a corresponding target particle size segment diameter. The liquid in the liquid storage tank is extracted to clean the residual particles in the temporary storage tank and is then pumped into the filter again to further concentrate and deliquescence the liquid-containing material, completing the grading and screening of a target particle size segment; then it switches to the next cyclone group in sequence until the nth cyclone group, and repeats the above process until the particles of the remaining particle size segments except the largest particle size segment are separated. Finally, the largest particles remaining in the mixing tank are extracted and enter the filter in the filtration and concentration module. The liquid in the liquid storage tank is extracted to clean the mixing tank and is pumped into the filter for concentration and deliquescence, completing the particle size grading work of the last particle size segment; the PLC control cabinet connects and controls electronic equipment including valves, flow meters, liquid level gauges, stirring motors, online particle size detectors and water pump motors through power supply lines and signal lines to realize unmanned automation of the device.

[0023] The main advantages of the device of the present invention are:

[0024] (1) The cyclone classification module of the present invention has the advantage over traditional gravity field classification in that the jet velocity in the cyclone is faster, the flow rate is larger, and the fluid has strong turbulent kinetic energy, which can generate a centrifugal force field that can achieve efficient classification. The cyclone size parameters and process parameters have a wide range of control and high separation accuracy. It is suitable for fine particle classification in narrow particle size segments and has strong adaptability to different classification requirements. The parallel connection of multiple cyclones enhances the accuracy of the cyclone for fine particle classification and can achieve precise classification of multiple narrow particle size segments.

[0025] (2) The advantages of the rehydration and purification module of the present invention over conventional cyclone classification technology are that the separation cyclone of the separation and concentration module can achieve the recovery of the continuous phase under high split ratio conditions, thus avoiding the large loss of the continuous phase caused by long-term operation of the device, thereby achieving the purpose of saving resources. At the same time, the separation and concentration module strengthens the classification of the primary product of the cyclone classification module and increases the solid-liquid ratio of the product through solid-liquid separation, significantly improving the classification accuracy and production efficiency.

[0026] (3) The technical coupling of the cyclone classification module and the separation and concentration module in the present invention is not simply connected in series. The combination of the two realizes the precise control of cyclone classification screening and separation concentration and desolidification, and has the chain control effects of feed flow control, separation enhancement control, etc. The diversified series and parallel combination of cyclones can meet a variety of process requirements and realize stepless control. The separation and concentration module greatly reduces the loss of the continuous phase, making the circulation purification process possible, and further strengthens the classification of the screening products of the cyclone classification module. This greatly improves the efficiency and accuracy of particle size classification. Only a single device is needed to meet the process requirements, and no mobile equipment support is required. The manufacturing process is simple and the equipment maintenance is convenient, which can create considerable economic value for the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present invention. They only constitute a part of this specification to further explain the present invention and do not constitute a limitation of the present invention.

[0028] In the drawings, the components are not necessarily drawn according to the actual scale.

[0029] Figure 1 Schematic diagram of the structure of the device of the present invention. The reference numerals represent the following devices and internal components:

[0030] Among them: 1 mixing tank, 2 first diaphragm pump, 3 cyclone (the cyclone above the mixing tank is used for particle size classification, and the cyclone above the temporary storage tank is used for solid-liquid separation), 4 online particle size detector, 5 temporary storage tank, 6 second diaphragm pump, 7 filter, 8 centrifugal pump, 9 liquid storage tank, 10 PLC control cabinet.

[0031] Figure 2 It is a schematic diagram of the process flow of the device of the present invention.

[0032] Among them: 1 stirring tank, 2 first diaphragm pump, 3 cyclone (the cyclone above the stirring tank is used for particle size classification, and the cyclone above the temporary storage tank is used for solid-liquid separation), 4 online particle size detector, 5 temporary storage tank, 6 second diaphragm pump, 7 filter, 8 centrifugal pump, 9 liquid storage tank.

[0033] Figure 3 It is a schematic diagram of the process principle of the device of the present invention.

[0034] Among them: 1 stirring tank, 2 first diaphragm pump, 3 cyclone (the cyclone above the stirring tank 1 is used for particle size classification, and the cyclone above the temporary storage tank 5 is used for solid-liquid separation), 4 online particle size detector, 5 temporary storage tank, 6 second diaphragm pump, 7 filter.

[0035] Figure 4(a) is a schematic diagram of the structure of the cyclone in the cyclone classification module and the purification and rehydration module of the device of the present invention. The reference numerals represent the following devices and internal components:

[0036] 3-1 cyclone feed port 3-2 cyclone overflow port 3-3 cyclone bottom flow port.

[0037] Figure 4(b) is a schematic diagram of the structure of the cyclone in the cyclone classification module and the separation and concentration module of the device of the present invention. The reference numerals represent the following devices and internal components:

[0038] D——Straight pipe diameter of cyclone separator

[0039] H——Length of straight pipe section of cyclone separator

[0040] d i ——Tangential inlet diameter of cyclone separator

[0041] d o ——Overflow port diameter

[0042] H0——depth of overflow port inserted into cyclone

[0043] θ——cone angle

[0044] d s ——Underflow mouth diameter.

[0045] Figure 5 It is a schematic diagram of the principle of the cyclone in the cyclone classification module and the separation and concentration module in the device of the present invention.

[0046] All documents mentioned in this application are incorporated herein by reference, just as if each document were incorporated herein by reference individually. It should also be understood that after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention, and that such equivalents also fall within the scope of the claims appended hereto. DETAILED DESCRIPTION

[0047] The present invention is further described below with reference to specific examples. However, it should be understood that these examples are only used to illustrate the present invention and do not constitute a limitation on the scope of the present invention. The test methods for which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the manufacturer. Unless otherwise specified, all percentages and parts are by weight. In the embodiments, the number of cyclones used for particle size classification in the cyclone classification module is represented by Ⅰ, Ⅱ, Ⅲ, ... n, and the number of cyclones used for solid-liquid separation in the purification and rehydration module is represented by 1, 2, 3, ... n; the number of cyclones in the two modules is consistent and one-to-one corresponding, and the number of cyclones in each module is one less than the number of target particle size segments, and cyclones with the same number (such as cyclone Ⅰ and cyclone 1) are connected in series in pairs as a group, and multiple groups are connected in parallel.

[0048] Application Examples

[0049] In a preferred embodiment, the cyclone classification module includes a cyclone, and the separation and concentration module includes two cyclones, and the target is to be divided into three particle size segments.

[0050] In another preferred embodiment, the cyclone classification module comprises three cyclones, and the separation and concentration module comprises three cyclones, and the target particle size is divided into four segments.

[0051] In another preferred embodiment, the cyclone classification module comprises 4 cyclones, and the separation and concentration module comprises 4 cyclones, and the target particle size is divided into 5 segments.

[0052] Example 1:

[0053] A factory in Shaanxi Province uses the device of this invention to size-classify silica particles. The raw silica particle size range is 25-150 μm, and the solids content of the silica mixed with water is approximately 2-5%. The flow rate of the first-stage cyclone group is 8 t / h, and the flow rate of the second-stage cyclone group is 12 t / h. The goal is to obtain particles in three consecutive narrow size ranges: 25-50 μm, 50-100 μm, and 150-150 μm.

[0054] Design parameters: such as Figure 3 The number of cyclones in the cyclone classification module shown is 2, where the diameters D of cyclones I and II are 75 and 100 mm respectively, and the cone angles are 15° and 15° respectively. The length H of the straight pipe section of cyclones I and II is twice the diameter D, and the feed port d i The size is 0.15 times the diameter D. Overflow port diameter d oThe size is 0.2 times the diameter D, and the depth h0 of the overflow port inserted into the cyclone is 0.2 times the diameter D. The size of the bottom flow port diameter ds is 0.07 times the diameter D. The number of cyclones in the separation and concentration module shown in Figure 4 is 2, where the diameters D of cyclones 1 and 2 are 50 and 75 mm respectively, and the cone angles θ are 10° and 10° respectively. The length H of the straight pipe section of cyclones 1 and 2 is 2 times the diameter D, and the feed port d i The size is 0.15 times the diameter D. Overflow port diameter d o The size is 0.2 times the diameter D, and the depth h0 of the overflow port inserted into the cyclone is 0.2 times the diameter D of the cyclone classifier. s The size is 0.07 times the diameter D.

[0055] Application effect: After being processed by the device of the present invention, the concentration of particles with a diameter of 100-150 μm is 95%, the concentration of particles with a diameter of 50-100 μm is 90%, and the concentration of particles with a diameter of 25-50 μm is 90%.

[0056] Example 2:

[0057] A factory in Shanxi Province uses the device of the present invention to size-classify silica particles. The raw silica particle size range is 50-200 μm, and the solids content of the silica mixed with water is approximately 3-8%. The flow rate of the first-stage cyclone group is 10 t / h, the second-stage cyclone group has a flow rate of 15 t / h, and the third-stage cyclone group has a flow rate of 18 t / h. The goal is to obtain particles in four consecutive narrow size ranges: 50-75 μm, 75-100 μm, 100-150 μm, and 150-200 μm.

[0058] Design parameters: such as Figure 3 The number of cyclones in the cyclone classification module shown is 3, where the diameters D of cyclones I, II, and III are 100, 125, and 150 mm respectively, and the cone angles are 15°, 15°, and 15° respectively. The length H of the straight pipe section of cyclones I, II, and III is twice the diameter D, and the feed port d i The size is 0.18 times the diameter D. Overflow port diameter d o The size is 0.25 times the diameter D, and the depth h0 of the overflow port inserted into the cyclone is 0.3 times the cyclone diameter D. s The size is 0.08 times the diameter D. As shown in Figure 4, the number of cyclones in the separation and concentration module is 3, where the diameters D of cyclones 1, 2, and 3 are 75, 100, and 125 mm respectively, and the cone angles θ are 10°, 10°, and 10° respectively. The length H of the straight pipe section of cyclones 1, 2, and 3 is 2 times the diameter D, and the feed port d i The size is 0.18 times the diameter D. Overflow port diameter d oThe size is 0.25 times the diameter D, and the depth h0 of the overflow port inserted into the cyclone is 0.3 times the cyclone diameter D. s The size is 0.08 times the diameter D.

[0059] Application effect: After being treated by the device of the present invention, the particle size concentration of 150-200 μm is 95%, the particle size concentration of 100-150 μm is 95%, the particle size concentration of 75-100 μm is 90%, and the particle size concentration of 50-75 μm is 90%.

[0060] Example 3:

[0061] A Shanghai factory uses the device of the present invention to size-classify silicon carbide particles. The raw silicon carbide particle size range is 25-200 μm, and the solids content of the silicon dioxide mixed with water is approximately 5-10%. The flow rate of the first-stage cyclone group is 8 t / h, the second-stage cyclone group is 12 t / h, the third-stage cyclone group is 18 t / h, and the fourth-stage cyclone group is 20 t / h. The goal is to obtain particles in five consecutive narrow size ranges: 25-50 μm, 50-75 μm, 75-100 μm, 100-150 μm, and 150-200 μm.

[0062] Design parameters: such as Figure 3 The number of cyclones in the cyclone classification module shown is 4, where the diameters D of cyclones I, II, III, and IV are 75, 100, 125, and 150 mm, respectively, and the cone angles are 15°, 15°, 15°, and 15°, respectively. The length H of the straight pipe section of cyclones I, II, III, and IV is twice the diameter D, and the feed port d i The size is 0.2 times the diameter D. Overflow port diameter d o The size is 0.3 times the diameter D, and the depth h0 of the overflow port inserted into the cyclone is 0.35 times the diameter D of the cyclone. s The size is 0.1 times the diameter D. As shown in Figure 4, the number of cyclones in the separation and concentration module is 4, where the diameters D of cyclones 1, 2, 3, and 4 are 50, 75, 100, and 125 mm respectively, and the cone angles θ are 10°, 10°, 10°, and 10° respectively. The length H of the straight pipe section of cyclones 1, 2, 3, and 4 is 2 times the diameter D, and the feed port d i The size is 0.2 times the diameter D. Overflow port diameter d o The size is 0.3 times the diameter D, and the depth h0 of the overflow port inserted into the cyclone is 0.35 times the diameter D of the cyclone classifier. s The size is 0.1 times the diameter D.

[0063] Application effect: After being treated by the device of the present invention, the particle size concentration of 150-200 μm is 95%, the particle size concentration of 100-150 μm is 95%, the particle size concentration of 75-100 μm is 90%, the particle size concentration of 50-75 μm is 90%, and the particle size concentration of 25-50 μm is 90%.

[0064] The above-mentioned embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. That is, any equivalent changes and modifications made according to the scope of the present patent application should fall within the technical scope of the present invention.

Claims

1. A device for continuous multi-stage narrow particle size segment micron particles and coarse particles classification screening, which is characterized by The device includes a cyclone classification module, a purification and rehydration module, and a filtration and concentration module connected in series in sequence. The cyclone classification module and the purification and rehydration module are respectively composed of n cyclones with the same structure and different specifications. The cyclones of the cyclone classification module and the purification and rehydration module correspond to each other one by one, and are connected in series in pairs to form a cyclone group. The n cyclone groups are connected in parallel, and the number n of cyclones is equal to the number m-1 of target particle size segments. The diameter of the straight pipe section of the cyclone in the cyclone classification module is larger than the diameter of the straight pipe section of the corresponding cyclone in the purification and rehydration module connected in series. In the cyclone classification module and the purification and rehydration module, the cyclones are arranged in parallel from small to large in size according to the direction of material flow; the cyclone classification module is installed above the stirring tank, the outlet at the bottom of the stirring tank is connected to the inlet of the first diaphragm pump, and an online particle size detector is installed on the pipeline. The measuring instrument comprises: in a cyclone classification module, a feed port of the cyclone is connected to the outlet of a first diaphragm pump, an underflow port of the cyclone is connected to the top of a stirring tank, and an overflow port of the cyclone is connected to the feed port of the cyclone in a purification and rehydration module. The purification and rehydration module is installed above a temporary storage tank. In the purification and rehydration module, the underflow port of the cyclone is connected to the top of the temporary storage tank, and the overflow port of the cyclone is connected to the top of the stirring tank; the bottom outlet of the temporary storage tank is connected to the inlet of a second diaphragm pump, and the outlet of the second diaphragm pump is connected to the inlet of a filter in a filtration and concentration module; the bottom outlet of a liquid storage tank is connected to the inlet of a centrifugal pump, and the outlet of the centrifugal pump is connected to the top of the stirring tank and the top of the temporary storage tank, respectively. A PLC control cabinet is connected to and controls electronic equipment including valves, flow meters, liquid level gauges, stirring motors, online particle size detectors, and water pump motors through power supply lines and signal lines.

2. The device according to claim 1, wherein In each cyclone group, the diameter of the straight pipe section of the cyclone used for particle size classification in the cyclone classification module is 25-50 μm larger than the diameter of the straight pipe section of the cyclone used for solid-liquid separation in the purification and rehydration module.

3. The device according to claim 1 or 2, characterized in that The length L of the straight pipe section of the cyclone is 1-2 times the diameter D, and the feed port diameter d i The size is 0.13-0.2 times the diameter D, the overflow port diameter d o The size is 0.2-0.3 times the diameter D, the depth h0 of the overflow port inserted into the cyclone is 0.2-0.35 times the diameter D, the cone angle θ ranges from 8-30°, and the bottom flow port diameter d s The size is 0.07-0.1 times the diameter D.

4. The device according to claim 1 or 2, characterized in that The diameter D of the straight pipe section of the cyclone in the cyclone classification module ranges from 35 to 550 mm, and the diameter D of the straight pipe section of the cyclone in the purification and rehydration module ranges from 10 to 500 mm.

5. The device according to claim 1 or 2, characterized in that The filtration and concentration module is composed of a plurality of bag filters matched with the graded particle size segments connected in parallel, and the pore size range of the bag filters is 0.5 μm-1000 μm.

6. A method for continuous multi-stage narrow particle size range micron particles and coarse particles classification screening using the device of claim 1, characterized in that: The method comprises the following steps: a solid-liquid mixture is uniformly mixed in a stirring tank, discharged from the bottom outlet of the stirring tank, and pumped into a cyclone for particle size classification in a cyclone classification module of a first cyclone group by a diaphragm pump; the underflow port of the cyclone discharges particles larger than the target particle size back into the stirring tank; the overflow port of the cyclone discharges the target particles into a feed port of a cyclone for solid-liquid separation in a purification and rehydration module; the underflow port of the cyclone in the purification and rehydration module discharges the target particles into a temporary storage tank; the overflow port of the cyclone in the purification and rehydration module discharges the separated clarified liquid phase back into the stirring tank for rehydration, completing liquid phase recovery until an online particle size detector determines that the particles in the particle size segment have been separated, and the classification work is terminated; the target particles in the temporary storage tank are discharged from the bottom of the temporary storage tank and pumped into a filter and concentration module equipped with a corresponding In the filter of the filter bag of the target particle size segment, the liquid in the liquid storage tank is extracted to clean the residual particles in the temporary storage tank and then drawn into the filter again to further concentrate and deliquore the liquid-containing material, completing the grading and screening of a target strength segment; then switch to the next cyclone group in sequence until the nth cyclone group, repeat the above process until the particles of the remaining particle size segments except the largest particle size segment are separated, and finally the largest particles remaining in the mixing tank are extracted into the filter in the filtration and concentration module, and the liquid in the liquid storage tank is extracted to clean the mixing tank and drawn into the filter for concentration and deliquoring, completing the particle size grading work of the last particle size segment; the PLC control cabinet is connected and controlled by power supply lines and signal lines, including valves, flow meters, liquid level meters, stirring motors, online particle size detectors and water pump motors, to realize unmanned automation of the device.

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