Ceramic slurry grinding production device

Abstract

The invention belongs to the technical field of ceramic slurry, and particularly relates to a ceramic slurry grinding production device which comprises a grinding container and a stirring mechanism, the inner wall of the grinding container is provided with at least one flow guide groove extending upwards in an inclined mode, the grinding container is provided with a discharging pipe, the discharging pipe is communicated with the top of the flow guide groove, and a screen is arranged between the discharging pipe and the top of the flow guide groove. Ceramic powder is continuously stirred, sheared and ground by a stirring mechanism and a grinding ball in a grinding container to obtain qualified slurry, and for the qualified slurry, due to factors such as reasonable particle size distribution and in-place coating of a dispersing agent, even if the ratio of powder to liquid is the same, better flowability is shown, and the quality of the slurry is improved. And due to the better rheological property, a higher circulation speed can be obtained in the grinding process, so that the slurry can upwards reach a higher height along the groove channel, the qualified slurry flows out firstly, and the remaining material is continuously ground, thereby improving the grinding efficiency. And when qualified slurry flows out, new materials are added at proper time, so that continuous operation is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramic slurries, and in particular relates to a ceramic slurry grinding production device. Background Art

[0002] Silicon nitride ceramic powder is a high-hardness powder with the characteristics of low bulk density, large specific surface area, and difficulty in wetting. Therefore, the grinding and production of silicon nitride slurry with high solid content is relatively difficult. In order to meet the requirements of high-precision ceramic forming based on high-solid content ceramic slurry, such as 3D printing, tape-casting of ultra-thin ceramic plates and special ceramic coatings, the problem of how to achieve efficient grinding of silicon nitride slurry with high solid content is involved. Among them, the photocuring printing equipment requires that the viscosity and fluidity of the ceramic slurry have sufficient self-leveling and reflow effects, and the ceramic sintering process requires that the volume proportion of ceramic particles in the ceramic slurry used for photocuring printing is sufficiently high. At the same time, the effective grinding of the slurry requires the liquid resin and ceramic powder to be fully and efficiently fused, and the powder particles are in a low energy state in the resin, without flocculation or agglomeration.

[0003] In the existing ceramic slurry production equipment, the disordered collision rate between ceramic particles and with the stirring paddle in the system is high, and ceramic particles of qualified and unqualified particle sizes are always in the system, which will convert too much energy into heat energy, resulting in low grinding efficiency and long cycle. In addition, the existing equipment can only produce the next batch after producing one batch of slurry, and cannot operate continuously, resulting in low production efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a ceramic slurry grinding production device with high grinding efficiency and continuous operation.

[0005] The present invention provides a ceramic slurry grinding production device, comprising: A grinding container, wherein the inner wall of the grinding container is provided with at least one diverting groove extending obliquely upward, the grinding container is provided with a discharge pipe, the discharge pipe is connected to the top of the diverting groove and is provided with a screen, and the grinding container is provided with a feed port; and The stirring mechanism is used to stir the ceramic slurry to rotate and flow in the grinding container.

[0006] Optionally, the inclination angle of the guide groove is 20°~55°.

[0007] Optionally, the width of the guide groove does not exceed 0.8 times the diameter of the grinding ball.

[0008] Optionally, the feed inlet includes a solid feed inlet and a liquid feed inlet, and the solid feed inlet and the liquid feed inlet are respectively arranged at the top and the bottom of the grinding container.

[0009] Optionally, the solid feed inlet is close to the axis of the grinding container, and the solid feed inlet is connected to a feed guide.

[0010] Optionally, a baffle is provided on the inner wall of the grinding container to limit the grinding balls to the area below the baffle.

[0011] Optionally, the baffle is in the shape of a circular ring structure, and the radial width of the baffle is 0.15 to 0.45 times the inner diameter of the grinding container, and the baffle is located at 0.4 to 0.6 times the height of the inner cavity of the grinding container.

[0012] Optionally, the inner cavity volume of the grinding container is 0.5L~2L.

[0013] Optionally, the stirring mechanism includes a motor and a stirring paddle connected to an output shaft of the motor.

[0014] Optionally, the stirring paddle includes a main shaft and multiple groups of blades arranged on the main shaft, each group of blades is evenly distributed around the main shaft, and the length of the blades gradually shortens from the end of the main shaft to near the motor.

[0015] The beneficial effect of the present invention is that the ceramic powder is continuously stirred, sheared and ground by the stirring mechanism and grinding balls in the grinding container, gradually producing ceramic powder of qualified particle size, and then forming qualified slurry. For the qualified slurry, due to factors such as reasonable particle size distribution and adequate dispersant coating, even if the powder and liquid ratio is the same, it will show better fluidity. The better rheological properties will obtain a higher circulation speed during the grinding process, so that these slurries can reach a higher height along the groove channel. At this point, two distinct effects exist within the ground slurry: Inadequately ground and dispersed ceramic powder, due to its significantly larger particle size, gradually sinks under the disturbance created by stirring, subjecting it to continuous shear grinding by the stirring paddles and grinding balls, gradually becoming finer and more dispersed. Meanwhile, the slurry with a qualified, fully dispersed and stable particle size is more susceptible to the fluid field carryover effect, causing it to rotate and flow more rapidly. Simultaneously, the grinding balls near the guide grooves, propelled by the stirring mechanism and guided by the guide grooves, roll rapidly upward or downward along the guide grooves (depending on whether the guide grooves align with the stirring direction). This strengthens this fluid field carryover effect, causing the slurry within the guide grooves to flow more rapidly upward or downward, passing through the screen first and flowing out continuously through the discharge pipe. The remaining material continues to be ground, thereby improving grinding efficiency. During the outflow of qualified slurry, new material can be added at the appropriate time based on the remaining slurry in the grinding vessel, enabling continuous operation and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the ceramic slurry grinding production device of the present invention; Figure 2 Schematic diagram of the internal structure of the grinding container of the present invention; Figure 3 It is a structural schematic diagram of the stirring mechanism of the present invention.

[0017] In the figure: 100, grinding container; 110, guide groove; 120, discharge pipe; 130, screen; 141, solid feed port; 142, liquid feed port; 150, baffle; 151, assembly groove; 160, feed guide member; 170, liquid feed pipe; 200, stirring mechanism; 210, motor; 220, main shaft; 230, paddle. DETAILED DESCRIPTION

[0018] like Figure 1-3 As shown, the present invention provides a ceramic slurry grinding production device, including: a grinding container 100 and a stirring mechanism 200, at least one guide groove 110 extending obliquely upward is provided on the inner wall of the grinding container 100, a discharge pipe 120 is provided on the grinding container 100, the discharge pipe 120 is connected to the top of the guide groove 110 and is provided with a screen 130, and a feed port is provided on the grinding container 100; the stirring mechanism 200 is used to stir the ceramic slurry to rotate and flow in the grinding container 100.

[0019] Compared with the prior art, the ceramic slurry grinding production device provided by the present invention continuously stirs, shears and grinds the ceramic powder in the grinding container 100 by the stirring mechanism 200 and the grinding balls, gradually producing ceramic powder of qualified particle size, and then forming qualified slurry. For the qualified slurry, due to factors such as reasonable particle size distribution and dispersant coating, even if the powder and liquid ratio is the same, it will show better fluidity. The better rheological properties will obtain a higher circulation speed during the grinding process, so that these slurries can reach a higher height along the groove channel. At this point, two distinct effects occur within the ground slurry: Inadequately ground and dispersed ceramic powder, due to its significantly larger particle size, gradually sinks under the agitation created by stirring, undergoing continuous shearing and grinding by the stirring paddles and grinding balls, gradually becoming finer and more dispersed. Meanwhile, slurry with a qualified particle size and sufficient dispersion is more susceptible to the fluid field carryover effect, causing it to rotate and flow more rapidly. Simultaneously, the grinding balls near the flow guide groove 110, propelled by the stirring mechanism 200 and guided by the flow guide groove 110, rapidly roll upward or downward along the flow guide groove 110 (depending on whether the guiding direction of the flow guide groove 110 is the same as the stirring direction). This strengthens the fluid field carryover effect, causing the slurry within the flow guide groove 110 to flow upward or downward more quickly, initially passing through the screen 130 and continuously flowing out of the discharge pipe 120. The remaining material continues to be ground, thereby improving grinding efficiency. During the outflow of qualified slurry, new material can be added in a timely manner based on the remaining slurry in the grinding container 100, enabling continuous operation and improving production efficiency.

[0020] It should be noted that the present invention, due to its structural characteristics and operating principle, is more suitable for grinding silicon nitride slurry. This is because silicon nitride powder has a lower bulk density and a higher specific surface area than zirconium oxide and alumina ceramics, and the powder is easily divided under the action of slow and continuous circulation: the powder dispersed for thorough grinding is more likely to settle downward due to factors such as agglomeration and large initial particle size. The organic resin or newly added organic resin, due to its lowest density, spontaneously moves upward, fully mixing with the gradually sinking newly added powder. At the same time, it is sheared and ground by the grinding balls in the filling device, such as ceramic ball mills (using silicon nitride ceramic balls as an example), while gradually moving slowly toward the edge of the grinding container 100 due to centrifugal force. If ceramics such as zirconium oxide and alumina are being ground, due to the significant difference in density compared to the resin, the newly added ceramic powder will quickly settle to the bottom of the grinding container 100 and remain there, unable to form an effective mixing effect due to the lifting effect caused by the low density of the organic resin, and also unable to fully move upward due to the diversion effect of the guide groove 110.

[0021] In one embodiment, the inclination angle of the guide groove 110 relative to the inner bottom surface of the grinding container 100 is determined by the following formula: ; in K 1 is the material experience constant, which is related to the physical properties of the grinding balls (such as density and particle size composition). θ 0 is the structural constant, which is related to the structural parameters of the barrel and the stirring paddle. η and ρ They are the dynamic viscosity (Pa·S) and density (kg / m 3 ), T is the fluidity of the slurry (mm), which is tested using a cement mortar fluidity tester.

[0022] When used to grind high solid content silicon nitride slurry, the value range of θ is: If the angle is too small, the liquid resin will be lost from the guide groove 110 too early, causing grinding difficulties or even grinding failure. If the angle is too large, the discharge efficiency will be reduced, affecting production efficiency.

[0023] In one embodiment, the width of the guide groove 110 does not exceed 0.8 times the diameter of the grinding ball; preferably, the width of the guide groove 110 is 0.6~0.8 times the diameter of the minimum specification grinding ball, which can effectively prevent the grinding ball from entering the guide groove 110 and hinder the slurry from flowing upward or downward along the guide groove 110.

[0024] In one embodiment, the feed port includes a solid feed port 141 and a liquid feed port 142, which are respectively disposed at the top and bottom of the grinding container 100. As will be appreciated, the solid feed port 141 is primarily used for adding silicon nitride powder, while the liquid feed port 142 is primarily used for injecting a mixture of resin and additives. Newly added resin, powder, grinding aid, and dispersant enter the system through the solid feed port 141 and the liquid feed port 142, thereby enabling the present invention to become a continuous, desktop-level production device for high-solids ceramic slurries.

[0025] Furthermore, solid feed port 141 is located near the axis of grinding container 100 and is connected to feed guide 160. Liquid feed port 142 is connected to liquid feed pipe 170. As will be appreciated, powder is added through feed guide 160, located near the top axis of grinding container 100, while liquid resin is pressure-fed through a resin inlet pipe located near the bottom center of grinding container 100.

[0026] In one embodiment, a baffle 150 is provided on the inner wall of the grinding container 100 to confine the grinding balls to the area below the baffle 150. It is understood that when the stirring mechanism 200 is in operation, the grinding balls rise along the inner wall of the grinding container 100 to the baffle 150, where they are blocked and fall from a height, driving the slurry to move. The slurry encounters the baffle 150 and the container wall, forming a backflow from bottom to top, thereby enhancing the shearing and grinding effect of the grinding balls on the powder particles. At the same time, due to the upward movement of the fluid, the finely ground slurry will pass through the baffle 150 and move upward along the guide groove 110, facilitating the discharge of the finished slurry.

[0027] Furthermore, the baffle 150 is annular and detachably connected to the inner wall of the grinding container 100. The radial width of the baffle 150 is 0.15 to 0.45 times the inner diameter of the grinding container 100, and the baffle 150 is located at a height of 0.4 to 0.6 times the inner height of the grinding container 100. The baffle 150 is provided with evenly distributed mounting slots 151 to facilitate the passage of the paddle 230 during installation and maintenance.

[0028] In one embodiment, the internal volume of the grinding container 100 is 0.5L to 2L. The ceramic slurry grinding production apparatus provided by the present invention is a desktop-level production device. Under the premise of mature process parameters such as grinding aids and dispersants, it can achieve continuous and efficient grinding of various ceramic slurries in a sufficiently small space, such as a 1L effective volume, and with less than 1kW of total machine power consumption, allowing for the immediate use of qualified slurry, thereby improving slurry production efficiency.

[0029] In one embodiment, the stirring mechanism 200 includes a motor 210 and a stirring paddle connected to an output shaft of the motor 210 .

[0030] In one embodiment, the agitator comprises a main shaft 220 and a plurality of groups of blades 230 disposed on the main shaft 220. Each group of blades 230 is evenly distributed around the main shaft 220, and the length of the blades 230 gradually decreases from the end of the main shaft 220 to the area near the motor 210. It is understood that the plurality of blades 230 are arranged in multiple layers along the main shaft 220, with each layer forming a group. Each group comprises at least three blades 230, with the blades 230 near the motor 210 being shorter, the blades 230 near the grinding container 100 being longer, and the blades 230 in the middle being of moderate length. The slurry at the middle blades 230 is generally of acceptable quality, exhibiting low viscosity and high fluidity. Furthermore, the number of grinding balls at this height is small, making it easier to form a significant rotating laminar flow at a lower stirring linear velocity. Furthermore, the flow rate decreases as the distance from the agitator (the closer to the wall of the grinding container 100) increases. At this point, only the slurry with higher fluidity can significantly elevate the liquid level due to the vortex effect generated by the rotation, until it reaches a level above the discharge port, allowing the slurry to naturally overflow and become acceptable. The shape of the blade 230 is preferably cylindrical, but may also be other shapes.

[0031] In this embodiment, the grinding container 100 is cylindrical in shape.

[0032] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0033] The one or more embodiments of this application are intended to encompass all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this application should be included in the scope of protection of this application.

Claims

1. A ceramic slurry grinding production device, characterized in that: include: A grinding container (100), wherein at least one flow guiding groove (110) extending obliquely upward is provided on the inner wall of the grinding container (100), a discharge pipe (120) is provided on the grinding container (100), a screen (130) is provided between the discharge pipe (120) and the top of the flow guiding groove (110), and a feed inlet is provided on the grinding container (100); as well as The stirring mechanism (200) is used to stir the ceramic slurry to rotate and flow in the grinding container (100).

2. The ceramic slurry grinding production device according to claim 1, characterized in that: The inclination angle of the guide groove (110) is 20° to 55°.

3. The ceramic slurry grinding production device according to claim 1, characterized in that: The width of the guide groove (110) does not exceed 0.8 times the diameter of the grinding ball.

4. The ceramic slurry grinding production device according to claim 1, characterized in that: The feed inlet comprises a solid feed inlet (141) and a liquid feed inlet (142), and the solid feed inlet (141) and the liquid feed inlet (142) are respectively arranged at the top and the bottom of the grinding container (100).

5. The ceramic slurry grinding production device according to claim 4, characterized in that: The solid feed inlet (141) is close to the axis of the grinding container (100), and the solid feed inlet (141) is connected to a feed guide member (160).

6. The ceramic slurry grinding production device according to any one of claims 1 to 5, characterized in that: A baffle plate (150) is provided on the inner wall of the grinding container (100) and is used to limit the grinding balls to the area below the baffle plate (150).

7. The ceramic slurry grinding production device according to claim 6, characterized in that: The baffle plate (150) is in the shape of a circular ring structure, and the radial width of the baffle plate (150) is 0.15 to 0.45 times the inner diameter of the grinding container (100), and the baffle plate (150) is located at 0.4 to 0.6 times the inner cavity height of the grinding container (100).

8. The ceramic slurry grinding production device according to any one of claims 1 to 5 and 7, characterized in that: The inner cavity volume of the grinding container (100) is 0.5L~2L.

9. The ceramic slurry grinding production device according to any one of claims 1 to 5 and 7, characterized in that: The stirring mechanism (200) comprises a motor (210) and a stirring paddle connected to an output shaft of the motor (210).

10. The ceramic slurry grinding production device according to claim 9, characterized in that: The stirring paddle comprises a main shaft (220) and a plurality of groups of paddles (230) arranged on the main shaft (220), each group of paddles (230) is evenly distributed around the main shaft (220), and the length of the paddles (230) gradually shortens from the end of the main shaft (220) to a position close to the motor (210).

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