Closed cycle vertical sand mill

Abstract

The present application relates to vertical sand mill technical field, specifically to a kind of closed circulation vertical sand mill, using the stirring tank, feed pump and vertical grinding device communicated in turn, vertical grinding device includes vertical grinding body, overflow shell, driving spindle, static ring, dynamic ring, centrifugal rotor and screen, when using, material is stirred in stirring tank, pumped into vertical grinding device by feed pump, material flows into overflow shell by screen and dynamic ring, without mechanical seal, avoid the problem that material easily leaks by using mechanical seal setting, screen, dynamic ring and static ring are used to prevent grinding medium from entering overflow shell, and grinding medium is thrown to periphery under the action of centrifugal rotor to avoid grinding medium and screen friction and cause screen damage, material is overflowed into stirring tank by the high-low liquid level difference of stirring tank, form closed circulation, ensure the stability of product quality.

Description

Technical Field

[0001] This invention relates to the field of vertical sand mill technology, and more specifically to a closed-loop vertical sand mill. Background Technology

[0002] Traditional vertical sand mills use a feed pump to feed a pre-dispersed and wetted liquid-solid mixture into the mill cylinder from the bottom. The material, along with the grinding media (such as zirconia beads, glass beads, zirconium silicate beads, etc.) inside the mill cylinder, is agitated by a high-speed rotating disperser. This creates intense shearing and impact forces between the solid particles in the material and the grinding media, achieving the purpose of grinding fine particles and dispersing aggregates. The ground and dispersed liquid-solid suspension then flows out through a separator (screen separator) at the top of the mill cylinder, enabling continuous processing and continuous discharge.

[0003] Traditional vertical sand mills mostly use mechanical seals to seal the through hole between the main shaft and the grinding cylinder / bearing seat to prevent material leakage. However, the materials being ground are usually nanoscale or solvent-based, so mechanical seals are still prone to leakage. In addition, the screen is usually fixed to the grinding cylinder, which can easily cause screen clogging. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a closed-loop vertical sand mill.

[0005] The objective of this invention is achieved through the following technical solution: a closed-loop vertical sand mill, comprising a mixing tank, a feed pump, and a vertical grinding device connected in sequence. The vertical grinding device includes a vertical grinding body, an overflow shell disposed on the top of the vertical grinding body, a drive shaft penetrating the overflow shell and extending into the vertical grinding body, a stationary ring connected between the vertical grinding body and the overflow shell, a rotating ring fixedly sleeved on the drive shaft and rotatably engaged with the stationary ring, a centrifugal rotor fixedly sleeved on the drive shaft and housed in the vertical grinding body, and a screen annularly fixedly connected between the centrifugal rotor and the rotating ring. The distance between the stationary ring and the rotating ring is smaller than the outer diameter of the grinding medium. The centrifugal rotor, screen, rotating ring, overflow shell, and mixing tank are connected in sequence along the material flow direction.

[0006] Preferably, there is a discharge gap between the screen and the drive shaft, the overflow housing has an overflow cavity, and the moving ring has a discharge channel communicating with the discharge gap and the overflow cavity.

[0007] Preferably, the overflow shell has a discharge port that communicates with the mixing tank at one end near the stationary ring.

[0008] Preferably, the vertical grinding device further includes a drive motor fixedly connected to the top of the overflow housing, and the output end of the drive motor is fixedly connected to the drive spindle.

[0009] Preferably, the top outer side of the overflow housing is provided with an overflow groove and a clearance hole for the drive spindle to pass through, the top inner side of the overflow housing is limited by a rotary sealing ring sleeved on the drive spindle, and the side wall of the overflow housing is provided with an overflow port communicating with the bottom side of the overflow groove.

[0010] Preferably, the vertical grinding body includes a base, a cooling water jacket fixedly connected to the base, an inner cylinder fixedly connected to the base and housed within the cooling water jacket, a top cover fixedly connected to the top of the cooling water jacket, and a guide cover fixedly connected to the top of the inner cylinder. The guide cover has a clearance opening in the middle, and a guide ring extending into the centrifugal rotor is provided from the clearance opening of the guide cover. The guide ring is inclined from top to bottom towards the screen.

[0011] Preferably, the side wall of the top cover has a medium inlet for adding grinding media, and the guide cover has a medium through hole connecting the medium inlet and the inner cylinder.

[0012] Preferably, the centrifugal rotor includes a centrifugal bottom ring and a centrifugal cylinder connected to the outer ring of the centrifugal bottom ring. The centrifugal bottom ring has a plurality of first through holes arranged in a ring, and the centrifugal cylinder has a plurality of second through holes arranged in a ring. An external throwing channel for the flow of grinding media is provided between the centrifugal cylinder and the flow guide cover.

[0013] Preferably, one end of the drive spindle extending into the inner cylinder is connected to a pin or a disc; the base has a feed port that communicates with the inner cylinder.

[0014] The beneficial effects of the present invention are as follows: The closed-loop vertical sand mill of the present invention adopts a mixing tank, a feed pump and a vertical grinding device connected in sequence. The vertical grinding device includes a vertical grinding body, an overflow shell disposed on the top of the vertical grinding body, a drive shaft that penetrates the overflow shell and extends into the vertical grinding body, a stationary ring connected between the vertical grinding body and the overflow shell, a rotating ring fixedly sleeved on the drive shaft and rotatably engaged with the stationary ring, a centrifugal rotor fixedly sleeved on the drive shaft and housed in the vertical grinding body, and a screen fixedly connected annularly between the centrifugal rotor and the rotating ring. The distance between the stationary ring and the rotating ring is smaller than the outer diameter of the grinding medium. The centrifugal rotor, screen, rotating ring, overflow shell and mixing tank are connected in sequence along the flow direction of the material. During operation, materials are stirred in the mixing tank and then pumped to the vertical grinding unit for grinding via a feed pump. The materials flow through a screen and a rotating ring into the overflow shell, eliminating the need for a mechanical seal and avoiding the leakage problems associated with mechanical seals. Simultaneously, the screen, rotating ring, and stationary ring prevent grinding media from entering the overflow shell, and the centrifugal rotor throws the grinding media to the periphery to prevent damage to the screen due to friction. The material overflows back into the mixing tank due to the high and low liquid level difference, forming a closed-loop circulation. This allows the material to continuously flow between the mixing tank and the grinding mill, creating a continuous processing process. This ensures uniform distribution and thorough grinding of the material within the grinding mill. Because the material is continuously agitated and mixed during circulation, localized over-grinding or under-grinding is avoided, thus guaranteeing product quality stability. Furthermore, it eliminates the need for downtime, cleaning, and restarting required in batch processing, significantly improving production efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the vertical grinding device described in this invention; Figure 3 This is a schematic diagram of the structure of the vertical grinding body described in this invention; Figure 4 This is a schematic diagram of the centrifugal rotor described in this invention; Figure 5 This is a schematic diagram of the flow guide cover described in this invention.

[0016] The attached figures are labeled as follows: 1. Mixing tank; 2. Feed pump; 3. Vertical grinding device; 31. Vertical grinding body; 311. Base; 312. Cooling water jacket; 313. Inner cylinder; 314. Top cover; 315. Guide cover; 32. Overflow shell; 33. Drive shaft; 34. Stationary ring; 35. Moving ring; 36. Centrifugal rotor; 361. Centrifugal bottom ring; 362. Centrifugal cylinder; 37. Screen; 4. Discharge gap; 5. Overflow cavity; 6. Discharge channel; 7. Discharge port; 8. Drive motor; 9. Overflow groove; 10. Rotary sealing ring; 11. Overflow port; 12. Clearance port; 13. Guide ring; 14. Medium port; 15. Medium through hole; 16. First through hole; 17. Second through hole; 18. External throwing channel; 19. Disc; 20. Feed port. Detailed Implementation

[0017] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0018] like Figure 1-5 As shown, a closed-loop vertical sand mill includes a mixing tank 1, a feed pump 2, and a vertical grinding device 3 connected in sequence. The vertical grinding device 3 includes a vertical grinding body 31, an overflow shell 32 disposed on the top of the vertical grinding body 31, a drive shaft 33 penetrating the overflow shell 32 and extending into the vertical grinding body 31, a stationary ring 34 connected between the vertical grinding body 31 and the overflow shell 32, a rotating ring 35 fixedly sleeved on the drive shaft 33 and rotatably engaged with the stationary ring 34, a centrifugal rotor 36 fixedly sleeved on the drive shaft 33 and housed in the vertical grinding body 31, and a screen 37 annularly fixedly connected between the centrifugal rotor 36 and the rotating ring 35. The distance between the stationary ring 34 and the rotating ring 35 is smaller than the outer diameter of the grinding medium, which can intercept the grinding medium while allowing the material to pass through smoothly. The centrifugal rotor 36, the screen 37, the rotating ring 35, the overflow shell 32, and the mixing tank 1 are connected in sequence along the material flow direction.

[0019] During operation, the material is stirred in the mixing tank 1. The material in the mixing tank 1 is pumped to the vertical grinding device 3 for grinding by the feed pump 2. The material flows into the overflow shell 32 through the screen 37 and the moving ring 35. No mechanical seal is required, avoiding the problem of easy material leakage that occurs with mechanical seals. At the same time, the screen 37, the moving ring 35, and the stationary ring 34 prevent the grinding media from entering the overflow shell 32. Under the action of the centrifugal rotor 36, the grinding media is thrown to the outside to avoid damage to the screen 37 due to friction between the grinding media and the screen 37. The material overflows back into the mixing tank 1 through the high and low liquid level difference, forming a closed loop. This allows the material to flow continuously between the mixing tank 1 and the grinding mill, forming a continuous processing process. This ensures that the material is evenly distributed and fully ground in the grinding mill. Because the material is continuously stirred and mixed during the circulation process, the problem of local over-grinding or under-grinding is avoided, thus ensuring the stability of product quality. It also avoids the steps of stopping, cleaning, and restarting in batch processing, thereby significantly improving production efficiency.

[0020] Furthermore, a discharge gap 4 exists between the screen 37 and the drive shaft 33, the overflow housing 32 has an overflow cavity 5, and the moving ring 35 has a discharge channel 6 communicating with the discharge gap 4 and the overflow cavity 5. When the drive shaft 33 rotates, the screen 37 rotates together with the drive shaft 33 to prevent material from clogging the screen 37; the finely ground material passes through the screen 37 and then enters the overflow cavity 5 through the discharge channel 6 for discharge, eliminating the need for a mechanical seal.

[0021] Furthermore, the overflow shell 32 has a discharge port 7 connected to the mixing tank 1 at one end near the stationary ring 34. The finely ground material passes through the screen 37 and enters the overflow inner cavity 5 through the discharge channel 6, and then overflows into the mixing tank 1 from the discharge port 7.

[0022] Furthermore, the vertical grinding device 3 also includes a drive motor 8 fixedly connected to the top of the overflow housing 32, and the output end of the drive motor 8 is fixedly connected to the drive spindle 33.

[0023] Furthermore, the top outer side of the overflow housing 32 is provided with an overflow groove 9 and a clearance hole for the drive spindle 33 to pass through. A rotary sealing ring 10, fitted onto the drive spindle 33, is provided on the top inner side of the overflow housing 32. An overflow port 11, communicating with the bottom side of the overflow groove 9, is provided on the side wall of the overflow housing 32. On one hand, the rotary sealing ring 10 prevents material from overflowing from the top of the overflow housing 32 and corroding the motor. On the other hand, the overflow groove 9 on the top of the overflow housing 32 and the overflow port 11 on the side wall ensure that even if material overflows from the top of the overflow housing 32, the overflowing material can be discharged promptly through the overflow groove 9 and the overflow port 11, preventing corrosion of the motor.

[0024] Furthermore, the vertical grinding body 31 includes a base 311, a cooling water jacket 312 fixedly connected to the base 311, an inner cylinder 313 fixedly connected to the base 311 and housed within the cooling water jacket 312, a top cover 314 fixedly connected to the top of the cooling water jacket 312, and a guide cover 315 fixedly connected to the top of the inner cylinder 313. The guide cover 315 has a clearance opening 12 in its center, and a guide ring 13 extends from the clearance opening 12 into the centrifugal rotor 36. The guide ring 13 is inclined from top to bottom towards the screen 37. The guide ring 13 facilitates the guidance of the grinding media to the centrifugal rotor 36, preventing the grinding media from rising and accumulating on the moving ring 35. The combined action of the centrifugal rotor 36 and the guide ring 13 further facilitates the throwing of the grinding media to the periphery, preventing the grinding media from rubbing against the screen 37 and causing damage to the screen 37.

[0025] Furthermore, the top cover 314 has a media inlet 14 on its side wall for adding grinding media, and the guide cover 315 has a media through hole 15 connecting the media inlet 14 and the inner cylinder 313. In this embodiment, the grinding media is zirconium balls.

[0026] Furthermore, the centrifugal rotor 36 includes a centrifugal bottom ring portion 361 and a centrifugal cylinder portion 362 connected to the outer ring of the centrifugal bottom ring portion 361. The centrifugal bottom ring portion 361 has a plurality of annularly distributed first through holes 16, and the centrifugal cylinder portion 362 has a plurality of annularly distributed second through holes 17. An external throwing channel 18 for the flow of grinding media is provided between the centrifugal cylinder portion 362 and the guide cover 315. The centrifugal rotation of the centrifugal bottom ring portion 361 and the centrifugal cylinder portion 362 throws out the grinding media, avoiding friction between the grinding media and the screen 37 and causing damage to the screen 37.

[0027] Furthermore, one end of the drive spindle 33 extending into the inner cylinder 313 is connected to a pin or a disc 19; the base 311 has a feed inlet 20 communicating with the inner cylinder 313. After the material enters the inner cylinder 313 through the feed inlet 20, the drive spindle 33 drives the pin or disc 19 to rotate, stirring the material and grinding media, generating frictional shearing to grind the material. In this embodiment, one end of the drive spindle 33 extending into the inner cylinder 313 is connected to a disc 19.

[0028] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A closed-loop vertical sand mill, characterized in that: The system includes a mixing tank (1), a feed pump (2), and a vertical grinding device (3) connected in sequence. The vertical grinding device (3) includes a vertical grinding body (31), an overflow housing (32) disposed on the top of the vertical grinding body (31), a drive spindle (33) that penetrates the overflow housing (32) and extends into the vertical grinding body (31), a stationary ring (34) connecting the vertical grinding body (31) and the overflow housing (32), and a ring that is fixedly sleeved on the drive spindle (33) and connected to the stationary ring (34). The centrifugal rotor (36) is fixedly sleeved on the drive shaft (33) and housed in the vertical grinding body (31), and the screen (37) is annularly fixedly connected between the centrifugal rotor (36) and the rotating ring (35). The distance between the stationary ring (34) and the rotating ring (35) is smaller than the outer diameter of the grinding medium. The centrifugal rotor (36), the screen (37), the rotating ring (35), the overflow shell (32) and the mixing tank (1) are connected in sequence along the flow direction of the material.

2. The closed-loop vertical sand mill according to claim 1, characterized in that: There is a discharge gap (4) between the screen (37) and the drive shaft (33), the overflow housing (32) has an overflow cavity (5), and the moving ring (35) has a discharge channel (6) that communicates with the discharge gap (4) and the overflow cavity (5).

3. A closed-loop vertical sand mill according to claim 1, characterized in that: The overflow shell (32) has a discharge port (7) connected to the mixing tank (1) at one end near the stationary ring (34).

4. A closed-loop vertical sand mill according to claim 1, characterized in that: The vertical grinding device (3) also includes a drive motor (8) fixedly connected to the top of the overflow housing (32), and the output end of the drive motor (8) is fixedly connected to the drive spindle (33).

5. A closed-loop vertical sand mill according to claim 4, characterized in that: The top outer side of the overflow housing (32) is provided with an overflow groove (9) and a clearance hole for the drive spindle (33) to pass through. The top inner side of the overflow housing (32) is limited and connected with a rotary sealing ring (10) sleeved on the drive spindle (33). The side wall of the overflow housing (32) is provided with an overflow port (11) communicating with the bottom side of the overflow groove (9).

6. A closed-loop vertical sand mill according to claim 1, characterized in that: The vertical grinding body (31) includes a base (311), a cooling water jacket (312) fixedly connected to the base (311), an inner cylinder (313) fixedly connected to the base (311) and housed in the cooling water jacket (312), a top cover (314) fixedly connected to the top of the cooling water jacket (312), and a guide cover (315) fixedly connected to the top of the inner cylinder (313). The guide cover (315) has a clearance opening (12) in the middle. The clearance opening (12) of the guide cover (315) extends into a guide ring (13) that extends into the centrifugal rotor (36). The guide ring (13) is inclined from top to bottom towards the screen (37).

7. A closed-loop vertical sand mill according to claim 6, characterized in that: The top cover (314) has a media inlet (14) for adding grinding media on its side wall, and the guide cover (315) has a media through hole (15) connecting the media inlet (14) and the inner cylinder (313).

8. A closed-loop vertical sand mill according to claim 6, characterized in that: The centrifugal rotor (36) includes a centrifugal bottom ring (361) and a centrifugal cylinder (362) connected to the outer ring of the centrifugal bottom ring (361). The centrifugal bottom ring (361) has a plurality of first through holes (16) arranged in annularly. The centrifugal cylinder (362) has a plurality of second through holes (17) arranged in annularly. There is an external throwing channel (18) between the centrifugal cylinder (362) and the flow guide cover (315) for the flow of grinding media.

9. A closed-loop vertical sand mill according to claim 6, characterized in that: The drive spindle (33) is connected to a pin or a disc (19) at one end of its extension into the inner cylinder (313); the base (311) has a feed port (20) that communicates with the inner cylinder (313).

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