Alkali washing device for post-treatment of cyanation liquid for o-chlorobenzonitrile production

Abstract

The invention discloses an alkali washing device for post-treatment of cyanation liquid for o-chlorobenzonitrile production, and relates to the field of alkali washing devices.The alkali washing device comprises an alkali washing box and a first motor, the first motor is installed at the upper end of the alkali washing box, the output end of the first motor is connected with a rotating shaft connected into the alkali washing box through a bearing, and a stirring mechanism is installed on the rotating shaft. According to the alkali washing device for post-treatment of the cyanation liquid for o-chlorobenzonitrile production, an adjustable stirring mechanism is adopted, when the device stirs and mixes materials, a stirring plate is in a vertical state, a scraping plate is in a locked state, it is guaranteed that the scraping plate does not make contact with the inner wall of the alkali washing box during stirring and mixing, and after material mixing is completed, the scraping plate is not in contact with the inner wall of the alkali washing box through the adjusting effect of an adjusting mechanism; according to the technical scheme, locking of the scraping plate can be relieved, the scraping plate makes contact with the inner wall of the alkali washing box under the centrifugal effect to achieve scraping of materials, the stirring plate can rotate to be in a horizontal state, wind resistance borne by the stirring plate during idling is reduced, and therefore noise is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of alkali washing devices, and particularly to an alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile. Background Art

[0002] In the production process of o-chlorobenzonitrile, o-chlorotrichlorobenzene and ammonium chloride with a weight ratio of 3.5:1 are subjected to a nitrilation reaction at 200 °C. After adding copper oxide accounting for 0.02 wt% of o-chlorotrichlorobenzene and reacting until the content of o-chlorotrichlorobenzene is below 0.2% to obtain a nitrile solution, the nitrile solution needs to be alkali-washed with a soda ash solution having a pH of 8. After the alkali washing is completed, crude o-chlorobenzonitrile is obtained by precipitation. The existing nitrile solution alkali washing device (water washing kettle) mainly consists of an alkali washing tank and a stirring mechanism. And to facilitate the subsequent removal of the crude o-chlorobenzonitrile adhered to the side wall of the alkali washing tank, a scraping plate structure in contact with the side wall of the alkali washing tank is generally installed at the end of the stirring rod. For example, a continuous water washing kettle in the preparation process of 3,4-dichloronitrobenzene with the publication number of CN213886184U, the motor drives the first stirring rod and the second stirring rod to rotate through the stirring rotating shaft. The first through hole and the second through hole increase the flow rate of the liquid, thereby making the materials inside the kettle body stirred evenly, improving the stirring efficiency. The support frame assembly stably supports the bottom of the water washing kettle, and the support frame structure has high strength, avoiding the phenomenon of the support frame cracking. Moreover, through the first cleaning brush and the second cleaning brush, it is convenient to clean the dirt on the inner wall of the kettle body, bringing great convenience to the preparation work of 3,4-dichloronitrobenzene. In the actual use process of the existing alkali washing device (water washing kettle), since the scraping plate is always in contact with and slides on the side wall of the alkali washing tank during the mixing and stirring of the materials, it is easy to cause the rapid wear of the scraping plate, greatly affecting the service life of the scraping plate. And when scraping the materials on the side wall of the alkali washing tank, there is no liquid in the alkali washing tank at this time, resulting in the stirring plate being in an idling state. At this time, the stirring plate will generate greater noise due to air resistance, affecting the working environment. Summary of the Invention

[0003] The purpose of the present invention is to provide an alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile to solve the problems raised in the above background art.

[0004] To achieve the above object, the present invention provides the following technical solution: An alkali washing device for post-treatment of nitrile solution in o-chlorobenzonitrile production, comprising an alkali washing tank and a first motor. The first motor is installed at the upper end of the alkali washing tank. The output end of the first motor is connected to a rotating shaft bearing-connected in the alkali washing tank. A stirring mechanism is installed on the rotating shaft. The stirring mechanism includes a rotating rod bearing-connected to the rotating shaft. A gear is fixed on the rotating rod. The gear is meshed with a rack, and the gear rotates 90° each time. The rack is connected to an adjusting mechanism. Stirring plates are symmetrically fixed on the left and right of the rotating rod. A sliding rod is slidably connected to the stirring plate. A first spring is fixed between the sliding rod and the stirring plate. The sliding rod is bearing-connected to a scraping plate. Connecting rods are symmetrically fixed on the upper and lower sides of the scraping plate. An inclined surface block is fixed on the connecting rod.

[0005] Preferably, a feed inlet is installed at the upper end of the alkali washing tank, and a discharge valve port is installed at the lower end of the alkali washing tank. The discharge valve port is fixedly connected to a separation tank. A scraping mechanism is installed on the separation tank. Through the feed inlet and the discharge valve port, the normal entry and exit of materials can be ensured, thereby ensuring the normal operation of the device.

[0006] Preferably, the adjusting mechanism includes a fixing plate fixed to the rack. A block that can only rotate towards one side of the central axis of the rotating shaft is connected to the fixing plate. A torsion spring is also connected between the block and the fixing plate. The block is engaged with the inclined surface block. Through the engagement between the block and the inclined surface block, the locking of the scraping plate can be realized, avoiding the continuous contact between the scraping plate and the inner wall of the alkali washing tank.

[0007] Preferably, a second spring is also fixed between the fixing plate and the rotating shaft. A vertical rod is fixed on the block. The vertical rod is slidably connected to the rotating shaft. When the fixing plate moves, with the sliding guiding effect between the vertical rod and the rotating shaft, the stable linear movement of the fixing plate can be ensured. With the elastic effect of the second spring, a basic acting force for the automatic reset of the fixing plate can be provided.

[0008] Preferably, an iron plate is fixed to the upper end of the vertical rod. The iron plate and an electromagnet form a magnetic attraction mechanism. The electromagnet is fixed inside the rotating shaft. Through the magnetic attraction between the iron plate and the electromagnet, a basic acting force for the movement of the vertical rod and the fixing plate can be provided.

[0009] Preferably, a filter screen is fixed inside the separation tank. An outlet is provided on the left side of the separation tank. A liquid discharge port is provided on the lower side of the separation tank. Through the above structure, solid-liquid separation can be realized, facilitating the collection of o-chlorobenzonitrile crude products.

[0010] Preferably, the scraping mechanism includes a fixed frame fixed to the right side of the separation box, a second motor is fixed on the fixed frame, and the output end of the second motor is connected to a reciprocating lead screw connected to the fixed frame through a bearing. The second motor can provide a basic guarantee for the influence of the reciprocating lead screw.

[0011] Preferably, the reciprocating lead screw is connected to the movable frame, and the movable frame is slidably connected to the separation box. The reciprocating lead screw can provide a basic acting force for the left and right reciprocating movement of the movable frame. With the sliding guiding effect between the movable frame and the separation box, the stability of the movement of the movable frame can be ensured.

[0012] Preferably, a fixed rod is slidably connected to the movable frame, a pushing plate is fixed to the lower side of the fixed rod, and the pushing plate is slidably connected to the filter screen. At the same time, one end of the third spring is fixed to the pushing plate, and one end of the third spring is fixed to the movable frame. By the movement of the movable frame, the pushing plate can be driven to move, which is convenient for collecting the crude o-chlorobenzonitrile separated on the filter screen.

[0013] Preferably, a magnet block is fixed to the upper end of the fixed rod, and a magnetic attraction structure is formed between the magnet block and the magnetic strip. The magnetic strip is fixed inside the separation box. The magnet block is slidably connected to the limiting plate, and the limiting plate is fixed inside the separation box. The distance between the left end face of the limiting plate and the separation box is greater than the distance between the left end face of the magnetic strip and the separation box. At the same time, the distance between the right end face of the limiting plate and the separation box is less than the distance between the right end face of the magnetic strip and the separation box. The distance between the limiting plate and the magnetic strip is greater than the thickness of the magnet block. Through the above structure, a basic guarantee can be provided for realizing the position adjustment of the pushing plate, so as to ensure that the pushing plate can continuously push the crude o-chlorobenzonitrile separated on the filter screen to the left, ensuring the normal operation of the device.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. For the alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile, an adjustable stirring mechanism is adopted. When the device stirs and mixes the materials, the stirring plate can be in a vertical state and the scraping plate can be in a locked state, ensuring that the scraping plate does not contact the inner wall of the alkali washing tank during stirring and mixing. After the mixing is completed, through the adjustment of the adjustment mechanism, the locking of the scraping plate can be released, so that the scraping plate contacts the inner wall of the alkali washing tank under the action of centrifugal force to realize the scraping of the materials, and the stirring plate can be rotated to a horizontal state to reduce the wind resistance during the idling of the stirring plate, thus effectively avoiding the generation of noise; 2. For the alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile, a magnetic attraction type self-adjusting mechanism is adopted, which can make the pushing plate contact the filter screen when moving left and right to realize the pushing function, and automatically separate from the filter screen when moving right, so as to realize that the separated crude o-chlorobenzonitrile can be continuously pushed to the left for collection. Brief Description of the Drawings

[0015] Figure 1 This is a front view sectional three - dimensional structure schematic diagram of the overall composition of the device of the present invention; Figure 2 This is a three - dimensional structure schematic diagram of the rotating shaft and the stirring mechanism of the present invention; Figure 3 This is a sectional three - dimensional structure schematic diagram of the stirring plate and the sliding rod of the present invention; Figure 4 This is a three - dimensional structure schematic diagram of the adjusting mechanism of the present invention; Figure 5 This is a front view sectional three - dimensional structure schematic diagram of the separation box and the scraping mechanism of the present invention; Figure 6 This is a bottom view sectional three - dimensional structure schematic diagram of the separation box and the scraping mechanism of the present invention; Figure 7 This is a three - dimensional structure schematic diagram of the movable frame and the pushing plate of the present invention.

[0016] In the figure: 1, caustic washing tank; 101, feed inlet; 102, discharge valve port; 2, first motor; 3, rotating shaft; 4, stirring mechanism; 401, rotating rod; 402, gear; 403, rack; 404, stirring plate; 405, sliding rod; 406, first spring; 407, scraper; 408, connecting rod; 409, inclined plane block; 5, adjusting mechanism; 501, fixing plate; 502, clamping block; 503, second spring; 504, vertical rod; 505, iron plate; 506, electromagnet; 6, separation box; 601, filter screen; 602, discharge port; 603, liquid discharge port; 7, scraping mechanism; 701, fixing frame; 702, second motor; 703, reciprocating lead screw; 704, movable frame; 705, fixed rod; 706, pushing plate; 707, third spring; 708, magnet block; 709, magnet bar; 710, limiting plate. Detailed Description of the Invention

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] Please refer to Figures 1-7, the present invention provides a technical solution: an alkali washing device for post-treatment of cyanidation liquid in the production of o-chlorobenzonitrile, including an alkali washing tank 1 and a first motor 2. The first motor 2 is installed at the upper end of the alkali washing tank 1, and the output end of the first motor 2 is connected to a rotating shaft 3 bearing-connected in the alkali washing tank 1. A stirring mechanism 4 is installed on the rotating shaft 3. The stirring mechanism 4 includes a rotating rod 401 bearing-connected to the rotating shaft 3. A gear 402 is fixed on the rotating rod 401. The gear 402 is meshed with a rack 403, and the rotation angle of the gear 402 each time is 90°. The rack 403 is connected to an adjusting mechanism 5. Stirring plates 404 are symmetrically fixed on the left and right of the rotating rod 401. A sliding rod 405 is slidably connected to the stirring plate 404. A first spring 406 is fixed between the sliding rod 405 and the stirring plate 404. The sliding rod 405 is bearing-connected to a scraping plate 407. Connecting rods 408 are symmetrically fixed on the upper and lower sides of the scraping plate 407. An inclined plane block 409 is fixed on the connecting rod 408.

[0019] A feed inlet 101 is installed at the upper end of the alkali washing tank 1, and a discharge valve port 102 is installed at the lower end of the alkali washing tank 1. The discharge valve port 102 is fixedly connected to a separation tank 6. Meanwhile, a scraping mechanism 7 is installed on the separation tank 6; a filter screen 601 is fixed in the separation tank 6. An outlet 602 is arranged on the left side of the separation tank 6, and a liquid discharge port 603 is arranged on the lower side of the separation tank 6; When using this alkali washing device for post-treatment of cyanidation liquid in the production of o-chlorobenzonitrile, as Figures 1-7 shown, first, the cyanidation liquid and soda ash solution are injected into the alkali washing tank 1 through the feed inlet 101 in a ratio of 1.18:1.20. Then, the first motor 2 is started to drive the rotating shaft 3 and the stirring plates 404 to rotate. At this time, the clamping block 502 and the inclined plane block 409 are in a clamping state, that is, the scraping plate 407 is locked, so that the scraping plate 407 cannot move towards the inner wall of the alkali washing tank 1 under the centrifugal force, ensuring the normal progress of stirring and mixing, thereby realizing the alkali washing effect of the cyanidation liquid. After the alkali washing is completed, the first motor 2 is turned off, so that the solid substances (crude o-chlorobenzonitrile) in the solution precipitate. After the precipitation is completed, by opening the discharge valve port 102, the liquid and the precipitated solid (crude o-chlorobenzonitrile) in the alkali washing tank 1 enter the separation tank 6 through the discharge valve port 102. With the function of the filter screen 601, solid-liquid separation can be achieved. At this time, the solid (crude o-chlorobenzonitrile) remains on the filter screen 601, and the liquid is discharged through the liquid discharge port 603 for collection; The scraping mechanism 7 includes a fixing frame 701 fixed to the right side of the separation box 6. A second motor 702 is fixed on the fixing frame 701, and the output end of the second motor 702 is connected to a reciprocating lead screw 703 whose bearing is connected to the fixing frame 701. The reciprocating lead screw 703 is connected to a movable frame 704, and the movable frame 704 is slidably connected to the separation box 6. A fixed rod 705 is slidably connected to the movable frame 704, and a pushing plate 706 is fixed to the lower side of the fixed rod 705. The pushing plate 706 is slidably connected to the filter screen 601. At the same time, one end of the pushing plate 706 is fixed to one end of a third spring 707, and one end of the third spring 707 is fixed to the movable frame 704. The upper end of the fixed rod 705 is fixed with a magnet block 708. The magnet block 708 and a magnet bar 709 form a magnetic attraction structure, and the magnet bar 709 is fixed inside the separation box 6. The magnet block 708 is slidably connected to a limiting plate 710, and the limiting plate 710 is fixed inside the separation box 6. The distance between the left end face of the limiting plate 710 and the separation box 6 is greater than the distance between the left end face of the magnet bar 709 and the separation box 6. At the same time, the distance between the right end face of the limiting plate 710 and the separation box 6 is less than the distance between the right end face of the magnet bar 709 and the separation box 6. The distance between the limiting plate 710 and the magnet bar 709 is greater than the thickness of the magnet block 708; When the solid-liquid separation is realized by opening the discharge valve port 102, as Figures 1-7As shown, at this time, the second motor 702 is synchronously started. The second motor 702 can drive the reciprocating lead screw 703 to rotate, so that the movable frame 704 makes an orderly left-right reciprocating movement. When the movable frame 704 moves to the left, the pushing plate 706 is synchronously driven to move to the left. At this time, the magnet block 708 contacts and slides with the lower end surface of the limiting plate 710, realizing the limiting function of the pushing plate 706, ensuring that the pushing plate 706 contacts and slides with the filter screen 601, and pushing the solid (crude o-chlorobenzonitrile) on the filter screen 601 to the left, so that the solid (crude o-chlorobenzonitrile) on the filter screen 601 is discharged through the discharge port 602 for the collection of the solid (crude o-chlorobenzonitrile). When the magnet block 708 moves to be separated from the left side of the limiting plate 710, at this time, the magnet block 708 adsorbs with the magnet bar 709, so that the pushing plate 706 moves upward and separates from the filter screen 601, and at this time, the movable frame 704 just moves to the leftmost position and starts to change direction and move to the right. When the movable frame 704 moves to the right, at this time, the magnet block 708 slides to the right on the magnet bar 709. When the magnet block 708 is separated from the right side of the magnet bar 709, the magnetic attraction between the magnet block 708 and the magnet bar 709 is released. At this time, the magnet block 708 contacts the upper end surface of the limiting plate 710. When the magnet block 708 is separated from the right side of the limiting plate 710, with the elastic action of the third spring 707, the pushing plate 706 moves downward and resets to contact the filter screen 601, and at this time, the movable frame 704 just moves to the rightmost position and starts to change direction and move to the left. According to the above principle, when the pushing plate 706 makes a left-right reciprocating movement, the solid (crude o-chlorobenzonitrile) on the filter screen 601 can be continuously pushed to the left for the collection of the solid (crude o-chlorobenzonitrile); The adjusting mechanism 5 includes a fixing plate 501 fixedly connected to the rack 403. A clamping block 502 that can only rotate to one side of the axis of the rotating shaft 3 is connected to the fixing plate 501. A torsion spring is also connected between the clamping block 502 and the fixing plate 501. At the same time, the clamping block 502 is in a clamping connection with the inclined surface block 409; A second spring 503 is also fixed between the fixing plate 501 and the rotating shaft 3. A vertical rod 504 is fixed on the clamping block 502, and the vertical rod 504 is in a sliding connection with the rotating shaft 3; An iron plate 505 is fixed at the upper end of the vertical rod 504. The iron plate 505 and the electromagnet 506 form a magnetic attraction mechanism, and the electromagnet 506 is fixed in the rotating shaft 3; After the liquid in the caustic washing tank 1 is discharged, it is inevitable that a certain amount of liquid and solid (crude o-chlorobenzonitrile) remain on the inner wall of the caustic washing tank 1, such as Figures 1-7As shown in the figure, at this time, only the electromagnet 506 needs to be started first. With the magnetic attraction between the electromagnet 506 and the iron plate 505, the vertical rod 504, the fixed plate 501 and the clamping block 502 move upward, so as to release the locking between the clamping block 502 and the inclined plane block 409. When the fixed plate 501 moves upward, the rack 403 is synchronously driven to move upward. With the meshing transmission between the rack 403 and the gear 402, the rotating rod 401 and the stirring plate 404 are forced to rotate 90°, so that the stirring plate 404 rotates to the horizontal state, which can reduce the wind resistance when the stirring plate 404 rotates idly, and then reduce the generation of noise. After the adjustment is completed, the first motor 2 is started to drive the rotating shaft 3, the stirring plate 404 and the scraping plate 407 to rotate. With the rotating centrifugal action, the scraping plate 407 is forced to move towards the inner wall of the alkali washing tank 1. With the sliding guiding action between the sliding rod 405 and the stirring plate 404, the stability of the movement of the scraping plate 407 can be ensured until the scraping plate 407 contacts and slides on the inner wall of the alkali washing tank 1. At this time, the liquid and solid adhered to the inner wall of the alkali washing tank 1 can be cleaned by the scraping plate 407. After the cleaning is completed, the electromagnet 506 and the first motor 2 are turned off. At this time, under the action of the second spring 503, the clamping block 502 is reset, and under the action of the first spring 406, the scraping plate 407 is reset. With the one-way rotation action of the clamping block 502, the clamping block 502 can be engaged and limited with the inclined plane block 409 for the next use. According to the above principle, the locking and unlocking of the scraping plate 407 can be realized, and the service life of the scraping plate 407 can be prevented from being reduced due to long-term contact and friction with the inner wall of the alkali washing tank 1. This is the working principle of the alkali washing device for the post-treatment of nitrile solution in the production of o-chlorobenzonitrile.

[0020] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0021] In this article, specific examples are used to elaborate on the principle and implementation mode of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that due to the limited nature of literal expression, and objectively there are infinite specific structures. For those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements, retouches or changes can also be made, or the above technical features can be combined in an appropriate way; these improvements, retouches, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, should all be regarded as the protection scope of the present invention.

Claims

1. An alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile, comprising an alkali washing tank (1) and a first motor (2), the first motor (2) is installed at the upper end of the alkali washing tank (1), and it is characterized in that: The output end of the first motor (2) is connected to a rotating shaft (3) which is connected to a bearing inside the caustic washing tank (1). A stirring mechanism (4) is installed on the rotating shaft (3). The stirring mechanism (4) includes a rotating rod (401) connected to the rotating shaft (3) by a bearing. A gear (402) is fixed on the rotating rod (401). The gear (402) is meshed with a rack (403), and each rotation angle of the gear (402) is 90°. The rack (403) is connected to an adjusting mechanism (5). Stirring plates (404) are symmetrically fixed on the left and right of the rotating rod (401). A sliding rod (405) is slidably connected to the stirring plate (404). A first spring (406) is fixed between the sliding rod (405) and the stirring plate (404). The sliding rod (405) is connected to a scraper (407) by a bearing. Connecting rods (408) are symmetrically fixed on the upper and lower sides of the scraper (407). An inclined block (409) is fixed on the connecting rod (408).

2. The caustic washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 1, characterized in that: A feed inlet (101) is installed at the upper end of the caustic washing tank (1), and a discharge valve port (102) is installed at the lower end of the caustic washing tank (1). The discharge valve port (102) is fixedly connected to a separation tank (6). A scraping mechanism (7) is installed on the separation tank (6).

3. The caustic washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 1, characterized in that: The adjusting mechanism (5) includes a fixing plate (501) fixedly connected to the rack (403). A clamping block (502) that can only rotate towards one side of the central axis of the rotating shaft (3) is connected to the fixing plate (501). A torsion spring is also connected between the clamping block (502) and the fixing plate (501). The clamping block (502) is in snap-fit connection with the inclined block (409).

4. An alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 3, characterized in that: A second spring (503) is also fixed between the fixing plate (501) and the rotating shaft (3). A vertical rod (504) is fixed on the clamping block (502). The vertical rod (504) is slidably connected to the rotating shaft (3).

5. An alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 4, characterized in that: An iron plate (505) is fixed at the upper end of the vertical rod (504). The iron plate (505) and an electromagnet (506) form a magnetic attraction mechanism. The electromagnet (506) is fixed inside the rotating shaft (3).

6. The alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 2, wherein: A filter screen (601) is fixed inside the separation tank (6). A discharge port (602) is arranged on the left side of the separation tank (6). A liquid discharge port (603) is arranged on the lower side of the separation tank (6).

7. An alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 2, characterized in that: The scraping mechanism (7) includes a fixing frame (701) fixed on the right side of the separation tank (6). A second motor (702) is fixed on the fixing frame (701). The output end of the second motor (702) is connected to a reciprocating lead screw (703) which is connected to a bearing on the fixing frame (701).

8. An alkali washing device for post-treatment of cyanidation liquid in the production of o-chlorobenzonitrile according to claim 7, characterized in that: The reciprocating lead screw (703) is connected to a movable frame (704). The movable frame (704) is slidably connected to the separation tank (6).

9. An alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 8, characterized in that: A fixed rod (705) is slidably connected to the movable frame (704), a pushing plate (706) is fixed to the lower side of the fixed rod (705), the pushing plate (706) is slidably connected to the filter screen (601), one end of the pushing plate (706) is fixedly connected to one end of a third spring (707), and one end of the third spring (707) is fixed to the movable frame (704).

10. An alkali washing device for post-treatment of nitrile solution in the production of o-chlorobenzonitrile according to claim 9, characterized in that: A magnet block (708) is fixed to the upper end of the fixed rod (705), a magnetic attraction structure is formed between the magnet block (708) and a magnet bar (709), the magnet bar (709) is fixed in the separation box (6), the magnet block (708) is slidably connected to a limiting plate (710), the limiting plate (710) is fixed in the separation box (6), the distance between the left end face of the limiting plate (710) and the separation box (6) is greater than the distance between the left end face of the magnet bar (709) and the separation box (6), the distance between the right end face of the limiting plate (710) and the separation box (6) is less than the distance between the right end face of the magnet bar (709) and the separation box (6), and the distance between the limiting plate (710) and the magnet bar (709) is greater than the thickness of the magnet block (708).

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