Aluminum oxide screening system

Abstract

The utility model discloses an aluminum oxide screening system. The technical problem that in the prior art, the screening efficiency is low is solved. The aluminum oxide screening system comprises a first stock bin, a three-way pipe, an airflow classifier, a cyclone separation cylinder, a dust remover, an induced draft fan, an iron remover, a second stock bin and a screening device, the three-way pipe is provided with a first opening, a second opening and a third opening, the first opening is communicated with a feeding port of the airflow classifier, the second opening is communicated with the first stock bin, and the third opening is communicated with the cyclone separation cylinder. The third opening is communicated with the outside, a fine material outlet of the airflow classifier is communicated with a feeding port of the cyclone separation barrel, a feeding port of the dust remover is communicated with a fine material outlet of the cyclone separator, and an air opening of the dust remover is communicated with the induced draft fan. The de-ironing separator and the second stock bin are sequentially communicated with a coarse material outlet of the airflow classifier; the screening device is provided with a feeding port and a product outlet, and the feeding port of the screening device is communicated with the second stock bin so that impurity particles generated when the iron remover is abraded by aluminum oxide can be removed. The aluminum oxide screening system is high in screening efficiency.

Description

Technical Field

[0001] This application belongs to the field of alumina particle size classification technology, specifically relating to an alumina screening system. Background Technology

[0002] Alumina is an important industrial raw material, widely used in refractory materials, electronic ceramics, structural ceramics, substrate glass, abrasives, and polishing. Industrially, alumina or aluminum hydroxide is often used as raw material, calcined at high temperatures in rotary kilns, tunnel kilns, and other equipment, undergoing a series of physical and chemical changes to ultimately transform into α-phase alumina, accompanied by approximately 14% volume shrinkage, resulting in a finer-grained product. However, the market has varying demands for the particle size of calcined α-alumina, particularly in the substrate glass industry where coarse-grained, free-flowing calcined α-alumina powder is required. Therefore, sieving of the calcined alumina is necessary to meet these particle size requirements.

[0003] In related technologies, vibrating screens and other methods are often used to screen α-alumina. However, this method results in poor production continuity and low production efficiency. Summary of the Invention

[0004] To address the technical problem of low production efficiency in current alumina screening methods, this application provides an alumina screening system.

[0005] This application provides an alumina screening system, including a first silo, a three-way pipe, an air classifier, a cyclone separator, a dust collector, an induced draft fan, an iron separator, a second silo, and a screen, wherein:

[0006] The three-way pipe has a first opening, a second opening and a third opening. The first opening is connected to the feed inlet of the air classifier, the second opening is connected to the first silo, and the third opening is connected to the outside. The fine material outlet of the air classifier is connected to the feed inlet of the cyclone separator, the feed inlet of the dust collector is connected to the fine material outlet of the cyclone separator, and the air outlet of the dust collector is connected to the induced draft fan.

[0007] The iron remover and the second hopper are sequentially connected to the coarse material outlet of the air classifier; the screener has a feed inlet and a product outlet, and the feed inlet of the screener is connected to the second hopper to remove impurity particles worn down by the alumina in the iron remover.

[0008] In some embodiments, the second hopper includes a hopper body and a discharge pipe connected to the bottom of the hopper body, the bottom area of ​​the hopper body being larger than the cross-sectional area of ​​the discharge pipe, and the discharge pipe communicating with the feed inlet of the screener.

[0009] In some embodiments, the silo body includes a pipe and a bottom plate, the inner diameter of the pipe decreasing from top to bottom, the bottom plate being connected to the lower end of the pipe, and the bottom plate having a through hole connecting the pipe and the discharge pipe, the discharge pipe being connected to the bottom plate.

[0010] In some embodiments, the iron remover is an electromagnetic iron remover, the screener is a drum screen located below the second hopper, and the alumina screening system further includes a weighing device located below the discharge port of the drum screen.

[0011] In some embodiments, a third hopper is also included, which is connected to the coarse material outlet of the cyclone separator, and the dust collection port of the dust collector is connected to the third hopper.

[0012] In some embodiments, the dust collection port of the dust collector is connected to the third silo via a screw feeder.

[0013] In some embodiments, the dust collector is further provided with a receiving pipe connected to the screw feeder; the vertical projection of the receiving pipe is located outside the dust collector, and the induced draft fan is located below the dust collector.

[0014] In some embodiments, the air classifier, the iron remover, the second hopper, and the screener are arranged sequentially from top to bottom.

[0015] In some embodiments, a purification screen connected to the first silo is also included, the purification screen being connected to the second opening of the tee pipe.

[0016] In some embodiments, the included axial angle between the first opening and the second opening of the tee is an acute angle. ...

[0017] According to the alumina screening system provided in this application embodiment, a first silo, an air classifier, a cyclone separator, a dust collector, and an induced draft fan are arranged sequentially. Therefore, under the action of the induced draft fan, the alumina raw material in the first silo can be screened into coarse and fine particles by the air classifier. The coarse particles can be supplied to the basic glass industry, while the fine particles can be processed by the cyclone separator and the dust collector to avoid environmental impact. Because alumina has very high hardness, the air classifier is subjected to abrasive action by the alumina, causing iron impurities or iron filings to fall into the coarse alumina material. The dust collector can remove these iron impurity particles. The dust collector is also subjected to abrasive action by the flowing alumina particles, causing large impurities to fall off. These large impurities are then screened out by the screener, leaving alumina that meets the particle size requirements, with fewer iron impurity particles and high purity.

[0018] The alumina screening system provided in this application uses an induced draft fan as its power source, which allows the raw alumina to flow continuously within the screening system under the action of airflow, resulting in high production efficiency. Attached Figure Description

[0019] Figure 1 A schematic diagram of the structure of an alumina screening system in one or more embodiments of this application is shown.

[0020] Figure 2 A schematic diagram of the second silo is shown.

[0021] Explanation of reference numerals in the attached figures:

[0022] 100-Alumina screening system, 101-First silo, 102-Purification screen, 103-T-pipe, 104-Air classifier, 105-Cyclone separator, 106-Dust collector, 107-Exhaust fan, 108-Iron remover, 109-Second silo, 1091-Silo body, 1091a-Pipe fittings, 1091b-Bottom plate, 1092-Discharge pipe, 110-Screw screen, 111-Weighing device, 112-Third silo, 113-Screw feeder, 114-Receiving pipe. Detailed Implementation

[0023] To enable those skilled in the art to more clearly understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] In related technologies, vibrating screens are used to classify alumina particles by size. However, because alumina particles are extremely small, the screen mesh is prone to clogging due to the small particle size. Very small feed rates are required to reduce the risk of clogging and achieve continuous production, which significantly reduces production efficiency.

[0025] This application provides an alumina screening system that enables continuous alumina production with large feed rates and high production efficiency, thus solving the technical problem of low production efficiency when using vibrating screens to screen alumina.

[0026] Please see Figure 1 The alumina screening system 100 provided in this application includes a first silo 101, a three-way pipe 103, an air classifier 104, a cyclone separator 105, a dust collector 106, an induced draft fan 107, an iron remover 108, a second silo 109, and a screen 110.

[0027] The three-way pipe 103 has a first opening, a second opening, and a third opening. The first opening is connected to the feed inlet of the air classifier 104, the second opening is connected to the first hopper 101, and the third opening is connected to the outside. The fine material outlet of the air classifier 104 is connected to the feed inlet of the cyclone separator 105, the feed inlet of the dust collector 106 is connected to the fine material outlet of the cyclone separator, and the air outlet of the dust collector 106 is connected to the induced draft fan 107. Under the action of the induced draft fan 107, the airflow flows from the three-way pipe 103... The third opening of the three-way pipe 103 leads sequentially through the first opening to the air classifier 104, the cyclone separator 105, and the dust collector 106. Alumina in the first hopper 101 falls through the second opening of the three-way pipe 103. Under the action of airflow, the alumina raw material in the three-way pipe 103 enters the air classifier 104. Under the action of the rotating impeller, particle size is classified. Coarse material is discharged through the coarse material outlet of the air classifier 104, and fine material is discharged through the fine material outlet of the air classifier 104. The fine material discharged from the air classifier 104 enters through the inlet of the cyclone separator 105. After classification, coarse material is discharged through the coarse material outlet of the cyclone separator 105, and fine material is discharged through the fine material outlet of the cyclone separator 105, and then enters the dust collector 106 for dust removal.

[0028] The air classifier 104 is an air classifier. Under the force of the induced draft fan 107, alumina enters through the feed inlet and moves at high speed to the classification zone with the upward airflow. Under the strong centrifugal force of the high-speed rotating classification turbine, the alumina is separated into coarse and fine particles. The coarse alumina powder impacts the wall of the classifier and falls down along the cylinder wall to the coarse material outlet, while the fine alumina powder, under the action of the airflow, enters the cyclone separator 105 through the impeller gap and the fine powder outlet. Since the air classifier 104 is not a screen, there is no clogging problem, ensuring continuous production under large feed rates.

[0029] The second hopper 109, the iron remover 108, and the screen 110 are sequentially connected to the coarse material outlet of the air classifier 104. The second hopper 109 can be used to buffer and hold the coarse alumina material after classification by the air classifier 104. During the operation of the air classifier 104, the alumina will collide and wear against the cylinder wall and impeller, and because alumina has a very high hardness, iron impurity particles will be shed from the cylinder wall and impeller of the air classifier 104 and enter the coarse alumina material. The iron remover 108 can remove these iron impurity particles. The iron remover 108, affected by the alumina, will also shed large particles, resulting in the coarse alumina material containing large particles that do not meet the requirements. The screen 110 can remove these large particles, and the alumina product meeting the particle size requirements is discharged from the product outlet of the screen 110.

[0030] After high-temperature calcination, some of the alumina particles are very large. In some embodiments, a purification screen 102, such as a drum screen, can be installed at the discharge port of the first silo 101. The discharge port of the first silo 101 is connected to the inlet of the purification screen 102. The fine material outlet of the purification screen 102 is connected to the three-way pipe 103 through a second opening. The alumina particles are first screened by the purification screen 102 to remove large-sized alumina.

[0031] The alumina in the first hopper 101 is discharged under gravity. The axial angle between the first and second openings of the three-way pipe 103 is acute, causing the discharged alumina to move obliquely upward under the action of airflow and enter the air classifier 104 for particle size classification through the feed inlet. This also reduces the height of the alumina screening system 100, lowering construction costs. In other embodiments, the height of the first hopper 101 can be increased so that it is higher than the air classifier 104, allowing the angle between the first and second openings of the three-way pipe 103 to be either a right angle or an obtuse angle.

[0032] After being separated by an air classifier 104, alumina is divided into coarse alumina and fine alumina. Among them:

[0033] For alumina coarse material, after iron removal by the iron separator 108, it is then screened by the screener 110. The iron separator 108 can be an electromagnetic iron separator or an iron rod iron separator, and the screener 110 can be a drum screen. For alumina screening systems 100 that do not include a screener 110 in their design and construction, since a screener 110 needs to be added later, there may not be enough space at the bottom of the second hopper 109 to accommodate it. In some embodiments, please refer to... Figure 2 The second hopper 109 includes a hopper body 1091 and a discharge pipe 1092 connected to the bottom of the hopper body 1091. The bottom area of ​​the hopper body 1091 is larger than that of the discharge pipe 1092. The discharge pipe 1092 is connected to the feed inlet of the screener 110.

[0034] Generally, the silo is funnel-shaped, and the cross-sectional area of ​​the discharge pipe 1092 is the same as the bottom area of ​​the silo body 1091. This reduces the amount of alumina residue in the silo body 1091. However, during the upgrade process, the space at the bottom of the silo is insufficient to accommodate the screen 110. By cutting off the bottom of the silo body 1091 and setting the bottom area of ​​the silo body 1091 to be larger than the cross-sectional area of ​​the discharge pipe 1092, the height of the silo body 1091 is reduced. This allows for a reduction in the height of the second silo 109, facilitating the placement of the screen 110 below the second silo 109. This can be used to upgrade existing alumina screening systems 100 that do not have screens 110 installed.

[0035] In other embodiments, the cross-sectional area of ​​the feed pipe 1092 is the same as the bottom area of ​​the hopper 1091, which is suitable for building a new alumina screening system 100 and can also increase the capacity of the second hopper 109.

[0036] In some embodiments, the hopper 1091 includes a pipe 1091a and a bottom plate 1091b. The inner diameter of the pipe 1091a decreases from top to bottom. The bottom plate 1091b is connected to the lower end of the pipe 1091a. The bottom plate 1091b is provided with a through hole that connects the pipe 1091a and the discharge pipe 1092. The discharge pipe 1092 is connected to the bottom plate 1091b, thereby forming a second hopper 109. In other embodiments, the hopper 1091 includes two pipes 1091a. The inner diameters of the two pipes 1091a decrease sequentially from top to bottom. The two pipes 1091a are connected in sequence. The lower diameter of the upper pipe 1091a is the same as the upper diameter of the lower pipe 1091a. The lower diameter of the lower pipe 1091a is the same as the diameter of the feed pipe 1092. This configuration can not only create a second hopper 109 with sufficient capacity to accommodate the screener 110, but also reduce the amount of alumina material remaining in the second hopper 109.

[0037] In some embodiments, the alumina screening system 100 further includes a weighing element 111, which can be used to directly place the packaging bag on the weighing element 111 to receive the fine material rejected by the screener 110 and weigh the fine material. The weighing element 111 can be a platform scale or other weighing device.

[0038] In some embodiments, the air classifier 104, the iron remover 108, the second hopper 109, the screener 110, and the weighing device 111 are arranged sequentially from top to bottom, and the functions of iron removal, screening, and weighing can be achieved by gravity without the need for additional power.

[0039] The fine alumina particles separated by the air classifier 104 are first separated into coarser particles by a cyclone separator, and then dust is collected by a dust collector 106. This setup allows the fine particles separated by the air classifier 104 to be processed sequentially by the cyclone separator and the dust collector 106, reducing the throughput of the dust collector 106. The resulting coarser particles, such as alumina coarser with a particle size of 20~50μm, can be used to manufacture ceramics.

[0040] Cyclone separator 105, also known as cyclone separator, when gas flows through cyclone separator 105, due to the cyclone chamber design inside the equipment, the airflow will form a vortex and generate high-speed rotation. Large alumina particles will be deflected to the outer wall by centrifugal force and eventually deposited at the bottom, while small alumina particles will be discharged from the top nozzle with the airflow.

[0041] In some embodiments, the alumina screening system 100 further includes a third hopper 112, which is connected to the coarse material outlet of the cyclone separator 105 to collect the secondary coarse material separated by the cyclone separator.

[0042] The dust collector 106 can be a pulse-jet bag filter, also known as a dust collector. In some embodiments, the dust collection port of the dust collector 106 is connected to the third hopper 112. The dust particles formed after processing by the dust collector 106 are very small, possibly 5-6 μm, making them difficult to utilize effectively. Connecting the dust collection port of the dust collector 106 to the third hopper 112 allows the collected dust to be mixed with coarse materials for use in ceramics production, etc., achieving effective utilization. Of course, in other embodiments, the dust collection port of the dust collector 106 can also be connected to a fourth hopper to achieve dust collection.

[0043] In some embodiments, the dust collection port of the dust collector 106 is connected to the third silo 112 via a screw feeder 113. The screw feeder 113 is a common material conveying device that uses the rotational motion of a screw to convey alumina dust from the dust collection port of the dust collector 106 to the third silo 112. The screw feeder 113 includes a motor, rotating blades, a central shaft, and a housing. The rotating blades are helically connected to the central shaft and located within the housing. The motor is drively connected to the central shaft; therefore, the rotation of the motor drives the central shaft to rotate, thereby driving the rotating blades to rotate, and thus driving the alumina dust collection. Since controlling the motor speed can control the conveying amount of the screw feeder 113, a quantitative feed can be achieved into the third silo 112, and the material can be uniformly mixed with the coarse and mild materials in the third silo 112. The feeding speed of the screw feeder 113 is adjusted according to the amount of coarse and mild materials in the third silo 112, thereby obtaining a product with a uniform mixture of dust and coarse and mild materials in a controllable ratio, meeting the downstream application requirements.

[0044] In some embodiments, the dust collector 106 is also provided with a receiving pipe 114 connected to the screw feeder 113. In the case of excessive dust collection, it is not advisable to send the collected dust back into the third hopper 112. The setting of the receiving pipe 114 allows the collected dust in the dust collector 106 to be directly discharged through the screw feeder 113 and the receiving pipe 114, avoiding the problem that too much collected dust enters the third hopper 112, resulting in too much collected dust in the secondary coarse material that is difficult to utilize.

[0045] In some embodiments, the vertical projection of the receiving pipe 114 is located outside the dust collector 106, and the induced draft fan 107 is located below the dust collector 106. Generally, the dust collector 106 is supported by a support frame and is in a suspended state. Arranging the induced draft fan 107 below the dust collector 106 can save space, while the vertical projection of the receiving pipe 114 being located outside the dust collector 106 facilitates the movement of transport vehicles and forklifts carrying collection tanks to the area below the receiving pipe 114 to collect the dust.

[0046] The alumina screening system 100 provided in this application has at least the following advantages:

[0047] (1) By adjusting the operating power of the air classifier 104 or the induced draft fan 107, different particle size gradients can be selected. The operation is not prone to clogging, has good continuity, large feed rate, high production efficiency, and good product particle size stability. At the same time, the iron remover 108 is equipped to remove mechanical iron and reduce the number of black spots in the alumina product. A purification screen 102 is set to initially remove large particle impurities. A screener 110 is set to remove large particle impurities worn off by the iron remover 108. The product has good particle size stability and high purity.

[0048] (2) The bottom area of ​​the second hopper 109 is larger than the cross-sectional area of ​​the feed pipe 1092, thereby reducing the height of the second hopper 109 and increasing the space at the bottom of the second hopper 109, which facilitates the arrangement of the screener 110 and realizes the transformation of the alumina screening system 100 without the screener 110.

[0049] (3) The dust collection port of the dust collector 106 is connected to the third silo 112 through the screw feeder 113 so as to feed the collected dust quantitatively and evenly into the alumina coarse material in the third silo 112 to realize the recycling of the collected dust.

[0050] The alumina sieving system provided in this application was used to classify alumina raw materials with D10 of 40.44 μm, D50 of 68.82 μm, and D90 of 123.6 μm in the first hopper. During the classification process, the impeller rotation frequency of the air classifier was controlled at 12 Hz, 13 Hz, 14 Hz, 15 Hz, and 16 Hz. The particle size distribution of the alumina finished product after screening by the screener at each frequency is shown in Table 1. The secondary coarse material in the third hopper has a D10 of 17.55 μm, a D50 of 33.62 μm, and a D90 of 53.21 μm. The fine powder in the dust collector has a D10 of 3.72 μm, a D50 of 7.93 μm, and a D90 of 24.3 μm.

[0051] Table 1

[0052]

[0053] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0054] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0055] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0056] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0057] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. An alumina screening system, characterized in that, It includes a first silo, a three-way pipe, an air classifier, a cyclone separator, a dust collector, an induced draft fan, a magnetic separator, a second silo, and a screen, wherein: The three-way pipe has a first opening, a second opening and a third opening. The first opening is connected to the feed inlet of the air classifier, the second opening is connected to the first silo, and the third opening is connected to the outside. The fine material outlet of the air classifier is connected to the feed inlet of the cyclone separator, the feed inlet of the dust collector is connected to the fine material outlet of the cyclone separator, and the air outlet of the dust collector is connected to the induced draft fan. The iron remover and the second hopper are sequentially connected to the coarse material outlet of the air classifier; the screener has a feed inlet and a product outlet, and the feed inlet of the screener is connected to the second hopper to remove impurity particles worn down by the alumina in the iron remover.

2. The alumina screening system according to claim 1, characterized in that, The second hopper includes a hopper body and a discharge pipe connected to the bottom of the hopper body. The bottom area of ​​the hopper body is larger than the cross-sectional area of ​​the discharge pipe, and the discharge pipe is connected to the feed inlet of the screener.

3. The alumina screening system according to claim 2, characterized in that, The silo body includes pipe fittings and a bottom plate. The inner diameter of the pipe fittings decreases from top to bottom. The bottom plate is connected to the lower end of the pipe fittings. The bottom plate has a through hole that connects the pipe fittings and the discharge pipe. The discharge pipe is connected to the bottom plate.

4. The alumina sieving system according to any one of claims 1-3, characterized in that, The iron remover is an electromagnetic iron remover, the screener is located below the second silo, and the alumina screening system also includes a weighing device located below the discharge port of the screener.

5. The alumina screening system according to any one of claims 1-3, characterized in that, It also includes a third hopper, which is connected to the coarse material outlet of the cyclone separator, and the dust collection port of the dust collector is connected to the third hopper.

6. The alumina screening system according to claim 5, characterized in that, The dust collection port of the dust collector is connected to the third silo via a screw feeder.

7. The alumina screening system according to claim 6, characterized in that, The dust collector is also provided with a receiving pipe connected to the screw feeder; the projection of the receiving pipe in the vertical direction is located outside the dust collector, and the induced draft fan is located below the dust collector.

8. The alumina screening system according to any one of claims 1-3, characterized in that, The air classifier, the iron remover, the second hopper, and the screener are arranged in sequence from top to bottom.

9. The alumina screening system according to any one of claims 1-3, characterized in that, It also includes a purification screen connected to the first silo, the purification screen being connected to the second opening of the three-way pipe.

10. The alumina screening system according to claim 9, characterized in that, The included axial angle between the first opening and the second opening of the tee is an acute angle.

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