A kind of mica paper production paper pulp stirring device

Abstract

The present application relates to mica paper production technical field, specifically, it relates to a paper pulp stirring device for mica paper production. It includes a reaction kettle, the reaction kettle is composed of a kettle body and a kettle cover, the kettle body includes an inner cylinder and an outer cylinder, in the stirring process, the liquid in the main cavity enters the premixing jacket, and flows along the bottom to complete the premixing, the thick pulp flows to the main cavity through the reflux port, and mixes with the slurry in the main cavity. In the present application, the large mica sheet is separated from the small mica sheet during feeding, and the slurry in the main cavity forms axial rotational flow during stirring, the liquid at the high position of the main cavity can enter the premixing jacket through the inlet, soak and hydraulically loosen the large mica sheet falling into the jacket, and then the premixing jacket surrounds the inclined bottom slope of the inner cylinder to directly transport the mixed thick pulp to the middle of the main cavity to participate in mixing, effectively reducing the difficulty of wetting and dispersing large mica sheet, and improving the uniformity and stability of the whole pulp.

Description

Technical Field

[0001] This invention relates to the field of mica paper production technology, and more specifically, to a pulp mixing device for mica paper production. Background Technology

[0002] Mica paper, as a functional material with excellent insulation properties, high temperature resistance and mechanical strength, is widely used in electrical, electronic and other fields. The production process of mica paper includes raw material pretreatment, pulping, forming, dehydration and drying, calendering and finishing. Through the processing of natural mica ore, a dense, uniform and stable finished mica paper product is formed.

[0003] In the production process of mica paper, pulp mixing is one of the key steps that determines product quality. It requires the full integration of mica sheets, water and various functional additives to form a uniform and stable suspension. In the existing technology, the mixing of mica pulp is usually completed using a reaction vessel. For example, a pulp mixing device for mica paper production with Chinese patent publication number CN216396094U can prevent the pulp from solidifying on the inner wall of the mixing tank, making it easy to clean, improving the utilization rate of pulp, and thus improving production efficiency.

[0004] In the aforementioned mixing device, the mica pulp is fed directly: mica flakes of varying sizes obtained from crushing and grinding natural mica ore are directly poured into the reactor along with water and various functional additives for mixing. During this process, small mica flakes, due to their small particle size, large specific surface area, and slow settling speed, can fully contact water and additives and achieve uniform mixing. However, large mica flakes, due to their higher density than water, settle faster during mixing, easily agglomerating and sinking to the bottom of the reactor. Furthermore, the surface of large mica flakes is highly hydrophobic, making it difficult for water to quickly penetrate their interior. During mixing, they are in an incompletely wetted state, with a wetted surface and a dry interior, thus forming stubborn agglomerates and resulting in uneven mixing of the mica pulp. Therefore, there is an urgent need for a pulp mixing device for mica paper production to solve the above problems. Summary of the Invention

[0005] This invention provides a pulp mixing device for mica paper production. By classifying mica flakes, it wets and disperses large mica flakes, achieving efficient mixing in direct feeding mode to obtain a uniform and stable pulp required for mica paper forming. This solves the problems mentioned in the background art, namely:

[0006] In the direct feeding mode, mica flakes of uneven size are mixed with water and additives. Large mica flakes are easy to settle due to their high density and strong hydrophobicity, making them difficult to wet and forming stubborn agglomerates, resulting in uneven mixing of mica pulp.

[0007] To achieve the above objectives, the pulp mixing device includes a reaction vessel, which consists of a vessel body and a vessel lid. The vessel lid is provided with a feed inlet. The reaction vessel is equipped with a stirring structure inside. The vessel body includes an inner cylinder and an outer cylinder that are coaxially sleeved together. The interior of the inner cylinder forms the main cavity, and the annular space between the inner cylinder and the outer cylinder forms a premixing jacket.

[0008] The top of the inner cylinder is provided with a flow guide hood with an inclined surface. The flow guide hood is used to guide the large mica sheets into the premixed jacket. The bottom of the premixed jacket is an inclined surface that surrounds the inner cylinder. The upper end of the inner cavity of the premixed jacket is provided with an inlet port, which is connected to the upper end of the main cavity. The lower end of the inner cavity of the premixed jacket is provided with a return port, which is connected to the middle end of the main cavity.

[0009] When the stirring structure is started, the end of the stirring structure can periodically move to a position opposite to the inlet to realize the intermittent opening and closing of the inlet. During the stirring process, the axial swirling flow formed in the main cavity can cause the liquid to enter the premixing jacket through the inlet and flow along the bottom of the premixing jacket carrying large mica flakes to complete the premixing. The premixed slurry flows back to the middle of the main cavity through the return port and mixes with the slurry in the main cavity.

[0010] In the above technical solution, the flow guide hood enables graded processing of mica sheets of different sizes, the premix jacket provides a pre-impregnation environment, and the intermittent opening and closing of the inlet and the axial swirling circulation replenishment of the main cavity, combined with the return port for precise return to the main cavity mixing high-efficiency zone, effectively solves the problems of large mica sheet settling and agglomeration and insufficient impregnation, ensuring the uniformity of pulp mixing and the structural integrity of mica sheets.

[0011] Based on this, the stirring structure includes a vertically arranged main shaft and multiple layers of stirring blades spaced apart along the axial direction of the main shaft. The projection length of the bottommost stirring blade on the horizontal plane is longer than that of any of the stirring blades above it. A folding rod is fixedly connected vertically upward to the outer end of the bottommost stirring blade. An opening and closing ring is fixedly installed at the top of the folding rod, and the opening and closing ring can cover the inlet.

[0012] The bottommost stirring blade, with its longer horizontal projection length, expands its contact range with the bottom area of ​​the main cavity. Taking advantage of the fact that mica flakes are denser than water and easily settle, its rotation can effectively disturb and lift the settling mica flakes at the bottom, reducing mica flake deposition. When the main shaft drives the multi-layer stirring blades to rotate, the bottommost stirring blade synchronously drives the folding rod and the opening and closing ring to make a circular motion around the main shaft, so that the opening and closing ring periodically covers or disengages from the inlet, thereby realizing the intermittent opening and closing of the inlet.

[0013] In addition, a micro peristaltic pump is installed inside the reflux port. The micro peristaltic pump can transport the concentrated slurry that has gathered at the bottom of the premixed jacket cavity to the main cavity for mixing in a low-shear manner.

[0014] The micro-peristaltic pump operates in an intermittent mode, providing sufficient static impregnation and dynamic hydraulic loosening time for the large mica sheets retained in the premixed jacket.

[0015] In this technical solution, the low-shear delivery mode of the micro peristaltic pump can reduce the secondary agglomeration of loose mica flakes in the concentrated pulp, ensuring the structural integrity and dispersion stability of the mica flakes. Its intermittent operation mode matches the pre-impregnation requirements of the premix jacket. By controlling the start-stop interval, sufficient static impregnation time is reserved for large mica flakes to achieve deep wetting. At the same time, in conjunction with the dynamic hydraulic loosening process in the premix jacket, it ensures that large mica flakes are fully dispersed before entering the main cavity, forming a uniform mixture with the pulp in the main cavity, thereby improving the pulp mixing quality and subsequent forming performance.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. In this pulp mixing device for mica paper production, the flow guide structure can separate large mica flakes from small mica flakes during the feeding process. During the mixing process, the pulp in the main chamber will form an axial swirling flow. The liquid at the high position of the main chamber can enter the premixing jacket through the inlet, soaking and hydraulically loosening the large mica flakes that fall into the jacket, so that they are mixed with the liquid to form a thick pulp. Then, with the help of the premixing jacket surrounding the bottom inclined surface of the inner cylinder, the mixed thick pulp is directly transported to the middle of the main chamber to participate in the mixing, which effectively reduces the difficulty of wetting and dispersing large mica flakes and improves the overall uniformity and stability of the pulp.

[0018] 2. In this pulp mixing device for mica paper production, the axial vortex formed during the mixing process leads the high-level liquid in the main chamber to the premixing jacket through the inlet. This helps to balance the liquid level inside the main chamber, reduces the problems of turbulent mixing and pulp splashing caused by excessively high local liquid levels, and improves the overall mixing effect. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the internal structure of the reactor in this invention;

[0021] Figure 3 This is a schematic diagram of the cross-sectional structure of the reactor body in this invention;

[0022] Figure 4 This is a schematic diagram showing the inlet port in the open state in this invention;

[0023] Figure 5 This is a schematic diagram showing the closed state of the inlet in this invention;

[0024] Figure 6This is a schematic diagram of the cross-sectional structure of the outer cylinder in this invention;

[0025] Figure 7 In this invention Figure 6 A schematic diagram of the structure at point A;

[0026] Figure 8 This is a schematic diagram of the stirring structure of the present invention;

[0027] Figure 9 This is a schematic diagram of the internal structure of the inlet in this invention;

[0028] Figure 10 This is a schematic diagram of the bottom structure of the inner cavity of the premixed jacket in this invention.

[0029] The meanings of the labels in the diagram are as follows:

[0030] 1. Reactor; 11. Inner cylinder; 12. Outer cylinder; 13. Premixing jacket; 14. Main cavity; 15. Flow guide; 16. Outer plug; 17. Spacer ring;

[0031] 10. Stirring structure; 101. Main shaft; 102. Stirring blades; 103. Bending rod; 104. Opening and closing ring;

[0032] 21. Inlet; 22. Outlet; 23. Miniature peristaltic pump. Detailed Implementation

[0033] 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.

[0034] In the current preparation of mica paper, natural mica ore is crushed and ground to obtain mica flakes of varying sizes. These flakes are then directly poured into reactor 1 along with water and functional additives for mixing. Smaller mica flakes, due to their small particle size, large specific surface area, and slow settling speed, can fully contact water and additives to achieve uniform mixing. Larger mica flakes, due to their higher density than water, settle quickly and tend to aggregate and sink to the bottom of reactor 1. Furthermore, their strong hydrophobic surface makes it difficult for water to quickly penetrate the interior, resulting in an incomplete wetting state with a wet surface and a dry interior. This leads to the formation of stubborn agglomerates, causing uneven mixing of the mica pulp.

[0035] In view of this, the present invention provides a pulp mixing device for mica paper production, see [link to relevant documentation]. Figures 1-3As shown, the reactor includes a reactor 1, which consists of a vessel body and a lid. The lid has an inlet for adding mica flakes, water, and additives. The bottom of the vessel body has an outlet. The reactor 1 is equipped with a stirring structure 10 for stirring and mixing the materials in the main cavity 14 and preventing mica flakes from depositing. The vessel body includes an inner cylinder 11 and an outer cylinder 12 that are coaxially connected. The interior of the inner cylinder 11 forms the main cavity 14, which serves as the core area for material mixing and is adapted to a multi-layer stirring flow field to achieve uniform mixing. The annular space between the inner cylinder 11 and the outer cylinder 12 forms a premixing jacket 13 for pre-impregnating and loosening large mica flakes and preventing large mica flakes from directly entering the main cavity 14 and causing uneven mixing.

[0036] The bottom of the premixed jacket 13 is inclined around the inner cylinder 11. An inlet 21 is provided at the upper end of the inner cavity of the premixed jacket 13. The inlet 21 is connected to the upper end of the main cavity 14 to ensure liquid circulation and replenishment. A return port 22 is provided at the lower end of the inner cavity of the premixed jacket 13. The return port 22 is connected to the middle end of the main cavity 14.

[0037] In the reaction vessel 1, a stirring structure 10 is installed to stir and mix the mica sheets, water, and additives. The stirring structure 10 includes a main shaft 101 arranged vertically and multiple layers of stirring blades 102 spaced apart along the axial direction of the main shaft 101, as detailed below. Figure 3 As shown, a motor is fixedly installed on the top of the kettle lid. The output shaft of the motor is coaxially connected to the main shaft 101. When the motor is running, the torque output is directly transmitted to the main shaft 101 and drives the main shaft 101 to drive the multi-layer stirring blades 102 to rotate synchronously, so as to stir the mica pulp in the main cavity 14.

[0038] Combined again Figure 3 As shown, a folding rod 103 is vertically and upwardly fixedly connected to the outer end of the bottommost stirring blade 102. An opening / closing ring 104 is fixedly installed at the top of the folding rod 103. The size of the opening / closing ring 104 matches the size of the inlet 21, completely covering it. During the rotation of the main shaft 101 driven by the motor, the multi-layer stirring blades 102 rotate synchronously with the main shaft 101. Figure 4 and Figure 5 As shown, the folding rod 103 rotates synchronously with the bottom stirring blade 102, driving the opening and closing ring 104 to make a circular motion around the main shaft 101. During the circular motion, the opening and closing ring 104 periodically covers or detaches from the inlet 21, realizing the intermittent opening and closing of the inlet 21. The intermittent opening and closing action will cause the water in the main cavity 14 to enter the premixing jacket 13 in a discontinuous manner.

[0039] When the opening and closing ring 104 covers the inlet 21, the water replenishment action of the main cavity 14 to the premixing jacket 13 stops. At this time, the large mica sheets in the premixing jacket 13 are in a relatively stable liquid-solid system, which can continuously complete the physical processes of wetting and initial dispersion. When the opening and closing ring 104 is removed from the inlet 21, the water in the main cavity 14 flows into the premixing jacket 13 again, replenishing the liquid level in the premixing jacket 13 and forming a new hydraulic disturbance, which drives the large mica sheets in the premixing jacket 13 to move, reducing the agglomeration caused by long-term static placement of local mica sheets. The intermittent opening and closing form can ensure that each batch of large mica sheets entering the premixing jacket 13 undergoes a similar soaking and hydraulic loosening process, and will not cause drastic fluctuations in the liquid level and flow field in the jacket due to continuous water intake, thereby ensuring that all large mica sheets obtain a stable soaking time and premixing time.

[0040] It should be noted that the dimensions of the inlet 21 and the opening / closing ring 104 shown in the attached diagram are for illustrative purposes only, and their appropriate dimensions can be determined according to specific working conditions.

[0041] Furthermore, the projection length of the bottommost stirring blade 102 on the horizontal plane is greater than that of any of the stirring blades 102 above it, which increases the contact area between the bottommost stirring blade 102 and the bottom area of ​​the main cavity 14. Based on the characteristic that mica sheets have a density greater than water and are easy to settle to the bottom of the main cavity 14 during stirring, the bottommost stirring blade 102 can cover a larger area of ​​the bottom space of the main cavity 14 when it rotates. The fluid dynamics generated by its rotation can act on the settling mica sheets, which can disturb and lift the mica sheets that have settled to the bottom of the main cavity 14, reducing the deposition of mica sheets at the bottom of the main cavity 14.

[0042] Depend on Figure 6 As can be seen, the flow guide 15 is located at the top of the inner cylinder 11, and its surface is distributed with several through holes. The outermost end of the flow guide 15 extends to the upper end of the inner cavity of the premix jacket 13. During the feeding process, the mica sheets fed from the feed port fall onto the surface of the flow guide 15. Small mica sheets can pass through the through holes on the surface of the flow guide 15 and enter the main cavity 14. Large mica sheets cannot pass through the through holes and slide along their surface under the guidance of the flow guide 15, eventually entering the inner cavity of the premix jacket 13.

[0043] The several through holes on the surface of the flow guide shroud 15 constitute a porous sieving structure, which can realize the sieving of large and small mica flakes. Specifically, the size range of mica flakes used in mica paper production is usually 0.05mm to 3mm. In the industry, mica flakes with a size greater than 1mm are generally defined as large mica flakes. These large mica flakes are more hydrophobic and denser than water, making them more difficult to initially wet and disperse, and they are prone to agglomerate during the stirring process. Based on this, the aperture of the through holes on the surface of the flow guide shroud 15 is set to 0.8mm to 0.9mm. Large mica flakes with a size greater than 1mm cannot pass through the through holes, are filtered and intercepted, and slide along the surface of the flow guide shroud 15, and are finally guided to the premixing jacket 13 for targeted premixing treatment. Small mica flakes with a size between 0.05mm and 1mm can directly pass through the through holes and enter the main cavity 14 to participate in the stirring, thereby realizing the graded treatment of large and small mica flakes.

[0044] Because mica sheets are thin, light, and irregularly shaped, they are easily dispersed during feeding due to airflow or impact. Therefore, please refer to... Figure 7 As shown, a partition ring 17 is fixedly installed at the bottom of the kettle lid. The inner wall of the partition ring 17 has an inward inclined structure. If the mica flakes fed from the feed inlet fall and disperse during feeding, they can be constrained by the partition ring 17. The dispersed mica flakes will first fall onto the inclined inner wall of the partition ring 17, slide along the inclined inner wall under the action of gravity, be gathered and guided to the central area of ​​the flow guide shroud 15 for grading.

[0045] Meanwhile, a gap is reserved between the lower edge of the partition ring 17 and the upper surface of the flow guide 15 to ensure that the mica sheet that does not pass through the through hole can enter the premixed jacket 13 along the surface of the flow guide 15.

[0046] Furthermore, an outer film is coated on the inner wall surface of the premixing jacket 13. The surface of the outer film is smooth (the outer film is a polytetrafluoroethylene coating). During the mixing process of mica pulp, the liquid in the main cavity 14 enters the premixing jacket 13 through the inlet 21 and drives the large mica flakes falling into the jacket to flow along the inclined surface at the bottom of the premixing jacket 13. The smooth outer film directly contacts the premixed pulp, providing a contact surface for the flow of the pulp, reducing the frictional resistance between the premixed pulp and the inner wall of the premixing jacket 13, reducing the situation where the pulp stagnates due to excessive resistance, ensuring that the large mica flakes are soaked and hydraulically loosened during the flow process, and ensuring that the premixed pulp can converge to the return port 22, maintaining the continuous and stable operation of the premixing process.

[0047] like Figure 8As shown, the return port 22 is located at the bottom of the inner cavity of the premixing jacket 13, and a micro peristaltic pump 23 is installed inside it. After the premixing jacket 13 completes the soaking and hydraulic loosening of large mica sheets and forms a thick slurry, the micro peristaltic pump 23 can transport the thick slurry gathered at the bottom of the inner cavity of the premixing jacket 13 to the main cavity 14 in a low-shear manner to participate in the mixing. The micro peristaltic pump 23 adopts an intermittent operation mode. During its stop operation phase, the large mica sheets in the premixing jacket 13 can be in a static or low-disturbance state, thereby providing the corresponding static soaking and dynamic hydraulic loosening time for the large mica sheets retained in the premixing jacket 13.

[0048] It is important to note that the return port 22 is located in the middle section of the main cavity 14. This allows the concentrated liquid mixed with large mica sheets to be directly introduced into the middle of the main cavity 14, which is compatible with the flow field equilibrium zone formed by the multi-layer stirring blades 102. This avoids the stratification and secondary agglomeration caused by top input, and also prevents excessive shearing and deposition caused by the high disturbance of the bottom stirring blades 102 when bottom input is used. While ensuring the integrity of the sheet structure of large mica sheets, the concentrated slurry is quickly encapsulated by the liquid and uniformly diffused through the gradient flow field, shortening the mixing cycle and ensuring that the overall slurry concentration and particle size distribution in the main cavity 14 are consistent, providing a stable slurry foundation for subsequent mica paper forming.

[0049] The working principle of the aforementioned micro peristaltic pump 23 is well known to those skilled in the art. The power end of the micro peristaltic pump 23 is driven by a micro motor to rotate an eccentric wheel. During the rotation of the eccentric wheel, the elastic cavity of the pump tube is squeezed in sequence, so that the pump tube is in an alternating state of negative pressure and positive pressure. When the pump tube is squeezed, the slurry in the tube flows towards the main cavity 14 under pressure. When the pump tube rebounds, the slurry at the bottom of the premixed jacket 13 is sucked into the pump tube. The continuous delivery of the slurry is achieved through this cyclic squeezing and rebound action. The micro peristaltic pump 23 adopts a low-voltage DC power supply (such as 24VDC) that complies with the safety specifications of industrial equipment. Its power cable and signal line are led out through a sealed interface (not shown in the figure) set on the reactor body and connected to an external control system. This power supply and control method not only provides stable and reliable power for the intermittent operation of the pump, ensuring that it can provide sufficient static impregnation and dynamic loosening time for large mica sheets, but also can adapt to the humid and slurry-rich working environment inside the reactor 1, ensuring the stability and safety of the equipment in long-term operation.

[0050] Among them, the micro peristaltic pump 23 delivers the slurry by squeezing the elastic cavity of the pump tube, which is a low-shear delivery method. Since the sheet-like structure of mica sheets is the core element to ensure the strength, insulation and other key properties of the finished mica paper, if a high-shear delivery method is used, the shear force generated during the delivery process will destroy the complete sheet-like shape of large mica sheets, resulting in the mica sheets breaking and delamination, which will affect the subsequent forming quality of mica paper. At the same time, low-shear delivery can reduce the secondary agglomeration of mica sheets in the concentrated slurry due to shearing action, and ensure that the mica sheets that have been dispersed in the premix jacket 13 are kept in a stable dispersed state before entering the main cavity 14, so as to achieve uniform mixing with the small mica sheets and slurry in the main cavity 14.

[0051] like Figure 9 As shown, the inner diameter of the inlet 21 near the main cavity 14 is smaller than the inner diameter near the premixing jacket 13. As a result, the inner wall of the channel forms an inclined state that gradually expands towards the premixing jacket 13. The liquid inside the main cavity 14 will form an axial swirling flow under the rotation of the stirring structure 10. The swirling effect will cause the liquid in the main cavity 14 to form a liquid level difference: the liquid level height near the edge of the inner wall of the main cavity 14 is higher than the liquid level height in the middle of the main cavity 14.

[0052] The inlet 21 on the inclined inner wall can correspond to the flow path of the axially swirling surface liquid, receive the axially swirling surface liquid, reduce the local resistance when the fluid flows out of the main cavity 14, and allow the axially swirling surface liquid in the main cavity 14 to flow smoothly into the premixed jacket 13, ensuring the stable liquid circulation between the main cavity 14 and the premixed jacket 13, and providing continuous liquid replenishment for the soaking and hydraulic loosening of large mica sheets in the premixed jacket 13.

[0053] Considering that after long-term operation of reactor 1, slurry may easily remain inside the premixing jacket 13, therefore, if Figure 10 As shown, an external channel is provided on the lower inner wall of the premixed jacket 13. The outer port of the external channel is sealed with a removable outer plug 16 by means of threaded connection or flange connection. During normal operation of the equipment, the outer plug 16 is in a closed state to ensure the sealing performance of the premixed jacket 13. When the equipment needs to be thoroughly cleaned, the outer plug 16 can be opened to allow the residual slurry in the premixed jacket 13 to be completely drained through the external channel, reducing the possibility of residual slurry drying and hardening in the premixed jacket 13. During equipment maintenance, the staff can inspect the inner wall of the premixed jacket 13 through the external channel to promptly detect problems such as wear of the inner wall coating or structural damage, reducing the difficulty of equipment maintenance.

[0054] Working principle:

[0055] First, water and additives are added through the feed inlet of reactor 1. After the addition is complete, mica flakes are added in batches. During the feeding process, because the mica flakes are thin and irregular in shape, they are prone to falling and scattering. The partition ring 17 at the bottom of the reactor lid gathers the scattered mica flakes and guides them to the central area of ​​the flow guide shroud 15 through the partition and guiding effect of the inclined inner wall. Then, the flow guide shroud 15 with a porous sieve structure can classify the mica flakes. Small mica flakes pass directly through the through holes into the main cavity 14, while large mica flakes are filtered and intercepted, and slide along the surface of the flow guide shroud 15 into the premixed jacket 13.

[0056] Meanwhile, the motor at the top of the main cavity 14 drives the main shaft 101 to rotate the multi-layer stirring blades 102 synchronously, stirring and mixing the small mica flakes, water and additives in the main cavity 14. The folding rod 103 on the outside of the bottom stirring blade 102 drives the opening and closing ring 104 to make a circular motion around the main shaft 101, periodically covering or disengaging from the inlet 21, realizing the intermittent opening and closing of the inlet 21, so that the liquid in the main cavity 14 enters the premixed jacket 13 in a discontinuous manner.

[0057] Meanwhile, large mica sheets flow along the bottom inclined surface of the premix jacket 13 with the liquid, completing soaking and hydraulic loosening. After accumulating a portion of concentrated pulp, the micro peristaltic pump 23 will transport the concentrated pulp gathered at the bottom of the premix jacket 13 to the middle area of ​​the main cavity 14, where it will be evenly mixed with the small mica sheets and pulp, ultimately achieving efficient mixing of mica pulp.

[0058] It should be noted that the solid arrows in the attached diagram indicate the flow direction of the mica sheets, the hollow arrows indicate the rotation direction of the stirring structure 10, and the dashed arrows indicate the flow direction of the liquid in the main cavity 14.

[0059] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pulp stirring device for mica paper production, comprising a reaction vessel (1), wherein the reaction vessel (1) is composed of a vessel body and a vessel lid, the vessel lid is provided with a feed inlet, and a stirring structure (10) is provided inside the reaction vessel (1), characterized in that: The vessel body includes an inner cylinder (11) and an outer cylinder (12) that are coaxially sleeved together. The interior of the inner cylinder (11) forms the main cavity (14), and the annular space between the inner cylinder (11) and the outer cylinder (12) forms the premixing jacket (13). The top of the inner cylinder (11) is provided with a flow guide shroud (15) with an inclined surface, which is used to guide the large pieces of mica sheet into the premixed jacket (13). The bottom of the premixed jacket (13) is an inclined surface that surrounds the inner cylinder (11) in a circumferential direction. An inlet (21) is provided at the upper end of the inner cavity of the premixed jacket (13), and the inlet (21) is connected to the upper end of the main cavity (14). A return port (22) is provided at the lower end of the inner cavity of the premixed jacket (13), and the return port (22) is connected to the middle end of the main cavity (14). The stirring structure (10) includes a vertically arranged main shaft (101) and multiple layers of stirring blades (102) spaced apart along the axial direction of the main shaft (101). The projection length of the bottommost stirring blade (102) on the horizontal plane is longer than that of any of the stirring blades (102) above it. A folding rod (103) is fixedly connected vertically upward to the outer end of the bottommost stirring blade (102). An opening and closing ring (104) is fixedly installed at the top of the folding rod (103). The opening and closing ring (104) can cover the inlet (21). When the stirring structure (10) is started, the end of the stirring structure (10) can periodically move to a position opposite to the inlet (21) to realize the intermittent opening and closing of the inlet (21). During the stirring process, the axial swirling flow formed in the main cavity (14) can cause the liquid to enter the premixing jacket (13) through the inlet (21) and flow along the bottom of the premixing jacket (13) carrying large pieces of mica to complete the premixing. The premixed slurry flows back to the middle of the main cavity (14) through the return port (22) and mixes with the slurry in the main cavity (14). The return port (22) is equipped with a micro peristaltic pump (23). The micro peristaltic pump (23) can transport the concentrated slurry gathered at the bottom of the premixed jacket (13) to the main chamber (14) for mixing in a low-shear manner. The micro peristaltic pump (23) operates in an intermittent mode to provide sufficient static impregnation and dynamic hydraulic loosening time for the large mica sheets retained in the premixed jacket (13).

2. The pulp agitating device for mica paper production according to claim 1, characterized in that: The surface of the flow guide (15) is provided with several through holes, and the outermost end of the flow guide (15) extends into the upper end of the inner cavity of the premixed jacket (13).

3. The pulp agitating device for mica paper production according to claim 1, characterized in that: A partition ring (17) is fixedly installed at the bottom of the vessel lid. The inner wall of the partition ring (17) is inclined inward. The partition ring (17) can gather the mica sheets falling from the feed port and guide them to the central area of ​​the flow guide shroud (15). A gap is formed between the lower edge of the partition ring (17) and the upper surface of the flow guide shroud (15).

4. The pulp agitating device for mica paper production according to claim 1, characterized in that: The inner wall surface of the premix jacket (13) is coated with an outer coating film, and the surface of the outer coating film is smooth, which is used for assisting the smooth flow of the premix slurry in the premix jacket (13).

5. The pulp agitating device for mica paper production as claimed in claim 1 wherein: The inner wall of the hole of the guide inlet (21) is inclined, and the inner diameter of the side of the guide inlet (21) close to the main cavity (14) is smaller than the inner diameter of the side close to the premix jacket (13).

6. The pulp agitating device for mica paper production according to claim 1, characterized in that: An outer connecting channel is arranged on the lower end inner wall of the premix jacket (13), and an outer plug (16) is sealingly installed on the outer port of the outer connecting channel.

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