A continuous forming device and method of millimeter-scale spherical alumina

Abstract

The application discloses a kind of millimeter spherical alumina continuous forming device and method, belong to spherical carrier technical field, and heating stirred tank is sent forming oil to storage and transport tank by first pipeline;Storage and transport tank is backflowed forming oil to heating stirred tank by second pipeline;Dropping ball device is used to form and drop droplet-shaped alumina sol;Spherical column is used to make alumina sol form spherical alumina;First conveyor belt is used to convey spherical alumina to water washing tank and clean;Second conveyor belt is used to convey cleaned spherical alumina to drying machine and dry;Collecting tank is used to collect the forming oil flowing from storage and transport tank, and backflow the collected forming oil to heating stirred tank by third pipeline.The millimeter spherical alumina forming device can realize industrial continuous production, and production efficiency is high;The prepared alumina pellet is good in sphericity, uniform in particle size, and high in yield.

Description

Technical Field

[0001] This invention belongs to the field of spherical carrier technology, specifically relating to a continuous forming apparatus and method for millimeter-scale spherical alumina. Background Technology

[0002] Spherical alumina is widely used as a catalyst support in moving bed and fluidized bed reactions due to its high strength and low wear. Its production processes can be divided into two categories: mechanical forming, such as rotary forming and extrusion (strip forming, shaping), which produces spherical alumina supports with inherent defects in strength and sphericity; and drop-forming, which produces spherical alumina supports with superior strength and sphericity compared to mechanical forming, and can produce supports in the millimeter range (1-2 mm in diameter). Depending on the forming agent in the forming column, it is further divided into hot oil column forming and oil-ammonia column forming. The basic principle of both is to drop aluminum sol into an oil column. Due to surface tension, the sol droplets shrink into spheres in the oil layer, solidify in the forming agent, and then undergo further processing to obtain spherical alumina.

[0003] The oil-ammonia column method involves an oil-water interface, with an upper oil layer and ammonia water at the bottom. When sol droplets cross the oil-water interface, the surface layer is easily peeled off, and an emulsion layer easily forms at the interface, causing particles to float. Ammonia water volatilizes during use, causing environmental pollution. Furthermore, the gel strength of the sol droplets after gelation in ammonia water is very low, requiring a long aging treatment to increase its solidification before further drying and other processes, resulting in a long preparation time and low efficiency.

[0004] In addition, traditional production of millimeter-sized oxide spheres is mostly done in batches, resulting in low production efficiency; the method of releasing spheres from the sphere-forming column using a forming agent (forming oil or ammonia) easily leads to poor sphericity and low yield of spheres.

[0005] The Chinese invention patent with announcement number "CN204247160U" and title "An experimental device for preparing spherical carriers by dripping balls" relates to an experimental device for preparing spherical carriers. It is used for dripping balls from an oil-ammonia column or a hot oil column in the laboratory to achieve automatic rotation of multi-channel dripping balls. However, when the oil column is replaced after the dripping balls are finished, intermittent operation is still required, and it is only suitable for small-scale preparation in the laboratory.

[0006] Chinese invention patent CN207970867U, entitled "Catalyst Spherical Support Forming Device," relates to a catalyst spherical support forming device, including a dropper. Its key feature is that a forming column is positioned below the dropper, and a drying tank is positioned below the forming column. The drying tank is connected to a balance tank via a hose and a feed pump. The balance tank is connected to the forming column via a hose and a gate valve. This device is only applicable to the oil-ammonia column method for preparing spherical alumina and is for batch production.

[0007] The Chinese invention patent with announcement number "CN211612603U" and title "An Oil-Ammonia Column Forming Device" relates to an oil-ammonia column forming device. This device is only applicable to the preparation of spherical alumina by the oil-ammonia column method and is a batch production process.

[0008] Chinese invention patents CN205095741U and CN205095740U, entitled "An Oxide Microsphere Forming Device," relate to an oxide microsphere forming device; and CN205095740U, entitled "A Spherical Oxide Forming Device," also relates to a spherical oxide forming device. Both of these forming devices enable integrated operation, have a simple process, low loss of sphericity, and can achieve a high sphere yield. However, these devices are only suitable for the oil-ammonia column method, where ammonia is volatile and causes environmental pollution. Furthermore, when the solidified microspheres are released from the forming column after dripping, the impact of ammonia water still affects the sphericity and breakage of the microspheres to some extent. Summary of the Invention

[0009] In view of this, the present invention provides a continuous forming apparatus and method for millimeter-scale spherical alumina, which solves the environmental problems of low efficiency in intermittent production of spherical alumina and environmental pollution caused by easy volatilization of ammonia in the oil-ammonia column method.

[0010] The continuous forming apparatus for millimeter-scale spherical alumina provided by this invention adopts the following technical solution:

[0011] A continuous forming apparatus for millimeter-sized spherical alumina includes a heated stirring vessel, a ball-dropping device, a ball-forming column, a storage and transportation tank, a first conveyor belt, a washing tank, a second conveyor belt, a dryer, and a collection tank;

[0012] The heating and stirring vessel delivers molding oil to the storage and transportation tank through the first pipeline. The heating and stirring vessel is equipped with a first temperature control heater to control the heating temperature of the molding oil in the heating and stirring vessel.

[0013] The storage and transportation tank returns molding oil to the heating and stirring vessel through a second pipeline. The storage and transportation tank is equipped with a second temperature control heater to control the heating temperature of the molding oil in the storage and transportation tank.

[0014] The ball-dropping device is located above the outside of the storage and transportation tank to form and vertically drip alumina sol.

[0015] The spherical column is vertically installed inside the storage and transportation tank to receive the alumina sol dripped from the ball-dropping device and to shape the alumina sol into spherical alumina.

[0016] The first conveyor belt is installed in the storage tank and is used to transport the spherical alumina formed by the spherical column to the washing tank for cleaning.

[0017] The second conveyor belt is installed in the washing tank and is used to convey the cleaned spherical alumina to the dryer for drying.

[0018] The collection tank is located below the oil outlet at the top of the storage and transportation tank. It is used to collect the molding oil that overflows from the storage and transportation tank and return the collected molding oil to the heating and stirring kettle through a third pipeline.

[0019] Furthermore, the first pipeline is sequentially equipped with a third valve, a second pump, and a second flow meter starting from the end closest to the heated stirring vessel;

[0020] The second pipeline is provided with a first flow meter, a first pump, a filter, and a second valve in sequence from one end of the heating and stirring vessel;

[0021] One end of the third pipeline is connected to the collection tank, and the other end is connected to the second pipeline, and is located between the second valve and the filter.

[0022] Furthermore, both the first pump and the second pump are gear pumps and are controlled by variable frequency motors;

[0023] Both the first flow meter and the second flow meter are rotor flow meters;

[0024] The filter is a bag filter or a basket filter.

[0025] Furthermore, the ball-dropping device includes a slurry mixing tank, a dispensing assembly, and a ball-dropping disc;

[0026] The inlet of the dispensing assembly is connected to the outlet of the slurry mixing tank; the outlet of the dispensing assembly is connected to the feed end of the drip ball disk; and a screw-type dispensing needle is connected to the outlet end of the drip ball disk.

[0027] The feed end of the ball-feeding disc is connected to the outlet of the dispensing assembly via a quick-connect air hose, and the outlet end of the ball-feeding disc is connected to the screw-type dispensing needle via a Luer connector.

[0028] Furthermore, the spherical column includes an upper end and a lower end;

[0029] The upper end of the column is lower than the upper end of the storage tank, and the wall surface is provided with a mesh, the diameter of which is smaller than the diameter of the spherical alumina.

[0030] The lower end of the column is shaped like a conical funnel.

[0031] Furthermore, one end of the first conveyor belt is located below the spherical column to receive the spherical alumina falling from the spherical column, and the other end is located above the storage tank and extends towards the washing tank to form an extension section;

[0032] The washing tank is located below the end of the extension of the first conveyor belt;

[0033] One end of the second conveyor belt is located at the bottom of the washing tank to receive spherical alumina from the extension section, and the other end is located above the washing tank and extends toward the dryer.

[0034] Furthermore, both the first conveyor belt and the second conveyor belt have their conveying speed controlled by a variable frequency motor;

[0035] Both the first and second conveyor belts are equipped with skirts to prevent spherical alumina from slipping off the sides of the conveyor belts and causing jamming.

[0036] Both the first conveyor belt and the second conveyor belt are provided with mesh with a diameter smaller than that of spherical alumina;

[0037] Both the first conveyor belt and the second conveyor belt are chain conveyor belts or mesh conveyor belts;

[0038] The dryer is a multi-layer mesh belt dryer.

[0039] Furthermore, a guide plate is provided on the wall of the washing tank near the first conveyor belt to guide the spherical alumina falling from the first conveyor belt to the second conveyor belt;

[0040] The guide plate is made of stainless steel.

[0041] Furthermore, both the heating and stirring vessel and the storage and transportation tank are provided with an insulation layer on their outer sides;

[0042] The top of the storage and transportation tank is equipped with a protective cover;

[0043] The longitudinal section of the storage and transportation tank is trapezoidal, and the capacity of the heating and stirring vessel is 1 to 4 times the capacity of the storage and transportation tank.

[0044] The continuous forming method for millimeter-sized spherical alumina provided by this invention adopts the following technical solution:

[0045] When the temperature of the molding oil in the heating and stirring vessel reaches the set temperature, the third valve is opened and the second pump is started, so that the heating and stirring vessel adds molding oil to the storage tank through the first pipeline, and the molding oil in the storage tank is heated by the second temperature control heater;

[0046] Open the second valve and start the first pump to circulate the molding oil in the heating and stirring vessel and the storage tank, and keep the molding oil level in the storage tank flush with the oil outlet of the storage tank.

[0047] The alumina sol required for the drop ball is prepared in the drop ball device, and the first conveyor belt, the second conveyor belt and the dryer are turned on; after the temperature of the molding oil in the storage tank reaches the set temperature and remains constant, the alumina sol is dropped vertically downward by the drop ball device to start the continuous molding of millimeter-sized spherical alumina.

[0048] Beneficial effects:

[0049] 1. The millimeter-sized spherical alumina forming device can realize continuous industrial production with high production efficiency; the prepared alumina spheres have good sphericity, uniform particle size, and high yield.

[0050] 2. The forming device for millimeter-sized spherical alumina is suitable for preparing spherical alumina by hot oil column method, which does not use volatile ammonia water and is more environmentally friendly.

[0051] 3. Both the heating and mixing tank and the storage tank are equipped with temperature control heaters and insulation layers, which can achieve uniform and constant oil temperature of the molding oil through heating and circulation.

[0052] 4. Multi-layer mesh belt dryers have the advantages of small footprint, fast drying speed, and high evaporation intensity.

[0053] 5. The outlet end of the drip ball disc is connected to the screw-type dispensing needle via a Luer connector. If the needle becomes clogged during production, the drip ball disc and needle can be quickly replaced, improving production efficiency.

[0054] 6. The longitudinal section of the storage and transportation tank is trapezoidal, which can reduce the amount of molding oil used. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of a millimeter-scale spherical oxide continuous forming device provided in an embodiment of the present invention;

[0056] Figure 2 for Figure 1 Schematic diagram of the structure of the medium-heated stirring vessel;

[0057] Figure 3 for Figure 1 Schematic diagram of the medium-drop ball device;

[0058] Figure 4 for Figure 1 Schematic diagram of the structure of the central storage and transportation tank;

[0059] Figure 5 for Figure 1 Schematic diagram of the greywater washing tank;

[0060] Among them, 1-heating and stirring vessel, 2-drip ball device, 3-ball forming column, 4-storage and transportation tank, 5-collection tank, 6-washing tank, 7-multi-layer mesh belt dryer, 801-first valve, 802-second valve, 803-third valve, 1001-first gear pump, 1002-second gear pump, 1101-first rotor flow meter, 1102-second rotor flow meter, 9-filter; 101-drive motor, 102-stirring paddle, 103-first temperature control heater, 201-slurry mixing vessel, 202-dispensing assembly; 203-drip ball disc; 401-first conveyor belt; 402-oil outlet; 403-second temperature control heater, 404-first ball valve; 601-guide plate, 602-second conveyor belt, 603-second ball valve. Detailed Implementation

[0061] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0062] Example 1:

[0063] like Figures 1-5 As shown, this embodiment provides a continuous forming apparatus for millimeter-sized spherical alumina, including a heating and stirring vessel 1, a ball-dropping device 2, a ball-forming column 3, a storage and transportation tank 4, a first conveyor belt 401, a washing tank 6, a second conveyor belt 602, a dryer, and a collection tank 5, wherein:

[0064] The heating and stirring vessel 1 supplies molding oil to the storage and transportation tank 4 through a first pipeline. The heating and stirring vessel 1 is equipped with a first temperature control heater 103 to control the heating temperature of the molding oil inside the heating and stirring vessel 1. The storage and transportation tank 4 returns molding oil to the heating and stirring vessel 1 through a second pipeline. The storage and transportation tank 4 is equipped with a second temperature control heater 403 to control the heating temperature of the molding oil inside the storage and transportation tank 4. The dripping ball device 2 is located above the outside of the storage and transportation tank 4 to form and vertically drip alumina sol. The ball-forming column 3 is vertically installed inside the storage and transportation tank 4 to receive the dripping alumina sol. The alumina sol dripped from the ball device 2 and formed into spherical alumina. The first conveyor belt 401 is set in the storage tank 4 to convey the spherical alumina formed by the ball column 3 to the washing tank 6 for cleaning. The second conveyor belt 602 is set in the washing tank 6 to convey the cleaned spherical alumina to the dryer for drying. The collection tank 5 is set below the oil outlet at the top of the storage tank 4 to collect the molding oil overflowing from the storage tank 4 and return the collected molding oil to the heating and stirring vessel 1 through the third pipeline.

[0065] Thus, the forming device for millimeter-sized spherical alumina can achieve continuous industrial production with high production efficiency; the prepared alumina microspheres have good sphericity, uniform particle size, and high yield.

[0066] Specifically, in this embodiment, the first pipeline, starting from the end closest to the heating and stirring vessel 1, is sequentially equipped with a third valve 803, a second pump, and a second flow meter; the second pipeline, starting from the end of the heating and stirring vessel 1, is sequentially equipped with a first flow meter, a first pump, a filter 9, and a second valve 802; both the first and second pumps are gear pumps, namely the first gear pump 1001 and the second gear pump 1002, and are both controlled by a variable frequency motor, which can control the circulation of molding oil between the heating and stirring vessel 1 and the storage tank 4. Both the first and second flow meters are rotor flow meters, namely the first rotor flow meter 1101 and the second rotor flow meter 1102; the filter can be a bag filter or a basket filter. One end of the third pipeline is connected to the collection tank 5, and the other end is connected to the second pipeline, located between the second valve 802 and the filter 9.

[0067] More specifically, such as Figure 1 and Figure 3 As shown, the present invention Figure 1 The droplet device 2 is positioned directly above the ball-forming column 3. The droplet device 2 includes a slurry mixing vessel 201, a dispensing assembly 202 (which may be a slurry pump), and a droplet disc 203. The inlet of the dispensing assembly 202 is connected to the outlet of the slurry mixing vessel 201, and the outlet of the dispensing assembly 202 is connected to the feed end of the droplet disc 203. A screw-type dispensing needle is connected to the outlet end of the droplet disc 203. More specifically, the feed end of the droplet disc 203 is connected to the outlet of the dispensing assembly 202 via a quick-connect air hose, and the outlet end of the droplet disc 203 is connected to the screw-type dispensing needle via a Luer connector. The slurry mixing vessel 201 is used to prepare the alumina sol for stirring the droplets; the dispensing assembly 202 is used for the quantitative delivery of the alumina sol; and the droplet disc 203, located directly above the ball-forming column 3, is used to dispense alumina sol droplets.

[0068] The ball-forming column 3 is vertically installed inside the storage and transportation tank 4, and is divided into an upper end and a lower end, with a total length of 100-300cm. The upper end of the column is lower than the upper end of the storage and transportation tank 4. The upper end of the ball-forming column 3 is cylindrical, and the wall surface is provided with mesh, with each mesh spaced 1-3mm apart. The mesh diameter is smaller than the diameter of the spherical alumina. This mesh facilitates the exchange and flow of the forming oil between the ball-forming column 3 and the storage and transportation tank 4. The lower end of the column is conical funnel-shaped, and the funnel surface is a smooth stainless steel plate, which is used to collect the gel alumina balls falling from the ball-dropping device 2 and guide them onto the first conveyor belt 401 directly below the ball-forming column 3.

[0069] One end of the first conveyor belt 401 is located directly below the spherical column 3 to receive spherical alumina falling from the column 3, and the other end is located above the storage tank 4 and extends into the washing tank 6 to form an extension section; the washing tank 6 is located below the end of the extension section of the first conveyor belt 401; one end of the second conveyor belt 602 is located at the bottom of the washing tank 6 to receive spherical alumina falling from the extension section of the first conveyor belt 401, and the other end is located above the washing tank 6 and extends into the dryer. In this embodiment, the conveying speed of both the first conveyor belt 401 and the second conveyor belt 602 is controlled by a variable frequency motor; both the first conveyor belt 401 and the second conveyor belt 602 are provided with skirts to prevent spherical alumina from slipping off the sides of the conveyor belt and causing jamming; both the first conveyor belt 401 and the second conveyor belt 602 are provided with mesh with a diameter smaller than that of the spherical alumina. In particular, the first conveyor belt 401 and the second conveyor belt 602 can both be chain conveyor belts or both be mesh conveyor belts, and the dryer can be a multi-layer mesh belt dryer 7.

[0070] Furthermore, a guide plate 601 is provided on the wall of the washing tank 6 near the first conveyor belt 401 to guide the spherical alumina falling from the first conveyor belt 401 to the second conveyor belt 602. The guide plate 601 can be made of stainless steel. Both the heating and stirring vessel 1 and the storage and transportation tank 4 are provided with insulation layers on their outer sides; the upper part of the storage and transportation tank 4 is provided with a protective cover; the longitudinal section of the storage and transportation tank 4 is trapezoidal, and the capacity of the heating and stirring vessel is 1 to 4 times the capacity of the storage and transportation tank.

[0071] In addition, in this embodiment, the drying temperature is 100-150℃; such as Figure 2 As shown, the heating and stirring vessel 1 includes: a drive motor 101 and a stirring paddle 102. The drive motor 101 drives the stirring paddle 102 to stir the molding oil in the heating and stirring vessel 1, making the oil temperature distribution more uniform. The first temperature-controlled heater 103 can control the temperature of the heat-conducting oil in the jacket of the stirring vessel 1, and achieve temperature control of the molding oil in the vessel through heat exchange. The heating and stirring vessel 1 has an insulation layer on the outside to reduce heat dissipation. Figure 4 As shown, the present invention Figure 1 The longitudinal section of the storage tank 4 is trapezoidal, which can reduce the amount of molding oil used. A baffle is installed on the first conveyor belt 401 to prevent spherical alumina from slipping off; the first conveyor belt 401 is driven by guide positioning wheels; the oil outlet 402 on the storage tank 4 can maintain a constant level of molding oil in the storage tank 4 during production; a protective cover is installed on the top of the storage tank 4; a second temperature control heater 403 is installed at the lower left end of the storage tank 4 for heating and temperature control of the heat transfer oil inside the storage tank 4; a drain outlet is installed at the bottom of the storage tank 4, and the drain outlet is connected to a ball valve 404; a drain outlet is installed at the bottom of the washing tank 6, and the drain outlet is connected to a second ball valve 603.

[0072] In this embodiment, the molding oil can be one or more of white oil, hydrogenated base oil, liquid paraffin, transformer oil, heat transfer oil or lubricating oil, and the oil temperature of the molding oil can be controlled at 90℃-105℃.

[0073] Example 2:

[0074] Based on the above embodiment one, a method for continuous forming of millimeter-sized spherical alumina is provided, comprising:

[0075] When the temperature of the molding oil in the heating and stirring vessel 1 reaches the set temperature, the third valve 803 is opened and the second pump is started, so that the heating and stirring vessel adds molding oil to the storage tank 4 through the first pipeline, and the molding oil in the storage tank 4 is heated by the second temperature control heater 403.

[0076] Open the second valve 802 and start the first pump to circulate the molding oil in the heating and stirring vessel 1 and the storage tank 4, and keep the level of the molding oil in the storage tank 4 flush with the oil outlet 402 of the storage tank 4.

[0077] The alumina sol required for the drop ball is prepared in the slurry mixing tank 201 of the drop ball device 2, and the first conveyor belt 401, the second conveyor belt 602 and the dryer are turned on; after the temperature of the molding oil in the storage tank 4 reaches the set temperature and remains constant, the alumina sol is dropped vertically downward by the drop ball device 2 to start the continuous molding of millimeter-sized spherical alumina.

[0078] In this embodiment, after production begins, the alumina sol is quantitatively delivered to the droplet disc 203 via the dispensing assembly 202. The droplet disc 203 shapes the alumina into droplets, which then enter the spherical column 3 to form spheres and solidify. The spherical alumina is guided by the funnel at the lower end of the spherical column 3 to the first conveyor belt 401. The first conveyor belt 401 transports the spherical alumina from the bottom of the storage tank 4 to the washing tank 6. The spherical alumina is then conveyed by the guide plate 601 in the washing tank 6 to the second transmission belt 602 located inside the washing tank 6, and then by the second conveyor belt 602 to the multi-layer mesh belt dryer 7 for drying.

[0079] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A continuous forming apparatus for millimeter-scale spherical alumina, characterized in that, It includes a heated stirring vessel, a pelletizing device, a pelletizing column, a storage and transportation tank, a first conveyor belt, a washing tank, a second conveyor belt, a dryer, and a collection tank; The heating and stirring vessel supplies molding oil to the storage tank through a first pipeline. The heating and stirring vessel is equipped with a first temperature control heater to control the heating temperature of the molding oil inside the heating and stirring vessel. The first pipeline is sequentially equipped with a third valve, a second pump, and a second flow meter from the end closest to the heating and stirring vessel. The storage and transportation tank returns molding oil to the heating and stirring vessel through a second pipeline. The storage and transportation tank is equipped with a second temperature control heater to control the heating temperature of the molding oil in the storage and transportation tank. The second pipeline is sequentially equipped with a first flow meter, a first pump, a filter, and a second valve starting from one end of the heating and stirring vessel. The ball-dropping device is located above the outside of the storage and transportation tank to form and vertically drip alumina sol. The spherical column is vertically installed inside the storage and transportation tank to receive the alumina sol dripped from the ball-forming device and to shape the alumina sol into spherical alumina. The spherical column includes an upper end and a lower end. The upper end of the column is lower than the upper end of the storage and transportation tank, and its wall surface is provided with mesh, the diameter of which is smaller than the diameter of the spherical alumina. The lower end of the column is in the shape of a conical funnel. The first conveyor belt is installed in the storage tank and is used to convey the spherical alumina formed by the spherical column to the washing tank for cleaning; one end of the first conveyor belt is located below the spherical column and is used to receive the spherical alumina falling from the spherical column, and the other end is located above the storage tank and extends into the washing tank to form an extension section; the washing tank is located below the end of the extension section of the first conveyor belt. The second conveyor belt is installed in the washing tank and is used to convey the cleaned spherical alumina to the dryer for drying; one end of the second conveyor belt is located at the bottom of the washing tank and is used to receive the spherical alumina from the extension section, and the other end is located above the washing tank and extends to the dryer; A collection tank is located below the oil outlet at the top of the storage and transportation tank. It is used to collect the molding oil that overflows from the storage and transportation tank and return the collected molding oil to the heating and stirring vessel through a third pipeline. One end of the third pipeline is connected to the collection tank, and the other end is connected to the second pipeline. It is located between the second valve and the filter to keep the molding oil level in the storage and transportation tank flush with the oil outlet of the storage and transportation tank.

2. The continuous forming apparatus for millimeter-scale spherical alumina according to claim 1, characterized in that, Both the first pump and the second pump are gear pumps and are controlled by variable frequency motors; Both the first flow meter and the second flow meter are rotor flow meters; The filter is a bag filter or a basket filter.

3. The continuous forming apparatus for millimeter-scale spherical alumina according to claim 1, characterized in that, The ball-dropping device includes a slurry mixing tank, a dispensing assembly, and a ball-dropping disc; The inlet of the dispensing assembly is connected to the outlet of the slurry mixing tank; the outlet of the dispensing assembly is connected to the feed end of the drip ball disk; and a screw-type dispensing needle is connected to the outlet end of the drip ball disk. The feed end of the ball-feeding disc is connected to the outlet of the dispensing assembly via a quick-connect air hose, and the outlet end of the ball-feeding disc is connected to the screw-type dispensing needle via a Luer connector.

4. A continuous forming apparatus for millimeter-scale spherical alumina according to any one of claims 1 to 3, characterized in that, Both the first conveyor belt and the second conveyor belt have their conveying speed controlled by variable frequency motors; Both the first and second conveyor belts are equipped with skirts to prevent spherical alumina from slipping off the sides of the conveyor belts and causing jamming. Both the first conveyor belt and the second conveyor belt are provided with mesh with a diameter smaller than that of spherical alumina; Both the first conveyor belt and the second conveyor belt are chain conveyor belts or mesh conveyor belts; The dryer is a multi-layer mesh belt dryer.

5. A continuous forming apparatus for millimeter-scale spherical alumina according to any one of claims 1 to 3, characterized in that, A guide plate is provided on the wall of the washing tank near the first conveyor belt to guide the spherical alumina falling from the first conveyor belt to the second conveyor belt. The guide plate is made of stainless steel.

6. A continuous forming apparatus for millimeter-scale spherical alumina according to any one of claims 1 to 3, characterized in that, Both the heating and stirring vessel and the storage and transportation tank are provided with a heat insulation layer on their outer sides. The top of the storage and transportation tank is equipped with a protective cover; The longitudinal section of the storage and transportation tank is trapezoidal, and the capacity of the heating and stirring vessel is 1 to 4 times the capacity of the storage and transportation tank.

7. A method of using the continuous forming apparatus for millimeter-scale spherical alumina according to any one of claims 1 to 6, characterized in that, include: When the temperature of the molding oil in the heating and stirring vessel reaches the set temperature, the third valve is opened and the second pump is started, so that the heating and stirring vessel adds molding oil to the storage tank through the first pipeline, and the molding oil in the storage tank is heated by the second temperature control heater; Open the second valve and start the first pump to circulate the molding oil in the heating and stirring vessel and the storage tank; The alumina sol required for the drop ball is prepared in the drop ball device, and the first conveyor belt, the second conveyor belt and the dryer are turned on; after the temperature of the molding oil in the storage tank reaches the set temperature and remains constant, the alumina sol is dropped vertically downward by the drop ball device to start the continuous molding of millimeter-sized spherical alumina.

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