A hopper for adding catalyst to a reaction vessel for p-methoxyacetophenone

Abstract

This invention discloses a hopper for adding catalyst to a p-methoxyacetophenone reactor, relating to the field of catalyst hopper technology. It includes a storage hopper with a motor fixed to its upper surface. The motor's output end is fixed to a rotating shaft, which is bearing-connected to the storage hopper. Stirring rods are also evenly arranged on the rotating shaft. This hopper for adding catalyst to a p-methoxyacetophenone reactor utilizes a crushing mechanism driven by a rotating shaft. Specifically, the rotating shaft causes a first reciprocating screw to drive a movable block and a sliding rod downwards. This causes a kneading disc, under its own weight and the gradual pressure provided by spring buffer, to knead the agglomerated catalyst on the screen. Through a shearing crushing method that slowly increases pressure, the binding force between agglomerated particles is effectively broken down while maximizing the preservation of the catalyst particle integrity. This avoids the destruction of the catalyst's active structure and dust generation caused by high-speed crushing, thus ensuring catalytic efficiency.

Description

Technical Field

[0001] This invention relates to the field of catalyst hopper technology, specifically a hopper for adding catalyst to a p-methoxyacetophenone reactor. Background Technology

[0002] p-Methoxyacetophenone is an important fragrance and pharmaceutical intermediate. Its industrial production is usually achieved by Friedel-Crafts acylation of anisole in the presence of a catalyst (such as a solid acid catalyst). In this process, the method of catalyst addition is one of the key factors affecting reaction efficiency, product purity, and production safety. Currently, there are two main ways to add catalysts to a reactor: 1. Manual feeding method: Manual feeding has drawbacks such as high labor intensity, poor precision control, easy introduction of pollution or moisture, and safety risks for operators who directly contact chemicals. 2. Mechanical feeding method: Although traditional mechanical feeding hoppers avoid the drawbacks of manual operation to some extent, they still have obvious shortcomings: First, catalysts (especially molecular sieves) are prone to moisture and clumping during storage and transportation. Traditional hoppers lack effective crushing mechanisms, and the direct feeding of clumped materials into the reactor may lead to uneven dispersion within the reactor, violent local reactions, affecting reaction selectivity and yield, and may even block the reactor inlet or distributor. Second, common hoppers mostly use simple gate control, with a large amount of material fed at one time, which easily accumulates at the bottom of the reactor, making it impossible to achieve uniform and gradual dispersion, which is not conducive to temperature control of exothermic reactions. Finally, some equipment with crushing functions mostly use high-speed impact crushing, which is prone to over-crushing the catalyst, destroying its active microcrystalline structure, and generating a large amount of dust. At the same time, it has the problems of high energy consumption and rapid equipment wear, which is difficult to meet the current use requirements. Summary of the Invention

[0003] The purpose of this invention is to provide a hopper for adding catalyst to a p-methoxyacetophenone reactor, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a hopper for adding catalyst to a methoxyacetophenone reactor, comprising a storage hopper, a motor fixed to the upper end face of the storage hopper, the output end of the motor being fixed to a rotating shaft, the rotating shaft being connected to the storage hopper by a bearing, and stirring rods being uniformly arranged on the rotating shaft; The crushing mechanism is connected to the rotating shaft, and the rotating shaft drives the crushing mechanism to perform reciprocating kneading motion relative to the screen to achieve the crushing effect of the agglomerated catalyst. The feeding mechanism achieves automatic and uniform dispersion of materials through intermittent quantitative feeding combined with centrifugal force. The feeding mechanism is installed inside the storage hopper and is connected to the rotating shaft.

[0005] Preferably, a flange is fixed to the lower side of the storage hopper, and a feed inlet is installed on the upper side of the storage hopper. The feed inlet is sealed in conjunction with the sealing cover. At the same time, several crushing teeth are fixed at equal angles inside the storage hopper. The sealing effect of the sealing cover on the feed inlet can effectively isolate external moisture and prevent the catalyst from agglomerating due to moisture. The crushing teeth can provide a basic guarantee for crushing agglomerated catalyst.

[0006] Preferably, the screen is located below the crushing mechanism, and the screen and the guide ring are slidably connected. The guide ring is fixed in the storage hopper and located below the crushing teeth. Through the function of the screen, large agglomerated catalyst particles can be isolated, thus providing a basic guarantee for the subsequent crushing of large agglomerated catalyst particles.

[0007] Preferably, the crushing mechanism includes a kneading disc slidably connected to a rotating shaft, and vertical rods are fixed at equal angles on the kneading disc. The vertical rods are slidably connected to a support, and the support is fixed inside the storage hopper. By moving the kneading disc, the agglomerated catalyst can be kneaded and crushed. The sliding guide between the vertical rods and the support can ensure the stability of the movement of the kneading disc.

[0008] Preferably, a sliding rod is slidably connected to the kneading disc, and one end of the sliding rod is fixedly connected to a spring, while the other end of the spring is fixed inside the kneading disc. At the same time, the sliding rod and the spring are distributed at equal angles about the center of the kneading disc. Through the elastic action of the spring, the pressure applied by the kneading disc to the catalyst can gradually increase, effectively preventing the catalyst from being over-crushed.

[0009] Preferably, a movable block is fixed at the upper end of the slide bar, and the movable block can move up and down in cooperation with the first reciprocating screw. The moving distance of the movable block is greater than the distance between the kneading disc and the screen. The first reciprocating screw is fixed on the rotating shaft. By limiting the moving distance of the movable block, the kneading of the catalyst can be guaranteed.

[0010] Preferably, the feeding mechanism includes a partition fixed inside the storage hopper, and a cylinder is fixed on the partition. The cylinder, the partition, and the rotating shaft are all connected by bearings. Four feeding pipes are also evenly distributed on the lower side of the partition. Through the action of the feeding pipes, the catalyst can be quantitatively stored, thereby providing a basic guarantee for the quantitative dispersion and feeding of the catalyst.

[0011] Preferably, the feeding tube is provided with a vertically movable circular rod, and a first circular plate is fixed to the upper end of the circular rod. A second circular plate is fixed to the circular rod below the first circular plate. The distance between the first and second circular plates is equal to the height of the feeding tube. The first and second circular plates are slidably connected to the feeding tube. By moving the first and second circular plates vertically, the opening and closing of the upper and lower openings of the feeding tube can be achieved, thus providing a basic guarantee for achieving quantitative feeding.

[0012] Preferably, a T-shaped slider is fixed to the lower end of the round rod, and the T-shaped slider is slidably connected to the distribution frame, and the distribution frame is slidably connected to the storage hopper. At the same time, distribution holes are evenly opened on the distribution frame, and a guide ring is fixed to the lower inner side of the distribution frame, and a square rod is fixed on the guide ring. The square rod is slidably connected to the rotating shaft. When the distribution frame rotates, the catalyst in the distribution frame can be evenly dispersed in the reactor through the distribution holes by the centrifugal force, ensuring the normal progress of the reaction. Moreover, the sliding action between the square rod and the rotating shaft can provide a basic guarantee for the synchronous rotation of the rotating shaft and the distribution frame.

[0013] Preferably, a ball is slidably connected in the groove of the guide ring, and the ball is fixed to the lower end of the guide rod. The upper end of the guide rod is fixed to the movable ring, and the movable ring is slidably connected to the partition plate. The movable ring can move up and down in cooperation with the second lead screw, and the second lead screw is fixed on the rotating shaft. The moving distance of the movable ring is less than the height of the distribution frame, and the moving distance of the movable ring is less than the distance between the first circular plate and the lower end face of the feed pipe. Through the above structure, a basic force can be provided to realize the up and down movement of the distribution frame, thereby further improving the distribution range of the catalyst and better meeting the feeding requirements of the catalyst.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The hopper for adding catalyst to the p-methoxyacetophenone reactor is equipped with a crushing mechanism driven by a rotating shaft. Specifically, the rotating shaft drives the first reciprocating screw to press down the movable block and slide bar, so that the kneading disc kneads the agglomerated catalyst on the screen under its own gravity and the gradual pressure provided by the spring buffer. Through the shearing crushing method of slowly increasing pressure, the binding force between the agglomerated particles can be effectively broken down, while protecting the integrity of the catalyst particles themselves to the maximum extent. This avoids the destruction of the active structure of the catalyst and the generation of dust caused by high-speed crushing, thereby ensuring catalytic efficiency. 2. The hopper for adding catalyst to the p-methoxyacetophenone reactor features a feeding mechanism driven by a rotating shaft. Specifically, the rotating shaft controls the periodic lifting and lowering of the movable ring and the distribution frame via a second lead screw, which in turn controls the opening and closing of the upper and lower openings of the feeding pipe by the first and second circular plates. This achieves intermittent feeding, first metering and storing, then centrifugally distributing the catalyst. Furthermore, the distribution frame, under the action of centrifugal force, evenly throws a measured amount of catalyst through the distribution holes. Simultaneously, the distribution frame itself continues to move up and down, further expanding the distribution range of the catalyst within the reactor. This addition method completely avoids localized accumulation of catalyst at the reactor inlet, ensuring sufficient and uniform contact between the catalyst and the reactants. For exothermic reactions such as Friedel-Crafts acylation, it effectively controls the reaction rate and heat release, significantly improving product yield and purity. Attached Figure Description

[0015] Figure 1 This is a front view cross-sectional three-dimensional structural diagram of the storage hopper of the present invention; Figure 2 This is a bottom-view cross-sectional three-dimensional structural diagram of the storage hopper of the present invention; Figure 3 This is a frontal three-dimensional structural diagram of the storage hopper of the present invention; Figure 4 This is a frontal cross-sectional three-dimensional structural diagram of the material crushing mechanism of the present invention; Figure 5 This is a frontal cross-sectional three-dimensional structural diagram of the feeding mechanism of the present invention; Figure 6 For the present invention Figure 5 Enlarged structural diagram at point A in the middle; Figure 7 This is a frontal cross-sectional three-dimensional structural diagram of the square rod and the second lead rod of the present invention.

[0016] In the diagram: 1. Storage hopper; 101. Flange; 102. Feed inlet; 103. Sealing cover; 104. Crushing teeth; 2. Motor; 3. Rotating shaft; 4. Stirring rod; 5. Screen; 6. Guide ring; 7. Crushing mechanism; 701. Kneading disc; 702. Vertical rod; 703. Support; 704. Slide rod; 705. Spring; 706. Movable block; 707. First reciprocating screw; 8. Discharge mechanism; 801. Partition plate; 802. Cylinder; 803. Discharge pipe; 804. Round rod; 805. First round plate; 806. Second round plate; 807. T-shaped slider; 808. Distributor frame; 809. Distributor hole; 810. Guide ring; 811. Square rod; 812. Sphere; 813. Guide rod; 814. Movable ring; 815. Second screw. Detailed Implementation

[0017] 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.

[0018] Please see Figures 1-7 The present invention provides a technical solution: a hopper for adding catalyst to a reaction vessel for methoxyacetophenone, comprising a storage hopper 1, a motor 2 fixed on the upper end face of the storage hopper 1, the output end of the motor 2 being fixed to a rotating shaft 3, the rotating shaft 3 being connected to the storage hopper 1 by a bearing, and a stirring rod 4 being evenly arranged on the rotating shaft 3. The crushing mechanism 7 is connected to the rotating shaft 3, and the rotating shaft 3 drives the crushing mechanism 7 to perform reciprocating kneading motion relative to the screen 5 to achieve the crushing effect of the agglomerated catalyst. The feeding mechanism 8 achieves automatic and uniform dispersion of materials through intermittent quantitative feeding combined with the action of centrifugal force. The feeding mechanism 8 is installed in the storage hopper 1 and is connected to the rotating shaft 3.

[0019] A flange 101 is fixed on the lower side of the storage hopper 1, and a feed inlet 102 is installed on the upper side of the storage hopper 1. The feed inlet 102 cooperates with the sealing cover 103 to achieve a seal. At the same time, several crushing teeth 104 are fixed at equal angles inside the storage hopper 1. When using the hopper for adding catalyst to the p-methoxyacetophenone reactor, such as Figures 1-7 As shown, firstly, the storage hopper 1 is connected to the catalyst feeding port of the reactor via flange 101. Then, by opening the sealing cover 103, the catalyst is fed into the storage hopper 1 through the feed port 102. With the help of the screen 5, the catalyst can be screened, so that the large particles of catalyst that are agglomerated and stuck together are left on the screen 5. After the catalyst is added, the feed port 102 can be sealed by the cooperation of the sealing cover 103 and the feed port 102. The feeding mechanism 8 includes a partition 801 fixed inside the storage hopper 1, and a cylinder 802 fixed on the partition 801. The cylinder 802, partition 801, and rotating shaft 3 are all connected by bearings. Four feeding pipes 803 are evenly distributed at angles on the lower side of the partition 801. A vertically movable circular rod 804 is installed inside each feeding pipe 803. A first circular plate 805 is fixed to the upper end of the circular rod 804, and a second circular plate 806 is fixed to the circular rod 804 below the first circular plate 805. The distance between the first circular plate 805 and the second circular plate 806 is equal to the height of the feeding pipe 803. The first circular plate 805, the second circular plate 806, and the feeding pipe 803 are slidably connected. A T-shaped slider 807 is fixed to the lower end of the circular rod 804, and the T-shaped slider 807 is slidably connected to the distributing frame 808. The material distribution frame 808 is slidably connected to the storage hopper 1. Meanwhile, the material distribution frame 808 has evenly spaced material distribution holes 809. A guide ring 810 is fixed to the lower inner side of the material distribution frame 808, and a square rod 811 is fixed to the guide ring 810. The square rod 811 is slidably connected to the rotating shaft 3. A ball 812 is slidably connected to the groove on the guide ring 810, and the ball 812 is fixed to the lower end of the guide rod 813. The upper end of the guide rod 813 is fixed to the movable ring 814, and the movable ring 814 is slidably connected to the partition plate 801. The movable ring 814 can move up and down in cooperation with the second screw 815, and the second screw 815 is fixed to the rotating shaft 3. The moving distance of the movable ring 814 is less than the height of the material distribution frame 808, and the moving distance of the movable ring 814 is less than the distance between the first circular plate 805 and the lower end face of the discharge pipe 803. When adding the catalyst to the reactor, such as Figures 1-7 As shown, at this time, only the motor 2 needs to be started. The motor 2 can drive the rotating shaft 3 and the stirring rod 4 to rotate. The stirring rod 4 can loosen the catalyst, facilitating the normal feeding of the catalyst. At this time, the first circular plate 805 is separated from the feeding pipe 803, allowing the catalyst to fall normally into the feeding pipe 803. Since the second circular plate 806 blocks the lower side of the feeding pipe 803, the catalyst can be temporarily stored in the feeding pipe 803. When the rotating shaft 3 rotates, it can synchronously drive the square rod 811 and the second lead screw 815 to rotate. When the second lead screw 815 rotates, through the cooperation of the second lead screw 815 and the movable ring 814, the movable ring 814 can move up and down in an orderly manner, such as... Figure 1 and Figure 5As shown, when the movable ring 814 moves down, it simultaneously drives the guide rod 813, the ball 812, the guide ring 810, and the distribution frame 808 to move down. By moving the distribution frame 808 down, the T-shaped slider 807, the round rod 804, the first round plate 805, and the second round plate 806 can be moved down simultaneously, which increases the distance between the second round plate 806 and the upper opening of the feed pipe 803, thereby increasing the amount of catalyst temporarily stored in the feed pipe 803. When the first round plate 805 slides in conjunction with the feed pipe 803, the second round plate 806 is separated from the lower opening of the feed pipe 803, so that the catalyst in the feed pipe 803 automatically falls into the distribution frame 808, so that the subsequent distribution frame 808 can disperse the catalyst. Moreover, the internal storage space of the feed pipe 803 can limit the amount of catalyst entering the distribution frame 808, so as to avoid storing too much catalyst in the distribution frame 808 and affecting the centrifugal dispersion effect of the subsequent catalyst. When the catalyst falls into the distribution frame 808, the upper distribution hole 809 of the distribution frame 808 separates from the storage hopper 1. When the rotating shaft 3 drives the square rod 811 to rotate, it synchronously drives the distribution frame 808 to rotate. Through the sliding action between the ball 812 and the guide ring 810, and the sliding action between the T-shaped slider 807 and the distribution frame 808, the normal rotation of the distribution frame 808 is ensured. The centrifugal force generated by the rotation of the distribution frame 808 allows the catalyst inside the distribution frame 808 to be evenly dispersed into the reaction chamber through the distribution hole 809. At this time, due to the cooperation between the second lead screw 815 and the movable ring 814, the catalyst is further dispersed into the reaction chamber. When the distribution frame 808 rotates to disperse the catalyst, the distribution frame 808 always moves downward. By moving the distribution frame 808, the distribution range of the catalyst can be further increased, avoiding the accumulation of catalyst in the reactor and affecting the subsequent reaction. According to the above principle, when the movable ring 814 moves upward from the lowest position, it simultaneously drives the distribution frame 808, the first circular plate 805 and the second circular plate 806 to reset. When the first circular plate 805 separates from the feed pipe 803, the second circular plate 806 slides in the feed pipe 803, thereby realizing the next material storage function, and thus realizing the indirect addition and automatic dispersion of the catalyst. The screen 5 is positioned below the crushing mechanism 7, and is slidably connected to the guide ring 6. The guide ring 6 is fixed inside the storage hopper 1 and is positioned below the crushing teeth 104. The crushing mechanism 7 includes a kneading disc 701 slidably connected to the rotating shaft 3, and vertical rods 702 are fixed at equal angles on the kneading disc 701. The vertical rods 702 are slidably connected to the support 703, and the support 703 is fixed inside the storage hopper 1. A sliding rod 704 is also slidably connected to the kneading disc 701. One end of the slide rod 704 is fixedly connected to the spring 705, and the other end of the spring 705 is fixed inside the kneading disc 701. The slide rod 704 and the spring 705 are distributed at equal angles about the center of the kneading disc 701. A movable block 706 is fixed to the upper end of the slide rod 704, and the movable block 706 can move up and down in cooperation with the first reciprocating screw 707. The moving distance of the movable block 706 is greater than the distance between the kneading disc 701 and the screen 5. The first reciprocating screw 707 is fixed on the rotating shaft 3. When rotating axis 3 rotates, as Figures 1-4 As shown, the rotation of the rotating shaft 3 synchronously drives the screen 5 and the first reciprocating screw 707 to rotate. The centrifugal force generated by the rotation of the screen 5 disperses the agglomerated catalyst on the screen 5, causing it to collide with the crushing teeth 104, thus achieving one-time crushing of the agglomerated catalyst. Furthermore, when the first reciprocating screw 707 rotates, its cooperation with the movable block 706 allows the movable block 706 and the sliding rod 704 to move up and down in an orderly manner. When the movable block 706 and the sliding rod 704 move downwards, the kneading disc 701 automatically moves downwards under gravity. Combined with the sliding guide action between the vertical rod 702 and the support 703, the stability of the kneading disc 701's movement is ensured. When the kneading disc 701 and the agglomerated catalyst on the screen 5 collide... In the initial stage, the kneading disc 701 exerts pressure on the catalyst under its own weight. Combined with the rotation of the screen 5, this achieves the kneading effect on the catalyst. Meanwhile, the movable block 706 and the sliding rod 704 continue to move downwards. Since the position of the kneading disc 701 is limited, the movable block 706 and the sliding rod 704 move downwards relative to the kneading disc 701. At this time, the spring 705 is compressed. Through the elastic force of the spring 705, the force exerted by the kneading disc 701 on the agglomerated catalyst gradually increases. This ensures both the crushing effect of the kneading disc 701 on the agglomerated catalyst and avoids excessive force from the kneading disc 701 on the agglomerated catalyst, which would lead to over-crushing. The crushed catalyst falls through the mesh of the screen 5 into the storage hopper 1.

[0020] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0021] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A hopper for adding catalyst to a reaction vessel for p-methoxyacetophenone, comprising a storage hopper (1), characterized in that: A motor (2) is fixed on the upper end face of the storage hopper (1). The output end of the motor (2) is fixed to the rotating shaft (3). The rotating shaft (3) is connected to the storage hopper (1) by a bearing. A stirring rod (4) is also evenly arranged on the rotating shaft (3). A screen (5) is fixed on the rotating shaft (3). The crushing mechanism (7) is connected to the rotating shaft (3), and the rotating shaft (3) drives the crushing mechanism (7) to perform reciprocating kneading motion relative to the screen (5) to achieve the crushing effect of the agglomerated catalyst. The feeding mechanism (8) achieves automatic and uniform dispersion of materials through intermittent quantitative feeding combined with centrifugal force. The feeding mechanism (8) is installed inside the storage hopper (1) and is connected to the rotating shaft (3). The feeding mechanism (8) includes a partition (801) fixed inside the storage hopper (1), and a cylinder (802) is fixed on the partition (801). The cylinder (802), the partition (801), and the rotating shaft (3) are all connected by bearings. Four feeding pipes (803) are also evenly distributed on the lower side of the partition (801). The feed tube (803) is equipped with a vertically movable circular rod (804), and a first circular plate (805) is fixed to the upper end of the circular rod (804). A second circular plate (806) is fixed to the circular rod (804) below the first circular plate (805). The distance between the first circular plate (805) and the second circular plate (806) is equal to the height of the feed tube (803). The first circular plate (805), the second circular plate (806) and the feed tube (803) are slidably connected. A T-shaped slider (806) is also fixed to the lower end of the circular rod (804). 07), and the T-shaped slider (807) and the material distribution frame (808) are slidably connected, and the material distribution frame (808) and the storage hopper (1) are slidably connected. At the same time, the material distribution frame (808) is evenly provided with material distribution holes (809). The lower inner side of the material distribution frame (808) is fixed with a guide ring (810), and a square rod (811) is fixed on the guide ring (810). The square rod (811) is slidably connected to the rotating shaft (3). A ball (812) is slidably connected in the groove on the guide ring (810), and the ball (812) is fixed. At the lower end of the guide rod (813), and at the upper end of the guide rod (813) fixed to the movable ring (814), and the movable ring (814) and the partition plate (801) are slidably connected, the movable ring (814) and the second lead screw (815) can move up and down, and the second lead screw (815) is fixed on the rotating shaft (3), the moving distance of the movable ring (814) is less than the height of the material distribution frame (808), and the moving distance of the movable ring (814) is less than the distance between the first circular plate (805) and the lower end face of the feed tube (803).

2. The hopper for adding catalyst to the reaction kettle for p-methoxy acetophenone according to claim 1, characterized in that: The storage hopper (1) is fixed with a flange (101) on the lower side and a feed inlet (102) is installed on the upper side of the storage hopper (1). The feed inlet (102) and the sealing cover (103) cooperate to achieve sealing. At the same time, a number of crushing teeth (104) are fixed at equal angles inside the storage hopper (1).

3. The hopper for adding catalyst to the reaction kettle for p-methoxy acetophenone according to claim 2, characterized in that: The screen (5) is located below the crushing mechanism (7), and the screen (5) and the guide ring (6) are slidably connected. The guide ring (6) is fixed in the storage hopper (1) and is located below the crushing tooth (104).

4. A hopper for adding catalyst to a p-methoxyacetophenone reactor according to claim 3, characterized in that: The crushing mechanism (7) includes a kneading disc (701) slidably connected to the rotating shaft (3), and vertical rods (702) are fixed at equal angles on the kneading disc (701). The vertical rods (702) and the support (703) are slidably connected, and the support (703) is fixed in the storage hopper (1).

5. A hopper for adding catalyst to a p-methoxyacetophenone reactor according to claim 4, characterized in that: A sliding rod (704) is slidably connected to the kneading disc (701), and one end of the sliding rod (704) is fixedly connected to the spring (705), and the other end of the spring (705) is fixed inside the kneading disc (701). At the same time, the sliding rod (704) and the spring (705) are distributed at equal angles about the center of the kneading disc (701).

6. A hopper for adding catalyst to a p-methoxyacetophenone reactor according to claim 5, characterized in that: The upper end of the slide bar (704) is fixed with a movable block (706), and the movable block (706) cooperates with the first reciprocating screw (707) to move up and down. The moving distance of the movable block (706) is greater than the distance between the kneading disc (701) and the screen (5). The first reciprocating screw (707) is fixed on the rotating shaft (3).

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