Optical detection device and method for acetic anhydride content

Abstract

The invention relates to the technical field of acetic anhydride content optical detection, in particular to an acetic anhydride content optical detection device and method.The acetic anhydride content optical detection device comprises a detection box, a cleaning seat is fixedly connected into the detection box, a squeezing plate is fixedly connected into the cleaning seat, a scrubbing mechanism is rotatably connected to the squeezing plate, and a wiping ring is arranged in the cleaning seat; the bottom of one side of the detection box is fixedly connected with the exhaust hood in a penetrating manner, the inner wall of the detection box is rotatably connected with the push-pull mechanism, the box cover is arranged above the detection box, and the Fourier transform infrared spectrometer is fixedly arranged on the inner wall of one side of the detection box. The outer wall of the light-transmitting tube type liquid pool is automatically cleaned, fingerprints can be effectively removed, it is ensured that an optical path is not interfered, light rays are prevented from being scattered or absorbed when passing through the light-transmitting tube type liquid pool, and the accuracy, efficiency, repeatability and consistency in the experiment process can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical detection of acetic anhydride content, and in particular to an optical detection device and method for acetic anhydride content. Background Art

[0002] Acetic anhydride (chemical formula: (CH3CO)2O(CH3CO)2O) is an organic compound that belongs to the acyl group. It is a dehydrated derivative of acetic acid (CH3COOH) and has a strong corrosive and pungent odor. Acetic anhydride has a wide range of applications in chemical reactions, particularly in organic synthesis.

[0003] The detection methods of acetic anhydride mainly include:

[0004] Gas chromatography (GC): This method is suitable for the determination of acetic anhydride content and impurity analysis, and has high sensitivity and high selectivity. Liquid chromatography (HPLC): It is suitable for the determination of moisture content and acid value, and can effectively separate the components in complex samples. Titration: The acid value is determined by acid-base titration, which is simple and easy to use and suitable for routine laboratory testing. Infrared spectroscopy (FTIR): The structure of acetic anhydride is analyzed using characteristic absorption peaks, and it is suitable for rapid identification. Each detection method has its own unique advantages and disadvantages. The laboratory will select the best detection method based on the sample type, detection requirements and equipment conditions.

[0005] When using infrared spectroscopy to detect acetic anhydride in a solution, the solution is held in a liquid pool. The outer walls of the liquid pool are prone to stains such as fingerprints. Existing technology does not allow for automatic cleaning of the outer walls before testing. These contaminants affect the transmittance of infrared light, and thus the quality of the spectrum. Any uneven or opaque areas will cause signal attenuation or error, affecting the test results.

[0006] In summary, the prior art lacks a technology for automatically cleaning the outer wall of a liquid pool. Summary of the Invention

[0007] The purpose of the present invention is to solve the shortcomings of the background technology and to propose an optical detection device and method for acetic anhydride content.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: an optical detection device for acetic anhydride content, comprising a detection box, a cleaning seat fixedly connected to the detection box, a squeezing plate fixedly connected to the cleaning seat, a scrubbing mechanism rotatably connected to the squeezing plate, a wiping ring provided in the cleaning seat, an exhaust hood fixedly connected to the bottom of one side of the detection box, a push-pull mechanism rotatably connected to the inner wall of the detection box, a box cover provided above the detection box, and a Fourier transform infrared spectrometer fixedly installed on the inner wall of one side of the detection box.

[0009] Preferably, a valve is fixedly connected through the bottom of the cleaning seat, a guide rod is fixedly connected to the inner wall of the cleaning seat, a placement rack is fixedly connected to the guide rod, a light-transmitting tube-shaped liquid pool is placed on the placement rack, and the bottom end of the light-transmitting tube-shaped liquid pool is in contact with the top surface of the squeeze-out plate.

[0010] Preferably, the lower surface of the upper side of the squeeze plate is annular in structure and is fixedly connected with a plurality of protrusions.

[0011] Preferably, one end of the wiping ring is slidably fitted with the guide rod, a fiber cloth is fixedly connected to the inner circle of the wiping ring, the fiber cloth is movably contacted with the outer circle of the upper end of the squeezing plate, and the fiber cloth is slidably contacted with the outer wall of the transparent tube-shaped liquid pool.

[0012] Preferably, the scrubbing mechanism includes a gear ring, which is rotatably connected to the squeezing plate, and two sliding rods are symmetrically arranged on the gear ring for sliding cooperation, a connecting rod is fixedly connected to the sliding rod, and the bottom end of the connecting rod is fixedly connected to a tension spring, the other end of the tension spring is fixedly connected to the gear ring, and the other end of the connecting rod is fixedly connected to a scrubbing block, the scrubbing block is in frictional contact with the fiber cloth, a contact rod is fixedly connected to the connecting rod, and the contact rod is in sliding contact with the protruding block, a driven wheel is provided for meshing transmission on the lower side of the gear ring, one end of the driven wheel is fixedly connected to a rotating shaft, the rotating shaft is rotatably connected to the inner wall of the cleaning seat, and the outer end of the rotating shaft is fixedly connected to a driving wheel.

[0013] Preferably, a motor is fixedly connected to the outer wall of the exhaust hood, the output end of the motor extends to the inner wall of the exhaust hood and is fixedly connected to a fan blade, one end of the fan blade is fixedly connected to a universal joint, the other end of the universal joint is fixedly connected to a worm, and the worm is rotatably connected to the exhaust hood.

[0014] Preferably, the push-pull mechanism includes a connecting rod group, one end of the connecting rod group is rotatably connected to a U-shaped frame, the other end of the U-shaped frame is fixedly connected to the wiping ring, one side of the U-shaped frame is fixedly connected to a transmission rack, the transmission rack is meshed with the driving wheel for transmission, the other end of the connecting rod group is fixedly connected to a transmission rod, the other end of the transmission rod is rotatably connected to the inner wall of the detection box, two gears are fixedly connected in a symmetrical structure on the transmission rod, an incomplete gear is provided on the lower side of the transmission rod, the incomplete gear is meshed with the gear for transmission, the incomplete gear is rotatably connected to the inner wall of the detection box, a worm wheel is fixedly connected to the lower side of the incomplete gear, and the worm wheel is meshed with the worm for transmission.

[0015] Preferably, an electric push rod is fixedly connected to the lower surface of one side of the box cover, and the other end of the electric push rod is fixedly connected to the inner wall of the detection box. A stop cover is slidingly provided at a position of the box cover close to the light-transmitting tube-shaped liquid pool, and one side of the stop cover is movably contacted with the top of the light-transmitting tube-shaped liquid pool. A plurality of springs are fixedly connected to the stop cover, and the other end of the spring is fixedly connected to the box cover. A filter element is threadedly provided on the box cover.

[0016] An optical detection method for acetic anhydride content specifically comprises the following steps:

[0017] S1. When testing the acetic anhydride content in a solution, first place the container containing the solution into the testing box and close the box cover;

[0018] S2. Then use the exhaust hood to extract the air in the test box and inject the filtered air into the test box;

[0019] S3. When the vacuum hood is pumping air, the wiping ring will be driven to move up and down by the push-pull mechanism to wipe the outer wall of the vessel containing the solution;

[0020] S4. When the wiping ring is retracted into the cleaning seat, the push-pull mechanism will drive the scrubbing mechanism to scrub the wiping ring to ensure its cleaning quality.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. By installing a wiping ring within the cleaning seat, driven by a push-pull mechanism, the wiping ring moves up and down, automatically cleaning the outer wall of the transparent tubular liquid pool. This effectively removes fingerprints, ensures an undisturbed optical path, and prevents light from scattering or absorption as it passes through the transparent tubular liquid pool. This significantly improves the accuracy, efficiency, repeatability, and consistency of experiments. This not only reduces human error and ensures optical measurement accuracy, but also improves work efficiency, reduces operational complexity, and contributes to equipment protection and long-term stable operation.

[0023] 2. In addition, the scrubbing mechanism within the cleaning seat also plays a vital role in the cleaning process. By installing a scrubbing mechanism within the cleaning seat, when the wiping ring is retracted into the cleaning seat, a push-pull mechanism activates the scrubbing mechanism, causing the scrubbing block to rotate and move up and down, scrubbing the fiber cloth on the wiping ring. This significantly improves the cleaning effect and quality of the wiping ring. During large-scale testing, the automatic scrubbing system not only ensures uniform cleaning and reduces wear and tear on cleaning tools, but also improves the cleaning quality of the translucent tubular liquid pool, providing efficient support.

[0024] 3. By installing an exhaust hood and filter element, dust and contaminants within the test chamber can be effectively removed, ensuring a clean and stable experimental environment. This improves the accuracy, repeatability, and consistency of optical testing for acetic anhydride content. This not only enhances the reliability of experimental data, reduces equipment contamination and maintenance costs, but also improves experimental efficiency. Furthermore, the cover on the chamber lid can cover the opening of the light-transmitting tubular liquid reservoir, reducing the ingress of dust-laden air into the solution and further enhancing the accuracy of test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the overall structure of an optical detection device and method for acetic anhydride content according to the present invention;

[0026] Figure 2 It is a partial cross-sectional schematic diagram of the overall structure of an optical detection device and method for acetic anhydride content of the present invention;

[0027] Figure 3 It is a partial cross-sectional expanded schematic diagram of the cleaning seat and other structures of an optical detection device and method for acetic anhydride content of the present invention;

[0028] Figure 4 This is a schematic diagram of the structure of a squeeze plate and other components of an optical detection device and method for acetic anhydride content of the present invention;

[0029] Figure 5 This is a schematic structural diagram of a scrubbing mechanism of an optical detection device and method for acetic anhydride content according to the present invention;

[0030] Figure 6 A partial cross-sectional schematic diagram of the structure of an exhaust hood and other components of an optical detection device and method for acetic anhydride content according to the present invention;

[0031] Figure 7 This is a schematic diagram of the push-pull mechanism structure of an optical detection device and method for acetic anhydride content of the present invention;

[0032] Figure 8 The present invention provides a partial cross-sectional schematic diagram of a box cover structure of an optical detection device and method for acetic anhydride content.

[0033] The following are marked in the figure: 1. Detection box; 2. Cleaning seat; 3. Squeeze plate; 4. Scrubbing mechanism; 5. Wiping ring; 6. Vacuum hood; 7. Push-pull mechanism; 8. Box cover; 9. Fourier transform infrared spectrometer; 201. Valve; 202. Guide rod; 203. Placement rack; 204. Transparent tube liquid pool; 301. Raised block; 501. Fiber cloth; 401. Gear ring; 402. Sliding rod; 403. Connecting rod; 404. Tension spring; 40 5. Scrubbing block; 406. Contact rod; 407. Driven pulley; 408. Rotating shaft; 409. Driving pulley; 601. Motor; 602. Fan blade; 603. Universal joint; 604. Worm; 701. Connecting rod assembly; 702. U-shaped frame; 703. Drive rack; 704. Drive rod; 705. Gear; 706. Incomplete gear; 707. Worm gear; 801. Electric push rod; 802. Shield; 803. Spring; 804. Filter element. DETAILED DESCRIPTION

[0034] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0035] like Figures 1-8 The optical detection device and method for acetic anhydride content shown in the figure include a detection box 1, a cleaning seat 2 is fixedly connected to the detection box 1, a squeezing plate 3 is fixedly connected to the cleaning seat 2, a scrubbing mechanism 4 is rotatably connected to the squeezing plate 3, a wiping ring 5 is provided in the cleaning seat 2, an exhaust hood 6 is fixedly connected and provided through the bottom of one side of the detection box 1, a push-pull mechanism 7 is rotatably connected to the inner wall of the detection box 1, a box cover 8 is provided above the detection box 1, and a Fourier transform infrared spectrometer 9 is fixedly installed on the inner wall of one side of the detection box 1.

[0036] like Figure 3 As shown, a valve 201 is fixedly connected to the bottom of the cleaning seat 2, a guide rod 202 is fixedly connected to the inner wall of the cleaning seat 2, a placement rack 203 is fixedly connected to the guide rod 202, a light-transmitting tube-shaped liquid pool 204 is placed on the placement rack 203, and the bottom end of the light-transmitting tube-shaped liquid pool 204 is in contact with the top surface of the squeeze-out plate 3.

[0037] like Figure 4 As shown, the lower surface of the upper side of the squeeze plate 3 is annular in structure and is fixedly connected with a plurality of protrusions 301 .

[0038] like Figure 3 As shown, one end of the wiping ring 5 is slidably fitted with the guide rod 202, a fiber cloth 501 is fixedly connected to the inner circle of the wiping ring 5, the fiber cloth 501 is movably contacted with the outer circle of the upper end of the squeezing plate 3, and the fiber cloth 501 is slidably contacted with the outer wall of the transparent tube-shaped liquid pool 204.

[0039] By installing a wiping ring 5 within the cleaning seat 2 and moving it up and down, driven by a push-pull mechanism 7, the wiping ring 5 automatically cleans the outer wall of the transparent tubular liquid pool 204. This effectively removes fingerprints, ensures an undisturbed optical path, and prevents light from scattering or absorbing as it passes through the transparent tubular liquid pool 204. This significantly improves the accuracy, efficiency, repeatability, and consistency of experimental procedures. This not only reduces human error and ensures optical measurement accuracy, but also improves work efficiency, reduces operational complexity, and contributes to equipment protection and long-term stable operation.

[0040] like Figure 5 As shown, the scrubbing mechanism 4 includes a gear ring 401, which is rotatably connected to the squeezing plate 3, and two sliding rods 402 are symmetrically arranged on the gear ring 401 for sliding cooperation, and a connecting rod 403 is fixedly connected to the sliding rod 402, and the bottom end of the connecting rod 403 is fixedly connected to a tension spring 404, and the other end of the tension spring 404 is fixedly connected to the gear ring 401, and the other end of the connecting rod 403 is fixedly connected to a scrubbing block 405, which is in frictional contact with the fiber cloth 501, and a contact rod 406 is fixedly connected to the connecting rod 403, and the contact rod 406 is in sliding contact with the raised block 301, and a driven wheel 407 is provided on the lower side of the gear ring 401 for meshing transmission, and one end of the driven wheel 407 is fixedly connected to a rotating shaft 408, which penetrates and is rotatably connected to the inner wall of the cleaning seat 2, and the outer end of the rotating shaft 408 is fixedly connected to a driving wheel 409. When the U-shaped frame 702 drives the wiping ring 5 to move down and retract into the cleaning seat 2, the transmission rack 703 on the U-shaped frame 702 will drive the driving wheel 409 to rotate, so that the driving wheel 409 drives the driven wheel 407 connected to the rotating shaft 408 to rotate, and then the driven wheel 407 will drive the gear ring 401 to rotate, so that when the contact rod 406 contacts the protruding block 301, the connecting rod 403 connected to the contact rod 406 will move down, and then move up and reset under the action of the tension spring 404, so that the scrubbing block 405 can move up and down during turnover.

[0041] like Figure 6 As shown, a motor 601 is fixedly connected to the outer wall of the hood 6. The output end of the motor 601 extends to the inner wall of the hood 6 and is fixedly connected to a fan blade 602. One end of the fan blade 602 is fixedly connected to a universal joint 603, and the other end of the universal joint 603 is fixedly connected to a worm 604. The worm 604 is rotatably connected to the hood 6. A one-way butterfly valve is installed on the inner wall of the output end of the hood 6. The motor 601 drives the connected fan blade 602 to rotate. At this time, the fan blade 602 will draw air out of the detection box 1. The external air is then filtered by the filter element 804 and enters the detection box 1.

[0042] like Figure 7As shown, the push-pull mechanism 7 includes a connecting rod group 701, one end of the connecting rod group 701 is rotatably connected to a U-shaped frame 702, the other end of the U-shaped frame 702 is fixedly connected to the wiping ring 5, and a transmission rack 703 is fixedly connected to one side of the U-shaped frame 702, which is engaged with the driving wheel 409 for transmission. The other end of the connecting rod group 701 is fixedly connected to a transmission rod 704, and the other end of the transmission rod 704 is rotatably connected to the inner wall of the detection box 1. Two gears 705 are fixedly connected on the transmission rod 704 in a symmetrical structure, and an incomplete gear 706 is provided on the lower side of the transmission rod 704. The incomplete gear 706 is engaged with the gear 705 for transmission. The incomplete gear 706 is rotatably connected to the inner wall of the detection box 1, and a worm gear 707 is fixedly connected to the lower side of the incomplete gear 706, which is engaged with the worm 604 for transmission. When the fan blade 602 rotates, the connected worm 604 will be driven to rotate through the universal joint 603, so that the worm 604 can drive the incomplete gear 706 connected to the worm wheel 707 to rotate. When the incomplete gear 706 is engaged with one of the gears 705, it will drive the connected transmission rod 704 to rotate in one direction. Then when the incomplete gear 706 is engaged with the other gear 705, it will drive the connected transmission rod 704 to rotate in the opposite direction, thereby driving the connected connecting rod group 701 to rotate, so that the connecting rod group 701 drives the connected U-shaped frame 702 to move up and down.

[0043] like Figure 8 As shown, an electric push rod 801 is fixedly connected to the lower surface of one side of the box cover 8, and the other end of the electric push rod 801 is fixedly connected to the inner wall of the detection box 1. A stop cover 802 is slidably provided near the position of the box cover 8 near the light-transmitting tubular liquid pool 204. One side of the stop cover 802 is movably contacted with the top of the light-transmitting tubular liquid pool 204. A plurality of springs 803 are fixedly connected to the stop cover 802, and the other end of the spring 803 is fixedly connected to the box cover 8. A filter element 804 is threadedly provided on the box cover 8. The stop cover 802 can reduce the entry of impurities in the air into the solution.

[0044] An optical detection method for acetic anhydride content specifically comprises the following steps:

[0045] S1. When testing the acetic anhydride content in the solution, first place the container containing the solution into the testing box 1 and close the box cover 8;

[0046] S2, then use the exhaust hood 6 to extract the air in the detection box 1, and inject the filtered air into the detection box 1;

[0047] S3. When the vacuum hood 6 is evacuating air, the push-pull mechanism 7 drives the wiping ring 5 to move up and down to wipe the outer wall of the vessel containing the solution;

[0048] S4. When the wiping ring 5 is retracted into the cleaning seat 2, the push-pull mechanism 7 drives the scrubbing mechanism 4 to scrub the wiping ring 5 to ensure its cleaning quality.

[0049] Working Principle: When testing the acetic anhydride content in a solution, first place the transparent tubular liquid pool 204 containing the solution on the placement rack 203 in the test box 1. Then, the electric push rod 801 drives the connected box cover 8 downward to close it. At this time, under the action of the spring 803, the blocking cover 802 covers the opening of the transparent tubular liquid pool 204.

[0050] Then, the motor 601 drives the connected fan blades 602 to rotate. At this time, the fan blades 602 will draw out the air in the detection box 1, and then the external air will enter the detection box 1 after being filtered by the filter element 804;

[0051] At the same time, when the fan blade 602 rotates, the connected worm 604 is driven to rotate through the universal joint 603, so that the worm 604 can drive the incomplete gear 706 connected to the worm wheel 707 to rotate. When the incomplete gear 706 is engaged with one of the gears 705, it drives the connected transmission rod 704 to rotate in one direction. Then, when the incomplete gear 706 is engaged with the other gear 705, it drives the connected transmission rod 704 to rotate in the opposite direction, thereby driving the connected connecting rod group 701 to rotate, so that the connecting rod group 701 drives the U-shaped frame 702 to move up and down;

[0052] When the U-shaped frame 702 moves up and down, it drives the connected wiping ring 5 to move up, and then the fiber cloth 501 on the wiping ring 5 will first contact the squeezing plate 3. At this time, the fiber cloth 501 is squeezed, so that the moisture inside is squeezed out. Then, the fiber cloth 501 on the wiping ring 5 will contact the outer wall of the transparent tubular liquid pool 204 to clean it.

[0053] Then, when the U-shaped frame 702 drives the wiping ring 5 to move down and retract into the cleaning seat 2, the transmission rack 703 on the U-shaped frame 702 will drive the driving wheel 409 to rotate, so that the driving wheel 409 drives the driven wheel 407 connected to the rotating shaft 408 to rotate, and then the driven wheel 407 will drive the gear ring 401 to rotate, so that when the contact rod 406 contacts the protruding block 301, the connecting rod 403 connected to the contact rod 406 will move down, and then move up and reset under the action of the tension spring 404, so that the scrubbing block 405 can move up and down during the turnover, scrubbing the contacted fiber cloth 501 to ensure the cleaning effect of the fiber cloth 501. After cleaning the outer wall of the transparent tube-shaped liquid pool 204, wait for the moisture on the outside to dry, and then use the Fourier transform infrared spectrometer 9 to start infrared spectrum scanning of the acetic anhydride solution.

[0054] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0055] The above shows and describes 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 above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An optical detection device for acetic anhydride content, comprising a detection box (1), characterized in that: A cleaning seat (2) is fixedly connected to the detection box (1), a squeeze plate (3) is fixedly connected to the cleaning seat (2), a scrubbing mechanism (4) is rotatably connected to the squeeze plate (3), a wiping ring (5) is provided in the cleaning seat (2), an exhaust hood (6) is fixedly connected to the bottom of one side of the detection box (1), a push-pull mechanism (7) is rotatably connected to the inner wall of the detection box (1), a box cover (8) is provided above the detection box (1), and a Fourier transform infrared spectrometer (9) is fixedly installed on the inner wall of one side of the detection box (1).

2. The optical detection device for acetic anhydride content according to claim 1, wherein: A valve (201) is fixedly connected to and penetrates the bottom of the cleaning seat (2); a guide rod (202) is fixedly connected to the inner wall of the cleaning seat (2); a placement rack (203) is fixedly connected to the guide rod (202); a light-transmitting tube-shaped liquid pool (204) is placed on the placement rack (203); and the bottom end of the light-transmitting tube-shaped liquid pool (204) is in contact with the top surface of the squeeze-out plate (3).

3. The optical detection device for acetic anhydride content according to claim 2, wherein: The lower surface of the upper side of the squeeze plate (3) is in an annular structure and is fixedly connected with a plurality of protruding blocks (301).

4. The optical detection device for acetic anhydride content according to claim 3, wherein: One end of the wiping ring (5) is slidably matched with the guide rod (202), a fiber cloth (501) is fixedly connected to the inner circle of the wiping ring (5), the fiber cloth (501) is movably contacted with the outer circle of the upper end of the squeeze plate (3), and the fiber cloth (501) is slidably contacted with the outer wall of the light-transmitting tube-shaped liquid pool (204).

5. The optical detection device for acetic anhydride content according to claim 4, characterized in that: The scrubbing mechanism (4) comprises a gear ring (401), the gear ring (401) is rotatably connected to the squeeze plate (3), two sliding rods (402) are symmetrically arranged on the gear ring (401) for sliding cooperation, a connecting rod (403) is fixedly connected to the sliding rod (402), a tension spring (404) is fixedly connected to the bottom end of the connecting rod (403), the other end of the tension spring (404) is fixedly connected to the gear ring (401), and a scrubbing block (405) is fixedly connected to the other end of the connecting rod (403). The scrubbing block (405) is arranged in frictional contact with the fiber cloth (501); a contact rod (406) is fixedly connected to the connecting rod (403); the contact rod (406) is arranged in sliding contact with the protruding block (301); a driven wheel (407) is arranged on the lower side of the gear ring (401) for meshing transmission; a rotating shaft (408) is fixedly connected to one end of the driven wheel (407); the rotating shaft (408) is rotatably connected to the inner wall of the cleaning seat (2); and a driving wheel (409) is fixedly connected to the outer end of the rotating shaft (408).

6. The optical detection device for acetic anhydride content according to claim 5, characterized in that: The outer wall of the exhaust hood (6) is fixedly connected to a motor (601), an output end of the motor (601) extends to the inner wall of the exhaust hood (6) and is fixedly connected to a fan blade (602), one end of the fan blade (602) is fixedly connected to a universal joint (603), the other end of the universal joint (603) is fixedly connected to a worm (604), and the worm (604) is rotatably connected to the exhaust hood (6).

7. The optical detection device for acetic anhydride content according to claim 6, characterized in that: The push-pull mechanism (7) comprises a connecting rod group (701), one end of the connecting rod group (701) is rotatably connected to a U-shaped frame (702), the other end of the U-shaped frame (702) is fixedly connected to the wiping ring (5), one side of the U-shaped frame (702) is fixedly connected to a transmission rack (703), the transmission rack (703) is meshed with the driving wheel (409) for transmission, the other end of the connecting rod group (701) is fixedly connected to a transmission rod (704), the other end of the transmission rod (704) is fixedly connected to the detection box ( 1) The inner wall is rotatably connected, and two gears (705) are fixedly connected and arranged on the transmission rod (704) in a symmetrical structure. An incomplete gear (706) is arranged on the lower side of the transmission rod (704), and the incomplete gear (706) is meshed with the gear (705) for transmission. The incomplete gear (706) is rotatably connected to the inner wall of the detection box (1), and a worm gear (707) is fixedly connected to the lower side of the incomplete gear (706), and the worm gear (707) is meshed with the worm (604) for transmission.

8. The optical detection device for acetic anhydride content according to claim 2, wherein: An electric push rod (801) is fixedly connected to the lower surface of one side of the box cover (8), and the other end of the electric push rod (801) is fixedly connected to the inner wall of the detection box (1). A stop cover (802) is slidably provided at a position of the box cover (8) close to the light-transmitting tube-shaped liquid pool (204), and one side of the stop cover (802) is movably contacted with the top of the light-transmitting tube-shaped liquid pool (204). A plurality of springs (803) are fixedly connected to the stop cover (802), and the other end of the spring (803) is fixedly connected to the box cover (8). A filter element (804) is threadedly provided on the box cover (8).

9. A method for optically detecting acetic anhydride content, using the optical detection device for acetic anhydride content according to any one of claims 1 to 8, comprising the following steps: S1. When testing the acetic anhydride content in a solution, first place the container containing the solution into the testing box (1) and close the box cover (8); S2, then using the exhaust hood (6) to extract the air in the detection box (1), and injecting the filtered air into the detection box (1); S3. When the vacuum hood (6) is evacuating air, the push-pull mechanism (7) drives the wiping ring (5) to move up and down to wipe the outer wall of the vessel containing the solution; S4. When the wiping ring (5) is retracted into the cleaning seat (2), the push-pull mechanism (7) drives the scrubbing mechanism (4) to scrub the wiping ring (5) to ensure its cleaning quality.

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