Device and method for multi-gradient fluidized graded screening of micron particles and coarse particles

Abstract

The invention belongs to the technical field of size grading, and particularly provides a multi-gradient fluidized grading screening device and method for micron particles and coarse particles. The device is composed of a jet flow sedimentation screening module and a self-absorption rotational flow screening module, wherein the jet flow sedimentation screening module comprises an inclined plate sedimentation tank, an interception inclined plate and a coarse separation product sedimentation tank; the self-suction cyclone screening module comprises a self-suction assembly, a particle pre-sequencing device and a cyclone separator, the self-suction assembly can suck in coarse separation products with liquid in the jet flow sedimentation screening module, and the coarse separation products enter the cyclone separator through the pre-sequencing assembly. Raw materials are roughly graded through the jet flow sedimentation module, collected in the coarse separation product sedimentation tank and further precisely graded through the self-absorption rotational flow screening module, large particles are discharged from a bottom flow opening in the bottom along with most of liquid, small particles are discharged from an overflow opening in the top along with a small part of liquid, and further fine separation of coarse separation products is achieved.

Description

Technical Field

[0001] The present invention relates to a device and method for multi-gradient fluidized classification and screening of micron particles and coarse particles, and particularly to a device for grading and screening the particle size of fine crystal particles in a liquid after a crystallization process by using a jet sedimentation screening module and a self-priming cyclone screening module, belonging to the technical field of particle size classification. Background Art

[0002] Particle size classification is a process of classifying or sorting the particulate matter in a mixed system according to its particle size. It is widely used in the mining industry, agricultural production and processing, especially in the precise multi-gradient fluidization classification process of fine particulate matter with a narrow particle size range during reaction growth, such as in industrial fields like food processing and pharmaceuticals. Current particle size classification techniques include the following:

[0003] Dry classification technique: The dry classification technique directly screens and granulates the material through a sieve without adding liquid. The dry classification technique can maintain the original physical and chemical properties of the material, without loss or dilution of active ingredients due to the addition of liquid, and has a short production cycle and low energy consumption, which is beneficial to reducing production costs. However, the particles in the dry classification technique have low strength and are prone to breakage and agglomeration during subsequent processing, and have high requirements for the moisture content and humidity of the material, and are not suitable for materials that are prone to agglomeration and caking.

[0004] Semi-dry classification technique: The semi-dry classification technique is a particle classification method with the humidity controlled at an appropriate level, which is a combination of wet and dry methods and is suitable for raw materials with a water content between 20% and 30%. During processing, the moisture content needs to be continuously adjusted. The products manufactured by the semi-dry method are usually denser than those manufactured by the wet method, but rougher than those manufactured by the dry method, with an uneven surface, but are better in terms of hardness and durability than the products manufactured by the wet method. This classification technique has high granulation efficiency, low cost, environmental protection and no pollution, and the product particles are uniform, but the applicable range is small.

[0005] Wet classification technique: The wet classification technique allows the material to be classified with liquid, or it is a particle size classification technique for materials with a liquid content > 30%, and is suitable for the particle classification process of slurry, paste and other liquid-containing reaction liquids or particles that need to be pre-mixed with liquid for protection. This technique has high separation efficiency and a wide applicable range. The wet classification technique can form a certain binding force between the material particles, increase the strength and stability of the particles, and reduce the breakage and agglomeration of the particles during subsequent processing, but the equipment is complex and the operating cost is relatively high.

[0006] Traditional particle size classification techniques often have problems such as difficulty in accurately classifying micron-sized particles and coarse particles, and difficulty in synchronously achieving fluidization for multi-gradient classification. To solve these problems, researchers and engineers have conducted a large amount of research and development and proposed many new particle size classification techniques. These techniques mainly improve the classification efficiency and accuracy and reduce energy consumption by improving equipment design and optimizing operating parameters.

[0007] Among the existing particle size classification devices, the most commonly used is the centrifugal classifier, which is a device that classifies particles by centrifugal force. Its principle is to utilize the different centrifugal forces received by particles of different sizes in the centrifugal force field to achieve classification. Centrifugal classifiers are usually suitable for the separation of finer particles. The gravity classifier is also a commonly used particle size classification device, and its principle is to classify particles based on the different sedimentation velocities of particles with different particle sizes in the gravity field. In this way, classification by particle size can be achieved according to the different sedimentation velocities of particles. The existing particle size classification devices have improved their designs and optimized their operating parameters, resulting in improved classification efficiency and accuracy. However, the existing single classification techniques still have difficulty meeting the requirements of throughput, classification efficiency, classification accuracy, etc. for high-precision classification of liquid-containing materials, and multiple classification techniques need to be combined to achieve higher requirements for particle size classification.

[0008] Chinese invention patent CN1102258904A discloses a particle size classification device, which consists of multiple filters, a filter box, and a volumetric flask that are stacked overlappingly. The filter includes a filter cup with upper and lower openings. A filter membrane and a filter pad are provided at the lower opening of the filter cup from top to bottom. A stirrer is provided inside the filter cup. An outlet is provided on the side of the filter box, and the outlet is connected to a container bottle. The volumetric flask is connected to a vacuum pump through a hose. This separation method is suitable for micro-nano particles, the equipment is simple, and the operation is easy. However, the separation process is not continuous. Over time, the filter membrane in the filter is prone to accumulation, resulting in classification failure, and the filter membrane needs to be frequently replaced. To avoid particle accumulation on the filter membrane, the throughput of each particle size classification is small, resulting in low classification efficiency, and it is difficult to synchronously achieve fluidization for multi-gradient classification.

[0009] Chinese invention patent CN103828861B discloses a particle size classification device, including a tangential solid-liquid inlet and a conical solid-liquid separation cavity. This device utilizes the swirling flow of solid-liquid in the separation cavity. Since the densities of large and small particles are different, during the rotational movement, larger particles and most of the liquid will gather on the outside to form an outer swirling flow and move downward due to centrifugal motion, while smaller particles will form an inner swirling flow with a small part of the liquid and move upward in the center of the cavity. The underflow port of the upper cyclone is connected in series with the feed port of the lower cyclone to achieve particle size classification. This method can theoretically achieve high-efficiency particle size classification, but the separation accuracy is relatively low, there is a pressure drop in the device, there are restrictions on multi-continuous gradient classification, and it is difficult to achieve high-precision classification of particles.

[0010] Therefore, there is an urgent need in the art to develop a device for particle size classification that can simultaneously achieve high-precision classification of micron particles and coarse particles and complete multi-gradient fluidization synchronously. Summary of the Invention

[0011] Micron particles refer to particles with a particle size between 1 micron and 100 microns, and coarse particles refer to particles with a particle size between 100 microns and 1000 microns. The purpose of the present invention is to address the problems that existing particle size classification devices are difficult to achieve high-precision classification of micron particles and coarse particles, and it is difficult to synchronously complete multi-gradient fluidization. A new type of particle size classification device is provided, which only requires a single device to meet the process requirements of particle size classification of products and recrystallization of the recovery of fine particles remaining in the liquid. The combination of the jet sedimentation screening module and the self-priming cyclone screening module can classify the crystal particle size after the recrystallization process. The device can collect the fine grains that do not meet the product standard and return them to the crystallization reaction kettle for recrystallization. The jet sedimentation screening module consists of an inclined plate sedimentation tank with a sloping bottom and several openings and several intercepting inclined plates. It utilizes the principle that the trajectory of different particle sizes in the two-phase mixture jet is different during the horizontal projectile motion, and with the enhanced screening of the intercepting inclined plates, the rough separation of particles is achieved. The two-phase fluid is sucked by a diaphragm pump and enters the inclined plate sedimentation tank through the inlet of the inclined plate sedimentation tank from the mixing tank. The particles settle in the sedimentation pool at the bottom of the inclined plate sedimentation tank along with the jet, and the rough separation process ends after the settlement is completed. The number of self-priming cyclone screening modules is the same as the number of openings at the bottom of the inclined plate sedimentation tank in the jet sedimentation screening module. The self-priming cyclone screening module consists of a cyclone separator, a pre-sorting component, and a self-priming component. The outlet of the rough separation product sedimentation pool at the bottom of the inclined plate sedimentation tank is connected to the inlet of the self-priming component of the self-priming cyclone screening module. The inlet of the contraction tube of the self-priming component is connected to the outlet of the water pump. The outlet of the diffuser tube of the self-priming component is connected to the inlet of the pre-sorting device. The outlet of the pre-sorting device is connected to the tangential inlet of the cyclone separator. The overflow port and the underflow port of the cyclone separator are connected to the product collection tank. Its principle is to utilize the self-priming ability of the self-priming component to suck out the liquid-carrying particles roughly separated in the sedimentation pool at the bottom of the inclined plate sedimentation tank of the jet sedimentation module. After the grading effect is enhanced by the pre-sorting device, they enter the cyclone separator. By using the principle that different particle sizes in the centrifugal force field are discharged from the overflow port and the underflow port of the cyclone separator along the inner and outer swirls, the further high-precision classification of the roughly separated particles is achieved.

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

[0013] To achieve the fluidized screening of micron particles and coarse particles with multi-gradient precision classification, a combined technology of jet sedimentation screening and self-priming cyclone screening is adopted. The principle is to first achieve rough classification by using the principle that particles with different particle sizes in a two-phase mixture jet have different trajectories of horizontal projectile motion. Then, for the rough classification materials of single-stage jet sedimentation, a Venturi structure is used to enable the cyclone to obtain self-priming ability, and the swirling flow field strengthens the rotational motion behavior of granular materials to avoid agglomeration of fine particles and achieve refined classification of products of micron particles and coarse particles. In the jet sedimentation module, the length and width of the inclined plate sedimentation tank, the height and size of the two-phase inflow nozzle, the setting position, size and number of the intercepting inclined plates, and the position and number of the liquid-carrying rough classification product outlets are determined according to the production requirements of different products. The basis is the basic principle of jet sedimentation, and the principle is as follows:

[0014] When particles enter the tank body with the same initial velocity, particles with different particle sizes have different sedimentation trajectories and different landing distances. The factors affecting the particle landing points are the following parameters: particle sedimentation velocity V r , incident height h, flow rate Q, and incident cross-sectional size S.

[0015] According to Stokes' formula, the sedimentation velocity V of the particle r :

[0016]

[0017] The physical meanings of each item are as follows:

[0018] v r ——Particle sedimentation velocity

[0019] g——Local acceleration due to gravity

[0020] ρ w ——Particle density

[0021] ρ o ——Liquid density

[0022] D o ——Particle diameter

[0023] η——Viscosity coefficient of the liquid

[0024] k——Shape factor. For spherical particles, k = 0.222

[0025] From this, the sedimentation time t of the particle is obtained:

[0026]

[0027] The lateral flow velocity V of the particle x :

[0028]

[0029] The lateral flow distance S of the particles x :

[0030] S x = V x ·t

[0031] The idea of the present invention is to combine the above two methods. The jet sedimentation screening module consists of an inclined plate sedimentation tank and an intercepting inclined plate. The two-phase fluid enters the inclined plate sedimentation tank from one side of the inclined plate sedimentation tank. Since the sedimentation velocities of particles with different particle sizes are different and the initial velocities in the horizontal direction are the same, the movement trajectories of the particles in the jet are different. The intercepting inclined plate in the inclined plate sedimentation tank plays a role in strengthening the rough separation of particles, enhancing the separation effect, and effectively improving the particle size concentration of the rough separation products in each sedimentation pool at the bottom of the inclined plate sedimentation tank. The rough separation products of the jet sedimentation are led out from the sedimentation pools at the bottom of the inclined plate sedimentation tank, sucked into the self-priming cyclone screening module by the self-priming component of the self-priming cyclone screening module, and pre-sorted in the pre-sorting device of the self-priming cyclone screening module. The target products are led out from the overflow port of the cyclone separator, and the non-target products are introduced into the product collection tank through the underflow port of the cyclone classification component. A pre-sorting component is provided at the tangential inlet of the cyclone separator. After passing through the pre-sorting component, the particles on the flow channel cross-section are pre-sorted according to particle size, and then pass through the tangential inlet, so that the two-phase fluid swirls in the cyclone separator with an inverted cone structure. Under the action of the centrifugal force generated by the swirl, most of the liquid and particles with larger particle sizes will be thrown to the outer wall surface of the cyclone separator and move downward along the wall and are discharged from the underflow port of the lower cyclone separator. A small part of the liquid and particles with smaller particle sizes will converge towards the middle and move upward along the inner swirl direction and are discharged from the overflow port of the upper cyclone separator, thereby realizing a more refined particle size classification.

[0032] In summary, the combined action of the jet sedimentation screening module and the self-priming cyclone screening module can achieve rapid, stable, and efficient particle size classification and improve production efficiency.

[0033] First, the present invention provides a device for multi-gradient fluidized classification and screening of micron particles and coarse particles:

[0034] A device for multi-gradient fluidized classification and screening of micron particles and coarse particles, characterized in that the device includes a jet sedimentation module and a self-priming cyclone screening module:

[0035] The jet sedimentation module includes an inclined plate sedimentation tank with a liquid inlet on one side, an intercepting inclined plate inside the inclined plate sedimentation tank, and a rough separation product sedimentation pool at the bottom. The number of the rough separation product sedimentation pools is the same as the number of target classification particle size segments. A rough separation product outlet is provided at the bottom of the rough separation product sedimentation pool;

[0036] Each rough separation product sedimentation pool is connected to a self-priming cyclone screening module through the rough separation product outlet;

[0037] Each self-priming cyclone screening module includes a self-priming component, a pre-sorting component, and a cyclone separator. The self-priming component is a Venturi tube composed of a contraction tube, a straight tube, and a diffuser tube in sequence. The inlet of the contraction tube is the liquid-phase fluid inlet, and a feed port is provided on the straight tube and connected to the coarse separation product outlet; the pre-sorting component is a cylindrical barrel, with a solid cylinder axially arranged in the center of the barrel. The cylindrical section of the inlet pipe on one side is connected to the outlet of the diffuser tube of the self-priming component, and the rectangular section is connected to the cylindrical section of the inlet pipe and the barrel. The cylindrical discharge port of the outlet pipe on the other side is connected to the tangential inlet of the cyclone separator, and the rectangular section is connected to the cylindrical section of the outlet pipe and the barrel; the upper straight tube section of the cyclone separator has an overflow port, and the bottom of the lower inverted cone is provided with an underflow port. The overflow port and the underflow port are connected to the product collection tank.

[0038] Preferably, the length L of the inclined plate sedimentation tank c ranges from 1000 mm to 2000 mm, the height H ranges from 200 mm to 400 mm, the width W ranges from 200 mm to 400 mm, and the bottom inclination angle α ranges from 3° to 8°; the height H1 of the inlet of the inclined plate sedimentation tank is 0.55 - 0.85 times the height H of the inclined plate sedimentation tank, the diameter d1 of the inlet of the inclined plate sedimentation tank ranges from 15 mm to 40 mm, the number of intercepting inclined plates is the number of coarse separation product sedimentation tanks - 1, and the distance h from the top of each intercepting inclined plate to the upper end of the inclined plate sedimentation tank n is 0.2 - 0.5 times H1, and the angle β between each intercepting inclined plate and the bottom of the inclined plate sedimentation tank n ranges from 45° to 60°, and the distance b from the bottom of each intercepting inclined plate to the left wall surface of the inclined plate sedimentation tank n is 0.15 - 0.85 times the width W of the inclined plate sedimentation tank; the diameter D of the coarse separation product sedimentation tank a is 70 - 90% of the width W of the inclined plate sedimentation tank, the inclination angle γ of the coarse separation product sedimentation tank ranges from 45° to 60°, and the distance a from the center of each coarse separation product sedimentation tank to the left wall of the inclined plate sedimentation tank n is 0.15 - 0.85 times the width W of the inclined plate sedimentation tank.

[0039] Preferably, the diameter D of the straight tube section of the self-priming component in the self-priming cyclone screening module is equal to the diameter D0 of the feed port, and the length L of the straight tube section of the self-priming component x is approximately 2 - 3 times the diameter D of the straight tube section. The range of the inlet diameter D1 of the contraction tube is 20 - 50 mm, and the center angle α of the contraction tube x ranges from 15° to 25°. The outlet diameter D2 of the diffuser tube is equal to the tangential inlet diameter d of the cyclone separator i , and the center angle β of the diffuser tube x ranges from 5° to 10°.

[0040] Preferably, the diameter D3 of the barrel of the pre-sorting component in the self-priming cyclone screening module is the tangential inlet diameter d of the cyclone separatori Three times that, the diameter d of the inner solid cylinder part is 1 / 3 of the diameter D3 of the cylinder body; the height H2 of the pre-sorting component cylinder body is equal to the diameter D3 of the cylinder body; the area a of the rectangular section of the inlet pipe of the pre-sorting component x ×b x is equal to the cross-sectional area of the cylindrical section, and the length a of the rectangular section x is slightly larger than the width b of the rectangular section x .

[0041] Preferably, the diameter D4 of the straight pipe section of the hydrocyclone of the self-priming cyclone screening module ranges from 10 to 150 mm, the length H3 of the straight pipe section is 100-200% of D4, and the tangential inlet diameter d of the hydrocyclone i is 0.13-0.2 times the diameter D4; the diameter d of the overflow port o is 0.2-0.3 times the diameter D4 of the straight pipe section, and the depth h of the overflow port inserted into the cyclone x is 0.2-0.35 times D4; the cone angle θ of the hydrocyclone component ranges from 8 to 30°, and the diameter d of the underflow port s is 0.07-0.1 times D4.

[0042] The present invention also provides a method for multi-gradient fluidized classification screening of micron particles and coarse particles, which is characterized in that two-phase fluid is injected from the inlet of the inclined plate sedimentation tank, and the solid-phase particles perform a projectile motion. The intercepting inclined plates inside the inclined plate sedimentation tank intercept the solid particles in the fluid to strengthen the particle size concentration of the coarsely separated products. The coarsely separated products are continuously accumulated in the coarsely separated product sedimentation tank at the bottom. After the coarse separation is completed, the liquid-carrying coarsely separated products are sucked out through the coarsely separated product outlet, and are sucked into the self-priming cyclone screening module by the self-priming component for further fine separation of the coarsely separated products. The two-phase fluid flowing out of the self-priming component enters the pre-sorting component to reorganize the particle sequence. After particle size pre-sorting, it enters the hydrocyclone. Larger particles enter the outer vortex and are discharged to the underflow port, and smaller particles are discharged to the overflow port along with the inner vortex. The products of each target particle size segment are collected by each product collection tank.

[0043] The main advantages of the device of the present invention are as follows:

[0044] (1) In the jet sedimentation screening module of the present invention, compared with traditional gravity sedimentation, the advantages are that the jet flow velocity is faster, the flow rate is larger, it has stronger impact force and kinetic energy, and it can realize the projectile motion of solid-phase particles in the liquid phase in a two-phase mixed solution with a higher concentration. At the same time, the particle size range of the pre-screened particles is adjustable and large, and it can efficiently screen non-target particles of large sizes and extremely small sizes. The multi-stage fluidization synchronous operation also greatly improves the particle size classification efficiency. The intercepting inclined plates strengthen the classification effect of the pre-screened particles and improve the particle size concentration of the coarsely separated products in the sedimentation tank. The jet sedimentation screening module improves the separation efficiency and separation effect of the device, has strong control ability, and is highly applicable.

[0045] (2) The self-priming cyclone screening module in the present invention has the following advantages compared with the traditional cyclone classification technology. The self-priming component in the self-priming cyclone screening module can eliminate the step of collecting and transferring the coarsely separated particles to the stirring tank, and directly mix the coarsely separated particles with the liquid phase by self-priming before entering the cyclone separator. The pre-sorting component can achieve pre-sizing of the particles before entering the cyclone separator, reduce the flow surface, increase the cyclone flow velocity, and effectively promote the larger particles to enter the outer vortex and discharge from the bottom outlet of the cyclone separator, blocking the larger particles from discharging from the overflow outlet of the cyclone separator with the inner vortex, thus improving the particle size classification efficiency. The self-priming cyclone screening module improves the separation efficiency and separation effect of the device, can save manufacturing costs, and has great application potential.

[0046] (3) The technical coupling of the self-priming cyclone screening module and the jet sedimentation screening module in the present invention is not a simple series connection, but combines the two through a self-priming structure to achieve precise control of jet sedimentation screening and self-priming cyclone screening, with interlocking control functions such as self-priming speed control and feed flow control, greatly improving the particle size classification efficiency and accuracy. Only a single device is required to meet the process requirements, and no dynamic equipment support is needed. The manufacturing process is simple and the equipment maintenance is convenient, which can create considerable economic value for enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings are used to provide a further understanding of the present invention. They only form a part of this specification to further explain the present invention and do not constitute a limitation to the present invention.

[0048] In the drawings, the components are not necessarily drawn to actual scale.

[0049] Figure 1 It is a schematic structural diagram of the device of the present invention. Among them, the reference numerals represent the following devices and internal components respectively:

[0050] 1 Jet sedimentation screening module 2 Self-priming cyclone screening module 3 Stirring tank 4 Diaphragm pump 5 Product collection tank

[0051] Figure 2 It is a schematic process flow diagram of the device of the present invention.

[0052] Figure 3(a) is a schematic structural diagram of the jet sedimentation screening module in the device of the present invention. Among them, the reference numerals represent the following devices and internal components respectively:

[0053] 1-1 Jet inlet of inclined plate sedimentation tank 1-2 Intercepting inclined plate 1-3 Coarsely separated product sedimentation tank

[0054] Figure 3(b) is a front view of the jet sedimentation screening module in the device of the present invention. Among them, the reference numeral represents the dimension of the following part:

[0055] Lc —— The length of the inclined plate sedimentation tank

[0056] H —— The height of the inclined plate sedimentation tank

[0057] H1 —— The height of the inlet of the inclined plate sedimentation tank

[0058] d1 —— The diameter of the inlet of the inclined plate sedimentation tank

[0059] h n —— The distance from the top of each intercepting inclined plate to the upper end of the inclined plate sedimentation tank

[0060] a n —— The distance from the center of the sedimentation tank of each rough separation product to the left wall of the inclined plate sedimentation tank

[0061] α —— The bottom inclination angle of the inclined plate sedimentation tank

[0062] β n —— The angle between each intercepting inclined plate and the bottom of the inclined plate sedimentation tank

[0063] γ —— The inclination angle of the sedimentation tank of the rough separation product

[0064] Figure 3(c) is a top view of the jet sedimentation screening module in the device of the present invention. Among them, the reference numerals respectively represent the dimensions of the following parts:

[0065] W —— The width of the inclined plate sedimentation tank

[0066] b n —— The distance from the bottom of each intercepting inclined plate to the left wall surface of the inclined plate sedimentation tank

[0067] D a —— The diameter of the sedimentation tank of the rough separation product

[0068] Figure 4 is a schematic principle diagram of the internal jet sedimentation screening module in the device of the present invention. Among them, the black dots are particles, the larger the black dot, the larger the particle size, and the black dot connection line and arrow indicate the movement trajectory of the particles of this size in the module. Figure 5(a) is a structural schematic diagram of the self - suction cyclone screening module in the device of the present invention. Among them, the reference numerals respectively represent the following devices and internal components:

[0069] 2 - 1 Self - suction component 2 - 2 Pre - sorting component 2 - 3 Cyclone separator

[0070] Figure 5(b) is a structural schematic diagram of the cyclone separator of the self - suction cyclone screening module in the device of the present invention.

[0071] Among them, the reference numerals respectively represent the dimensions of the following parts:

[0072] D4 —— The diameter of the straight pipe section of the cyclone separator

[0073] H3——Length of the straight pipe section of the cyclone separator

[0074] d i ——Tangential inlet diameter of the cyclone separator

[0075] d o ——Overflow port diameter

[0076] h x ——Depth of the overflow port inserted into the cyclone

[0077] θ——Cone angle

[0078] d s ——Underflow port diameter

[0079] Figure 5(c) is a schematic structural diagram of the self-priming component of the self-priming cyclone screening module in the device of the present invention.

[0080] Figure 5(d) is a front view of the self-priming component of the self-priming cyclone screening module in the device of the present invention. Among them, the reference numerals represent the dimensions of the following parts respectively:

[0081] D——Diameter of the straight pipe section of the self-priming component

[0082] D1——Inlet diameter of the contraction pipe

[0083] D2——Outlet diameter of the diffuser pipe

[0084] α x ——Central angle of the contraction pipe

[0085] β x ——Central angle of the diffuser pipe

[0086] Figure 5(e) is a top view of the self-priming component of the self-priming cyclone screening module in the device of the present invention. Among them, the reference numerals represent the dimensions of the following parts respectively:

[0087] D0——Inlet diameter of the self-priming component

[0088] L x ——Length of the straight pipe section of the self-priming component

[0089] Figure 5(f) is a schematic structural diagram of the pre-sorting component of the self-priming cyclone screening module in the device of the present invention.

[0090] Figure 5(g) is a front view of the pre-sorting component of the self-priming cyclone screening module in the device of the present invention. Among them, the reference numerals represent the dimensions of the following parts respectively:

[0091] D3——Diameter of the cylinder of the pre-sorting component

[0092] H2——Height of the cylinder of the pre-sorting component

[0093] Figure 5(h) is the left view of the pre-sorting component of the self-priming cyclone screening module in the device of the present invention. Among them, the reference numerals respectively represent the dimensions of the following parts:

[0094] d——Diameter of the solid cylindrical part inside the pre-sorting component

[0095] a x ——Length of the rectangular section

[0096] b x ——Width of the rectangular section

[0097] Figure 6 is a schematic diagram of the principle of the cyclone separator of the self-priming cyclone screening module in the device of the present invention.

[0098] Figure 7 is a schematic diagram of the principle of the self-priming component of the self-priming cyclone screening module in the device of the present invention.

[0099] Figure 8 is a schematic diagram of the principle of the pre-sorting component of the self-priming cyclone screening module in the device of the present invention. Specific embodiments

[0100] The present invention will be further described below through examples and drawings.

[0101] In a preferred embodiment, the jet sedimentation screening module includes an inclined plate sedimentation tank and 2 intercepting inclined plates. The length of the inclined plate sedimentation tank is 1000 mm, including 3 groups of self-priming cyclone screening modules, and the target is divided into 3 particle sizes.

[0102] In another preferred embodiment, the jet sedimentation screening module includes an inclined plate sedimentation tank and 2 intercepting inclined plates. The length of the inclined plate sedimentation tank is 1500 mm, including 3 groups of self-priming cyclone screening modules, and the target is divided into 3 particle sizes.

[0103] In another preferred embodiment, the jet sedimentation screening module includes a sedimentation tank and 3 intercepting inclined plates. The length of the inclined plate sedimentation tank is 2000 mm, including 4 groups of self-priming cyclone screening modules, and the target is divided into 4 particle sizes.

[0104] The test methods without specific conditions in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, all percentages and parts are by weight.

[0105] Example 1:

[0106] A certain factory in Shaanxi Province uses the device of the present invention for particle size classification after recrystallization of potassium nitrate containing impurities. The particle size range of the potassium nitrate raw material is 75 - 350 μm. After mixing potassium nitrate with water, the solid content is about 5 - 10%, and the flow rate of the solid-liquid mixture is 1.5 t / h. The target is to obtain particles with sizes of 250 - 350 μm, 150 - 250 μm, and 75 - 150 μm.

[0107] Design parameters: The length L of the inclined plate sedimentation tank of the jet sedimentation screening module shown in Figure 3 is 1000 mm, the height H is 200 mm, the width W is 200 mm. The size of the inlet diameter d1 of the inclined plate sedimentation tank is 15 mm, the inlet height H1 is 170 mm, the bottom inclination angle α is 3°, the number of intercepting inclined plates is 2, and the diameter D of the coarse fraction product sedimentation tank a = 140 mm, and the bottom inclination angle γ of the coarse fraction product sedimentation tank is 45°. The distance a1 from the center of the first coarse fraction product sedimentation tank to the left wall of the inclined plate sedimentation tank is 160 mm, the distance h1 from the top of the first intercepting inclined plate to the upper end of the inclined plate sedimentation tank is 40 mm, the angle β1 between the first intercepting inclined plate and the bottom of the inclined plate sedimentation tank is 60°, and the distance b1 from the bottom of the first intercepting inclined plate to the left side wall surface of the inclined plate sedimentation tank is 230 mm; the distance a2 from the center of the second coarse fraction product sedimentation tank to the left wall of the inclined plate sedimentation tank is 500 mm, the distance h2 from the top of the second intercepting inclined plate to the upper end of the inclined plate sedimentation tank is 80 mm, the angle β2 between the second intercepting inclined plate and the bottom of the inclined plate sedimentation tank is 45°, and the distance b2 from the bottom of the second intercepting inclined plate to the left side wall surface of the inclined plate sedimentation tank is 570 mm; the distance a3 from the center of the third coarse fraction product sedimentation tank to the left wall of the inclined plate sedimentation tank is 850 mm. The number of self-priming cyclone screening modules shown in Figure 5 is 3. Among them, the straight pipe section diameters D4 of the cyclone separators are 100, 125, and 150 mm respectively, and the cone angles θ are 15°, 20°, and 20° respectively. The length H3 of the straight pipe section of the cyclone separator is twice the straight pipe section diameter D4 of the cyclone separator, and the tangential inlet diameter d of the cyclone separator i is 0.13 times the straight pipe section diameter D4. The size of the overflow port diameter d o is 0.2 times the straight pipe section diameter D4, and the depth h at which the overflow port is inserted into the cyclone is x 0.2 times the straight pipe section diameter D4. The size of the underflow port diameter d s is 0.07 times the straight pipe section diameter D4. The straight pipe section diameters D of the straight pipe sections of the self-priming components of the self-priming cyclone screening module and the size of the feed port diameter D0 are both 10 mm, and the length L of the straight pipe section x is about twice the straight pipe section diameter D. The size of the inlet diameter D1 of the contraction pipe is 25 mm, and the center angle α x of the contraction pipe is 15°. The size of the outlet diameter D2 of the diffuser pipe is the same as the tangential inlet diameter d of the cyclone separator i , and the center angle β xThe size is 5°. The cylinder diameter D3 of the pre-sorting component of the self-priming cyclone screening module is 3 times the tangential inlet diameter d of the cyclone separator in the self-priming cyclone screening module, and the diameter d of the internal solid cylinder part is 1 / 3 of the cylinder diameter D3. The cylinder height H2 of the pre-sorting component is equal to the cylinder diameter D3. The area a i of the rectangular section x ×b x is approximately equal to the cross-sectional area of the cylindrical section, and the length a x of the rectangular section is slightly larger than the width b x of the rectangular section.

[0108] Application effect: After being processed by the device of the present invention, the yield of particles with a size of 250 - 180 μm is 95%, the yield of particles with a size of 180 - 100 μm is 90%, and the yield of particles with a size of 100 - 50 μm is 90%.

[0109] Example 2:

[0110] A certain factory in Hubei Province uses the device of the present invention for particle size classification after recrystallization of potassium nitrate containing impurities. The particle size range of the potassium nitrate raw material is 70 - 250 μm. After potassium nitrate is mixed with water, the solid content is about 5 - 10%, and the flow rate of the solid-liquid mixture is 2 t / h. The target is to obtain particles with sizes of 180 - 250 μm, 100 - 180 μm, and 50 - 100 μm.

[0111] Design parameters: As shown in Figure 3, the length L of the inclined plate sedimentation tank of the jet sedimentation screening module is 1500 mm, the height H is 300 mm, the width W is 300 mm, the size of the inlet diameter d1 of the inclined plate sedimentation tank is 25 mm, the inlet height H1 is 260 mm, the bottom inclination angle α is 5°, the number of intercepting inclined plates is 2, and the diameter D of the rough separation product sedimentation tank a= 240 mm, the bottom inclination angle γ of the first-stage product sedimentation tank is 45°. The distance a1 from the center of the first-stage product sedimentation tank to the left wall of the inclined plate sedimentation tank is 250 mm, the distance h1 from the top of the first intercepting inclined plate to the upper end of the inclined plate sedimentation tank is 60 mm, the angle β1 between the first intercepting inclined plate and the bottom of the inclined plate sedimentation tank is 60°, and the distance b1 from the first intercepting inclined plate to the left wall surface of the inclined plate sedimentation tank is 370 mm; the distance a2 from the center of the second-stage product sedimentation tank to the left wall of the inclined plate sedimentation tank is 750 mm, the distance h2 from the top of the second intercepting inclined plate to the upper end of the inclined plate sedimentation tank is 130 mm, the angle β2 between the second intercepting inclined plate and the bottom of the inclined plate sedimentation tank is 45°, and the distance b2 from the second intercepting inclined plate to the left wall surface of the inclined plate sedimentation tank is 870 mm; the distance a3 from the center of the third-stage product sedimentation tank to the left wall of the inclined plate sedimentation tank is 1300 mm. The number of self-priming cyclone screening modules shown in Figure 5 is 3, where the straight pipe section diameters D4 of the cyclone separators are 75, 100, and 125 mm respectively, and the cone angles θ are 15°, 20°, and 20° respectively. The length H of the straight pipe section of the cyclone separator is 2 times the straight pipe section diameter D4 of the cyclone separator, and the tangential inlet diameter d i of the cyclone separator is 0.15 times the straight pipe section diameter D4. The overflow port diameter d o is 0.25 times the straight pipe section diameter D4, and the depth h x of the overflow port inserted into the cyclone is 0.3 times the straight pipe section diameter D4. The underflow port diameter d s is 0.08 times the straight pipe section diameter D4. The straight pipe section diameters D of the self-priming components of the self-priming cyclone screening module and the feed port diameter D0 are both 10 mm, and the straight pipe section length L x is approximately 2.5 times D. The inlet diameter D1 of the contraction pipe is 32 mm, and the center angle α x of the contraction pipe is 20°. The outlet diameter D2 of the diffuser pipe is the same as the tangential inlet diameter d i of the cyclone separator, and the center angle β x of the diffuser pipe is 8°. The cylinder diameter D3 of the pre-sorting component of the self-priming cyclone screening module is 3 times the tangential inlet diameter d i of the cyclone separator in the self-priming cyclone screening module, and the diameter d of the internal solid cylinder part is 1 / 3 of the cylinder diameter D3. The height H2 of the pre-sorting component is equal to the cylinder diameter D3. The area a x ×b x of the rectangular section is approximately equal to the cross-sectional area of the cylindrical section, and the length a x of the rectangular section is slightly larger than the width b x of the rectangular section.

[0112] Application effect: After being processed by the device of the present invention, the yield of particles with a size of 180 - 250 μm is 95%, the yield of particles with a size of 100 - 180 μm is 95%, and the yield of particles with a size of 50 - 180 μm is 90%.

[0113] Example 3:

[0114] A certain factory in Shanghai uses the device of the present invention to perform particle size classification on recrystallized potassium nitrate containing impurities. The particle size range of the potassium nitrate raw material is 40 - 300 μm. After potassium nitrate is mixed with water, the solid content is about 5 - 10%, and the flow rate of the solid - liquid mixture is 4 t / h. The target is to obtain particles with sizes of 200 - 300 μm, 130 - 200 μm, 70 - 130 μm, and 40 - 70 μm.

[0115] Design parameters: The length L of the inclined - plate sedimentation tank of the jet - sedimentation screening module shown in Figure 3 is 2000 mm, the height H is 400 mm, the width W is 400 mm. The size of the inlet diameter d1 of the inclined - plate sedimentation tank is 32 mm, the inlet height H1 is 340 mm, the bottom inclination angle α is 8°, the number of intercepting inclined plates is 3, and the diameter D a of the coarse - fraction product sedimentation tank is 360 mm, and the bottom inclination angle γ of the coarse - fraction product sedimentation tank is 45°. The distance a1 from the center of the first coarse - fraction product sedimentation tank to the left wall of the inclined - plate sedimentation tank is 250 mm, the angle β1 between the first intercepting inclined plate and the bottom of the inclined - plate sedimentation tank is 60°, and the distance b1 from the first intercepting inclined plate to the left - hand side wall surface of the inclined - plate sedimentation tank is 430 mm; the distance a2 from the center of the second coarse - fraction product sedimentation tank to the left wall of the inclined - plate sedimentation tank is 750 mm, the distance h2 from the top of the second intercepting inclined plate to the upper end of the inclined - plate sedimentation tank is 100 mm, the angle β2 between the second intercepting inclined plate and the bottom of the inclined - plate sedimentation tank is 50°, and the distance b2 from the second intercepting inclined plate to the left - hand side wall surface of the inclined - plate sedimentation tank is 930 mm; the distance a3 from the center of the third coarse - fraction product sedimentation tank to the left wall of the inclined - plate sedimentation tank is 1250 mm, the distance h3 from the top of the third intercepting inclined plate to the upper end of the inclined - plate sedimentation tank is 170 mm, the angle β2 between the third intercepting inclined plate and the bottom of the inclined - plate sedimentation tank is 45°, and the distance b3 from the third intercepting inclined plate to the left - hand side wall surface of the inclined - plate sedimentation tank is 1430 mm; the distance a4 from the center of the fourth coarse - fraction product sedimentation tank to the left wall of the inclined - plate sedimentation tank is 1750 mm. The number of self - suction cyclone screening modules shown in Figure 5 is 4. Among them, the straight - pipe section diameter D4 of the cyclone separator and the cone angle θ are 15°, 15°, 20°, and 20° respectively. The length H of the straight - pipe section of the cyclone separator is 2 times the straight - pipe section diameter D4 of the cyclone separator, and the tangential inlet diameter d i of the cyclone separator is 0.2 times the straight - pipe section diameter D4. The overflow - port diameter d o is 0.3 times the straight - pipe section diameter D4, and the depth h x of the overflow port inserted into the cyclone is 0.35 times the straight - pipe section diameter D4. The underflow - port diameter ds Its size is 0.1 times the diameter D4 of the straight pipe section. The diameters D of the straight pipe section and D0 of the feed inlet of the self-priming component of the self-priming cyclone screening module are both 15 mm, and the length L of the straight pipe section x is approximately 3 times D. The inlet diameter D1 of the contraction pipe is 40 mm, the central angle α of the contraction pipe is 25°, and the outlet diameter D2 of the diffuser pipe is the same as the tangential inlet diameter d of the cyclone separator i in size. The central angle β of the diffuser pipe is 10°. The cylinder diameter D3 of the pre-sorting component of the self-priming cyclone screening module is 3 times the tangential inlet diameter d of the cyclone separator in the self-priming cyclone screening module i . The diameter d of the internal solid cylinder part is 1 / 3 of the cylinder diameter D3. The height H2 of the pre-sorting component is equal to the cylinder diameter D3. The area a x ×b x of the rectangular section is approximately equal to the cross-sectional area of the cylindrical section, and the length a x of the rectangular section is slightly larger than the width b x .

[0116] Application effect: After being processed by the device of the present invention, the yield of particles with a size of 200 - 300 μm is 95%, the yield of particles with a size of 120 - 200 μm is 95%, the yield of particles with a size of 70 - 130 μm is 90%, and the yield of particles with a size of 40 - 70 μm is 90%.

[0117] The above-listed embodiments are only preferred embodiments of the present invention and are not used to limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made according to the content of the scope of this patent application should fall within the technical scope of the present invention.

[0118] All the documents mentioned in the present invention are cited as references in this application, just as if each document is cited separately as a reference. In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A device for multi-gradient fluidized classification and screening of micron particles and coarse particles, characterized in that: The device comprises a jet settling module and a self-priming cyclone screening module: The jet sedimentation module comprises an inclined plate sedimentation tank with a liquid inlet on one side, an intercepting inclined plate inside the inclined plate sedimentation tank, a coarse product sedimentation tank at the bottom, the number of which is consistent with the number of target classification particle size segments, and a coarse product outlet at the bottom of the coarse product sedimentation tank; Each coarse product settling tank is connected to a self-priming cyclone screening module via a coarse product outlet; Each self-priming cyclone screening module includes a self-priming component, a pre-sorting component and a cyclone separator. The self-priming component is a venturi tube which is composed of a contraction tube, a straight tube and a diffusion tube in sequence. The inlet of the contraction tube is the inlet of the liquid fluid, and a feed port is arranged on the straight tube to be connected with the outlet of the coarse product; the pre-sorting component is a cylindrical barrel, a solid cylinder is arranged axially in the center of the barrel, the cylindrical section of the inlet pipe on one side is connected with the diffusion pipe outlet of the self-priming component, the rectangular section connects the cylindrical section of the inlet pipe and the barrel, the cylindrical discharge port of the outlet pipe on the other side is connected with the tangential inlet of the cyclone separator, and the rectangular section connects the cylindrical section of the outlet pipe and the barrel; the upper straight pipe section of the cyclone separator has an overflow port, and the bottom end of the lower inverted cone is provided with an underflow port, and the overflow port and the underflow port are connected to the product collection tank.

2. The grading and screening device according to claim 1, characterized in that: The length L of the inclined plate sedimentation tank c The range is 1000mm-2000mm, the height H range is 200mm-400mm, the width W range is 200mm-400mm, and the bottom inclination angle α ranges from 3-8°; the inlet height H1 of the inclined plate sedimentation trough is 0.55-0.85 times the height H of the inclined plate sedimentation trough, the inlet diameter d1 of the inclined plate sedimentation trough ranges from 15-40mm, the number of intercepting inclined plates is the number of coarse product sedimentation tanks - 1, and the distance h from the top of each intercepting inclined plate to the upper end of the inclined plate sedimentation trough n The angle β between each intercepting inclined plate and the bottom of the inclined plate sedimentation tank is 0.2-0.5 times of H1. n The range is 45°-60°, and the distance b from the bottom of each intercepting inclined plate to the left wall of the inclined plate sedimentation tank is n The diameter D of the coarse product sedimentation tank is 0.15-0.85 times the width W of the inclined plate sedimentation tank; a The bottom inclination angle γ of the coarse product sedimentation tank is in the range of 45°-60°, and the distance a from the center of each coarse product sedimentation tank to the left wall of the inclined plate sedimentation tank is n It is 0.15-0.85 times the width W of the inclined plate sedimentation tank.

3. The grading and screening device according to claim 1, characterized in that: The straight pipe section diameter D of the self-priming component in the self-priming cyclone screening module is equal to the feed port diameter D0, and the length of the straight pipe section of the self-priming component is L x It is about 2-3 times the diameter D of the straight pipe section. The inlet diameter D1 of the shrink tube is in the range of 20-50mm. The center angle of the shrink tube is α x The range is 15-25°, the diffuser outlet diameter D2 and the tangential inlet diameter d of the cyclone separator i Equal, the diffuser center angle β x The range is 5-10°.

4. The grading and screening device according to claim 1, characterized in that: The cylinder diameter D3 of the pre-sorting component in the self-priming cyclone screening module is the tangential inlet diameter d of the cyclone separator. i The diameter d of the inner solid cylindrical part is 1 / 3 of the cylinder diameter D3; the cylinder height H2 of the pre-sorting component is equal to the cylinder diameter D3; the rectangular section area a of the inlet pipe of the pre-sorting component x ×b x is equal to the cross-sectional area of ​​the cylindrical segment, and the length of the rectangular segment is a x Slightly larger than the width of the rectangular segment b x .

5. The grading and screening device according to claim 1, characterized in that: The diameter D4 of the straight pipe section of the cyclone separator of the self-priming cyclone screening module is in the range of 10-150 mm, the length H3 of the straight pipe section is 100-200% of D4, and the tangential inlet diameter d of the cyclone separator is i The overflow port diameter d is 0.13-0.2 times of the diameter D4; o The size is 0.2-0.3 times the diameter of the straight pipe section D4, and the overflow port is inserted into the cyclone to a depth of h x It is 0.2-0.35 times of D4; the cone angle θ of the cyclone separator assembly ranges from 8-30°, and the bottom flow port diameter d s The size is 0.07-0.1 times that of D4.

6. A method for multi-gradient fluidized classification and screening of micron particles and coarse particles, characterized in that: The two-phase fluid is injected into the inclined plate sedimentation trough from the inlet, and the solid phase particles move in a projectile motion. The intercepting inclined plate inside the inclined plate sedimentation trough intercepts the solid particles in the fluid to enhance the particle size concentration of the coarse product. The coarse product is continuously accumulated in the coarse product sedimentation tank at the bottom. After the coarse separation is completed, the liquid coarse product is sucked out and sucked into the self-priming component into the self-priming cyclone screening module for further fine separation of the coarse product. The two-phase fluid flowing out of the self-priming component enters the pre-sorting component to reorganize the particle sequence, and enters the cyclone separator after particle size pre-sorting. The larger particles enter the external cyclone and are discharged to the bottom flow port, and the smaller particles are discharged to the overflow port with the internal cyclone. The products of each target particle size segment are collected by each product collection tank.

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