Soil total nitrogen digestion method and device

Abstract

The invention relates to the technical field of soil detection equipment, in particular to a soil total nitrogen digestion method and device. The driving motor is fixedly connected with the outer wall of the cooking device through a bracket; the shaking device is located in the cooking device; according to the device, the relative position of the sliding plate and the bottom plate can be flexibly adjusted by arranging the adjusting screw rod, so that the device can adapt to test tubes with different heights and sizes, and the compatibility of the device to experimental sample containers with different specifications is improved. Therefore, when a soil total nitrogen digestion experiment is carried out, specific adaptive equipment does not need to be searched for test tubes with different sizes, the complexity of experiment preparation work is reduced, the convenience of experiment operation is improved, and various experiment requirements can be met.

Description

Technical Field

[0001] The invention relates to the technical field of soil detection equipment, and in particular to a method and a device for decomposing total nitrogen in soil. Background Art

[0002] In the research and experimental field of soil total nitrogen content determination, traditional digestion methods and devices have many limitations and are difficult to meet the requirements of modern scientific research and experiments for accuracy, efficiency and ease of operation, which provides the background basis for the birth of this invention.

[0003] Traditional soil total nitrogen digestion devices perform poorly in terms of sample container adaptability. They can often only adapt to test tubes or containers of specific sizes. When faced with experimental sample containers of different heights and diameters, experimenters need to spend a lot of time and energy to find suitable adapters, or make cumbersome adjustments and modifications to the sample containers, which greatly increases the complexity of experimental preparation, reduces the efficiency of experimental operations, and limits the flexibility and diversity of experiments. In addition, traditional devices are not ideal in promoting the mixing of digestion liquid and soil. There is a lack of effective shaking or mixing mechanism, or even if there is a shaking function, its movement is not smooth and continuous enough, and the digestion liquid cannot react evenly with the total nitrogen components in the soil, which easily causes incomplete or uneven local reactions. This makes the digestion reaction incomplete, affects the accuracy and precision of the determination of soil total nitrogen content, and cannot provide reliable data support for soil research and related applications, restricting the development of soil science research and its practical application in agricultural production and other fields. In summary, the traditional soil total nitrogen digestion method and device have deficiencies in many aspects, and a new device and method that can solve these problems is urgently needed. The present invention came into being in this context, aiming to improve the efficiency, accuracy and ease of operation of the soil total nitrogen digestion experiment, and promote the development of soil science research and related fields. Summary of the invention

[0004] In view of the deficiencies in the prior art, the technical solution adopted by the present invention to solve the technical problems is: a soil total nitrogen digestion device, comprising: a cooking device; a driving motor, the driving motor is fixedly connected to the outer wall of the cooking device through a bracket; a shaking device, the shaking device is located inside the cooking device; a fixing device, the bottom end of the fixing device is slidably connected to the top end of the shaking device; the fixing device comprises a fixing frame, the inner wall of the fixing frame is fixedly connected to a bottom plate, the top end of the fixing frame is fixedly connected to a sliding plate, the inner wall of the sliding plate is provided with a locking mechanism, a placement opening is opened in the wall of the bottom plate, and both ends of the outer wall of the fixing frame are symmetrically fixedly connected to limiting columns, and the wall of the limiting columns is provided with a card slot.

[0005] The present invention is further configured such that the outer wall of the base plate is fixedly connected to a sliding rod, the inner wall of the base plate is rotatably connected to an adjusting screw, the outer wall of the sliding rod is slidably connected to the inner wall of the sliding plate, and the outer wall of the adjusting screw is threadedly connected to the inner wall of the sliding plate.

[0006] The present invention is further configured such that the locking mechanism includes a rotating rod, a rotating handle is fixedly connected to the outer wall of the rotating rod, a torsion spring is fixedly connected to the outer wall of the rotating rod, a pull rod is symmetrically rotationally connected to the outer wall of the rotating handle, a sliding block is rotationally connected to the outer wall of the pull rod, and a clamping block is fixedly connected to the outer wall of the sliding block.

[0007] The present invention is further configured such that the outer wall of the rotating rod is rotatably connected to the inner wall of the sliding plate, the end of the torsion spring away from the rotating rod is fixedly connected to the outer wall of the rotating handle, the outer wall of the sliding block is slidably connected to the inner wall of the sliding plate, the outer wall of the clamping block is fixedly connected to a friction pad, and the outer wall of the clamping block is fixedly connected to a resistance block.

[0008] The present invention is further configured as follows: the shaking device includes a support frame, the four corners of the support frame are fixedly connected with limiting rods, the bottom end of the limiting rods is fixedly connected with a connecting rod, the outer surface of the connecting rod is symmetrically fixedly connected with a buffer spring, the bottom end of the connecting rod is fixedly connected with a pushing rod, and the outer wall of the support frame is symmetrically provided with a clamping mechanism.

[0009] The present invention is further configured such that the outer wall of the support frame is slidably connected to the outer wall of the cooking device, the outer wall of the limit rod is slidably connected to the inner wall of the cooking device, and the end of the buffer spring away from the connecting rod is fixedly connected to the inner wall of the cooking device.

[0010] The present invention is further configured such that the bottom end of the push rod is slidably connected to a swing rod, the outer wall of the swing rod is slidably connected to a moving block, the outer wall of the swing rod is rotatably connected to the inner wall of the cooking device, the outer wall of the moving block is rotatably connected to a swing handle, and the outer wall of the swing handle is fixedly connected to the output end of the driving motor.

[0011] The present invention is further configured such that the clamping mechanism includes a movable plate, an outer wall of the movable plate is symmetrically provided with entry grooves, an inner wall of the entry groove is fixedly connected with a clamping block, an outer wall of the movable plate is fixedly connected with a movable rod, an outer wall of the movable rod is slidably connected with a linkage block, and an outer wall of the linkage block is fixedly connected with a push spring.

[0012] The present invention is further configured such that the outer wall of the movable plate is slidably connected to the outer wall of the support frame, the outer wall of the linkage block is fixedly connected to the outer wall of the support frame, the end of the push spring away from the linkage block is fixedly connected to the outer wall of the movable rod, the outer wall of the card block is slidably connected to the inner wall of the card slot, and the inner wall of the entry slot is slidably connected to the outer wall of the limit column.

[0013] The method for detoxifying soil total nitrogen includes the following steps:

[0014] Step 1: Place the test tube containing the soil sample in the fixture, adjust the adjusting screw in the fixture to move the sliding plate up and down relative to the bottom plate to adapt to the height of the test tube, and then use the locking mechanism to firmly fix the test tube to prevent it from moving during the digestion process;

[0015] Step 2: Connect the fixture that fixes the test tube to the shaking device, place the fixture on the support frame, make the limit rod enter the entry slot of the clamping mechanism, and clamp it through the cooperation between the clamping block and the clamping slot to ensure a stable connection;

[0016] Step 3: Start the cooking device, set the temperature and time for cooking, and start the driving motor at the same time. Through the coordinated action of the push rod, the connecting rod and the buffer spring, the support frame moves up and down in the cooking device, driving the test tube to shake, so that the cooking liquid and the soil are mixed, and the cooking reaction is promoted;

[0017] Step 4: After digestion is completed, turn off the cooking device and the drive motor, wait for the digestion device to cool down, carefully loosen the clamping mechanism and the locking mechanism, take out the test tube, transfer the digested solution to a suitable container, and use the Kjeldahl method for subsequent nitrogen content determination.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The present invention can adjust the relative position of the sliding plate and the bottom plate by setting an adjusting screw, and can adapt to test tubes of different heights and sizes, thereby improving the compatibility of the device with experimental sample containers of different specifications. This makes it unnecessary to find specific adapter equipment for test tubes of different sizes when conducting soil total nitrogen digestion experiments, reduces the complexity of experimental preparation work, improves the convenience of experimental operation, and can meet a variety of experimental needs.

[0020] 2. The present invention provides a locking mechanism, and the clamping block can tightly clamp the test tube under the action of components such as a torsion spring. The friction pad on the outer wall of the clamping block increases the friction force, and the abutment block further enhances the abutment effect, ensuring that the test tube does not move up and down during the digestion process. This stable fixing method is crucial to ensure the accuracy of the experiment. It avoids problems such as sample leakage and uneven reaction caused by shaking or displacement of the test tube, allowing the digestion reaction to be carried out under stable conditions, thereby improving the reliability and repeatability of the experimental results.

[0021] 3. The present invention realizes convenient connection and separation through the clamping mechanism by setting a shaking device and a fixing device. During installation, it is only necessary to insert the limit rod on the fixing frame into the clamping mechanism through the entry slot, and the clamping block is automatically clamped into the clamping slot under the action of the push spring, which is simple and quick to operate. When separation is required, the moving rod can be pulled outward to overcome the spring elastic force to separate the clamping block from the clamping slot, which facilitates various links of experimental operation, such as sample installation and disassembly, cleaning and maintenance of the device, etc., and improves work efficiency.

[0022] 4. The present invention provides a clamping mechanism to achieve convenient connection while ensuring the stability of the connection between the fixing device and the shaking device during the shaking process. This ensures that the fixing device will not loosen or fall off when the driving motor drives the shaking device to work, ensuring that the soil and reagents in the test tube can be mixed in a stable environment. The stable connection helps to achieve uniform and effective shaking, promotes full contact and reaction between the digestion liquid and the soil, and further improves the experimental effect.

[0023] 5. The present invention provides a shaking device, and the driving motor drives the shaking device to drive the test tube up and down, so that the reagents and soil in the test tube are fully mixed during the digestion process. The buffer spring plays a buffering and resetting role during the movement of the connecting rod, ensuring the stability and continuity of the shaking movement. This continuous mixing action allows the digestion liquid to react evenly with the total nitrogen components in the soil, avoiding the situation of incomplete or uneven local reaction, improving the efficiency and thoroughness of the digestion reaction, and thus more accurately determining the total nitrogen content in the soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of the present invention;

[0025] Figure 2 It is a schematic diagram of the structure of the fixing device of the present invention;

[0026] Figure 3 It is a structural schematic diagram of the sliding rod of the present invention;

[0027] Figure 4 It is a structural schematic diagram of the locking mechanism of the present invention;

[0028] Figure 5 It is a schematic diagram of the structure of the shaking device of the present invention;

[0029] Figure 6 It is a structural schematic diagram of the clamping mechanism of the present invention.

[0030] In the figure: 1. cooking device; 2. driving motor; 3. shaking device; 31. supporting frame; 32. limiting rod; 33. buffer spring; 34. clamping mechanism; 341. moving plate; 342. clamping block; 343. moving rod; 344. pushing spring; 345. linkage block; 346. entering slot; 35. swinging rod; 36. moving block; 37. swinging handle; 38. pushing rod; 39. connecting rod; 4. fixing device; 41. fixing frame; 42. limiting column; 43. clamping slot; 44. bottom plate; 45. sliding plate; 46. sliding rod; 47. adjusting screw; 48. locking mechanism; 481. rotating rod; 482. torsion spring; 483. rotating handle; 484. pulling rod; 485. sliding block; 486. clamping block; 487. resisting block; 488. friction pad; 49. placing opening. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0032] Example:

[0033] See also Figure 1 - Figure 6 The present invention provides a technical solution: a soil total nitrogen digestion device, comprising: a cooking device 1; a driving motor 2, the driving motor 2 is fixedly connected to the outer wall of the cooking device 1 through a bracket; a shaking device 3, the shaking device 3 is located inside the cooking device 1; a fixing device 4, the bottom end of the fixing device 4 is slidably connected to the top end of the shaking device 3; the fixing device 4 comprises a fixing frame 41, the inner wall of the fixing frame 41 is fixedly connected with a bottom plate 44, the top end of the fixing frame 41 is fixedly connected with a sliding plate 45, the inner wall of the sliding plate 45 is provided with a locking mechanism 48, a placement opening 49 is opened in the wall of the bottom plate 44, and the two ends of the outer wall of the fixing frame 41 are symmetrically fixedly connected with limiting columns 42, and the wall of the limiting columns 42 is provided with a card slot 43.

[0034] The outer wall of the bottom plate 44 is fixedly connected with a sliding rod 46 , the inner wall of the bottom plate 44 is rotatably connected with an adjusting screw 47 , the outer wall of the sliding rod 46 is slidably connected to the inner wall of the sliding plate 45 , and the outer wall of the adjusting screw 47 is threadedly connected to the inner wall of the sliding plate 45 .

[0035] The locking mechanism 48 includes a rotating rod 481, the outer wall of which is fixedly connected to a rotating handle 483, the outer wall of which is fixedly connected to a torsion spring 482, the outer wall of which is symmetrically rotatably connected to a pull rod 484, the outer wall of which is rotatably connected to a sliding block 485, and the outer wall of which is fixedly connected to a clamping block 486.

[0036] The outer wall of the rotating rod 481 is rotatably connected to the inner wall of the sliding plate 45, the end of the torsion spring 482 away from the rotating rod 481 is fixedly connected to the outer wall of the rotating handle 483, the outer wall of the sliding block 485 is slidably connected to the inner wall of the sliding plate 45, the outer wall of the clamping block 486 is fixedly connected with a friction pad 488, and the outer wall of the clamping block 486 is fixedly connected with a resistance block 487.

[0037] The shaking device 3 includes a support frame 31, and the four corners of the support frame 31 are fixedly connected with a limiting rod 32, the bottom end of the limiting rod 32 is fixedly connected with a connecting rod 39, the outer surface of the connecting rod 39 is symmetrically fixedly connected with a buffer spring 33, the bottom end of the connecting rod 39 is fixedly connected with a pushing rod 38, and the outer wall of the support frame 31 is symmetrically provided with a clamping mechanism 34.

[0038] The outer wall of the support frame 31 is slidably connected to the outer wall of the cooking device 1 , the outer wall of the limit rod 32 is slidably connected to the inner wall of the cooking device 1 , and the end of the buffer spring 33 away from the connecting rod 39 is fixedly connected to the inner wall of the cooking device 1 .

[0039] The bottom end of the push rod 38 is slidably connected to the swing rod 35, the outer wall of the swing rod 35 is slidably connected to the moving block 36, the outer wall of the swing rod 35 is rotatably connected to the inner wall of the cooking device 1, the outer wall of the moving block 36 is rotatably connected to the swing handle 37, and the outer wall of the swing handle 37 is fixedly connected to the output end of the driving motor 2.

[0040] The clamping mechanism 34 includes a movable plate 341, the outer wall of which is symmetrically provided with an entry groove 346, the inner wall of which is fixedly connected with a clamping block 342, the outer wall of the movable plate 341 is fixedly connected with a movable rod 343, the outer wall of the movable rod 343 is slidably connected with a linkage block 345, and the outer wall of the linkage block 345 is fixedly connected with a push spring 344.

[0041] The outer wall of the movable plate 341 is slidably connected to the outer wall of the support frame 31, the outer wall of the linkage block 345 is fixedly connected to the outer wall of the support frame 31, the end of the pushing spring 344 away from the linkage block 345 is fixedly connected to the outer wall of the movable rod 343, the outer wall of the clamping block 342 is slidably connected to the inner wall of the clamping slot 43, and the inner wall of the slot 346 is slidably connected to the outer wall of the limiting column 42.

[0042] The method for detoxifying soil total nitrogen includes the following steps:

[0043] Step 1: Place the test tube containing the soil sample in the fixing device 4, adjust the adjusting screw 47 in the fixing device 4 to move the sliding plate 45 up and down relative to the bottom plate 44 to adapt to the height of the test tube, and then use the locking mechanism 48 to firmly fix the test tube to prevent it from moving during the digestion process;

[0044] Step 2: Connect the fixture 4 that fixes the test tube to the shaking device 3, place the fixture 41 on the support frame 31, make the limit rod 32 enter the entry groove 346 of the clamping mechanism 34, and clamp the clamping block 342 and the clamping groove 43 to ensure stable connection;

[0045] Step 3: Start the cooking device 1, set the temperature and time for cooking, and start the driving motor 2 at the same time. Through the coordinated action of the push rod 38, the connecting rod 39 and the buffer spring 33, the support frame 31 moves up and down in the cooking device 1, driving the test tube to shake, so that the cooking liquid and the soil are mixed, and the cooking reaction is promoted;

[0046] Step 4: After the digestion is completed, turn off the digestion device 1 and the drive motor 2, wait for the digestion device to cool down, carefully loosen the clamping mechanism 34 and the locking mechanism 48, take out the test tube, transfer the digested solution to a suitable container, and use the Kjeldahl method for subsequent nitrogen content determination.

[0047] Working principle:

[0048] When in use, first put the soil and reaction reagents into the corresponding test tubes, first through the fixing device 4, by rotating the adjusting screw 47, since the adjusting screw 47 is threadedly connected to the inner wall of the sliding plate 45, and the sliding plate 45 is connected to the bottom plate 44 through the sliding rod 46, with the rotation of the adjusting screw 47, the sliding plate 45 can move up and down relative to the bottom plate 44, so as to be adjusted according to the height of different test tubes to adapt to test tubes of different sizes. When the adjustment is completed, place the test tube downward, and through the squeezing of the test tube, the stop block 487 pushes the clamping block 486 to slide on the sliding plate 45, so that the test tube can pass through the sliding plate 45 until the bottom end of the test tube contacts the placement port 49 on the bottom plate 44, and the locking mechanism 48 is used to further fix the sample container. When fixing is required, the torsion spring 482 drives the rotating rod 481 to rotate on the sliding plate 45, so that the rotating handle 483 rotates, and the rotating handle 483 drives the pull rod 484 to rotate, so that the pull rod 484 pulls the sliding block 485 to slide on the inner wall of the sliding plate 45, so that the clamping block 486 moves closer to the outer wall of the test tube. The friction pad 488 on the outer wall of the clamping block 486 increases the friction with the sample container, and the abutment block 487 at the top plays a better abutting role, thereby firmly fixing the sample container in the fixing device 4 to prevent it from moving up and down;

[0049] When the test tube is installed, the fixing frame 41 is placed on the support frame 31 by shaking the device 3, and the limiting column 42 is forced downward to enter the clamping mechanism 34, so that it passes through the moving plate 341 through the entry slot 346. In this process, the block 342 is squeezed, so that the moving plate 341 slides on the support frame 31. Under the action of the push spring 344, the outer wall of the block 342 is slidably connected with the clamping slot 43 in the wall of the limiting rod 32 to achieve clamping. At this time, the moving plate 341 is fixedly connected with the outer wall of the support frame 31. When it is necessary to loosen, the moving rod 343 is pulled outward to slide on the linkage block 345, overcoming the elastic force of the push spring 344, so that the block 342 is separated from the clamping slot 43, and the fixing device 4 can be separated from the shaking device 3;

[0050] After the fixing is completed, the cooking device 1 is first started to digest the reagent in the test tube, and the driving motor 2 is started to work, and its output end drives the swing handle 37 to rotate. When the swing handle 37 rotates, it drives the moving block 36 connected to it to slide on the swing rod 35. Since the swing rod 35 is rotatably connected to the inner wall of the cooking device 1, and the push rod 38 slidably connected to the swing rod 35 is fixedly connected to the connecting rod 39, when the moving block 36 moves, it will push the swing rod 35 to swing, and then drive the connecting rod 39 to move up and down through the push rod 38. One end of the buffer spring 33 symmetrically fixed on the connecting rod 39 is fixedly connected to the inner wall of the cooking device 1. During the movement of the connecting rod 39, the buffer spring 33 plays a role of buffering and resetting. When the push rod 38 pushes the connecting rod 39 upward, the buffer spring 33 is compressed; when the push rod 38 moves downward, the buffer spring 33 rebounds to help the connecting rod 39 reset, and so on and so forth, so that the connecting rod 39 drives the support frame 31 to move up and down in the cooking device 1, so that the reagent and soil in the test tube are mixed during the digestion process.

[0051] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A soil total nitrogen digestion device, characterized in that: include: A cooking device (1); A driving motor (2), wherein the driving motor (2) is fixedly connected to the outer wall of the steaming device (1) via a bracket; A shaking device (3), wherein the shaking device (3) is located inside the cooking device (1); A fixing device (4), the bottom end of which is slidably connected to the top end of the shaking device (3); The fixing device (4) comprises a fixing frame (41), the inner wall of the fixing frame (41) is fixedly connected to a bottom plate (44), the top of the fixing frame (41) is fixedly connected to a sliding plate (45), the inner wall of the sliding plate (45) is provided with a locking mechanism (48), a placement opening (49) is provided in the wall of the bottom plate (44), and the two ends of the outer wall of the fixing frame (41) are symmetrically fixedly connected to limit columns (42), and a card slot (43) is provided in the wall of the limit column (42).

2. The soil total nitrogen digestion device according to claim 1, characterized in that: The outer wall of the base plate (44) is fixedly connected to a sliding rod (46), the inner wall of the base plate (44) is rotatably connected to an adjusting screw (47), the outer wall of the sliding rod (46) is slidably connected to the inner wall of the sliding plate (45), and the outer wall of the adjusting screw (47) is threadedly connected to the inner wall of the sliding plate (45).

3. The soil total nitrogen digestion device according to claim 1, characterized in that: The locking mechanism (48) includes a rotating rod (481), the outer wall of the rotating rod (481) is fixedly connected to a rotating handle (483), the outer wall of the rotating rod (481) is fixedly connected to a torsion spring (482), the outer wall of the rotating handle (483) is symmetrically rotationally connected to a pull rod (484), the outer wall of the pull rod (484) is rotationally connected to a sliding block (485), and the outer wall of the sliding block (485) is fixedly connected to a clamping block (486).

4. The soil total nitrogen digestion device according to claim 3 is characterized in that: The outer wall of the rotating rod (481) is rotatably connected to the inner wall of the sliding plate (45); the end of the torsion spring (482) away from the rotating rod (481) is fixedly connected to the outer wall of the rotating handle (483); the outer wall of the sliding block (485) is slidably connected to the inner wall of the sliding plate (45); the outer wall of the clamping block (486) is fixedly connected to a friction pad (488); and the outer wall of the clamping block (486) is fixedly connected to a resisting block (487).

5. The soil total nitrogen digestion device according to claim 1, characterized in that: The shaking device (3) comprises a support frame (31), the four corners of the support frame (31) are fixedly connected to limit rods (32), the bottom end of the limit rod (32) is fixedly connected to a connecting rod (39), the outer surface of the connecting rod (39) is symmetrically fixedly connected to a buffer spring (33), the bottom end of the connecting rod (39) is fixedly connected to a push rod (38), and the outer wall of the support frame (31) is symmetrically provided with a clamping mechanism (34).

6. The soil total nitrogen digestion device according to claim 5, characterized in that: The outer wall of the support frame (31) is slidably connected to the outer wall of the cooking device (1), the outer wall of the limit rod (32) is slidably connected to the inner wall of the cooking device (1), and the end of the buffer spring (33) away from the connecting rod (39) is fixedly connected to the inner wall of the cooking device (1).

7. The soil total nitrogen digestion device according to claim 6, characterized in that: The bottom end of the push rod (38) is slidably connected to a swing rod (35), the outer wall of the swing rod (35) is slidably connected to a moving block (36), the outer wall of the swing rod (35) is rotatably connected to the inner wall of the cooking device (1), the outer wall of the moving block (36) is rotatably connected to a swing handle (37), and the outer wall of the swing handle (37) is fixedly connected to the output end of the driving motor (2).

8. The soil total nitrogen digestion device according to claim 5, characterized in that: The clamping mechanism (34) comprises a movable plate (341), the outer wall of the movable plate (341) is symmetrically provided with an entry groove (346), the inner wall of the entry groove (346) is fixedly connected with a clamping block (342), the outer wall of the movable plate (341) is fixedly connected with a movable rod (343), the outer wall of the movable rod (343) is slidably connected with a linkage block (345), and the outer wall of the linkage block (345) is fixedly connected with a push spring (344).

9. The soil total nitrogen digestion device according to claim 8, characterized in that: The outer wall of the movable plate (341) is slidably connected to the outer wall of the support frame (31), the outer wall of the linkage block (345) is fixedly connected to the outer wall of the support frame (31), the end of the push spring (344) away from the linkage block (345) is fixedly connected to the outer wall of the movable rod (343), the outer wall of the clamping block (342) is slidably connected to the inner wall of the clamping slot (43), and the inner wall of the entry slot (346) is slidably connected to the outer wall of the limiting column (42).

10. A method for digesting total nitrogen in soil, for using the device for digesting total nitrogen in soil according to claim 9, characterized in that: The following steps are involved: Step 1: Place the test tube containing the soil sample in the fixing device (4), adjust the adjusting screw (47) in the fixing device (4) to move the sliding plate (45) up and down relative to the bottom plate (44) to adapt to the height of the test tube, and then use the locking mechanism (48) to firmly fix the test tube to prevent it from moving during the digestion process; Step 2: Connect the fixing device (4) that fixes the test tube to the shaking device (3), place the fixing frame (41) on the support frame (31), make the limit rod (32) enter the entry groove (346) of the clamping mechanism (34), and achieve clamping through the cooperation between the clamping block (342) and the clamping groove (43), so as to ensure stable connection; Step 3: Start the cooking device (1), set the temperature and time for cooking, and start the driving motor (2) at the same time. Through the coordinated action of the push rod (38), the connecting rod (39) and the buffer spring (33), the support frame (31) moves up and down in the cooking device (1), driving the test tube to shake, so that the cooking liquid and the soil are mixed, thereby promoting the cooking reaction; Step 4: After the digestion is completed, turn off the digestion device (1) and the drive motor (2), wait for the digestion device to cool down, carefully loosen the clamping mechanism (34) and the locking mechanism (48), take out the test tube, transfer the digested solution to a suitable container, and use the Kjeldahl method to perform subsequent nitrogen content determination.

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