Multi-channel water sample ph adjusting device

Abstract

This invention discloses a multi-channel water sample pH adjustment device, comprising a sealed container, a chassis, a turntable, a pusher drive unit, a screw tube, and a cleaning tube. The chassis has an annular groove and a collection groove, and a magnetic stirring drive unit is installed on its lower surface. The turntable is detachably connected to the turntable drive unit and located above the chassis. Multiple slots are arranged in a circumferential array on the turntable, and push holes are provided along the length of the slots. The pusher of the pusher drive unit can push the sample container from the working position to the stationary position through the push holes. An alkali solution tube and an acid solution tube are internally installed in the screw tube, and a pH electrode and a temperature sensor are integrated at the bottom. An annular flow channel is formed between the cleaning tube and the screw tube and connected to a water supply connector. This invention achieves high-throughput, automated processing through a single working head combined with a replaceable turntable and pusher movement. The sealed container and working head cleaning structure prevent cross-contamination and safely handle gas-producing samples, making it suitable for fully automated pH adjustment of batch water samples.

Description

Technical Field

[0001] This invention belongs to the field of water quality analysis pretreatment technology, specifically relating to a device for automatic pH adjustment of batch water samples in the laboratory. Background Technology

[0002] pH is a fundamental indicator in water quality analysis. Whether analyzing surface water, groundwater, industrial wastewater, or soil extracts, the sample pH usually needs to be adjusted to a specific range before subsequent measurements can be performed. Currently, laboratory pH adjustment for batches of water samples relies primarily on manual operation. Operators must repeatedly perform the steps of adding chemicals, stirring, measuring pH, and readjusting for each sample until the pH reaches the target range. When dealing with a large number of samples, manual operation presents the following problems: First, manually adjusting the pH can only process one sample at a time. The operation requires repeated use of droppers to add chemicals, stir, rinse the electrode, and read the values, which is time-consuming and labor-intensive, and the processing throughput is extremely low.

[0003] Secondly, there are subjective differences in the control of drug dosage, stirring time, and timing of pH reading among different operators. Even the same operator is prone to operational errors due to fatigue during long-term repetitive work, resulting in poor data comparability between samples of the same batch.

[0004] In addition, manually recording process data is cumbersome and prone to errors, and key process parameters such as dosage and stirring time are difficult to trace completely, which does not meet the requirements of modern laboratory quality management standards.

[0005] To address the aforementioned issues, several automated pH adjustment devices have been proposed. For example, Chinese patent CN107930567A discloses a fully automated rotary pH adjustment device, including a lifting device, inlet pipe, glass electrode, sample bottle, magnetic stirrer, rotary machine, micro-pump, and control system. The rotary machine automatically switches between workstations, enabling continuous processing of multiple samples. While this solution achieves automated switching, all workstations are located on the same circular track, and the processed samples remain near the working head, failing to separate the processing and settling areas. Furthermore, the device operates in an open environment, raising concerns about the generation of harmful gases during the adjustment process (such as those released when adding acid to sulfur-containing wastewater). The samples have safety hazards, and different samples share the same electrode and liquid inlet without a cleaning structure, which poses a risk of cross-contamination.

[0006] Chinese patent CN110632335A discloses a fully automated system for batch pH measurement, including a sample tray, a robotic arm, an automatic liquid addition and stirring device, and an electrode probe. The robotic arm moves to add liquid, stir, and measure multiple samples. While the system includes a cleaning tank for cleaning the electrodes and stirring device, this cleaning is only for cleaning samples after measurement, not for cleaning the same working head between different samples. Furthermore, the robotic arm-based method of moving the working head is structurally complex and can only process one sample at a time, leaving room for improvement in processing efficiency.

[0007] In summary, existing technologies still have shortcomings in achieving high-throughput continuous processing, completely eliminating cross-contamination between samples, and safely handling gas-generating samples. There is an urgent need for a pH adjustment device that can balance processing efficiency, sample isolation, and safety protection. Summary of the Invention

[0008] Therefore, the present invention aims to provide a multi-channel water sample pH adjustment device to solve the technical problems of existing technologies in processing batches of water samples, which cannot simultaneously achieve high-throughput continuous processing, completely eliminate cross-contamination between samples, and safely handle gas-producing samples.

[0009] Through long-term exploration and experimentation, and continuous reform and innovation, the inventors have provided a multi-channel water sample pH adjustment device to solve the above-mentioned technical problems. The device comprises: A sealed container with a lid on top and an exhaust pipe connected to the side wall; A chassis is fixed inside the sealed container. The upper surface of the chassis is provided with an annular groove, and the bottom outer ring of the annular groove is provided with a liquid collection tank. The liquid collection tank is connected to a waste liquid pipe. A magnetic stirring drive unit is installed on the lower surface of the chassis. A turntable is detachably connected to the power output shaft of the turntable drive unit and is located directly above the chassis. The turntable has n through slots arranged in a circular array along its circumference, and each slot has a push hole along its length. A push rod drive unit is connected to a push rod, which is configured to extend from outside the turntable through the push hole into the slot to push a sample container placed in the slot from the working position to the stationary position. The screw tube is connected to the lifting drive unit. An alkaline solution tube and an acid solution tube are installed inside the screw tube. A pH electrode and a temperature sensor are integrated at the bottom of the screw tube. A cleaning pipe extends downward through the cover, and an annular flow channel is formed between the cleaning pipe and the screw pipe. The cleaning pipe is connected to a water supply connector. The working position is located directly above the magnetic stirring drive unit. The turntable rotates at an angle of 360° / n each time. The lower end of the screw tube can extend into the interior of the sample container located at the working position. The magnetic stirring drive unit is magnetically coupled to the stir bar placed in the sample container. The cleaning tube guides the cleaning liquid to the outer wall of the screw tube through the annular flow channel. The lower part of the slot is connected to the annular groove, and the annular groove is connected to the liquid collection tank.

[0010] Preferably, n ≥ 6.

[0011] Preferably, the alkali solution tube and the acid solution tube are respectively connected to a high-precision stepper motor injection pump or a micro peristaltic pump, the minimum dosing increment of which is 0.1 μL.

[0012] Preferably, the sidewall of the slot is in frictional engagement with the outer wall of the sample container, and the length of the slot is not less than twice the diameter of the sample container, and the width of the slot is equal to the diameter of the sample container.

[0013] Preferably, the centerline of the push hole and the horizontal opposite side of the slot are located on the same plane.

[0014] Preferably, the exhaust pipe is connected to a negative pressure pump, which is used to extract the gas in the sealed container to the exhaust gas treatment device.

[0015] Preferably, the device further includes an intelligent closed-loop control system, which is electrically connected to the pH electrode, the temperature sensor, the pump connected to the alkali pipe, the pump connected to the acid pipe, and the magnetic stirring drive unit.

[0016] Preferably, the sample container is a finger-shaped tube, and each sample container contains an independent stir bar.

[0017] Preferably, the turntable and the power output shaft of the turntable drive unit are detachably connected via a snap-fit ​​or threaded connection structure.

[0018] Preferably, all components in contact with liquids are made of acid, alkali and corrosive gas resistant materials, and have a modular structure that allows for quick disassembly and replacement.

[0019] Compared with the prior art, the present invention has the following beneficial effects: First, this invention employs a single precision screw tube working head to serve multiple sample containers on a turntable. A pusher moves the processed sample containers from the working position to the resting position, separating sample loading and processing in time, thus enabling batch, assembly-line operations. Users only need to load multiple samples at once; once started, the device can automatically, continuously, and unattended complete the processing of all samples, significantly improving processing efficiency compared to manual operation.

[0020] Secondly, during sample switching, this invention uses a cleaning tube to guide distilled water to the outer wall of the screw tube for rinsing. Waste liquid is collected and discharged through the slot, annular groove, and collection tank, achieving physical isolation and cleaning of the working head between different samples, fundamentally eliminating cross-contamination between samples. Simultaneously, each sample container has a built-in independent magnetic stir bar, and the magnetic stirring drive unit is located on the lower surface of the chassis for non-contact operation, further avoiding cross-contact between the dosing and measuring components and between different samples.

[0021] Third, this invention places the entire treatment process within a sealed container and connects the exhaust gas pipe to a negative pressure pump, which is beneficial for preventing the generation of hazardous gases during the adjustment process (such as those released when adding acid to sulfur-containing wastewater). or susceptible to airborne pathogens Interfering samples can be immediately extracted, ensuring the safety of operators and avoiding interference from ambient gases on pH readings.

[0022] Fourth, this invention integrates the alkali tube, acid tube, pH electrode, and temperature sensor at the bottom of the same screw tube. When the screw tube moves down, all components are simultaneously immersed in the sample container. Together with the magnetic stirring drive unit on the lower surface of the chassis, a precise alignment structure of "stirring directly below + measuring directly below" is formed, ensuring that each sample undergoes the exact same dosing, mixing, and measurement process, eliminating individual differences between operators, and ensuring the comparability of data between samples in the same batch.

[0023] Fifth, this invention controls the dosage by using a high-precision stepper motor-type syringe pump or a micro peristaltic pump, with a minimum dosage increment of 0.1 μL. Combined with real-time feedback from pH electrodes and temperature sensors, it achieves precise and stable closed-loop control, making it particularly suitable for pH adjustment of trace samples.

[0024] Sixth, all components of this invention that come into contact with liquids are made of acid- and alkali-resistant and corrosion-resistant gas-resistant materials, and have a modular structure that allows for quick disassembly and replacement, ensuring the long-term reliable operation of the device. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a front view schematic diagram of the multi-channel water sample pH adjustment device of the present invention.

[0027] Figure 2 for Figure 1 A schematic diagram of the right-side structure.

[0028] Figure 3 for Figure 1 A top-view structural diagram.

[0029] Figure 4 for Figure 1 A schematic diagram of the three-dimensional structure.

[0030] Figure 5 for Figure 2 Schematic diagram of the AA section structure.

[0031] Figure 6 This is a schematic diagram of the internal three-dimensional structure of the multi-channel water sample pH adjustment device of the present invention.

[0032] Figure 7 This is a three-dimensional structural diagram of the chassis in the multi-channel water sample pH adjustment device of the present invention.

[0033] Figure 8 This is a partially enlarged schematic diagram of the working head and cleaning tube working together in the multi-channel water sample pH adjustment device of the present invention.

[0034] The markings in the diagram are as follows: 100 sealed containers, 110 enclosure, 111 Exhaust pipe, 120 cap, 121 water supply connector, 122 cleaning tube, 123 Annular Flow Channel 200 chassis, 210 annular groove, 220 collection tank, 230 waste liquid pipe, 240 magnetic stirring drive unit, 300 turntable, 310 slot, 320 push hole, 330 turntable drive unit, 340 pushrod drive unit, 341 putter, 400 screw tube, 401 working head, 410 alkali solution tube, 420 acid solution tube, 430pH electrode 431 First electrode, 432 second electrode, 433 third electrode, 434 reference electrode, 440 temperature sensor, 450 lifting drive unit, 500 sample containers. Detailed Implementation

[0035] The following description, in conjunction with the accompanying drawings and a specific embodiment, will be provided.

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

[0038] See Figures 1 to 8 This embodiment describes a multi-channel water sample pH adjustment device, which includes a sealed container 100, a chassis 200, a turntable 300, a push rod drive unit 340, a screw tube 400, and a cleaning tube 122. The sealed container 100 consists of a housing 110 and a cover 120, and all dosing, mixing, switching, and cleaning processes are carried out within the sealed container 100.

[0039] The sealed container 100 has an openable cover 120 at its top, and the cover 120 and the housing 110 are airtightly fitted together by a sealing ring. A waste gas pipe 111 is connected to the side wall of the housing 110. The waste gas pipe 111 is used to connect to a negative pressure pump (not shown in the figure) to dissipate waste gas (such as...) that overflows during sample adjustment within the sealed container 100. , The exhaust gas is drawn into the waste gas treatment device, which not only ensures the safety of operators but also avoids interference from ambient gases with pH readings.

[0040] The chassis 200 is fixedly installed inside the sealed container 100, located in the lower middle part of the housing 110. The upper surface of the chassis 200 has an annular groove 210 with a smooth surface, used to restrict the flow direction of the cleaning waste liquid, causing it to collect only in the collection tank 220. The bottom outer ring of the annular groove 210 has a collection tank 220, which is connected to a waste liquid pipe 230. The waste liquid pipe 230 extends to the outside of the sealed container 100 and connects to a waste liquid bucket (not shown), used to collect and discharge the wastewater generated during cleaning.

[0041] A through hole is provided in the middle of the chassis 200 for the power output shaft of the turntable drive unit 330 to pass through. The power output shaft of the turntable drive unit 330 is rotatably engaged with the through hole in the middle of the chassis 200. A magnetic stirring drive unit 240 is mounted on the lower surface of the chassis 200. The magnetic stirring drive unit 240 is located directly below the working position (i.e., directly below the screw tube 400) and is used to cooperate with the independent magnetic stir bar in the sample container 500 to drive the stir bar to rotate in a non-contact manner, thereby achieving uniform mixing of the sample solution.

[0042] The turntable 300 is detachably connected to the power output shaft of the turntable drive unit 330 and is located directly above the chassis 200. The turntable 300 and the power output shaft can be connected by a snap-fit ​​or threaded connection structure to allow for the replacement of different turntable models according to different sample container specifications. The turntable drive unit 330 is preferably a servo motor or a stepper motor, capable of precisely controlling the rotation angle of the turntable 300.

[0043] The turntable 300 has n through slots 310 arranged in a circular array along its circumference, where n ≥ 6, for example, 6, 8, 12, 24, or 48 slots. Each slot 310 is used to hold a sample container 500. The length of the slot 310 is arranged radially along the turntable 300, and its length is not less than twice the diameter of the sample container 500, while its width is equal to the diameter of the sample container 500. The sidewalls of the slots 310 form a friction fit with the outer wall of the sample container 500, thereby stably fixing the sample container 500. To further increase stability, elastic elements (such as spring sheets or rubber pads) can also be provided in the middle of the sidewalls of the slots 310 to prevent the sample container 500 from tipping over or shifting during the rotation of the turntable and the movement of the push rod.

[0044] Push holes 320 are provided along the length of each slot 310. The axis of the push hole 320 is on the same plane as the horizontal opposite side of the slot 310, so as to ensure that the push rod 341 can smoothly push the sample container 500 from the working position to the stationary position.

[0045] The push rod drive unit 340 is fixedly mounted on the side wall or cover 120 of the sealed container 100, and is preferably driven by a motor. The push rod drive unit 340 is connected to the push rod 341, which is configured to extend from outside the turntable 300 into the slot 310 through the push hole 320. When the push rod 341 extends into the slot 310, its front end abuts against the side wall of the sample container 500, pushing the sample container 500 from the working position (located directly above the magnetic stirring drive unit 240) inward along the slot 310 to the stationary position. After the pushing is completed, the push rod drive unit 340 drives the push rod 341 back to the outside of the turntable 300, waiting for the next slot 310 to switch to the working position before performing the pushing operation again.

[0046] The screw tube 400 is mounted on the cover 120 via a lifting drive unit 450, which is preferably a motor-driven lead screw and nut mechanism or a cylinder. The lower part of the screw tube 400 is a cylindrical working head 401, and the bottom of the working head 401 is preferably chamfered to facilitate liquid flow.

[0047] The screw tube 400 has an internally connected alkali solution tube 410 and acid solution tube 420, which are respectively connected to a high-precision stepper motor-type syringe pump or a micro peristaltic pump (not shown in the figure). These pumps can precisely control the dosing flow rate, with a minimum dosing increment of 0.1 μL, making them particularly suitable for pH adjustment of trace samples. Both the alkali solution tube 410 and the acid solution tube 420 are made of acid and alkali resistant tubing (such as PTFE tubing).

[0048] The bottom of the screw tube 400 also integrates a pH electrode 430 and a temperature sensor 440. The pH electrode 430 may include a first electrode 431, a second electrode 432, a third electrode 433, and a reference electrode 434, or a composite electrode may be used depending on actual needs. The temperature sensor 440 is preferably an NTC thermistor or a Pt1000 platinum resistance temperature sensor. The leads of the pH electrode 430 and the temperature sensor 440 are led out from inside the screw tube 400 and connected to the control system.

[0049] When the lifting drive unit 450 drives the screw tube 400 to descend, the working head 401 is inserted into the sample container 500 located in the working position. At this time, the outlets of the alkali tube 410 and acid tube 420, the detection end of the pH electrode 430, and the temperature sensing end of the temperature sensor 440 are all immersed below the liquid surface of the sample solution.

[0050] The cleaning pipe 122 extends downward through the cover 120, with its lower end located around the screw tube 400. An annular flow channel 123 is formed between the cleaning pipe 122 and the screw tube 400. A water supply connector 121 is connected to the upper end of the cleaning pipe 122, which is used to connect to an external distilled water source. When it is necessary to clean the outer wall of the screw tube 400, distilled water enters the cleaning pipe 122 through the water supply connector 121, flows downward along the annular flow channel 123, and rinses the outer wall of the screw tube 400. The flushed waste liquid falls through the slot 310 into the annular groove 210 of the chassis 200, then collects in the collection tank 220, and finally is discharged through the waste liquid pipe 230.

[0051] The sample container 500 is preferably a finger-shaped tube (or centrifuge tube, sample tube), and each sample container 500 contains an independent magnetic stir bar (not shown in the figure). The magnetic stir bar is a permanent magnet coated with polytetrafluoroethylene, which rotates under the drive of the rotating magnetic field generated by the magnetic stirring drive unit 240 to stir the sample solution.

[0052] The following describes the working process of the device in detail, taking the processing of a batch of n (e.g., n=8) water samples as an example.

[0053] Step 1: Sample loading The operator opens the cover 120 and inserts n sample containers 500 into the n slots 310 of the turntable 300. Each sample container 500 is pre-filled with water sample whose pH needs to be adjusted and a magnetic stir bar is placed inside. Depending on the characteristics of the sample, the operator can also set parameters such as the target pH value, allowable error range, dosing rate, and stirring time via the control panel (not shown). After loading, the cover 120 is closed, and the negative pressure pump is started to maintain a slight negative pressure within the sealed container 100.

[0054] Step 2: Initialization The control system controls the turntable drive unit 330 to drive the turntable 300 to rotate, switching the first slot 310 (i.e., the first sample container 500) to the working position (directly above the magnetic stirring drive unit 240). At this time, the sample container 500 is located directly below the screw tube 400. The control system records the current sample number and reads the initial temperature value from the temperature sensor 440.

[0055] Step 3: Lowering the working head and initial measurement The lifting drive unit 450 drives the screw tube 400 to descend, and the working head 401 is inserted into the sample container 500 until the pH electrode 430 and the temperature sensor 440 are submerged below the liquid surface. The control system reads the initial pH value of the current sample through the pH electrode 430 and the solution temperature through the temperature sensor 440.

[0056] Step 4: Closed-loop pH adjustment The control system compares the measured initial pH value with the target pH value: If the initial pH value is lower than the target pH value (i.e., the sample is acidic), the control system starts the injection pump connected to the alkali solution tube 410 and adds alkali solution to the sample container 500 according to the preset dosing strategy (such as segmented dosing, PID control, etc.).

[0057] If the initial pH value is higher than the target pH value (i.e., the sample is alkaline), the control system will start the injection pump connected to the acid solution tube 420 to add acid solution to the sample container 500.

[0058] During the dosing process, the magnetic stirring drive unit 240 is simultaneously activated, driving the magnetic stir bar inside the sample container 500 to rotate, ensuring that the added acid or alkali solution is rapidly and uniformly mixed with the sample. The pH electrode 430 monitors the pH value changes in real time and feeds the data back to the control system. The control system dynamically adjusts the dosing rate based on the difference between the real-time pH value and the target pH value: rapid dosing is used when the difference is large, and micro-droplet dosing (minimum increment 0.1 μL) is used when the value is close to the target value to avoid over-adjustment.

[0059] Once the pH value reaches the target range (e.g., target value ±0.05) and stabilizes for a period of time (e.g., 5 seconds), the control system stops adding the drug and records process data such as the final pH value, total amount of drug added, and adjustment time.

[0060] Step 5: Working head rises and sample is moved After pH adjustment, the lifting drive unit 450 drives the screw tube 400 to rise, and the working head 401 retracts from the sample container 500. Subsequently, the push rod drive unit 340 drives the push rod 341 to extend into the slot 310 through the push hole 320. The front end of the push rod 341 abuts against the side wall of the sample container 500, pushing it from the working position inward along the slot 310 to the stationary position. At this time, the sample container 500 has moved away from directly below the screw tube 400 and entered the area waiting to be removed.

[0061] Step 6: Cleaning the working head Simultaneously or after the pusher moves the sample container 500, the cleaning system is activated: the water supply connector 121 supplies distilled water to the cleaning pipe 122, and the distilled water flows downward along the annular flow channel 123 to rinse the outer wall of the working head 401 of the screw tube 400. During rinsing, the magnetic stirring drive unit 240 can continue to rotate to ensure that residual liquid adhering to the outer wall of the working head is washed away. The waste liquid generated during rinsing falls through the slot 310 into the annular groove 210 of the chassis 200, then collects in the collection tank 220, and finally is discharged into the waste liquid bucket through the waste liquid pipe 230. The rinsing time can be set to 5-10 seconds, and the water supply is stopped after rinsing is completed.

[0062] Step 7: Switch to the next sample The turntable drive unit 330 drives the turntable 300 to rotate 360° / n, switching the next slot 310 (i.e., the next sample container 500) to the working position. Repeat steps 3 to 6 above to process all samples in sequence.

[0063] Step 8: Remove the processed sample After all samples have been processed, the control system issues a prompt signal. The operator then opens the cover 120 and removes the pH-adjusted sample container 500 from the settling area of ​​the turntable 300. Since the sample container 500 has been moved to the settling position, the operator does not need to reach under the working head, making the handling safer and more convenient. If the next batch of samples needs to be processed, the turntable 300 can be removed for cleaning or replaced with another turntable pre-loaded with samples, enabling continuous assembly line operation.

[0064] IV. Exhaust Gas Treatment Instructions Throughout the treatment process, the negative pressure pump operates continuously, maintaining a slight negative pressure (e.g., -50 to -200 Pa) within the sealed container. This is especially important for processes that generate acidic gases (such as those released from sulfur-containing wastewater). ) or alkaline mist (such as the release of alkali from ammonia-containing wastewater) The samples, and the waste gases, are extracted through waste gas pipe 111 to a waste gas treatment device (such as an alkaline absorption bottle or activated carbon adsorber), preventing leakage into the laboratory environment and ensuring the safety of operators. Simultaneously, the negative pressure environment also reduces the amount of gas in the air. Interference with pH readings of alkaline samples.

[0065] V. Control System The device also includes an intelligent closed-loop control system (not shown separately in the accompanying drawings), which includes a controller (such as a PLC or microcontroller), a touch screen operation panel, a memory, and drive circuits for each of the aforementioned actuators. The control system is electrically connected to the pH electrode 430, the temperature sensor 440, the pump connected to the alkali solution pipe 410, the pump connected to the acid solution pipe 420, the magnetic stirring drive unit 240, the lifting drive unit 450, the turntable drive unit 330, the push rod drive unit 340, and the negative pressure pump.

[0066] The functions of the control system include: It receives parameters set by the user via the touchscreen (target pH value, error range, sample quantity, dosing speed mode, stirring speed, cleaning time, etc.). The control turntable drive unit enables automatic sample switching; The lifting drive unit controls the lifting and lowering of the screw tube; Real-time acquisition of pH and temperature values, and execution of closed-loop control algorithms (such as PID regulation or piecewise approximation algorithms). Control the start / stop of the dosing pump and the dosing rate; Control the start / stop and speed of the magnetic stirring drive unit; Control the timing of the actuator drive unit; Control the opening and closing of the solenoid valve for the water supply to the cleaning pipe; Record the processing data for each sample (initial pH, final pH, dosage, adjustment time, temperature, etc.), and export the data via USB interface or network.

[0067] All components in contact with liquids (including the alkali tubing 410, acid tubing 420, the working head 401 of the screw tube 400, cleaning tubing 122, sample container 500, waste tubing 230, etc.) are made of materials resistant to acids, alkalis, and corrosive gases, such as polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), titanium alloy, glass, or ceramics. The connection interfaces of the alkali tubing 410 and acid tubing 420 use quick-connect couplings, and the syringe pump module can be completely disassembled for easy replacement and cleaning. The turntable 300 is detachably connected to the drive shaft, allowing users to quickly replace turntables with different slot sizes according to sample container specifications (e.g., 0.5 mL, 1.5 mL, 2.0 mL, 5 mL finger tubes). The working head 401 of the screw tube 400 can also be designed as a replaceable structure to accommodate samples of different volumes or different electrode configurations.

[0068] Example 1

[0069] In this embodiment, n=12, and the sample container is a 2.0 mL finger tube.

[0070] To address the common laboratory requirements for pH adjustment of soil extracts, this device is configured as follows: A turntable 300 has 12 slots 310, each slot 310 being 11 mm wide (fitting a 2.0 mL finger tube with an outer diameter of 10.8 mm) and 25 mm long (approximately twice the diameter of the finger tube). The alkali solution tube 410 and acid solution tube 420 are connected to stepper motor-driven syringe pumps with a minimum dosing increment of 0.1 μL. The pH electrode 430 is a composite glass electrode, and the temperature sensor 440 is a Pt1000.

[0071] The operator placed 12 soil extract samples into 12 finger tubes, each with a volume of 1.5 mL, added a magnetic stir bar, and then placed them into the slots 310 of the turntable 300. The target pH was set to 7.00 ± 0.05, and the device was started. The device automatically completed the pH adjustment for all 12 samples, taking approximately 12–15 minutes in total (1–1.25 minutes per sample on average), which is 4–5 times more efficient than manual operation (approximately 5–8 minutes per sample). Because the working head was rinsed with distilled water between samples, the pH cross-contamination rate between adjacent samples was less than 0.05 pH units, meeting the accuracy requirements for water quality analysis pretreatment.

[0072] Example 2

[0073] In this embodiment, n=24, and the sample container is a 0.5 mL centrifuge tube.

[0074] To address the pH adjustment requirements for high-throughput micro-samples (such as drug metabolite solutions), this device is configured as follows: A turntable 300 has 24 slots 310, each 8 mm wide (accommodating 0.5 mL centrifuge tubes with an outer diameter of 7.8 mm). Alkali tubing 410 and acid tubing 420 are connected to a micro-peristaltic pump, with a minimum dosing increment of 0.5 μL (this can be achieved with time control due to pump accuracy limitations). Since the sample volume is only 0.3–0.5 mL, higher dosing accuracy is required. Therefore, the dosing rate in the closed-loop control strategy is set to "micro-volume mode": first, 80% of the estimated amount is quickly added, then added dropwise in the smallest increments, with stirring for 3 seconds after each drop before measurement, until the target value is reached. This device can process 24 micro-samples at a time, with a total processing time of approximately 30 minutes, meeting the needs of high-throughput screening experiments.

[0075] Example 3

[0076] For a certain industrial wastewater (including pH adjustment (approximately 100 mg / L) is required (from pH=12.0 to pH=7.0), as a large amount of acid is released during the acid addition process. Toxic gases are present, posing safety risks during operation. When using this device, the operator places the wastewater sample into the sealed container 100, closes the lid 120, and starts the negative pressure pump to maintain the negative pressure inside the container at approximately -100 Pa. During the acid addition process, [the following is a separate, unrelated sentence:] Toxic gases are generated. The gas is immediately drawn away by the exhaust pipe 111 and replaced with NaOH absorption liquid, ensuring that operators are completely protected from toxic gases. Simultaneously, the negative pressure environment also reduces... The residue in the solution resulted in a more stable pH reading. Testing showed that the pH value of the treated sample was accurately controlled at 7.00 ± 0.02, and no pH was detected in the ambient air outside the device. leakage.

[0077] Example 4: Quick Turntable Change When processing sample containers of different sizes (e.g., changing from 2.0 mL finger tubes to 15 mL centrifuge tubes), the operator simply removes the original turntable 300 from the power output shaft and replaces it with a turntable of the corresponding slot size. Simultaneously, depending on the sample volume, the screw tube working head 401 of the appropriate length can be replaced, ensuring that the working head can be inserted below the liquid surface. The entire replacement process takes no more than 2 minutes, achieving rapid switching.

[0078] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0080] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0081] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0082] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-channel water sample pH adjustment device, characterized in that, include: A sealed container (100) has a cover (120) on its top and an exhaust pipe (111) connected to its side wall. A chassis (200) is fixed inside the sealed container (100). The upper surface of the chassis (200) is provided with an annular groove (210). The bottom outer ring of the annular groove (210) is provided with a liquid collection tank (220). The liquid collection tank (220) is connected to a waste liquid pipe (230). A magnetic stirring drive unit (240) is installed on the lower surface of the chassis (200). The turntable (300) is detachably connected to the power output shaft of the turntable drive unit (330) and located directly above the chassis (200). The turntable (300) has n through slots (310) arranged in a circular array along the circumference, and push holes (320) are provided along the length direction of each slot (310). A push rod drive unit (340) is connected to a push rod (341), which is configured to extend from outside the turntable (300) through the push hole (320) into the slot (310) to push a sample container (500) placed in the slot (310) from the working position to the stationary position; A screw tube (400) is connected to a lifting drive unit (450). An alkaline solution tube (410) and an acid solution tube (420) are installed inside the screw tube (400). A pH electrode (430) and a temperature sensor (440) are integrated at the bottom of the screw tube (400). A cleaning pipe (122) extends downward through the cover (120), and an annular flow channel (123) is formed between the cleaning pipe (122) and the screw pipe (400). The cleaning pipe (122) is connected to a water supply connector (121). The working position is located directly above the magnetic stirring drive unit (240). The turntable (300) rotates at an angle of 360° / n each time. The lower end of the screw tube (400) can extend into the sample container (500) located at the working position. The magnetic stirring drive unit (240) is magnetically coupled to the stir bar placed in the sample container (500). The cleaning tube (122) guides the cleaning liquid to the outer wall of the screw tube (400) through the annular flow channel (123). The lower part of the slot (310) is connected to the annular groove (210). The annular groove (210) is connected to the liquid collection tank (220).

2. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, The n≥6.

3. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, The alkali solution tube (410) and the acid solution tube (420) are respectively connected to a high-precision stepper motor injection pump or a micro peristaltic pump, the minimum dosing increment of which is 0.1~1μL.

4. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, The sidewall of the slot (310) is in frictional engagement with the outer wall of the sample container (500), and the length of the slot (310) is not less than twice the diameter of the sample container (500), and the width of the slot (310) is equal to the diameter of the sample container (500).

5. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, The centerline of the push hole (320) and the horizontal opposite side of the slot (310) are on the same plane.

6. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, The exhaust pipe (111) is connected to a negative pressure pump, which is used to pump the gas in the sealed container (100) to the exhaust gas treatment device.

7. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, It also includes an intelligent closed-loop control system, which is electrically connected to the pH electrode (430), the temperature sensor (440), the pump connected to the alkali pipe (410), the pump connected to the acid pipe (420), and the magnetic stirring drive unit (240).

8. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, The sample container (500) is a finger-shaped tube, and each sample container (500) contains an independent stir bar.

9. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, The turntable (300) and the power output shaft of the turntable drive unit (330) are detachably connected by a snap-fit ​​or threaded connection structure.

10. The multi-channel water sample pH adjustment device according to claim 1, characterized in that, All components that come into contact with liquids are made of acid, alkali and corrosive gas resistant materials, and have a modular structure that allows for quick disassembly and replacement.

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