A paper pulp refining equipment and its process

Abstract

This invention provides a paper pulp refining device and process, relating to the field of papermaking technology. It includes a carrier plate, a fixed outer shell, an upper grinding disc, a drive assembly, a middle grinding disc, a disc cover, a lower grinding disc, and a discharge pipe. This invention uses a rotating middle grinding disc to form a first processing area with the upper grinding disc and a second processing area with the lower grinding disc, thereby maintaining appropriate fiber thickness and length and improving the fibrillation rate. During the rotation of the slitting scraper at the bottom of the upper grinding disc, it shears and kneads the fibers against the edge of the second groove. The pulp flowing into the second groove flows obliquely upward under the action of centrifugal force. In the shallower part of the second groove, the fibers can be repeatedly sheared and kneaded, improving refining efficiency. Under the action of centrifugal force, the pulp flows outward, ensuring smooth flow throughout the process and reducing the likelihood of clogging. Furthermore, the use of centrifugal force to drive the pulp flow accelerates the refining efficiency.

Description

Technical Field

[0001] This invention relates to the field of papermaking technology, specifically to a paper pulp refining equipment and its process. Background Technology

[0002] In recent years, with the rapid development of my country's economy and the improvement of people's living standards, the consumption of household paper has shown a steady growth trend, and the production capacity of household paper has also been gradually increasing. There is still considerable room for growth in my country's per capita consumption of household paper, indicating a huge potential for growth.

[0003] In recent years, my country's tissue paper market has been one of the most active paper product markets in the world. The continuous expansion of tissue paper production capacity has stimulated domestic economic growth and improved people's living standards. At the same time, the competitive pressure in the tissue paper market will further increase. Therefore, the optimization of paper pulp refining equipment and its processes is one of the more important research topics in the next few years.

[0004] The pulp is separated into long-fiber pulping line and short-fiber pulping line starting from the pulper, and the subsequent refining is also carried out separately until the pulp is mixed. After the long and short fibers are evenly mixed, the pulp is loaded. This process requires more than two sets of refining equipment, which makes the investment in papermaking cost relatively large. However, the current refining equipment is not suitable for adding some short fibers into the long fiber pulping pot during pulping and pulping them together with the long fibers before refining. Therefore, the present invention provides a paper pulp refining equipment and process to reduce the equipment cost investment in the refining process. Summary of the Invention

[0005] Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a paper pulp refining device and its process, which solves the problem that current refining devices are not suitable for adding some short fibers into the long fiber disintegration pot during pulp disintegration and disintegrating them together with the long fibers before refining.

[0007] Technical solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A paper pulp refining apparatus, comprising:

[0010] A carrier plate, the bottom of which is fixedly mounted with a base frame;

[0011] A fixed outer shell is fixedly installed on the top of the carrier plate, and the inner side of the fixed outer shell forms a stepped section that is larger at the top and smaller at the bottom;

[0012] The upper grinding disc is fixedly installed on the stepped part of the fixed outer shell. The upper grinding disc includes a first disc body. The top of the first disc body is provided with a strip-shaped hole arranged radially along the first disc body. A slitting scraper is fixedly connected to the bottom of the first disc body. The slitting scraper is long and strip-shaped and arranged radially along the first disc body. There are multiple slitting scrapers arranged in a ring array.

[0013] A drive assembly, which is fixedly mounted on a base frame and whose rotating shaft extends into the interior of a fixed housing;

[0014] The middle grinding disc is located inside the fixed outer shell, below the upper grinding disc. The middle grinding disc is fixedly connected to the rotating shaft. The top of the middle grinding disc has a first groove and a second groove. The first groove and the second groove are both elongated and arranged radially along the middle grinding disc. The depth of the first groove and the second groove gradually increases from the outer end toward the center of the middle grinding disc. The deepest part of the first groove has an overflow port leading to the bottom of the middle grinding disc. One first groove and one second groove constitute a unit hole group. There are multiple unit hole groups, which are arranged in a ring array. The top of the middle grinding disc has an annular groove. The outer ends of all the first grooves and the second grooves are connected to the annular groove. The bottom of the middle grinding disc is a conical surface.

[0015] The disc cover includes an annular component, and a blocking plate is fixedly connected to the inner side of the annular component. The annular component corresponds to an annular groove, and the number and position of the blocking plates correspond to the first groove opening.

[0016] The lower grinding disc is fixedly connected to the bottom end of the fixed housing, and the top of the lower grinding disc is provided with a conical surface. The top of the lower grinding disc corresponds to the bottom end of the middle grinding disc. The inner side of the fixed housing and located between the middle grinding disc and the lower grinding disc form an annular cavity.

[0017] The discharge pipe has one end fixedly connected to the fixed outer shell and is connected to the annular chamber.

[0018] Preferably, the top end of the rotating shaft passes through the upper grinding disc, and the rotating shaft is rotatably connected to the upper grinding disc. A rotating grate is fixedly connected to the top end of the rotating shaft, and a feed hopper is fixedly connected to the top of the fixed outer shell.

[0019] Preferably, the rotating grate includes: a mounting ring and a strip, the mounting ring being sleeved on the rotating shaft and fixedly connected by a key, and one end of the strip being fixedly connected to the outer side of the mounting ring.

[0020] Preferably, the feed hopper includes: an annular shallow portion, an annular deep portion is provided on the inner side of the annular shallow portion, a central cap is fixedly connected to the center of the annular deep portion, and a drop hole is provided at the inner bottom of the annular deep portion.

[0021] Preferably, the discharge pipe includes: a guide pipe and a conveying pipe, the conveying pipe being fixedly connected to the carrier plate, one end of the guide pipe being fixedly connected to the fixed housing, and the other end of the guide pipe being fixedly connected to the side of the conveying pipe.

[0022] Preferably, the lower grinding disc has a central hole, the rotating shaft is located inside the central hole of the lower grinding disc, and the rotating shaft and the central hole of the lower grinding disc are rotatably connected by a sealed bearing.

[0023] Preferably, the bottom conical surface of the middle grinding disc is provided with a spiral protrusion, and the top conical surface of the lower grinding disc is provided with a plurality of concentric annular protrusions.

[0024] A paper pulp refining process, characterized by comprising the following steps;

[0025] S1. During pulping, short fibers and long fibers are ground together using the above-mentioned pulping equipment.

[0026] S2. During the grinding process, the rotation speed of the drive component shaft is controlled to be 100-500 rpm.

[0027] Preferably, the ratio of short fibers to long fibers is 1:3.5-5.2.

[0028] Beneficial effects

[0029] This invention provides a paper pulp refining apparatus and process. It has the following beneficial effects:

[0030] 1. This invention employs a rotating middle grinding disc and an upper grinding disc to form a first processing area, and a lower grinding disc to form a second processing area. This allows for maintaining appropriate fiber thickness and length, thereby improving the fiber sizing rate. Specifically, during the rotation of the slitting scraper at the bottom of the upper grinding disc, the fiber is sheared and kneaded against the edge of the second groove. The slurry flowing into the second groove flows obliquely upward under the action of centrifugal force. The fiber can be repeatedly sheared and kneaded at a shallower position in the second groove, improving the pulping efficiency. Furthermore, centrifugal force drives the slurry into the annular groove. When there is a large amount of solution inside the annular groove or when rotation stops, the slurry is forced into the first groove and then flows down from the overflow port. The same applies to the second processing area, where the slurry flows outward under the action of centrifugal force. The entire process ensures smooth slurry flow and reduces the risk of clogging. Moreover, the use of centrifugal force to drive the slurry flow accelerates the pulping efficiency.

[0031] 2. This invention uses a mixture of long and short fibers for pulping, which reduces the cutting ratio of long fibers to a certain extent, increases the tensile strength and stiffness of the product, and uses the paper pulping equipment provided by this device, thereby optimizing the pulping process, reducing the use of pulping auxiliary equipment, and reducing the equipment cost investment in the pulping process. Attached Figure Description

[0032] Figure 1 This is a perspective view of a paper pulp refining apparatus proposed in this invention;

[0033] Figure 2 This is a front view of a paper pulp refining apparatus proposed in this invention;

[0034] Figure 3 This is a side view of a paper pulp refining apparatus proposed in this invention;

[0035] Figure 4 This is a top view of a paper pulp refining apparatus proposed in this invention;

[0036] Figure 5 for Figure 4 Cross-sectional view of section line AA in the middle;

[0037] Figure 6 for Figure 5 Enlarged view of a section at point B in the middle;

[0038] Figure 7 This is a three-dimensional schematic diagram of the upper, middle, and lower grinding discs of a paper pulp refining device proposed in this invention;

[0039] Figure 8 This is a three-dimensional schematic diagram of the upper and middle grinding discs of a paper pulp refining device proposed in this invention;

[0040] Figure 9 This is a three-dimensional schematic diagram of the upper and middle grinding discs of a paper pulp refining device proposed in this invention;

[0041] Figure 10 This is a three-dimensional schematic diagram of the grinding disc in a paper pulp refining device proposed in this invention.

[0042] Figure 11 This is a top view of the grinding disc in a paper pulp refining device proposed in this invention.

[0043] Figure 12 This is a three-dimensional schematic diagram of the disc cover of a paper pulp refining device proposed in this invention.

[0044] The components are as follows: 1. Carrier plate; 2. Base frame; 3. Drive assembly; 4. Discharge pipe; 41. Drain pipe; 42. Conveying pipe; 5. Fixed outer shell; 6. Feed hopper; 61. Shallow annular section; 62. Deep annular section; 63. Drop hole; 64. Center cap; 7. Upper grinding disc; 71. First disc body; 72. Strip hole; 73. Slitting scraper; 8. Rotating shaft; 9. Rotating grate; 91. Mounting ring; 92. Strip component; 10. Middle grinding disc; 101. First groove; 102. Second groove; 103. Overflow port; 104. Annular groove; 11. Lower grinding disc; 12. Annular chamber; 13. Disc cover; 131. Blocking plate; 132. Annular component. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1:

[0047] like Figures 1-12 As shown, an embodiment of the present invention provides a paper pulp refining device, including a carrier plate 1, a fixed outer shell 5, an upper grinding disc 7, a drive assembly 3, a middle grinding disc 10, a disc cover 13, a lower grinding disc 11, and a discharge pipe 4.

[0048] A base frame 2 is fixedly installed on the bottom of the carrier plate 1 for fixing the drive assembly 3. The drive assembly 3 is fixedly installed on the base frame 2. The drive assembly 3 uses an AC variable frequency speed control motor to control the rotation speed of the rotating shaft 8. The fixed housing 5 is fixedly installed on the top of the carrier plate 1, and the inner side of the fixed housing 5 forms a stepped part that is larger at the top and smaller at the bottom. The upper grinding disc 7 is fixedly installed on the stepped part of the fixed housing 5. The stepped part is used to position the upper grinding disc 7. The upper grinding disc 7 includes a first disc body 71. The top of the first disc body 71 has a strip-shaped hole 72 arranged radially along the first disc body 71. The slurry located above can flow downward along the strip-shaped hole 72. Multiple strip-shaped holes 72 can be provided to uniformly deliver the slurry downward. The first grinding disc 71 is fixedly connected to the bottom of a slitting scraper 73. The slitting scraper 73 is elongated and arranged radially along the first grinding disc 71. There are multiple slitting scrapers 73 arranged in a circular array. The middle grinding disc 10 is located inside the fixed housing 5, below the upper grinding disc 7. The area between the middle grinding disc 10 and the upper grinding disc 7 forms the first processing area. The rotating shaft 8 of the drive assembly 3 extends into the fixed housing 5. The middle grinding disc 10 is fixedly connected to the rotating shaft 8. The drive assembly 3 drives the rotating shaft 8 to rotate, thereby driving the middle grinding disc 10 to rotate relative to the stationary upper grinding disc 7. The bottom of the slitting scraper 73 shears and kneads the slurry in the first processing area. The top of the middle grinding disc 10 has a first slot 10. 1. The second slot 102, the first slot 101, and the second slot 102 are all elongated and arranged radially along the middle grinding disc 10. The depth of the first slot 101 and the second slot 102 gradually increases from the outer end toward the center of the middle grinding disc 10. The slurry tends to flow downward under its own gravity, but in the rotating second slot 102, it also tends to move upward under the action of centrifugal force. The deepest part of the first slot 101 is provided with an overflow port 103 leading to the bottom of the middle grinding disc 10. One first slot 101 and one second slot 102 constitute a unit hole group. Multiple unit hole groups are provided and distributed in a ring array. The top of the middle grinding disc 10 is provided with an annular groove 104. All the first slots 101 and 102 are arranged in a ring array. The outer ends of the slots 101 and 102 are both connected to the annular groove 104. The cover 13 includes an annular component 132. A blocking plate 131 is fixedly connected to the inner side of the annular component 132. The annular component 132 corresponds to the annular groove 104. The number and position of the blocking plates 131 correspond to the first slot 101. The lower grinding disc 11 is fixedly connected to the bottom end of the fixed housing 5. The top of the lower grinding disc 11 is provided with a conical surface. The bottom end of the middle grinding disc 10 is a conical surface. The top of the lower grinding disc 11 corresponds to the bottom end of the middle grinding disc 10, forming a conical second processing area. An annular chamber 12 is formed on the inner side of the fixed housing 5 between the middle grinding disc 10 and the lower grinding disc 11. One end of the discharge pipe 4 is fixedly connected to the fixed housing 5, and the discharge pipe 4 is connected to the annular chamber 12.

[0049] In use, the pulped slurry is transported to the inside of the fixed housing 5, above the upper grinding disc 7, and flows downward through the strip hole 72 into the first processing area. After initial processing, it flows into the inside of the second groove 102 and rotates together with the middle grinding disc 10. Under the action of centrifugal force, it flows outward along the inner bottom of the second groove 102 and simultaneously flows upward, where it undergoes a second shearing and kneading with the slitting scraper 73. Then, it enters the annular groove 104. Liquid accumulates inside the annular groove 104, and some of the slurry enters the first groove 101. Subsequently, it flows into the second processing area from the overflow port 103. The fluid inside the second processing area continues to rotate with the middle grinding disc 10. After being kneaded in the second processing area, it flows outward into the annular chamber 12 under the action of centrifugal force and finally flows outward through the discharge pipe 4.

[0050] In one embodiment, the top end of the rotating shaft 8 passes through the upper grinding disc 7, and the rotating shaft 8 is rotatably connected to the upper grinding disc 7. A rotating grate 9 is fixedly connected to the top end of the rotating shaft 8, and a feed hopper 6 is fixedly connected to the top of the fixed housing 5.

[0051] The rotating grate 9 rotates together with the rotating shaft 8, which can scrape the strip hole 72 of the upper grinding disc 7 to prevent liquid from accumulating at the edge of the strip hole 72 and causing blockage. The feed hopper 6 is used to provide a larger feeding area to prevent the slurry from spilling on the top of the fixed housing 5.

[0052] In one embodiment, the rotating grate 9 includes: a mounting ring 91 and a strip 92. The mounting ring 91 is sleeved on the rotating shaft 8 and fixedly connected by a key, so that the mounting ring 91 rotates together with the rotating shaft 8. One end of the strip 92 is fixedly connected to the outer side of the mounting ring 91, and the strip 92 extends radially along the rotating shaft 8.

[0053] In one embodiment, the feed hopper 6 includes: an annular shallow portion 61, an annular deep portion 62 is provided on the inner side of the annular shallow portion 61, a center cap 64 is fixedly connected to the center of the annular deep portion 62, and a drop hole 63 is provided at the inner bottom of the annular deep portion 62.

[0054] The center cap 64 makes way for the top of the rotating shaft 8, while the liquid flowing downward from the drop hole 63 at the annular depth 62 is more uniform.

[0055] In one embodiment, a drainage tube 41 and a delivery tube 42 are provided. The delivery tube 42 is fixedly connected to the carrier plate 1. One end of the drainage tube 41 is fixedly connected to the fixed housing 5, and the other end of the drainage tube 41 is fixedly connected to the side of the delivery tube 42.

[0056] The conveying pipe 42 has two ends. One end is a spare end, which is blocked with a cap, and the other end is the use end, from which the slurry flows out.

[0057] In one embodiment, the lower grinding disc 11 has a central hole, and the rotating shaft 8 is located inside the central hole of the lower grinding disc 11. The rotating shaft 8 and the central hole of the lower grinding disc 11 are rotatably connected by a sealed bearing.

[0058] In one embodiment, the bottom conical surface of the middle grinding disc 10 is provided with a spiral protrusion, and the top conical surface of the lower grinding disc 11 is provided with a plurality of concentric annular protrusions. When the middle grinding disc 10 and the lower grinding disc 11 rotate relative to each other, the spiral protrusions and the annular protrusions also form a shearing point to knead the slurry.

[0059] Example 2:

[0060] A paper pulp refining process includes the following steps;

[0061] S1. When the pulp is broken down, short fibers and long fibers are used together with the paper pulp refining equipment in Example 1 for refining. The ratio of short fibers to long fibers is 1:3.5-5.2, preferably 1:4.6, so that the produced tissue paper has moderate tensile strength and stiffness.

[0062] S2. During the grinding process, the rotation speed of the drive component shaft is controlled at 100-500 rpm so that the liquid in the second slot 102 has sufficient centrifugal force to flow obliquely upward along the second slot 102. Moreover, the rotation speed of the shaft should preferably not exceed 500 rpm to avoid excessive centrifugal force, which would prevent the slurry from flowing downward from the first slot 101 or cause it to flow too slowly.

[0063] In the production of household paper, the coating agent used is NT Coat 2165 from Lantian Agricultural Science and Technology. Compared with other coating agents, this coating agent has medium to high viscosity. Using this coating agent can balance the amount used and the texture of the product, producing a texture that is not too fine, while reducing the amount of coating agent used. The release agent used is 2201 oil-based release agent, which produces a coarser texture. The modifier used is NT Opt im 2502, which can improve the uniformity of the coating, the softness and hardness of the coating, and the quality of the product.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A paper pulp refining apparatus, comprising a carrier plate (1), wherein a base frame (2) is fixedly mounted on the bottom of the carrier plate (1), characterized in that, Also includes: The fixed outer shell (5) is fixedly installed on the top of the carrier plate (1), and the inner side of the fixed outer shell (5) forms a stepped part that is larger at the top and smaller at the bottom; The upper grinding disc (7) is fixedly installed on the stepped part of the fixed outer shell (5). The upper grinding disc (7) includes a first disc body (71). The top of the first disc body (71) is provided with a strip hole (72) arranged radially along the first disc body (71). The bottom of the first disc body (71) is fixedly connected with a slitting scraper (73). The slitting scraper (73) is long and is arranged radially along the first disc body (71). There are multiple slitting scrapers (73) arranged in a ring array. The drive assembly (3) is fixedly mounted on the base frame (2), and the shaft (8) of the drive assembly (3) extends into the interior of the fixed housing (5); The middle grinding disc (10) is located inside the fixed outer shell (5) and below the upper grinding disc (7). The middle grinding disc (10) is fixedly connected to the rotating shaft (8). The top of the middle grinding disc (10) has a first groove (101) and a second groove (102). The first groove (101) and the second groove (102) are both elongated and arranged radially along the middle grinding disc (10). The depth of the first groove (101) and the second groove (102) gradually increases from the outer end toward the center of the middle grinding disc (10). As the number of slots increases, an overflow port (103) leading to the bottom of the middle grinding disc (10) is provided at the deepest part of the first slot (101). A first slot (101) and a second slot (102) are used as a unit hole group. The number of the unit hole groups is set to be multiple and distributed in a ring array. An annular groove (104) is provided at the top of the middle grinding disc (10). The outer ends of all the first slots (101) and the second slots (102) are connected to the annular groove (104). The bottom end of the middle grinding disc (10) is a conical surface. The disc cover (13) includes an annular part (132), and a blocking plate (131) is fixedly connected to the inner side of the annular part (132). The annular part (132) corresponds to the annular groove (104), and the number and position of the blocking plates (131) correspond to the first groove (101). The lower grinding disc (11) is fixedly connected to the bottom end of the fixed outer shell (5), and the top of the lower grinding disc (11) is provided with a conical surface. The top of the lower grinding disc (11) corresponds to the bottom end of the middle grinding disc (10). The inner side of the fixed outer shell (5) and located between the middle grinding disc (10) and the lower grinding disc (11) form an annular cavity (12). The discharge pipe (4) is fixedly connected at one end to the fixed outer shell (5) and is connected to the annular chamber (12).

2. The paper pulp refining equipment according to claim 1, characterized in that: The top end of the rotating shaft (8) passes through the upper grinding disc (7), and the rotating shaft (8) is rotatably connected to the upper grinding disc (7). A rotating grate (9) is fixedly connected to the top end of the rotating shaft (8), and a feed hopper (6) is fixedly connected to the top of the fixed outer shell (5).

3. The paper pulp refining equipment according to claim 2, characterized in that, The rotating grate (9) includes: a mounting ring (91) and a strip (92). The mounting ring (91) is sleeved on the rotating shaft (8) and fixedly connected by a key. One end of the strip (92) is fixedly connected to the outer side of the mounting ring (91).

4. The paper pulp refining equipment according to claim 2, characterized in that, The feed hopper (6) includes: an annular shallow part (61), an annular deep part (62) is provided on the inner side of the annular shallow part (61), a center cap (64) is fixedly connected to the center of the annular deep part (62), and a drop hole (63) is provided at the inner bottom of the annular deep part (62).

5. The paper pulp refining equipment according to claim 1, characterized in that, The discharge pipe (4) includes: a guide pipe (41) and a conveying pipe (42). The conveying pipe (42) is fixedly connected to the carrier plate (1). One end of the guide pipe (41) is fixedly connected to the fixed outer shell (5), and the other end of the guide pipe (41) is fixedly connected to the side of the conveying pipe (42).

6. The paper pulp refining equipment according to claim 1, characterized in that: The lower grinding disc (11) has a central hole, and the rotating shaft (8) is located inside the central hole of the lower grinding disc (11). The rotating shaft (8) and the central hole of the lower grinding disc (11) are rotatably connected by a sealed bearing.

7. The paper pulp refining equipment according to claim 1, characterized in that: The bottom conical surface of the middle grinding disc (10) is provided with a spiral protrusion, and the top conical surface of the lower grinding disc (11) is provided with a number of concentric annular protrusions.

8. A paper pulp refining process, characterized in that, Includes the following steps; S1. During pulp refining, short fibers and long fibers are refined using a paper pulp refining apparatus according to any one of claims 1-7; S2. During the grinding process, the rotation speed of the drive component shaft is controlled to be 100-500 rpm.

9. The paper pulp refining process according to claim 8, characterized in that: The ratio of short fibers to long fibers is 1:3.5-5.2.

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