Classified screening device and method for hollow glass beads

Abstract

The invention relates to the technical field of floating and sinking separation, in particular to a hollow glass bead classification screening device and method. The invention provides a brand-new classification screening device for hollow glass beads. The hollow glass beads are put to the upstream side of the sorting pool, the hollow glass beads are gradually layered in water flow due to different buoyancy in the process of flowing along with the water flow, the hollow glass beads mixed in water flow respectively flow out through outflow ports corresponding to different water layers at different heights, and classified screening of different particle sizes is achieved after dehydration. The grading screening device not only can realize particle size grading, effectively control particle size distribution and narrow the particle size distribution interval, but also can sort out superfine hollow glass beads, and improves the grading precision.

Description

Technical Field

[0001] The invention relates to the technical field of separation by floating and sinking, and in particular to a hollow glass microbead grading and screening device and method. Background Art

[0002] Hollow glass microspheres are also called hollow glass microspheres. They are micron-sized hollow glass microspheres with smooth surfaces. They are also inorganic non-metallic powder materials with a true density of 0.1-0.8 g / cm 3 . The particle size of hollow glass microspheres is positively distributed from 1μm to 200μm, with a wide particle size distribution range and a large span between particle sizes D10 and D90. Some application industries require that the particle size distribution range of powder materials is relatively small and the particle size distribution is relatively concentrated. Excessive particle size distribution restricts the application of hollow glass microspheres in high-tech industries. Particle size classification is an effective way to narrow the particle size distribution range and reduce the span between D10 and D90. It is necessary to classify the hollow glass microspheres by particle size.

[0003] At present, the mainstream methods of micro-powder particle size classification are divided into dry and wet processes. Since hollow glass microspheres are hollow, thin-walled, and low-density, their dry classification mainly includes screen classification and airflow classification. However, dry classification has the following disadvantages: first, it is easy to cause air pollution, and second, the classification accuracy is not high. In addition, due to the hollow and thin-walled characteristics of hollow glass microspheres, the high-speed rotation and cutting of the classification disk during the classification process of the airflow classifier will cause a large number of hollow glass microspheres to break.

[0004] The wet classification process mainly uses classification equipment represented by cyclones, and its working principle is centrifugal sedimentation. For example, for the classification of mineral powder: after the mixed liquid containing two-phase (or three-phase) substances enters the cyclone from the tangential direction of the feed port at a certain pressure, a strong three-dimensional elliptical strong cyclonic flow is generated. Due to the difference in particle size and quality between coarse particles (or heavy phase) and fine particles (or light phase), most of the coarse particles spiral down to the bottom under the action of gravity, centrifugal force, fluid resistance, etc., and are discharged from the sand settling port as sediment. The fine particles form an inner spiral mineral flow in the center, move upward with the water flow, and are discharged from the overflow pipe as overflow. This method is only suitable for the classification of heavy powder particles such as mineral powder, and the classification accuracy is not high. The density of hollow glass microspheres is low, so this method is not suitable.

[0005] Existing classification methods all use centrifugal force to achieve particle size classification, and can only perform rough and broad classification, with the particle size distribution range usually above 30μm. It is difficult to achieve effective classification for particle size distribution ranges below 30μm, or even below 20μm or below 10μm; in addition, the production efficiency is low, and for screen classification, it is difficult to clean the screen, resulting in great production difficulties and no industrial production conditions.

[0006] With the development of high-tech and new materials industries, higher and higher requirements are put forward for hollow glass microspheres, which require not only comprehensive performance indicators such as density and particle size, but also further require the particle size distribution range. The classification of hollow glass microspheres has become an important topic in the application of hollow glass microspheres, and the research on hollow glass microsphere classification technology and equipment is very necessary. Summary of the invention

[0007] The purpose of the present invention is to provide a hollow glass microsphere grading and screening device to solve the problem that the existing grading method has low grading accuracy for hollow glass microspheres, especially hollow glass microspheres with ultra-fine particle sizes. At the same time, the purpose of the present invention is also to provide a hollow glass microsphere grading and screening method to solve the same problem.

[0008] The hollow glass microbead grading and screening device of the present invention comprises a sorting tank and a dehydration device, wherein the side of the sorting tank provided with a water injection port is the upstream side, and the downstream side of the sorting tank is provided with different outflow ports in the up and down directions, respectively, and each outflow port is connected to a water delivery pipeline for delivering slurry flowing out of the sorting tank to the dehydration device, and the hollow glass microbeads dropped into the sorting tank from the bottom of the upstream side are gradually stratified in the water flow due to different buoyancy during the flow of the water flow, and flow out through different outflow ports respectively, and achieve grading and screening of different particle sizes after dehydration.

[0009] Furthermore, the grading and screening device also includes a pulping device for making powdered hollow glass microbeads and water into a slurry. The discharge port of the pulping device is connected to a delivery pipeline, and the outlet of the delivery pipeline is located at the bottom of the upstream side of the sorting tank and constitutes a delivery port.

[0010] Furthermore, the outflow opening is in the shape of a horizontally extending long strip, and the outflow openings are arranged in layers in the up and down directions.

[0011] Furthermore, the outflow port is a closing structure whose height gradually decreases along the outflow direction.

[0012] Furthermore, an adjustment plate rotatably arranged around a horizontal axis is hinged between adjacent flow outlets, and the adjustment plate adjusts different pitch angles to adjust the water layer heights corresponding to two adjacent flow outlets.

[0013] Furthermore, the dehydration device is a scraper-type centrifugal dehydrator.

[0014] Furthermore, a circulating water channel is provided between the water outlet of the dehydration device and the water inlet of the separation tank, so that the water separated by the dehydration device can be used for re-slurrying.

[0015] Furthermore, a circulating water channel is provided between the water outlet of the dewatering device and the pulping device, so that the water separated by the dewatering device can be used for pulping again.

[0016] Furthermore, the circulating water circuit includes a water reservoir, a circulating pipe and a circulating pump.

[0017] The present invention provides a new hollow glass microbead grading and screening device. Hollow glass microbeads are placed on the upstream side of a sorting pool. As the hollow glass microbeads flow with the water, they are gradually stratified in the water flow due to different buoyancy. The hollow glass microbeads mixed in the water flow out through outlets at different heights corresponding to different water layers, and grading and screening of different particle sizes are achieved after dehydration. This grading and screening device can not only achieve particle size grading, effectively control particle size distribution, and narrow the particle size distribution range, but also can sort out ultrafine hollow glass microbeads, thereby improving grading accuracy.

[0018] The hollow glass microsphere classification and screening method of the present invention comprises the steps of putting hollow glass microspheres into water, wherein microspheres of different particle sizes have different densities and different floating speeds, collecting water with microspheres suspended in different water layer depths, and then dehydrating the water to obtain microspheres of different particle sizes.

[0019] Furthermore, the powdered hollow glass microspheres and water are first made into a slurry, and then the microsphere slurry is put into water for subsequent classification and screening.

[0020] Furthermore, the hollow glass microbeads are placed in a water flow with a stable flow rate, and water at different water layer depths is collected on the downstream side of the water flow and transported to different dehydration devices for dehydration.

[0021] The hollow glass microbead grading and screening method of the present invention is to place the microbeads into water, utilize the different floating speeds to be in different water layer depths within a certain period of time, collect the water with microbeads suspended in different water layer depths, and then dehydrate to obtain microbeads of different particle sizes. This grading and screening device can not only realize particle size classification, effectively control particle size distribution, and narrow the particle size distribution range, but also sort out ultrafine hollow glass microbeads, thereby improving the classification accuracy. The grading medium (water) of the buoyancy classification method can be recycled to reduce environmental pollution and achieve the purpose of green production. In addition, the grading process does not use a screen, and there is no problem of screen cleaning, which can reduce the difficulty of production, improve production efficiency, and is simple to operate and easy to realize industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a simplified structural diagram of the hollow glass microbead grading and screening device of the present invention.

[0023] In the figure: 1. pulping device; 2. water injection port; 3. delivery port; 4. sorting tank; 5. regulating plate; 8. outflow port; 9. control valve; 12. water pipeline; 16. scraper-type centrifugal dehydrator; 17. water outlet; 21. water reservoir; 22. circulation pump; 23. pulp delivery pump. DETAILED DESCRIPTION

[0024] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0025] Hollow glass microspheres are powder materials, which are composed of many hollow microsphere particles with different densities and particle sizes. The density of particles is related to the particle size. Generally, the smaller the particle size, the greater the density of the particle. Conversely, the larger the particle size, the smaller the density of the particle. When hollow glass microspheres enter water, they are subject to two opposite forces in the vertical direction: gravity and buoyancy. Since the true density of hollow glass microspheres is 0.1-0.8g / cm 3 , and the density of water is 1.0 g / cm 3 The density of hollow glass microspheres is less than the density of water, that is, the buoyancy of hollow glass microspheres is greater than their gravity. The smaller the particle size, the smaller the volume of the particle, and the smaller the buoyancy in the water. Therefore, the smaller the particle size, the smaller the comprehensive force in the vertical direction (buoyancy minus gravity), resulting in the slower floating of particles with smaller particle size. For example, for microsphere particles of the same mass, small particles have small buoyancy, and their comprehensive force in water is small, so they float slowly; large particles have large buoyancy, and their comprehensive force in water (buoyancy minus gravity) is large, so they float quickly.

[0026] Utilizing the above rules, the hollow glass microbead grading and screening device of the present invention is provided with a sorting pool, so that the hollow glass microbeads are put into the sorting pool and flow with the water flow in the sorting pool. In the process of flowing with the water flow, the hollow glass microbeads are gradually stratified in the water flow due to different buoyancy. Different outflow ports are respectively arranged in the up and down directions on the downstream side of the sorting pool, and these outflow ports correspond to water layers at different heights. Then, after the hollow glass microbeads flowing with the water flow reach the downstream side, the particle sizes of the hollow glass microbeads in the slurry flowing out of different outflow ports are naturally different. The slurry flowing out of different outflow ports is dehydrated to obtain hollow glass microbeads with different particle sizes, thereby realizing the grading and screening of the hollow glass microbeads.

[0027] The hollow glass microsphere grading and screening device of the present invention can effectively achieve high-precision particle size classification through buoyancy classification, and realize the collection of particle size distribution range below 10 μm or even below 5 μm. For ultrafine powders, effective classification can also be performed. At the same time, the powder can be graded in multiple stages at one time, greatly improving the classification efficiency. Moreover, the entire classification process does not have a high-speed and high-pressure process, avoiding the breakage of the hollow glass microspheres and adversely affecting their yield.

[0028] Based on the above concept, the present invention further provides a variety of different embodiments for illustration.

[0029] In one embodiment, if Figure 1As shown, the hollow glass microbead grading and screening device includes a sorting pool 4 and a dehydration device. The sorting pool 4 can be a common rectangular water pool, or it can be set to an L shape or a U shape according to the actual site needs. Taking the rectangular water pool as an example, one end of the sorting pool 4 is provided with a water injection port 2, and the other end is provided with an outflow port 8. When water is injected into the sorting pool 4 through the water injection port 2, the water naturally flows to the other end, so the end where the water injection port 2 is located is the upstream side, and the end where the outflow port 8 is located is the downstream side. There are multiple outflow ports 8 arranged on the downstream side of the sorting pool 4, and they are arranged in the up and down directions, corresponding to water layers of different depths. Each outflow port 8 is connected to a water supply pipeline 12 for transporting the slurry flowing out of the sorting pool 4 to the dehydration device. The hollow glass microbeads placed in the sorting pool 4 from the upstream side gradually stratify in the water flow due to different buoyancy during the flow of the water flow, and flow out through different outflow ports 8 respectively, and achieve grading and screening of different particle sizes after dehydration.

[0030] On the basis of the above embodiments, in one embodiment, the sorting pool 4 is further provided with a delivery port 3 for delivering hollow glass microbeads on the upstream side. For example, a funnel-shaped discharge hopper can be used to deliver microbeads into the sorting pool 4 through the funnel-shaped discharge hopper, and the lower end outlet of the funnel-shaped discharge hopper is the delivery port 3.

[0031] Since the buoyancy of hollow glass microbeads is greater than their gravity, they will float upward after being put into water. Therefore, in order to better stratify the microbeads in water according to their different particle sizes, the introduction port 3 is preferably set on the upstream side of the sorting pool 4 near the bottom.

[0032] On the basis of the above-mentioned embodiments, in one embodiment, the body-shaped micro-beads can be directly put into the sorting pool 4. In a preferred embodiment, in order to avoid uneven putting of the powdered micro-beads in the process of putting them into the water, and the existence of agglomeration after being put into the water, and the inability to quickly disperse and suspend in the water layer, the grading and screening device also includes a pulping device 1, which is used to stir the powdered hollow glass micro-beads and water into a slurry state, and the discharge port of the pulping device 1 is connected to a putting pipeline, and a slurry pump 23 is connected in series to the putting pipeline, and the outlet of the putting pipeline is at the bottom of the upstream side of the sorting pool 4 and constitutes the above-mentioned putting port 3. The micro-beads and water can be mixed uniformly in advance by the pulping device 1, so that the putting speed can be controlled by controlling the flow rate of slurry injected into the sorting pool 4, and after the prepared slurry is put into the sorting pool 4, the micro-beads can naturally float up and disperse into different height layers of the water flow.

[0033] On the basis of the above-mentioned embodiments, in one embodiment, the outflow port 8 is a plurality of rows of conical holes arranged on the pool wall of the sorting pool 4, each row of conical holes is arranged horizontally, different rows of conical holes are layered up and down, and the rear end of each row of conical holes converges into the same water pipeline 12. In another embodiment, the outflow port 8 is a horizontally extending long strip, and a plurality of long strip outflow ports 8 are arranged at one time in the up and down directions. The outflow port 8 can be formed by directly opening a long groove on the pool wall, or independently manufacturing a long groove-shaped outflow port 8 and installing it on the pool wall. The long groove includes horizontal groove walls opposite to each other, vertical groove walls at both ends connecting the upper and lower horizontal groove walls, and a rear end groove wall on the downstream side, and an outlet is provided on the rear end groove wall, and the outlet is connected to the water pipeline 12.

[0034] The upper and lower opposite transverse groove walls can be arranged in parallel, that is, the height of the outflow port 8 along the outflow direction remains unchanged. In order to facilitate the smooth outflow of the water flow of the mixed microbeads in the sorting tank 4, the outflow port 8 is a closing structure with a gradually decreasing height along the outflow direction, and the size of the small end of the closing is equivalent to the caliber of the water delivery pipeline 12. In practical applications, a control valve 9 can be installed at the front end of the water delivery pipeline 12 to control the opening and closing.

[0035] On the basis of the above embodiment, in a preferred embodiment, an adjustment plate 5 is hinged between adjacent outflow ports 8 and is arranged to rotate around a horizontal axis, and the adjustment plate 5 adjusts different pitch angles to adjust the water layer heights corresponding to two adjacent outflow ports 8. By changing the number of layers of the outflow ports 8 arranged in the up and down directions, a rough adjustment of the particle size range for graded screening can be achieved, and the setting of the adjustment plate 5 can fine-tune the particle size range for graded screening, making the graded screening more refined.

[0036] On the basis of the above-mentioned embodiment, the dehydration device may be a filtering dehydration device or a centrifugal dehydration device. In one embodiment, a scraper-type centrifugal dehydrator 16 is used.

[0037] On the basis of the above-mentioned embodiments, in an optimized embodiment, in order to realize green production and reduce the waste of water resources, a circulating water circuit is provided between the water outlet 17 of the dehydration device and the water inlet 2 of the sorting tank 4, so that the water separated by the dehydration device can be used for pulping, or a circulating water circuit is provided between the water outlet 17 of the dehydration device and the pulping device 1, so that the water separated by the dehydration device can be used for pulping. The circulating water circuit can be a circulating water pipe directly connecting the water outlet 17 of the dehydration device and the sorting tank 4 / pulping device 1, and a circulating pump 22 is connected in series to the circulating water pipe, or the circulating water circuit includes a water reservoir 21, a circulating pipe and a circulating pump 22, and the water outlet 17 of the dehydration device is provided corresponding to the water reservoir 21, and the water discharged from the dehydration device flows into the water reservoir 21, and is sent to the sorting tank 4 and the pulping device 1 through the circulating pipe and the circulating pump 22. Since there are multiple dehydration devices, the water outlets 17 of the multiple dehydration devices can be merged into a pipeline and discharged into the water reservoir 21 through the water outlets 17 of the pipeline.

[0038] The hollow glass microbead grading and screening device of the present invention may be used in the following different situations: The first implementation: Add 5 cubic meters of water to the pulping device and select HL20 specification (density 0.2 g / cm 3 ) is added to the pulping device for pulping, and then the circulation pump 2, control valve 9, and scraper centrifugal dehydrator are turned on in sequence. The water flow rate in the sorting tank is adjusted to 0.5 m / s through the circulation pump, and the slurry pump is turned on to allow the slurry to enter the sorting tank at a uniform speed of 2 cubic meters per hour. The test data when all the adjustment plates are in the horizontal position are as follows (where D10, D50, and D90 are the three parameters of particle size distribution respectively): When the adjustment plate at the bottom layer tilts upward by 15 degrees, the water layer that can be collected by the outlet at the bottom layer becomes higher, and the particle size of the collected material will float upward. The actual test results are as follows: The adjustment plate at the bottom layer is adjusted upward by 15 degrees, and the adjustment plate at the top layer is adjusted upward by 15 degrees. The actual test results are as follows: Second implementation: Add 5 cubic meters of water to the pulping device and select HS60 specification (density 0.6 g / cm 3 ) 2 tons of hollow glass microbeads are added to the pulping device for pulping, and then the circulation pump 2, control valve 9, and scraper centrifugal dehydrator are turned on in sequence. The water flow rate in the sorting tank is adjusted to 0.3 m / s through the circulation pump, and the slurry pump is turned on to allow the slurry to enter the sorting tank at a uniform speed of 1.5 cubic meters per hour. The bottom adjustment plate is adjusted upward by 10 degrees, the second adjustment plate from bottom to top is horizontal, and the top adjustment plate is adjusted downward by 15 degrees. The actual experimental data are as follows: During the production process, a small amount of material will be lost because the dehydrator filter bag cannot completely intercept the material. The actual collection accounts for 98.76% of the total, with a loss of 1.24%.

[0039] The third implementation scenario: Add 5 cubic meters of water to the pulping device, select 2 tons of HS60 hollow glass microbeads and add them to the pulping device for pulping. Then turn on the circulation pump 2, control valve 9, and scraper centrifugal dehydrator in turn. Adjust the water flow rate in the sorting tank to 0.5 m / s through the circulation pump. Turn on the slurry pump to allow the slurry to enter the sorting tank at a uniform speed of 1 cubic meter / hour. Adjust the bottom adjustment plate downward by 5 degrees, and the second adjustment plate from bottom to top is horizontal. Adjust the top adjustment plate upward by 10 degrees. The actual experimental data are as follows: During the production process, a small amount of material will be lost because the dehydrator filter bag cannot completely intercept the material. The actual collection accounts for 98.89% of the total, with a loss of 1.11%.

[0040] The results show that after the raw materials are classified by buoyancy method, four stages of material classification are achieved. The particle size distribution of each stage is relatively concentrated, the distribution range is narrowed, and the particle size span (the difference between D90 and D10) is much smaller than the raw material particle size span.

[0041] Embodiment of the hollow glass microsphere classification screening method of the present invention: A basic embodiment includes placing hollow glass microbeads into water, where microbeads of different particle sizes have different densities and different floating speeds, collecting water with microbeads suspended in different water layer depths, and then dehydrating the water to obtain microbeads of different particle sizes.

[0042] Since the hollow glass microbeads are generally in a relatively small size range and are in a powdery form, directly placing them in water may cause agglomeration, which is not conducive to rapid and uniform dispersion in water. In an optimized embodiment, the powdery hollow glass microbeads and water are first made into a slurry, and then the microbead slurry is placed in water for subsequent classification and screening. After entering the water, the microbead slurry can be quickly diluted and dispersed, which is convenient for improving the efficiency and accuracy of classification and screening.

[0043] To facilitate collection, in a preferred embodiment, the hollow glass microbeads are placed in a water flow with a stable flow rate, and water at different water layer depths is collected on the downstream side of the water flow and transported to different dehydration devices for dehydration.

[0044] A more specific grading and screening method is also introduced in the embodiment of the hollow glass microbead grading and screening device, which will not be described in detail herein.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. Hollow glass microbead grading and screening device, characterized in that: The invention comprises a sorting tank and a dehydration device. The side of the sorting tank provided with a water injection port is the upstream side. The downstream side of the sorting tank is provided with different outflow ports in the upper and lower directions respectively. Each outflow port is connected with a water pipeline for conveying the slurry flowing out of the sorting tank to the dehydration device. The hollow glass microbeads dropped into the sorting tank from the bottom of the upstream side are gradually stratified in the water flow due to different buoyancy during the flow of the water, and flow out through different outflow ports respectively. After dehydration, grading and screening of different particle sizes are realized.

2. The hollow glass microbead grading and screening device according to claim 1 is characterized in that: The grading and screening device also includes a pulping device for making powdered hollow glass microbeads and water into a slurry. The discharge port of the pulping device is connected to a delivery pipeline, and the outlet of the delivery pipeline is located at the bottom of the upstream side of the sorting tank and constitutes a delivery port.

3. The hollow glass microbead grading and screening device according to claim 1 or 2, characterized in that: The outflow port is in the shape of a horizontally extending long strip, and the outflow ports are arranged in layers in the up and down directions.

4. The hollow glass microbead grading and screening device according to claim 3 is characterized in that: The outflow port is a closing structure with a height gradually decreasing along the outflow direction.

5. The hollow glass microbead grading and screening device according to claim 3, characterized in that: An adjustment plate is hinged between adjacent flow outlets and is arranged to rotate around a horizontal axis. The adjustment plate adjusts different pitch angles to adjust the water layer heights corresponding to two adjacent flow outlets.

6. The hollow glass microbead grading and screening device according to claim 1 or 2, characterized in that: The dehydration device is a scraper type centrifugal dehydrator.

7. The hollow glass microbead grading and screening device according to claim 1, characterized in that: A circulating water channel is provided between the water outlet of the dewatering device and the water inlet of the sorting tank, so that the water separated by the dewatering device can be used for pulping again.

8. The hollow glass microbead grading and screening device according to claim 2, characterized in that: A circulating water channel is provided between the water outlet of the dewatering device and the pulping device, so that the water separated by the dewatering device can be used for pulping again.

9. The hollow glass microbead grading and screening device according to claim 7 or 8, characterized in that: The circulating water circuit comprises a water reservoir, a circulating pipeline and a circulating pump.

10. A hollow glass microsphere classification and screening method, characterized in that: The method comprises putting hollow glass microbeads into water, wherein microbeads of different particle sizes have different densities and different floating speeds, collecting water with suspended microbeads at different water layer depths, and then dehydrating the water to obtain microbeads of different particle sizes.

11. The hollow glass microsphere classification and screening method according to claim 10, characterized in that: Firstly, the powdered hollow glass microspheres and water are made into a slurry, and then the microsphere slurry is put into water for subsequent classification and screening.

12. The hollow glass microsphere classification and screening method according to claim 10, characterized in that: The hollow glass microbeads are placed in a water flow with a stable flow rate, and water at different water layer depths is collected on the downstream side of the water flow and transported to different dehydration devices for dehydration.

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