A laboratory soil sample fine grinding device

Abstract

This invention belongs to the field of soil sample preparation technology, specifically relating to a laboratory soil sample fine grinding device, including a base, a multi-layered stacked pulverizing sieve cylinder, a top cover, and a rocker assembly. The pulverizing sieve cylinder is divided into a fine grinding chamber and a sieving chamber by an S-shaped partition plate. A sieve screen is installed at the bottom of the sieving chamber, with the mesh size decreasing progressively from top to bottom. Fine grinding wheels are installed in the fine grinding chamber. The rocker assembly connects the layers of fine grinding wheels in series for synchronous drive, and a sealing insert controls the opening and closing of the fine grinding chamber and the sieving chamber. The device can switch between upright sieving and inverted fine grinding states. The top cover has an air inlet pipe for introducing ionized gas to eliminate static electricity in the soil powder. This invention achieves integrated closed operation of fine grinding and sieving, reducing sample transfer loss and dust pollution. Fine grinding ensures uniform particle size, and the static electricity elimination design solves the problem of fine powder clogging the sieve. It is easy to operate and suitable for detecting soil organic carbon, total phosphorus, heavy metals, and other indicators.

Description

Technical Field

[0001] This invention belongs to the field of soil sample preparation technology, and specifically relates to a laboratory soil sample fine grinding device. Background Technology

[0002] Currently, in the laboratory, fine grinding of air-dried soil samples usually requires manual agate mortar and pestle grinding, and all samples must be passed through a 0.149mm nylon sieve for the detection of mineral elements such as organic carbon and total phosphorus, as well as heavy metals. Manual processing requires two separate sieving steps and back-and-forth transfer of soil samples. Each additional transfer step results in more loss and contamination. When an open sieve is shaken, dust flies out, which can lead to sample loss, respiratory hazards for laboratory personnel, and cross-contamination of samples by dust falling onto the workbench. Air-dried ultrafine soil powder is electrostatically adsorbed and clumps together, adhering to the screen. It is difficult to pass through the screen quickly by manual vibration. Frequent scraping of the screen can easily cause deformation of the screen wires and rapid screen wear. The uneven force of manual vibration results in incomplete screening of fine powder, leaving a large amount of qualified fine powder on the screen. Summary of the Invention

[0003] Based on the problems mentioned in the background art above, the present invention provides a laboratory soil sample fine grinding device to solve the problems of low efficiency of existing soil sample fine grinding and sieving, serious sample loss and pollution, dust flying, electrostatic clogging, and poor particle size uniformity.

[0004] The technical solution adopted in this invention is as follows: A laboratory soil sample fine grinding device includes a base, a grinding sieve assembly, a top cover, and a rocker arm assembly; The pulverizing screen assembly includes multiple stacked pulverizing screen cylinders. An S-shaped partition plate is fixed inside each pulverizing screen cylinder, dividing the internal space of the pulverizing screen cylinder into a fine grinding chamber and a screening chamber. A screen is provided at the bottom of the screening chamber, and the mesh size of the screens in each pulverizing screen cylinder decreases progressively from top to bottom. A fine grinding wheel is provided in the fine grinding chamber, and a mud outlet is provided at one end of the S-shaped partition plate. The fine grinding chamber and the screening chamber can be connected through the mud outlet. The top cover is fitted onto the top of the uppermost crushing screen cylinder, and the rocker assembly is inserted through the top cover and connected in series with the fine grinding wheels in each fine grinding chamber, so as to drive each fine grinding wheel to rotate synchronously. The base is located at the bottom of the crushing screen assembly, and a waste cylinder is provided on the base to receive the powder that leaks down from the bottom crushing screen cylinder; The crushing screen assembly is equipped with a sealing insert, which can be inserted and removed along the axial direction of the crushing screen cylinder to open or close the mud outlet; the device can be switched between upright and inverted states. When inverted, the fine grinding chamber is located at the bottom for fine grinding operations, and when upright, the screening chamber is located at the bottom for screening operations.

[0005] Based on the above technical solution, the present invention has made the following improvements: Furthermore, the bottom of the pulverizing screen cylinder is equipped with an S-shaped sealing strip. When the upper pulverizing screen cylinder is stacked on top of the lower pulverizing screen cylinder, the upper S-shaped sealing strip overlaps and seals with the lower S-shaped isolation plate, achieving independent separation between the fine grinding chamber and the sieving chamber between the layers. This prevents soil samples from rolling randomly through the gap between the S-shaped isolation plate and the upper pulverizing screen cylinder during the fine grinding process.

[0006] Furthermore, the bottom edge of the crushing screen cylinder is provided with a downwardly extending connecting piece, on which a slot is formed. The top outer wall of the lower crushing screen cylinder is provided with a protrusion that matches the slot. The multiple crushing screen cylinders are coaxially stacked and positioned through the insertion and engagement of the slot and the protrusion. By engaging the slot of the connecting piece at the bottom of the crushing screen cylinder with the protrusion at the top of the lower screen cylinder, the multiple screen cylinders can be quickly and coaxially positioned and stacked, resulting in high assembly efficiency. After stacking, there is no relative rotation in the circumference, and the interlayer position remains stable during the inverted fine grinding and upright shaking sieving processes.

[0007] Furthermore, the rocker assembly includes a connecting rod and a handle fixed to the top of the connecting rod. A mounting tube is located at the center of the bottom of the fine grinding chamber, and a stepped hole is formed at the center of each fine grinding wheel. The connecting rod passes through the stepped holes of each fine grinding wheel and the mounting tube of the corresponding layer from top to bottom. An axial groove is formed on the outer wall of the connecting rod, and a retaining strip is formed on the inner wall of the stepped hole of the fine grinding wheel to engage with the groove. The insertion ends of the groove and the retaining strip are respectively provided with mutually cooperating guide wedge surfaces. A single connecting rod connects all the fine grinding wheels from top to bottom, achieving synchronous transmission through the engagement of the groove and the retaining strip. This eliminates the need for separate drive components for each layer, resulting in a compact overall structure and stable and reliable transmission torque. The guide wedge surfaces at the ends of the groove and the retaining strip can automatically align and guide the connecting rod during insertion, significantly reducing the alignment difficulty of multi-layer assembly. The connecting rod can more easily penetrate into the fine grinding wheels below to complete the series connection, improving the efficiency of assembly and disassembly operations.

[0008] Furthermore, an air inlet pipe is installed on the top cover corresponding to the sieving chamber. The air inlet pipe is used to introduce ionized nitrogen gas to neutralize the static charge of the dry soil powder. The air inlet pipe includes a tube body with a closed bottom, and the internal channel of the tube body has a stepped diameter reduction structure. The side wall of the tube body has upward-sloping exhaust holes, and the top cover has an annular guide groove on the outer periphery of the air inlet pipe. The stepped diameter reduction channel design inside the air inlet pipe can increase the ejection velocity of ionized nitrogen gas and enhance the gas diffusion dynamics. The upward-sloping exhaust holes on the side wall can prevent the airflow from directly blowing onto the soil sample, causing dust to churn and splash, and reducing the risk of fine powder rising and adhering to the screen. The annular guide groove in the top cover can evenly guide and diffuse the airflow in all directions, so that the ionized gas can fully cover the entire sieving chamber, making the neutralization of the static charge of the soil powder more comprehensive and thorough, and further improving the effect of eliminating static electricity and preventing screen blockage.

[0009] Furthermore, the sealing insert includes a plate, a pre-reserved opening at the bottom of the plate, and an ear plate fixed to the top of the plate. When the sealing insert is fully inserted into the crushing screen cylinder, the pre-reserved opening is below the bottom of the crushing screen cylinder, and the mud outlet is sealed by the plate. After the sealing insert is pulled upward, the pre-reserved opening aligns with the mud outlet, and the fine grinding chamber and the screening chamber are connected through the pre-reserved opening and the mud outlet. The on / off state of the fine grinding chamber and the screening chamber can be quickly switched by axially inserting and pulling the sealing insert, and the operation logic is simple and intuitive. When the sealing insert is fully inserted, the pre-reserved opening is below the bottom of the crushing screen cylinder, and the solid part of the plate completely seals the mud outlet, which can completely isolate the fine grinding chamber and the screening chamber, prevent soil samples from entering the screening chamber during fine grinding, and ensure the independence of the fine grinding process. After pulling upward, the bottom of the pre-reserved opening aligns with the bottom of the crushing screen cylinder, so that the soil sample transfer is smooth, and at the same time, it prevents the upper layer of soil sample from flowing into the lower layer along the pre-reserved opening and the insertion opening. The ear plate at the top makes it easy to hold and apply force, and the insertion and removal operation is convenient and labor-saving.

[0010] Furthermore, the bottom end of the ear plate is provided with a spring piece, and the spring piece is provided with a limiting hook that matches the edge of the top cover; when the sealing insert is pulled upward, the limiting hook can be made to fit with the lower end of the top cover. When the limiting hook is fitted with the lower end of the top cover, the bottom end of the reserved opening is flush with the bottom surface of the corresponding crushing screen cylinder. By moving the spring piece to one side, the limiting hook can be moved from the outer edge of the top cover to the bottom of the top cover. When the sealing insert is lifted, the lifting height is limited by the limiting hook, which is convenient for control and avoids the reserved opening from connecting the upper and lower crushing screen cylinders due to insufficient lifting height of the sealing insert, which would cause soil debris to leak from the reserved opening to the lower layer.

[0011] Furthermore, the base includes a base and a support base. The base is rotatably connected to the bottom of the crushing and screening group, and the support base is fixed to the bottom end of the base. A handle groove is provided on the support base. A universal ball bearing is installed at the bottom end of the base.

[0012] Furthermore, the side wall of the base is hinged with an L-shaped fastener, and the top of the fastener is threaded with a locking screw. After the fastener is flipped upward and fastened to the edge of the top cover, tightening the locking screw will press and fix the multi-layer crushing screen cylinder between the base and the top cover.

[0013] Furthermore, the outer wall of the waste cylinder is provided with a radially protruding positioning pin, and the inner wall of the base is provided with a positioning groove that matches the positioning pin. The waste cylinder is positioned inside the base by the insertion and cooperation of the positioning pin and the positioning groove.

[0014] Furthermore, the screen aperture of the penultimate crushing screen cylinder is 0.149mm, the screen aperture of the bottom crushing screen cylinder is less than 0.149mm, and no fine grinding wheel is installed in the bottom crushing screen cylinder.

[0015] The effects of adopting the above solution are as follows: Integrated fine grinding and sieving reduces sample loss and contamination: The S-shaped isolation plate divides the inside of the single cylinder into a fine grinding chamber and a sieving chamber. With the device switching between forward and inverted modes, fine grinding and sieving can be completed in the same cylinder without the need for multiple soil sample transfers, which greatly reduces the loss and cross-contamination risks caused by sample transfer.

[0016] Fully enclosed operation to prevent dust from flying: The whole adopts a stacked and sealed structure, and the fine grinding and sieving processes are completed in a closed chamber to prevent dust from spilling out, which not only protects the health of the experimental personnel, but also avoids cross-contamination between different samples.

[0017] The electrostatic elimination design solves the problem of screen blockage: Ionized nitrogen gas is introduced through the air inlet pipe to neutralize the static charge generated by the friction of dry soil powder, eliminating the phenomenon of soil powder adhering to the screen and adhering to the cavity wall from the source, improving the screening efficiency and reducing screen scraping wear.

[0018] Multi-stage fine grinding and sieving ensures good particle size uniformity: The mesh size of the multi-layer crushing sieve cylinder decreases from top to bottom, and the coarse particles are refined layer by layer. Finally, qualified soil samples with a particle size of 0.149mm can be accurately obtained. The samples are highly representative and ensure the accuracy of subsequent testing.

[0019] Simple to operate and highly efficient: A single rocker arm synchronously drives multiple fine grinding wheels, and the cycle of fine grinding and sieving can be completed by switching between forward and reverse positions. There are few operation steps, and a single person can process multiple sets of samples at the same time, which significantly improves the efficiency of pre-experimental treatment. Attached Figure Description

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of a laboratory soil sample fine grinding device placed upright in an embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of an inverted laboratory soil sample grinding device according to an embodiment of the present invention. Figure 2 ; Figure 3 This is a schematic diagram showing the disassembled structure of the crushing screen assembly and the base in an embodiment of the present invention; Figure 4 This is a schematic diagram of the waste cylinder structure in an embodiment of the present invention; Figure 5 This is a schematic diagram of the longitudinal section of the pulverizing screen assembly in an embodiment of the present invention; Figure 6 for Figure 5 Enlarged structural diagram at point A; Figure 7 for Figure 5 Enlarged structural diagram at point B; Figure 8This is a schematic diagram of the top cover structure in an embodiment of the present invention; Figure 9 for Figure 8 Enlarged structural diagram at point C; Figure 10 This is a schematic diagram of the structure of the pulverizing screen cylinder in an embodiment of the present invention. Figure 1 ; Figure 11 This is a schematic diagram of the structure of the pulverizing screen cylinder in an embodiment of the present invention. Figure 2 ; Figure 12 This is a schematic diagram of the structure of the fine grinding wheel and the crushing sieve cylinder in an embodiment of the present invention. Figure 2 ; Figure 13 for Figure 12 Enlarged structural diagram at point D; Figure 14 This is a schematic diagram of the opening and closing plate in an embodiment of the present invention; Figure 15 This is a schematic diagram of the longitudinal section of the crushing screen assembly when the opening and closing plate descends to close the S-shaped isolation plate in an embodiment of the present invention; Figure 16 This is a schematic diagram of the longitudinal section of the crushing screen assembly when the opening and closing plate rises to open the S-shaped isolation plate in an embodiment of the present invention. Figure 17 This is a schematic diagram of an inverted laboratory soil sample grinding device according to an embodiment of the present invention. Figure 3 ; Figure label: 1-Base, 11-Support base, 12-Handle groove, 13-Base, 131-Positioning groove, 14-Fastener, 15-Locking screw; 2-Scrap cylinder, 21-Positioning pin, 22-Handle ring, 23-Protruding strip; 3-Pulverizing screen cylinder, 31-S-shaped isolation plate, 311-Sludge outlet, 32-Fine grinding wheel, 321-Fine grinding strip, 322-Stepped hole, 323-Clamping strip, 324-First guide wedge surface, 33-Screen, 351-Fine grinding chamber, 352-Sieving chamber, 36-Connecting piece, 361-Slot, 37-S-shaped seal, 38-Reserved insertion port, 39-Installation tube; 4-Top cover, 41-Drainage channel, 43-Identification area; 5-Rockstick assembly, 51-Connecting rod, 511-Slot, 512-Second guide wedge surface, 52-Handle; 6-Intake pipe, 61-Pipe body, 62-Channel, 63-Exhaust port; 7-Closed insert, 71-Plate body, 72-Ear plate, 73-Reserved opening. Detailed Implementation

[0021] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0022] like Figures 1-4 As shown in the figure, the laboratory soil sample fine grinding device provided in this embodiment mainly consists of a base 1, a waste cylinder 2, a crushing sieve group, a top cover 4, a rocker arm assembly 5, an air inlet pipe 6, and a sealing insert 7.

[0023] The base 1, serving as the fundamental supporting component of the device, includes a base 13 and a support 11. The base 13 is a cylindrical structure with an open top, and its bottom end is fixedly connected to the support 11. The side wall of the support 11 has a recessed handle groove 12, which facilitates the experimenter's hand-held shaking of the device. Multiple universal ball bearings are evenly installed at the bottom of the base 13. When the device is placed upright on the workbench, the universal ball bearings can be used to achieve overall horizontal shaking, assisting in the screening operation. The inner bottom of the base 13 is used to place the waste cylinder 2. The outer wall of the waste cylinder 2 is symmetrically provided with radially protruding positioning pins 21, and the inner wall of the base 13 is correspondingly provided with vertical positioning grooves 131. During installation, the positioning pins 21 are aligned with the positioning grooves 131 and inserted to achieve circumferential positioning of the waste cylinder 2. The top of the waste cylinder 2 is also provided with a handle ring 22 for easy handling.

[0024] like Figures 10-12 As shown, the pulverizing screen assembly is stacked on top of the base 13. In this embodiment, the pulverizing screen assembly includes three layers of pulverizing screen cylinders 3, which are the first layer, the second layer, and the third layer from top to bottom. Each pulverizing screen cylinder 3 has an S-shaped partition plate 31 fixed inside. The S-shaped partition plate 31 divides the inside of the cylinder 34 into two independent semi-cavities, namely the fine grinding chamber 351 and the sieving chamber 352, which are arranged in a yin-yang pattern. The bottom of the sieving chamber 352 is a screen 33. The mesh size of the screen 33 in the three layers of pulverizing screen cylinders 3 decreases from top to bottom. The aperture of the second layer (second to last layer) screen 33 is 0.149 mm, and the aperture of the third layer (bottom layer) screen 33 is less than 0.149 mm. Furthermore, the bottom pulverizing screen cylinder 3 does not have a fine grinding wheel 32 to avoid excessive grinding of soil powder with qualified particle size.

[0025] like Figure 5 , Figures 7-9The fine grinding chamber 351 shown is equipped with a fine grinding wheel 32. The outer circumference of the fine grinding wheel 32 is provided with multiple axially extending fine grinding strips 321 for crushing soil particles. A vertical mounting tube 39 is fixed at the bottom center of the fine grinding chamber 351. A stepped hole 322 is opened in the center of the fine grinding wheel 32. The mounting tube 39 is inserted into the lower part of the stepped hole 322 to provide rotational support for the fine grinding wheel 32.

[0026] like Figure 11 , Figure 12 As shown, the multi-layer crushing screen cylinder 3 achieves stacking and positioning through an interlocking structure: each layer of crushing screen cylinder 3 has a downwardly extending connecting piece 36 at its bottom edge, and a slot 361 is provided on the connecting piece 36; the top outer wall of the lower layer crushing screen cylinder 3 has a protrusion 23 that matches the slot 361. When stacking, the slot 361 of the upper layer connecting piece 36 is aligned with the protrusion 23 of the lower layer and inserted to achieve coaxial positioning and prevent relative rotation between layers. At the same time, each layer of crushing screen cylinder 3 has an S-shaped sealing strip 37 at its bottom. After the upper layers are stacked, the S-shaped sealing strip 37 at the bottom of the upper layer coincides with the top edge of the S-shaped isolation plate 31 of the lower layer to seal, ensuring that the fine grinding chamber 351 and the screening chamber 352 of the upper and lower layers are independent and do not cross-contamination.

[0027] like Figures 14-17 As shown, one end of the S-shaped isolation plate 31 has a mud outlet 311 for connecting the fine grinding chamber 351 and the screening chamber 352; the side wall of the crushing screen cylinder 3 has a vertical reserved insertion slot 38 corresponding to the position of the mud outlet 311, and the sealing insert 7 is inserted into the crushing screen cylinder 3 through the reserved insertion slot 38. The sealing insert 7 is composed of a plate body 71, a reserved opening 73 and an ear plate 72. The ear plate 72 is fixed to the top of the plate body 71 for easy lifting operation; the reserved opening 73 is opened at the bottom of the plate body 71, and the bottom end of the ear plate 72 is provided with a spring piece 74, and the spring piece 74 is provided with a limiting hook 741 that matches the edge of the top cover 4. When the sealing insert 7 is fully inserted downwards, the reserved opening 73 is located below the bottom of the crushing screen cylinder 3, and the solid part of the plate 71 blocks the mud outlet 311, isolating the fine grinding chamber 351 and the screening chamber 352 from each other; when the sealing insert 7 is pulled upwards until the limit hook 741 is in contact with the top cover 4 (as shown in the image), the sealing insert 7 is fully inserted downwards. Figure 17 As shown), the bottom of the reserved opening 73 is aligned with the bottom of the mud outlet 311, and the soil sample in the fine grinding chamber 351 can enter the screening chamber 352 through the mud outlet 311 and the reserved opening 73.

[0028] The top cover 4 is fitted onto the top of the uppermost crushing screen cylinder 3. Two L-shaped fasteners 14 are symmetrically hinged to the side wall of the base 13, with locking screws 15 threaded to the top of each fastener 14. After stacking, the fasteners 14 are flipped upwards and fastened to the edge of the top cover 4. The locking screws 15 are then tightened to press against the upper surface of the top cover 4, thus pressing and fixing the multi-layer crushing screen cylinder 3 between the base 13 and the top cover 4, achieving overall sealing and locking. The top of the top cover 4 has an marking area 43, which corresponds to the location of the fine grinding chamber 351 (e.g., ...). Figure 2 (As shown).

[0029] The rocker assembly 5 includes a connecting rod 51 and a handle 52, with the handle 52 fixed to the top of the connecting rod 51. A through hole is provided in the center of the top cover 4. The connecting rod 51 passes through the through hole, sequentially passing through the stepped holes 322 of each layer of fine grinding wheels 32 from top to bottom, and finally inserts into the corresponding layer's mounting tube 39. Multiple axial grooves 511 are provided on the outer wall of the connecting rod 51. The inner wall of the stepped holes 322 of the fine grinding wheels 32 is provided with corresponding retaining strips 323. After the retaining strips 323 are engaged in the grooves 511, rotating the connecting rod 51 synchronously drives all the fine grinding wheels 32 to rotate. A second guide wedge surface 512 is provided at the lower end of the groove 511, and a first guide wedge surface 324 is provided at the upper end of the retaining strip 323. The two wedge surfaces cooperate with each other to facilitate automatic alignment of the groove 511 and the retaining strip 323 when the connecting rod 51 is inserted.

[0030] like Figure 5 , Figure 6 and Figure 8 As shown, an air inlet pipe 6 is installed on the top cover 4 at the position corresponding to the sieving chamber 352, and the air inlet pipe 6 is connected to an ionized nitrogen gas source. The air inlet pipe 6 includes a pipe body 61 with a closed bottom. The channel 62 inside the pipe body 61 has a stepped diameter reduction structure, which can increase the airflow velocity. Multiple upward-sloping exhaust holes 63 are opened on the side wall of the pipe body 61. The airflow is blown out obliquely upward from the exhaust holes 63, and diffuses after impacting the inner wall of the top cover 4, avoiding direct blowing of soil samples and dust splashing. An annular guide groove 41 is opened on the inner top surface of the top cover 4 around the air inlet pipe 6, which can guide the airflow evenly in all directions, increase the diffusion range of ionized gas in the chamber, and more comprehensively neutralize the static electricity of soil powder.

[0031] The method of using this device is as follows: Sample loading and assembly: Stack the crushing screen cylinders 3 in order of increasing screen size from top to bottom, insert the sealing insert 7 and push it to the bottom to seal the mud outlet 311; add the air-dried soil sample to be finely ground through the opening of the fine grinding chamber 351 of the uppermost crushing screen cylinder 3, cover the top cover 4, fasten the fastener 14 and tighten the locking screw 15; insert the connecting rod 51 so that the fine grinding wheels 32 of each layer are engaged with the connecting rod 51.

[0032] Inverted fine grinding: The entire device is inverted, at which point the fine grinding chamber 351 is located at the bottom, and the soil sample gathers at the bottom of the fine grinding chamber 351 under the action of gravity; rotating the handle 52 drives the fine grinding wheels 32 of each layer to rotate synchronously, crushing and pulverizing the soil sample.

[0033] Material transfer and screening: After fine grinding, pull up the sealing insert 7 to align the reserved opening 73 with the mud outlet 311; slowly rotate the device to allow the soil sample in the fine grinding chamber 351 to flow into the screening chamber 352 through the mud outlet 311 and the reserved opening 73; push back the sealing insert 7 to close the mud outlet 311, and place the device upright, at which point the screening chamber 352 is located at the bottom.

[0034] Screening and Circulation: The hand-held handle groove 12 shakes the device, which, in conjunction with the universal ball bearings at the bottom of the base 13, performs horizontal vibration. The soil sample in the screening chamber 352 is classified by the screen 33; fine powder that meets the particle size standard falls to the lower layer, while coarse particles that do not meet the standard remain on the screen 33. The device is then inverted again, and the coarse particles on the screen are poured back into the fine grinding chamber 351 for further fine grinding. The above process is repeated until the particles are fully finely ground and screened.

[0035] Sampling and collection: After processing, open the device. The soil sample with a particle size of 0.149mm is retained in the second-layer crushing screen cylinder 3 and can be directly taken out for testing.

[0036] During the screening process, ionized nitrogen gas can be continuously introduced through the air inlet pipe 6 to neutralize the static electricity of the dry soil powder, reduce screen adhesion and cavity wall adsorption, and improve screening efficiency.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A laboratory soil sample fine grinding device, characterized in that: The system includes a base (1), a crushing screen assembly, a top cover (4), and a rocker arm assembly (5). The crushing screen assembly includes multiple stacked crushing screen cylinders (3). An S-shaped partition plate (31) is fixed inside the crushing screen cylinder (3). The S-shaped partition plate (31) divides the internal space of the crushing screen cylinder (3) into a fine grinding chamber (351) and a screening chamber (352). A screen (33) is provided at the bottom of the screening chamber (352). The mesh number of the screen (33) of each layer of crushing screen cylinder (3) decreases from top to bottom. A fine grinding wheel (32) is provided inside the fine grinding chamber (351). A mud outlet (311) is opened at one end of the S-shaped partition plate (31). The fine grinding chamber (351) and the screening chamber (352) can be connected through the mud outlet (311). The top cover (4) covers the top of the uppermost crushing screen cylinder (3), and the rocker assembly (5) passes through the top cover (4) and is connected in series with the fine grinding wheels (32) in each fine grinding chamber (351) to drive each fine grinding wheel (32) to rotate synchronously. The base (1) is located at the bottom of the crushing screen assembly, and the base (1) is provided with a waste cylinder (2) for receiving the powder that leaks down from the bottom crushing screen cylinder (3). The crushing screen assembly is equipped with a sealing insert (7), which can be inserted and removed along the axial direction of the crushing screen cylinder (3) to open or close the mud outlet (311); the device can switch between upright and inverted states. When inverted, the fine grinding chamber (351) is located at the bottom for fine grinding operations, and when upright, the screening chamber (352) is located at the bottom for screening operations.

2. The laboratory soil sample fine grinding device according to claim 1, characterized in that: The bottom of the crushing screen cylinder (3) is provided with an S-shaped seal (37). When the upper crushing screen cylinder (3) is stacked on top of the lower crushing screen cylinder (3), the upper S-shaped seal (37) overlaps and seals with the lower S-shaped isolation plate (31), thereby achieving independent separation between the fine grinding chamber (351) and the screening chamber (352) between the layers.

3. The laboratory soil sample fine grinding device according to claim 1, characterized in that: The bottom edge of the crushing screen cylinder (3) is provided with a downwardly extending connecting piece (36), and a slot (361) is provided on the connecting piece (36). The top outer wall of the lower crushing screen cylinder (3) is provided with a protrusion (23) that matches the slot (361). Adjacent crushing screen cylinders (3) are coaxially stacked and positioned by the insertion and cooperation of the slot (361) and the protrusion (23).

4. The laboratory soil sample fine grinding device according to claim 1, characterized in that: The rocker assembly (5) includes a connecting rod (51) and a handle (52) fixed to the top of the connecting rod (51). The bottom center of the fine grinding chamber (351) is provided with an installation tube (39). The center of the fine grinding wheel (32) is provided with a stepped hole (322). The connecting rod (51) passes through the stepped hole (322) of each fine grinding wheel (32) and the installation tube (39) of the corresponding layer from top to bottom. The outer wall of the connecting rod (51) is provided with an axial groove (511). The inner wall of the stepped hole (322) of the fine grinding wheel (32) is provided with a locking strip (323) that engages with the groove (511). The insertion end of the groove (511) is provided with a second guide wedge surface (512). The insertion end of the locking strip (323) is provided with a first guide wedge surface (324) that engages with the second guide wedge surface (512).

5. The laboratory soil sample fine grinding device according to claim 1, characterized in that: The top cover (4) is equipped with an air inlet pipe (6) at the position corresponding to the screening chamber (352). The air inlet pipe (6) is used to introduce ionized nitrogen gas to neutralize the static charge of the dry soil powder. The air inlet pipe (6) includes a pipe body (61) with a closed bottom. The internal channel (62) of the pipe body (61) has a stepped diameter reduction structure. The side wall of the pipe body (61) is provided with an upwardly inclined exhaust hole (63). The top cover (4) is provided with an annular guide groove (41) on the outer periphery of the air inlet pipe (6).

6. The laboratory soil sample fine grinding device according to claim 1, characterized in that: The sealing insert (7) includes a plate (71), a reserved opening (73) at the bottom of the plate (71), and an ear plate (72) fixed to the top of the plate (71). When the sealing insert (7) is fully inserted into the crushing screen cylinder (3), the reserved opening (73) is located below the bottom of the crushing screen cylinder (3), and the mud outlet (311) is closed by the plate (71). After the sealing insert (7) is pulled up, the reserved opening (73) and the mud outlet (311) are in the same position, and the fine grinding chamber (351) and the screening chamber (352) are connected through the reserved opening (73) and the mud outlet (311).

7. The laboratory soil sample fine grinding apparatus according to claim 6, characterized in that: The ear plate (72) is provided with a spring piece (74) at the bottom end. The spring piece (74) is provided with a limiting hook (741) that matches the edge of the top cover (4). When the sealing insert (7) is pulled up, the limiting hook (741) can be attached to the lower end of the top cover (4). When the limiting hook (741) is attached to the lower end of the top cover (4), the bottom end of the reserved opening (73) is flush with the bottom surface inside the corresponding crushing screen cylinder (3).

8. The laboratory soil sample fine grinding device according to claim 1, characterized in that: The base (1) is rotatably connected to the base (1), and the crushing sieve group is placed and fixed on the base (13); the base (1) is provided with a support seat (11), the support seat (11) is provided with a handle groove (12), and the bottom of the base (1) is equipped with a universal ball bearing.

9. The laboratory soil sample fine grinding apparatus according to claim 8, characterized in that: The side wall of the base (13) is hinged with an L-shaped fastener (14), and the top of the fastener (14) is threaded with a locking screw (15). After the fastener (14) is flipped upward and fastened to the edge of the top cover (4), tightening the locking screw (15) will press and fix the multi-layer crushing screen cylinder (3) between the base (13) and the top cover (4).

10. The laboratory soil sample fine grinding apparatus according to claim 8, characterized in that: The outer wall of the waste cylinder (2) is provided with a radially protruding positioning pin (21), and the inner wall of the base (13) is provided with a positioning groove (131) that matches the positioning pin (21). The waste cylinder (2) is positioned inside the base (13) by the insertion and cooperation of the positioning pin (21) and the positioning groove (131).

Images