Soil particle size sample preparation equipment

Abstract

The embodiment of the invention provides soil particle size sample preparation equipment. The soil particle size sample preparation equipment comprises a main machine body, a centrifugal device, a liquid-solid interface recognition device, a supernatant suction device, a first vertical driving mechanism, a second vertical driving mechanism, a third vertical driving mechanism, a reagent adding device and a controller, the controller controls the first vertical driving mechanism to move vertically, controls the laser light source to emit light and receives an output signal of the laser receiver, determines the height of a solid-liquid separation surface of the centrifugal tube according to the change characteristics of the output signal, and controls the second vertical driving mechanism to drive the liquid taking needle head to move to the solid-liquid separation surface to the lowest extent; and after the second vertical driving mechanism is controlled to drive the adding needle head to be inserted into the centrifugal tube, the adding pump is controlled to operate to add the reaction solvent into the centrifugal tube. According to the scheme, the centrifugal tube can be transferred among different stations without a grabbing device such as a manipulator, the problem of sample splashing caused by inaccurate grabbing of the centrifugal tube by the manipulator can be avoided, and meanwhile, the overall manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of soil science and technology, and in particular to a soil particle size sample preparation device. Background Art

[0002] Soil particle size composition is a stable natural property of soil, including soil particle size, gradation and particle group content. Soil particle size composition is an important basis for soil engineering classification. "Determination of Soil Particle Size - Pipette Method and Hydrometer Method" (HJ1068-2019) provides a standard measurement method for soil particle size composition. As recorded in Sections 5 and 8 of the previous standard, insoluble salts such as organic matter and gypsum will cause flocculation, and iron oxide and carbonate will interfere with soil particle dispersion, which will affect the determination of soil particle size. Before measuring soil particle size, corresponding treatment methods need to be used to remove the aforementioned interfering substances. Since the chemical properties of the aforementioned various types of interfering substances are not the same, corresponding types of reagents need to be used to remove corresponding types of interfering substances; in order to speed up the preparation of soil particle size samples, after the soil samples are treated with corresponding types of reagents, centrifugal precipitation is also required to form the supernatant of the previous reaction reagent, and after removing the supernatant, subsequent types of reagents are added to continue to remove interfering substances. Accordingly, during a soil particle size sample preparation process, the soil particle size sample needs to be transferred between the preparation station and the centrifuge for multiple times, which requires the configuration of transfer equipment such as a robotic arm, or requires manual operation. Summary of the invention

[0003] The disclosed embodiment provides a soil particle size sample preparation device, characterized in that it includes a main body, a centrifugal device, a liquid-solid interface identification device, a supernatant suction device, a first vertical drive mechanism, a second vertical drive mechanism, a third vertical drive mechanism, a reagent injection device and a controller; The shell of the main body forms a centrifugal cavity with an upper opening; The centrifugal device comprises a centrifugal rotor and a driving motor with a vertically arranged output shaft; the centrifugal rotor and the output shaft are both arranged in the centrifugal chamber; the centrifugal rotor comprises a rotor body and a plurality of hanging baskets for hanging centrifuge tubes; the rotor body is fixed on the output shaft; each hanging basket is mounted on the rotor body through a horizontally arranged pin shaft; The liquid-solid interface identification device comprises a laser light source and a laser receiver which are arranged at a relative interval; the laser light source is arranged horizontally in an emitting direction, and the distance between the laser light source and the laser receiver is greater than the diameter of the centrifuge tube hung on the hanging basket; The first vertical driving mechanism is used to drive the liquid-solid interface identification device to move in a vertical direction, so that the laser light source and the laser receiver move to both sides of the centrifuge tube; The supernatant liquid suction device comprises a suction pump and a liquid extraction needle for extracting the supernatant liquid; the liquid extraction needle is installed on the second vertical driving mechanism; The second vertical driving mechanism is used to drive the liquid collection needle to be inserted into the centrifuge tube from the bottle mouth of the centrifuge tube along the vertical direction; The reagent filling device comprises a filling pump and a filling needle for filling the reaction reagent into the centrifuge tube, and the third vertical driving mechanism is used to drive the filling needle to be inserted into the centrifuge tube from the bottle mouth of the centrifuge tube; The controller is used to control the rotation of the driving motor to realize the centrifugal operation of the soil sample in the centrifuge tube, control the first vertical driving mechanism to move vertically after the centrifugal operation is completed and the driving motor stops, and control the laser light source to emit light and receive the output signal of the laser receiver, determine the height of the solid-liquid separation surface of the centrifuge tube according to the change characteristics of the output signal, control the second vertical driving mechanism to drive the liquid collection needle to move to the lowest position of the solid-liquid separation surface; and after controlling the second vertical driving mechanism to drive the filling needle to be inserted into the centrifuge tube, control the filling pump to run and add reaction solvent to the centrifuge tube.

[0004] Optionally, the suction pump is a metering pump; when the suction pump performs a suction operation, the volume of the supernatant extracted from the centrifuge tube is measured and sent to the controller; The controller determines the amount of reagent to be added according to the volume of the extracted supernatant, and controls the adding pump to add the reaction reagent into the centrifuge tube according to the amount of reagent to be added.

[0005] Optionally, the reagent adding device further comprises a plurality of reaction reagent storage tanks and a multi-inlet and one-outlet multi-way valve; Each liquid inlet of the multi-way valve is directly connected to one of the reaction reagent storage tanks, and the liquid outlet of the multi-way valve is directly connected to the liquid inlet of the filling pump; The controller is communicated with the control end of the multi-way valve and is used to determine the communication state of the multi-way valve according to the sample processing progress.

[0006] Optionally, a conductivity meter is provided on the liquid collection needle, and a signal output end of the conductivity meter is connected to the controller; During the process of the liquid collection needle performing the liquid collection operation on the supernatant formed by the first reaction reagent, the controller determines the type of the second reaction reagent added later according to the measured conductivity generated by the conductivity meter, and determines the connection state of the multi-way valve according to the type of the second reaction reagent; Among them, when the measured conductivity is lower than the conductivity corresponding to the reaction end standard of the first reaction reagent, the second reaction reagent is the reaction reagent required to remove the next type of impurities, and when the measured conductivity is higher than the conductivity corresponding to the reaction end standard of the first reaction reagent, the second reaction reagent is still the first reaction reagent.

[0007] Optionally, the supernatant suction device further includes a waste liquid tank; The liquid discharge port of the suction pump is directly connected to the waste liquid tank.

[0008] Optionally, the hanging basket is provided with a clamping ring for cooperating with a limiting convex ring on the centrifuge tube to achieve fixed suspension of the centrifuge tube on the hanging basket; The preparation equipment also includes a fourth vertical driving mechanism, a supporting platform and a reaction promoting device; The support platform is arranged in the centrifugal chamber and is located at the lower side of the centrifugal rotor; the fourth vertical driving mechanism is used to drive the support platform to move in the vertical direction, so that the support platform lifts the centrifugal tube and the limiting convex ring leaves the clamping ring; The reaction promoting device is arranged on the supporting platform and is used for accelerating the reaction speed between the reaction reagent and the soil sample in the centrifuge tube.

[0009] Optionally, the reaction promoting device is a heater and / or an ultrasonic oscillator.

[0010] Optionally, the centrifuge tube has a cone structure at the lower end; The supporting part of the supporting platform for supporting the centrifuge tube is provided with a conical groove adapted to the cone structure at the bottom of the centrifuge tube; The reaction promoting device is arranged in the conical groove, or at the notch of the conical groove.

[0011] Optionally, the soil particle size sample preparation device further includes a protective cover and an opening and closing actuator; The opening and closing actuator is used to drive the opening and closing control of the protective cover relative to the centrifugal cavity opening; Before and during the process of the controller controlling the centrifugal device to perform a centrifugal operation, the controller controls the opening and closing actuator to operate, so as to achieve the buckling of the protective cover with the opening of the centrifugal chamber.

[0012] Optionally, the soil particle size sample preparation device further includes a negative pressure exhaust device; The protective cover and / or the main body are provided with exhaust holes; the negative pressure exhaust device is connected to the exhaust holes.

[0013] The soil particle size preparation equipment according to the disclosed embodiment does not require a grasping device such as a robot to realize the transfer of the centrifuge tube between different workstations. Instead, the filling and suction operations of the centrifuge tube liquid are realized by the cooperation of the vertical drive mechanism and the centrifugal device. This can also avoid the problem of sample spillage caused by the robot grasping the centrifuge tube incorrectly, while reducing the overall manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor, including Figure 1 is a partial structural top view of a soil particle size preparation device provided by an embodiment of the present disclosure; Figure 2 yes Figure 1 AA section diagram in; Wherein: 100-main body, 101-centrifugal chamber, 200-centrifugal device, 210-centrifugal rotor, 211-rotor body, 212-hanging basket, 220-driving motor, 300-liquid-solid interface identification device, 301-laser light source, 302-laser receiver, 400-supernatant suction device, 401-suction pump, 402-liquid collection needle, 403-waste liquid tank, 510-first vertical driving mechanism, 520-second vertical driving mechanism, 530-third vertical driving mechanism, 540-fourth vertical driving mechanism, 600-reagent filling device, 601-filling pump, 602-filling needle, 603-multi-way valve, 604-reagent storage tank, 700-supporting platform, 800-heater, 900-ultrasonic oscillator. DETAILED DESCRIPTION

[0016] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0017] The term "including" and its variations used in this document are open inclusions, i.e., "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". Relevant definitions of other terms will be given in the description below. In this document, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0018] In order to achieve more convenient and unattended automated preparation of soil particle size samples, the embodiments of the present disclosure provide a new soil particle size sample preparation device.

[0019] Figure 1 is a partial structural top view of the soil particle size preparation device provided in an embodiment of the present disclosure, Figure 2 yes Figure 1 As shown in the figure, the soil particle size preparation device provided by the embodiment of the present disclosure includes a main body 100, a centrifugal device 200, a liquid-solid interface identification device 300, a supernatant suction device 400, a first vertical driving mechanism 510, a second vertical driving mechanism 520 and a controller (the controller is not shown in the figure).

[0020] The main body 100 is a soil particle size preparation device that carries other devices and mechanisms, so that each device and mechanism forms an integral body. The shell of the main body 100 forms a centrifugal chamber 101 with an upper opening, and the centrifugal chamber 101 is used to accommodate a centrifugal device 200 such as the aforementioned to ensure safety during the centrifugal operation. As shown in the figure, the centrifugal chamber 101 is generally a cylindrical chamber.

[0021] The centrifugal device 200 is a device for centrifuging a soil particle size sample so that the particles in the soil are deposited and form a supernatant through centrifugal operation. The centrifugal device 200 includes a centrifugal rotor 210 and a drive motor 220, and the output shaft of the drive motor 220 is vertically arranged.

[0022] In the disclosed embodiment, at least the centrifugal rotor 210 of the centrifugal device 200 and the output shaft of the drive motor 220 are arranged in the centrifugal chamber 101. In practical applications, the lower side of the centrifugal chamber 101 of the main body 100 is provided with a mounting position and an output shaft through hole for mounting the drive motor 220. The drive motor 220 is mounted at the mounting position by fixing components such as bolts, and its output shaft passes through the output shaft through hole and extends into the centrifugal chamber 101. In practical applications, considering that the centrifugal speed needs to be controlled during the centrifugation process to achieve a reasonable centrifugal effect, the drive motor 220 preferably adopts a servo motor.

[0023] The centrifugal rotor 210 is a component that can suspend a centrifugal tube and rotate with the output. The centrifugal rotor 210 includes a rotor body 211 and a plurality of hanging baskets 212. The rotor body 211 is fixed on the output shaft of the drive motor 220, and includes a plurality of hanging arms extending outward. A pin shaft mounting hole or a pin shaft clamping hole is provided on the hanging arm, which is horizontally opened and extends in a direction perpendicular to the output shaft of the drive motor 220. The hanging basket 212 is matched with the aforementioned pin shaft mounting hole or pin shaft clamping hole through a horizontally arranged pin shaft to realize the installation of the hanging basket 212 on the rotor body 211, and the hanging basket 212 can be rotated relative to the pin shaft mounting hole or the pin shaft clamping hole. In the process of the drive motor 220 running and driving the rotor body 211 to rotate, under the action of centrifugal force, the hanging basket 212 rotates around the pin shaft relative to the rotor body 211, and changes from a vertical state to an inclined state. When the centrifugal tube is installed on the hanging basket 212, the centrifugal tube will also change from a vertical state to an inclined state. Correspondingly, when the soil particle size sample solution is contained in the centrifuge tube, the soil particle size sample solution will be centrifugally precipitated as the hanging basket 212 rotates to form a precipitate and a supernatant.

[0024] The liquid-solid interface identification device 300 is a device for identifying the interface height of the precipitate and the supernatant after the soil sample solution in the centrifuge tube is centrifuged to form the precipitate and the supernatant (it should be noted that the identification interface mentioned here needs to be realized under the action of the first vertical drive mechanism 510, which will be analyzed later). The liquid-solid interface identification device includes a laser light source 301 and a laser receiver 302 that are relatively spaced. The emission direction of the laser light source 301 is set horizontally, that is, the light emitted by the laser light source 301 is irradiated on the laser receiver 302 at a horizontal angle. The distance between the laser light source 301 and the laser receiver 302 is greater than the diameter of the centrifuge tube hung on the hanging basket 212, that is, when the laser light source 301 is located on one side of the centrifuge tube, the laser receiver 302 is located on the other side of the centrifuge tube. It should be noted here that in order to allow the light emitted by the laser light source 301 to pass through the centrifuge tube (and the supernatant in the centrifuge tube), the centrifuge tube should be made of transparent materials, and in specific implementation, it can be made of acid-resistant and alkali-resistant materials such as glass and PP.

[0025] The first vertical drive mechanism 510 is a mechanism for driving the aforementioned 300 solid-liquid interface recognition device to move in the vertical direction, thereby moving the laser light source 301 and the laser receiver 302 to both sides of the centrifuge tube. In actual use, in order to ensure that the moving stroke (that is, the real-time height) of the solid-liquid interface recognition device 300 can be accurately controlled and determined, the first vertical drive mechanism 510 can use components such as ball screws that accurately feedback the height. In a specific implementation, the aforementioned liquid-solid interface recognition device 300 is installed at the free end of the first vertical drive mechanism 510, so that the aforementioned laser light source 301 and the laser receiver 302 can move on both sides of the centrifuge tube. In a specific implementation, the first vertical drive mechanism 510 can be installed in the centrifugal chamber 101 (lower than the position of the centrifugal rotor 210), or it can be installed in the upper outer part of the centrifugal chamber 101 (higher than the position of the centrifugal rotor 210).

[0026] The following is an analysis of how to realize the solid-liquid interface formed by centrifugation through the cooperation of the first vertical driving mechanism 510 and the liquid-solid interface recognition device 300. In the embodiment of the present disclosure, the first vertical driving mechanism 510 drives the solid-liquid interface recognition device 300 to move in the vertical direction. During the execution of the above-mentioned operation, the laser light source 301 continuously emits laser light so that the laser light is irradiated from one side of the centrifuge tube into the centrifuge tube. When the laser light source 301 irradiates the supernatant area, because the supernatant has a weak blocking effect on the laser, the laser energy irradiated from the other side of the centrifuge tube and irradiated to the laser receiver 302 is relatively strong; and when the laser light source 301 irradiates the sediment area, because the sediment has a strong blocking effect on the laser, the laser energy irradiated from the other side of the centrifuge tube and irradiated to the laser receiver 302 is relatively weak (even no laser photons are irradiated to the laser receiver 302). Accordingly, the horizontal height of the solid-liquid separation interface can be determined by the intensity change of the output signal of the laser receiver 302, combined with the displacement of the first vertical driving mechanism 510.

[0027] The supernatant suction device 400 is a device for realizing the discharge of the supernatant after solid-liquid separation, and includes a suction pump 401 and a liquid collection needle 402. The liquid collection needle 402 is mounted on the second vertical drive mechanism 520, and moves in the vertical direction under the drive of the second vertical drive mechanism 520. In the embodiment disclosed herein, the second vertical drive mechanism 520 is arranged directly above the centrifugal chamber 101, and directly opposite to a position where a centrifuge tube is placed. When the second vertical drive mechanism 520 drives the liquid collection needle 402 to move downward in the vertical direction, it can make the liquid collection needle 402 be inserted into the centrifuge tube from the bottle mouth of the centrifuge tube. After the liquid collection needle is inserted into the centrifuge tube and inserted below the liquid level of the supernatant, the suction pump 401 is operated, and the corresponding supernatant can be discharged from the centrifuge tube.

[0028] In addition, the sample preparation device in the embodiment of the present disclosure also includes a third vertical drive mechanism 530 and a reagent filling device 600. The reagent filling device 600 includes a filling pump 601 and a filling needle 602 for filling the reaction reagent into the centrifuge tube. Similar to the aforementioned second vertical drive mechanism 520, the third vertical drive mechanism 530 is used to drive the filling needle 602 to be inserted into the centrifuge tube from the bottle mouth of the centrifuge tube, and the filling pump 601 is connected to the reagent storage tank 604 to control the filling of the reagent into the centrifuge tube.

[0029] As shown in the figure, the second vertical driving mechanism 520 and the third vertical driving mechanism 530 are fixed on the main body 100 through a support frame.

[0030] In the disclosed embodiment, the controller is used to control each device and actuator to perform corresponding control operations. Specifically, after adding a preset weight of soil sample to the centrifuge tube and placing the centrifuge tube on the hanging basket 212, the controller controls the aforementioned device or actuator to perform the following operations: (1) Control the third vertical drive mechanism to operate so that the filling needle 602 is inserted into the centrifuge tube, and then control the filling pump 601 to add a specific type of reaction solvent into the centrifuge tube, and after adding the reaction solvent, the third drive mechanism is reversed to make the filling needle 602 extend out of the centrifuge tube; (2) After waiting for the reaction solvent in the centrifuge tube and the soil sample to react for a period of time, the drive motor 220 is controlled to rotate to realize the centrifugal operation of the soil sample to form a centrifugal precipitate and supernatant; (3) After the centrifugal operation is completed and the centrifuge tube is restored to the vertical setting, the centrifuge tube is controlled to rotate to a specific position, and the first vertical control mechanism is controlled to operate, the laser transmitter is controlled to emit laser, and the receiving signal generated by the laser receiver 302 is received. ; Determine the time point at which the received signal undergoes a typical change feature, and use the height corresponding to the aforementioned typical change time point as the liquid level height or the solid-liquid interface height, and according to the connection (that is, when the first vertical driving mechanism 510 drives the solid-liquid interface identification device to move up and down, it will identify the liquid level height and the solid-liquid interface height in the centrifuge tube); then control the first vertical control mechanism to return; (4) Control the second vertical control mechanism to act so that the liquid collection needle 402 is inserted into the centrifuge tube, and control the suction pump 401 to act when the height of the liquid collection needle 402 reaches the liquid level to achieve liquid collection; at the same time, determine the operating power of the suction pump 401 according to the moving speed of the second digital display control mechanism and the cross-sectional area of ​​the corresponding height of the centrifuge tube; when the liquid collection needle 402 moves to the solid-liquid interface height, stop the suction pump 401 from running, and control the second vertical control mechanism to act in the reverse direction so that the liquid collection needle 402 is extracted from the centrifuge tube. By repeatedly executing the aforementioned (2)-(4) in the future, it is possible to remove various impurities in the soil sample.

[0031] In combination with the aforementioned structural analysis and action execution analysis, it can be conceived that, by using the soil particle size sample preparation device of the embodiment scheme of the present disclosure, after placing the centrifuge tube containing the soil sample on the hanging basket 212 of the centrifuge device 200, the controller then controls the aforementioned devices or actuators to act sequentially, thereby realizing the addition of corresponding types of reagents, chemical reactions, centrifugal operations and supernatant removal operations.

[0032] In the specific implementation, a reasonable solution reaction reagent filling strategy is formulated in accordance with the provisions of HJ1068-2019, and the aforementioned filling strategy is deployed in the controller, and the soil sample preparation equipment can be used to realize the automated preparation of soil particle size samples. As analyzed above, the embodiment of the present disclosure does not have a grasping device such as a manipulator to realize the transfer of the centrifuge tube between different stations, but only utilizes the cooperation of the vertical drive mechanism and the centrifugal device 200 to realize the filling and suction operations of the centrifuge tube liquid, without the need to deploy a complex manipulator, and can also avoid the problem of sample spillage caused by the manipulator not grasping the centrifuge tube accurately.

[0033] In practical applications, the soil sample can be prevented from spilling out of the centrifuge tube during rotation by properly setting the height of the centrifuge tube and the operation of the centrifuge device 200. More preferably, the centrifuge tube is provided with a bottle cap (e.g., a bottle cap formed by a one-way valve flap) that is self-sealing but allows the liquid collection needle 402 and the filling needle 602 to pass through, thereby preventing the solution from spilling out during the centrifugal operation.

[0034] In practical applications, in order to ensure the dynamic balance of the centrifugal device 200 during the centrifugal operation, the weight of the centrifuge tube needs to be within a reasonable error range (for example, the weight deviation of each centrifuge tube does not exceed 0.1g). However, due to the different material components in the soil sample, the volume of the formed precipitate and the volume of the supernatant are not the same. If the liquid-solid separation surface is determined according to the above method, it is also necessary to consider the change in the weight of the centrifuge tube caused by the extraction of the supernatant, and the problem that the dynamic balance may be destroyed due to the above weight change.

[0035] To solve the above-mentioned problems, the suction pump 401 in the embodiment of the present disclosure is configured as a metering pump. When the liquid collection needle 402 is inserted into the liquid surface of the supernatant and the suction pump 401 performs a suction operation, the suction pump 401 generates a metering signal for measuring the volume of the supernatant extracted from the centrifuge tube, and sends the metering signal to the controller. The controller can determine the volume of the supernatant extracted from the centrifuge pump based on the aforementioned metering signal. Accordingly, in the process of adding a reaction reagent to the centrifuge tube using an actual filling device, the controller determines the amount of the reaction reagent to be added to the centrifuge tube during the next filling operation based on the volume of the aforementioned supernatant. In a specific implementation, considering that the specific gravities of different types of reaction reagents are not much different, the controller can directly use the volume of the extracted supernatant as the volume of the reaction reagent that needs to be added to the centrifuge tube.

[0036] Referring to HJ1068-2019, in order to remove different types of interfering substances such as organic matter, gypsum, iron oxide, carbonate, etc., it is necessary to use corresponding types of reaction reagents to react with the aforementioned substances in the soil sample respectively. The aforementioned different types of reaction reagents are stored in different reaction reagent storage tanks 604 respectively. In order to use a set of third vertical drive mechanism 530 and reagent filling device 600 to realize the filling of various reaction reagents, the reagent filling device 600 also includes a multi-way valve 603. The multi-way valve 603 is a valve with multiple inlets and one outlet, and only one liquid inlet can be connected to the liquid outlet during operation. Each liquid inlet of the multi-way valve 603 is directly connected to a reaction reagent storage tank 604, and the liquid outlet of the multi-way valve 603 is directly connected to the liquid inlet of the filling pump 601. In addition, the controller is connected to the control end of the multi-way valve 603, and determines the connection state of the multi-way valve 603 according to the progress of the sample processing, specifically, controls which liquid inlet and liquid outlet of the multi-way valve 603 are directly connected according to the type of solution to be added next time.

[0037] According to the HJ1068-2019 standard, in the process of removing soluble salts, gypsum, iron oxide and carbonate, the removal process of the corresponding impurities is completed when the conductivity of the supernatant is less than 40ms / m. In order to determine the type of reaction reagent to be added to the centrifuge tube in the next step according to the above standards, a conductivity meter is also provided on the liquid collection needle 402, and the signal output end of the conductivity meter is connected to the controller. In the process of the liquid collection needle 402 performing the liquid collection operation for the supernatant formed by the first reaction reagent, the controller determines the type of the second reaction reagent added later according to the real-time conductivity generated by the conductivity meter, and determines the connection state of the multi-way valve 603 according to the type of the second reaction reagent. Specifically, if the real-time conductivity is lower than the conductivity corresponding to the reaction end standard of the first reaction reagent, the second reaction reagent is the reaction reagent required to remove the next type of impurities; and if the real-time conductivity is higher than the conductivity corresponding to the reaction end standard of the first reaction reagent, the second reaction reagent is still the aforementioned first reaction reagent.

[0038] like Figure 1 and Figure 2 As shown, in the embodiment of the present disclosure, the supernatant suction device 400 includes, in addition to the aforementioned suction pump 401 and suction needle, a waste liquid tank 403. The discharge port of the suction pump 401 is directly connected to the waste liquid tank 403. It can be imagined that the supernatant extracted by the supernatant suction device 400 is discharged into the waste liquid tank 403 to avoid pollution problems caused by direct discharge.

[0039] As analyzed above, the hanging basket 212 in the embodiment of the present disclosure is used to install and fix the centrifuge tube to ensure the stability of the connection of the centrifuge tube during the centrifugal operation. In a specific implementation, the structure for directly fixing the centrifuge tube on the hanging basket 212 is a snap ring, which cooperates with the limiting convex ring on the centrifuge tube and realizes the suspension and fixation of the centrifuge tube under the gravity of the centrifuge tube. In addition, the preparation device also includes a fourth vertical drive mechanism 540, a support platform 700 and a reaction-promoting device. The support platform 700 and the fourth vertical drive mechanism are arranged on the lower side of the centrifuge tube. The fourth vertical drive mechanism 540 is used to drive the support platform 700 to move in the vertical direction, so that the support platform 700 lifts the centrifuge tube and makes the limiting convex ring leave the snap ring. The reaction-promoting device is arranged on the support platform 700 to accelerate the reaction speed of the reaction reagent and the soil sample in the centrifuge tube.

[0040] In a specific implementation, the reaction-promoting device can be a heater 800 and an ultrasonic oscillator 900. In the process of heating the centrifuge tube and the soil sample and the reaction solvent therein by using the heater 800, if the clamping connection between the limiting protrusion and the clamping ring is maintained, the heat will be conducted to the rotor body 211 through the limiting protrusion and the clamping ring, and the heating power of the heater 800 needs to be increased accordingly to keep the centrifuge tube at the target temperature. Similarly, if the clamping connection between the limiting protrusion and the clamping ring is maintained, the vibration generated by the ultrasonic vibrator is transmitted to the rotor body 211 and the drive motor 220 through the limiting protrusion and the clamping ring, and long-term operation may damage the structure and dynamic balance characteristics of the drive motor 220. The aforementioned support platform 700 and the fourth vertical drive mechanism 540 enable the support platform 700 to hold up the centrifuge tube, disconnect the direct contact between the limiting protrusion and the clamping ring, and can isolate the conduction of heat and ultrasonic vibration waves through the limiting protrusion and the clamping ring, thereby avoiding the aforementioned problems.

[0041] In specific implementation, in some embodiments, in order to enable the centrifuge tube to remain upright (especially under ultrasonic vibration) without tilting after the support platform 700 lifts the centrifuge tube, the lower end of the centrifuge tube is set to a cone structure. The corresponding support platform 700 is used to support the centrifuge tube. The supporting part is provided with a conical groove adapted to the lower cone structure of the centrifuge tube. The aforementioned reaction-promoting device is arranged in the conical groove or at the notch of the conical groove so as to be able to directly contact the centrifuge tube.

[0042] Furthermore, in order to ensure safety during the centrifugal operation, avoid centrifugal spraying of soil samples and liquids due to equipment problems, and ensure personnel safety, the soil particle size sample preparation device may also include a protective cover and an opening and closing actuator. The opening and closing actuator is used to drive the opening and closing control of the protective cover relative to the opening of the centrifugal chamber 101. Before and during the controller controls the centrifugal device 200 to perform the centrifugal operation, the controller controls the opening and closing actuator to operate to achieve the buckling of the protective cover with the opening of the centrifugal chamber 101.

[0043] Referring to the HJ1068-2019 standard, hydrogen peroxide is required to remove organic matter in the soil sample during the sample preparation process. In the process of removing organic matter with hydrogen peroxide, a large amount of foam may be generated, and harmful gases may also be generated. In order to avoid the generation of bubbles and quickly discharge the generated harmful gases, exhaust holes are provided on the protective cover or the main body 100. In addition, the soil particle size sample preparation equipment also includes a negative pressure exhaust device. The negative pressure exhaust device is connected to the exhaust hole and is started during the operation of the process of removing organic matter with hydrogen peroxide to exhaust the gas in the centrifugal chamber 101 and remove the foam generated during the hydrogen peroxide reaction by negative pressure.

[0044] The above are only specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A soil particle size sample preparation device, characterized in that: It includes a main body, a centrifugal device, a liquid-solid interface identification device, a supernatant suction device, a first vertical driving mechanism, a second vertical driving mechanism, a third vertical driving mechanism, a reagent adding device and a controller; The shell of the main body forms a centrifugal cavity with an upper opening; The centrifugal device comprises a centrifugal rotor and a driving motor with a vertically arranged output shaft; the centrifugal rotor and the output shaft are both arranged in the centrifugal chamber; the centrifugal rotor comprises a rotor body and a plurality of hanging baskets for hanging centrifuge tubes; the rotor body is fixed on the output shaft; each hanging basket is mounted on the rotor body through a horizontally arranged pin shaft; The liquid-solid interface identification device comprises a laser light source and a laser receiver which are arranged at a relative interval; the laser light source is arranged horizontally in an emitting direction, and the distance between the laser light source and the laser receiver is greater than the diameter of the centrifuge tube hung on the hanging basket; The first vertical driving mechanism is used to drive the liquid-solid interface identification device to move in a vertical direction, so that the laser light source and the laser receiver move to both sides of the centrifuge tube; The supernatant liquid suction device comprises a suction pump and a liquid extraction needle for extracting the supernatant liquid; the liquid extraction needle is installed on the second vertical driving mechanism; The second vertical driving mechanism is used to drive the liquid collection needle to be inserted into the centrifuge tube from the bottle mouth of the centrifuge tube along the vertical direction; The reagent filling device comprises a filling pump and a filling needle for filling the reaction reagent into the centrifuge tube, and the third vertical driving mechanism is used to drive the filling needle to be inserted into the centrifuge tube from the bottle mouth of the centrifuge tube; The controller is used to control the rotation of the driving motor to realize the centrifugal operation of the soil sample in the centrifuge tube, control the first vertical driving mechanism to move vertically after the centrifugal operation is completed and the driving motor stops, and control the laser light source to emit light and receive the output signal of the laser receiver, determine the height of the solid-liquid separation surface of the centrifuge tube according to the change characteristics of the output signal, control the second vertical driving mechanism to drive the liquid collection needle to move to the lowest position of the solid-liquid separation surface; and after controlling the second vertical driving mechanism to drive the filling needle to be inserted into the centrifuge tube, control the filling pump to run and add reaction solvent to the centrifuge tube.

2. The preparation equipment according to claim 1, characterized in that: The suction pump is a metering pump; when the suction pump performs a suction operation, the volume of the supernatant extracted from the centrifuge tube is measured and sent to the controller; The controller determines the amount of reagent to be added according to the volume of the extracted supernatant, and controls the adding pump to add the reaction reagent into the centrifuge tube according to the amount of reagent to be added.

3. The preparation equipment according to claim 2, characterized in that: The reagent filling device also includes a plurality of reaction reagent storage tanks and a multi-way valve with multiple inlets and one outlet; Each liquid inlet of the multi-way valve is directly connected to one of the reaction reagent storage tanks, and the liquid outlet of the multi-way valve is directly connected to the liquid inlet of the filling pump; The controller is communicated with the control end of the multi-way valve and is used to determine the communication state of the multi-way valve according to the sample processing progress.

4. The preparation equipment according to claim 3, characterized in that: The liquid collection needle is provided with a conductivity meter, and the signal output end of the conductivity meter is connected to the controller; During the process of the liquid collection needle performing the liquid collection operation on the supernatant formed by the first reaction reagent, the controller determines the type of the second reaction reagent added later according to the measured conductivity generated by the conductivity meter, and determines the connection state of the multi-way valve according to the type of the second reaction reagent; Among them, when the measured conductivity is lower than the conductivity corresponding to the reaction end standard of the first reaction reagent, the second reaction reagent is the reaction reagent required to remove the next type of impurities, and when the measured conductivity is higher than the conductivity corresponding to the reaction end standard of the first reaction reagent, the second reaction reagent is still the first reaction reagent.

5. The preparation equipment according to claim 1, characterized in that: The supernatant suction device also includes a waste liquid tank; The liquid discharge port of the suction pump is directly connected to the waste liquid tank.

6. The preparation equipment according to any one of claims 1 to 5, characterized in that: The hanging basket is provided with a clamping ring for cooperating with a limiting convex ring on the centrifuge tube to realize the fixed suspension of the centrifuge tube on the hanging basket; The preparation equipment also includes a fourth vertical driving mechanism, a supporting platform and a reaction promoting device; The support platform is arranged in the centrifugal chamber and is located at the lower side of the centrifugal rotor; the fourth vertical driving mechanism is used to drive the support platform to move in the vertical direction, so that the support platform lifts the centrifugal tube and the limiting convex ring leaves the clamping ring; The reaction promoting device is arranged on the supporting platform and is used to accelerate the reaction speed between the reaction reagent and the soil sample in the centrifuge tube.

7. The preparation device according to claim 6, characterized in that: The reaction promoting device is a heater and / or an ultrasonic oscillator.

8. The preparation equipment according to claim 6, characterized in that: The lower end of the centrifuge tube is a cone structure; The supporting part of the supporting platform for supporting the centrifuge tube is provided with a conical groove adapted to the cone structure at the bottom of the centrifuge tube; The reaction promoting device is arranged in the conical groove, or at the notch of the conical groove.

9. The preparation device according to any one of claims 1 to 5, characterized in that: It also includes a protective cover and an opening and closing actuator; The opening and closing actuator is used to drive the opening and closing control of the protective cover relative to the centrifugal cavity opening; Before and during the process of the controller controlling the centrifugal device to perform a centrifugal operation, the controller controls the opening and closing actuator to operate, so as to achieve the buckling of the protective cover with the opening of the centrifugal chamber.

10. The preparation device according to claim 9, characterized in that: Also includes a negative pressure exhaust device; The protective cover and / or the main body are provided with exhaust holes; the negative pressure exhaust device is connected to the exhaust holes.

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