Stirring and dispersing device suitable for polyimide resin synthesis

Abstract

The utility model discloses a stirring and dispersing device suitable for polyimide resin synthesis, which is arranged in a reaction kettle and comprises a stirring shaft and a stirring frame arranged at the lower part of the stirring shaft, and the stirring frame comprises a stirring outer frame, an upper rhombic stirring body and a lower rhombic stirring body, the upper rhombic stirring body and the lower rhombic stirring body are located at the upper end and the lower end of the stirring frame respectively, the stirring shaft penetrates through the middle of the upper rhombic stirring body and extends to the middle of the lower rhombic stirring body, and the stirring shaft is fixedly connected with the upper rhombic stirring body and the lower rhombic stirring body; a baffle is further arranged between the stirring outer frame and the inner wall of the reaction kettle, and the upper end of the baffle extends to the position above the upper rhombic stirring body and is detachably fixed to the reaction kettle. The stirring frame is combined with the baffle, so that the exchange mixing speed of materials in the central areas of the bottom and the upper part of the reaction kettle and external materials during stirring is increased, and the problems of slow dispersion, bottom sinking and poor longitudinal dispersion effect of common stirring are effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of stirring technology, specifically to a stirring and dispersing device suitable for the synthesis of polyimide resins. Background Technology

[0002] Polyimide resins react rapidly, requiring the added materials to be quickly and evenly mixed, while also ensuring good mixing and dispersion during the reaction process. Conventional glass reactors, due to their structure, have limited stirring area, resulting in poor longitudinal dispersion and a tendency for vortex formation during stirring, causing materials to settle to the bottom.

[0003] Chinese patent document CN 221182789U discloses a device for improving the stirring efficiency of a photosensitive polyimide resin polymerization reactor. The device includes a reactor body, a rotating assembly above the reactor body, and a stirring assembly inside the reactor. The stirring assembly includes a stirring shaft with a four-bladed oblique impeller mounted on it, and a spiral blade at the bottom of the stirring shaft. The reactor body includes a vessel opening and a vessel body, with a baffle installed on the inner wall of the vessel body. The anchor-type stirring method used in the aforementioned patent document has drawbacks such as a small dispersion stirring area and low rotation speed. Furthermore, the baffle needs to be fixed inside the reactor and connected to the reactor jacket, which disrupts the overall structure inside the reactor and easily creates dead zones for material residue. The four-bladed oblique impeller and bottom spiral blade used do not provide sufficient mixing effect for the bottom material.

[0004] Chinese patent document CN 221906556U discloses a novel frame-type stirring paddle, including a stirring shaft and blades. One end of the blades is mounted on the stirring shaft. The blades include two vertical frames and multiple horizontal blades disposed between the two vertical frames. The multiple horizontal blades are spaced apart along the length of the vertical frames. Both ends of each horizontal blade are connected to the stirring shaft and the vertical frames, respectively. The stirring surface of the vertical frames is inclined relative to the vertical plane. The aforementioned patent document relies on the stirring paddle itself to disperse the original liquid laterally, but the longitudinal dispersion is still not ideal, especially when there is a large height difference between the bottom and top of the original liquid. The dispersion effect is not obvious when the liquid level is low, and the upper frame type does not achieve ideal dispersion in a steady vortex flow state. Utility Model Content

[0005] In order to overcome the technical problems existing in the prior art, this utility model provides a stirring and dispersing device suitable for the synthesis of polyimide resin, which enhances the mixing rate of materials at the bottom and upper central areas of the reactor and external materials during stirring.

[0006] The present invention adopts the following technical solution:

[0007] A stirring and dispersing device suitable for the synthesis of polyimide resin is placed inside a reaction vessel. It includes a stirring shaft and a stirring frame installed below the stirring shaft. The stirring frame includes an outer stirring frame, an upper rhomboid stirring body, and a lower rhomboid stirring body. The upper and lower rhomboid stirring bodies are located at the upper and lower ends of the stirring frame, respectively. The stirring shaft passes through the middle of the upper rhomboid stirring body from top to bottom and extends to the middle of the lower rhomboid stirring body. The stirring shaft is fixedly connected to the upper and lower rhomboid stirring bodies. A baffle is also provided between the outer stirring frame and the inner wall of the reaction vessel. The upper end of the baffle extends above the upper rhomboid stirring body and is detachably fixed to the reaction vessel.

[0008] Preferably, the baffle includes a vessel body baffle, a transition baffle, and a vessel opening baffle. The vessel body baffle is located in the vessel body of the reactor, the vessel opening baffle is located near the vessel opening of the reactor, and the transition baffle is inclined and its two ends are connected to the vessel opening baffle and the vessel body baffle.

[0009] Preferably, the upper end of the reactor lid is provided with a feed inlet, and a soft plug is fitted on the upper part of the baffle. The soft plug is placed in the feed inlet, and the baffle and the feed inlet are sealed together by the soft plug.

[0010] Preferably, the soft plug is a silicone plug.

[0011] Preferably, the vessel baffle forms a 5-10° inclination angle with the stirring shaft.

[0012] More preferably, the surface of the baffle is provided with a corrosion-resistant layer.

[0013] The technical solution of this utility model has the following advantages:

[0014] This invention employs a combination of a stirring frame and baffles, which effectively addresses the problems of slow dispersion, bottom settling, and poor longitudinal dispersion in the original structure. During the stirring process, the stirring and dispersing device of this invention enhances the lateral and longitudinal exchange efficiency of the added materials and the materials during polymerization through the coordinated action between the stirring frame and the baffles. It also breaks the vortex settling structure, increases the speed of material mixing, and promotes a more uniform reaction. This invention is particularly suitable for reactions where the added materials, such as polyimide, are solid-liquid mixtures with a certain viscosity and a relatively fast reaction rate. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of this utility model, the drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the stirring and dispersing device provided by this utility model.

[0017] The diagram is labeled as follows:

[0018] 1-Reaction vessel

[0019] 11-Bottle body, 12-Bottle opening, 13-Bottle cover, 131-Feed inlet

[0020] 2-Stirring shaft

[0021] 3-Stirring frame

[0022] 31-Outer mixing frame, 32-Upper diamond-shaped mixing body, 33-Lower diamond-shaped mixing body, 34-Impeller, 4-Baffle

[0023] 41-Baffle plate for vessel body, 42-Transition baffle plate, 43-Baffle plate for vessel opening

[0024] 5-Soft plug. Detailed Implementation

[0025] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] like Figure 1 As shown, this utility model provides a stirring and dispersing device suitable for the synthesis of polyimide resin. It is placed inside a reaction vessel 1, which includes a vessel body 11, a vessel opening 12, and a vessel cover 13. The stirring and dispersing device includes a stirring shaft 2 and a stirring frame 3 installed below the stirring shaft 2. The stirring frame 3 includes a stirring outer frame 31, an upper rhomboid stirring body 32, and a lower rhomboid stirring body 33. The upper rhomboid stirring body 32 and the lower rhomboid stirring body 33 are located at the upper and lower ends of the stirring frame 3, respectively. Multiple flat... The impeller 34 is arranged in rows. The stirring shaft 2 runs from top to bottom through the middle of the upper rhomboid stirring body 32 and extends to the middle of the lower rhomboid stirring body 33. The stirring shaft 2 is fixedly connected to the upper rhomboid stirring body 32 and the lower rhomboid stirring body 33, so that the stirring shaft 2 and the entire stirring frame 3 form a whole. The upper end of the stirring shaft 2 is fixed to the motor. A baffle 4 is also provided between the stirring outer frame 31 and the inner wall of the reactor 1. The upper end of the baffle 4 extends to the top of the upper rhomboid stirring body 32 and is fixed to the reactor 1 in a detachable manner.

[0029] The upper rhomboid stirring body 32 and the lower rhomboid stirring body 33 of this invention have an integral rhomboid structure, which enhances the mixing rate of materials at the bottom and upper central area of ​​the reactor and the external materials during stirring. The stirring frame 3 is rectangular in shape, and under the high-speed rotation of the stirring outer frame 31, it enhances the lateral mixing rate of materials in the central area and the reactor wall area during stirring.

[0030] The baffle 4 comprises three parts: a vessel body baffle 41, a transition baffle 42, and a vessel opening baffle 43. The vessel body baffle 41 is located in the vessel body 11 of the reactor 1. The vessel opening baffle 43 is located near the vessel opening 12 of the reactor 1. The transition baffle 42 is inclined and its two ends are connected to the vessel opening baffle 43 and the vessel body baffle 41. The upper part of the baffle 4, the vessel opening baffle 43, is perpendicular to the vessel opening 12. The lower part is inclined to form the transition baffle and extends downward to form the vessel body baffle 41. The vessel body baffle 41 is parallel to the stirring shaft. Preferably, the vessel body baffle 41 is inclined at a certain angle to form the baffle body. The baffle body can forcibly break the vortex effect, making the longitudinal dispersion effect significantly enhanced, especially the bottom sediment material is quickly dispersed into the whole vessel.

[0031] The inclined blades 34 inside the stirring frame 3 are fixedly connected to the stirring shaft 2 by welding or bolts, which enhances the mechanical strength of the blades 34. The upper end of the reactor 1 has a feed inlet 131 on the vessel cover 13. A soft plug 5, such as a silicone plug, is fitted on the upper part of the baffle 4. The soft plug 5 is placed in the feed inlet 131, and the baffle 4 and the feed inlet 131 are sealed and fixed by the soft plug 5, which enhances the resistance of the baffle 4 to turbulence and expands the scope of application.

[0032] The combination of the stirring frame 31 and the baffle 4 in this invention effectively addresses the problems of slow dispersion, bottom settling, and poor longitudinal dispersion in the original structure. During the stirring process, the coordinated action of the stirring frame 3 and the baffle 4 enhances the exchange efficiency of the added materials and the materials in the lateral and longitudinal directions during polymerization, disrupts the vortex settling structure, and increases the mixing speed of the materials, which is conducive to a more uniform reaction. This is particularly suitable for reactions where the added materials, such as polyimide, are solid-liquid mixtures with a certain viscosity and a relatively fast reaction rate.

[0033] The specific operation involves the following steps: Based on the reactor dimension design drawing, the material for the stirring frame is cut to the required size. Each blade assembly is then fixed to the shape of this novel stirring frame using welding or other methods. The baffle's width, bevel angle, and droop height are designed according to the dimensions of the reactor and stirring frame. It is made of a special metal material and cut to the required shape. After opening the reactor lid and placing the baffle in the position shown in the diagram, the baffle is fixed in place using a soft sealing material such as a silicone plug at the reactor opening. The upper part of the baffle is fixed to the reactor support frame with bolts.

[0034] This invention employs a frame-type integral stirring structure, enhancing the strength of the stirring blades, broadening its applicability, and increasing its rotation speed. Simultaneously, the baffle does not contact the inside of the reactor, preserving the original reactor structure and eliminating dead zones for material residue. The baffle located within the reactor body, combined with transverse stirring, disrupts the steady-flow state of the liquid, significantly improving the longitudinal dispersion effect, especially at the bottom and top, resulting in better circulation and more uniform overall dispersion under turbulent conditions. Furthermore, the upper and lower rhomboid stirring elements, under the action of the baffle, effectively disrupt the vortex state above the liquid and reduce material accumulation at the bottom, significantly improving dispersion even at lower liquid levels.

[0035] Experiments on the synthesis of polyimide resin verified that the resin molecular weight distribution width decreased, there was no obvious solid residue at the bottom during the polymerization process, the liquid-phase transition was faster, and the mixing was more uniform; the PDI (Polymer Dioxide Dispersion) could be reduced from 1.8-1.9 to 1.5-1.6, indicating that the monomer dispersion was more uniform and the molecular weight was more homogeneous during the polymerization process. The uniform molecular weight distribution of the resin allows for faster and better dissolution and dispersion, resulting in a resin with superior properties.

[0036] Any aspects not mentioned in this utility model are applicable to the prior art.

[0037] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this utility model.

Claims

1. A stirring and dispersing device suitable for the synthesis of polyimide resins, placed inside a reaction vessel (1), comprising a stirring shaft (2) and a stirring frame (3) mounted on the lower part of the stirring shaft (2), characterized in that, The stirring frame (3) includes a stirring outer frame (31), an upper rhomboid stirring body (32), and a lower rhomboid stirring body (33). The upper rhomboid stirring body (32) and the lower rhomboid stirring body (33) are located at the upper and lower ends of the stirring frame (3), respectively. The stirring shaft (2) passes through the middle of the upper rhomboid stirring body (32) from top to bottom and extends to the middle of the lower rhomboid stirring body (33). The stirring shaft (2) is fixedly connected to the upper rhomboid stirring body (32) and the lower rhomboid stirring body (33). A baffle (4) is also provided between the stirring outer frame (31) and the inner wall of the reactor (1). The upper end of the baffle (4) extends above the upper rhomboid stirring body (32) and is fixed to the reactor (1) in a detachable manner.

2. The stirring and dispersing apparatus for polyimide resin synthesis according to claim 1, characterized in that, The baffle (4) includes a vessel body baffle (41), a transition baffle (42) and a vessel mouth baffle (43). The vessel body baffle (41) is located in the vessel body (11) of the reactor (1). The vessel mouth baffle (43) is located near the vessel mouth (12) of the reactor (1). The transition baffle (42) is inclined and its two ends are connected to the vessel mouth baffle (43) and the vessel body baffle (41).

3. The stirring and dispersing apparatus for polyimide resin synthesis according to claim 2, characterized in that, The upper end of the reactor (1) is provided with a feed inlet (131) on the reactor lid (13). A soft plug (5) is fitted on the upper part of the baffle (4). The soft plug (5) is placed in the feed inlet (131) and the baffle (4) and the feed inlet (131) are sealed together by the soft plug (5).

4. The stirring and dispersing apparatus for polyimide resin synthesis according to claim 3, characterized in that, The soft plug (5) is a silicone plug.

5. The stirring and dispersing apparatus for polyimide resin synthesis according to claim 2, characterized in that, The vessel baffle (41) forms a 5-10° inclination angle with the stirring shaft (2).

6. The stirring and dispersing apparatus for polyimide resin synthesis according to any one of claims 1-5, characterized in that, The surface of the baffle (4) is provided with a corrosion-resistant layer.

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