Water quality automatic detection platform based on multiple channels

Abstract

The invention discloses an automatic water quality detection platform based on multiple channels, and belongs to the technical field of water quality analysis and detection. Comprising a multi-channel detection assembly, a liquid injector, a liquid injector control assembly, an argon supply and cleaning system, a liquid injector cleaning system and a water sample storage and supply assembly. The multi-channel detection assembly is used for detecting the heavy metal content in the water sample. And the liquid injector control assembly controls the position of the liquid injector. And the argon supply and cleaning system is communicated and connected with the gas inlet and the gas outlet of the graphite pipe. And the liquid injector cleaning system is used for cleaning the liquid injector after liquid injection is completed. The water sample storage and supply assembly comprises a water storage box; and the water storage box is matched and connected with the liquid injector through a liquid adding pipe arranged at the bottom. The full-flow water sample heavy metal content detection can be carried out on multiple groups of water samples, the content of multiple heavy metals in the same water sample can be detected at the same time, the automation degree of heavy metal content detection is improved, and the detection efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of water quality analysis and testing technology, specifically relating to a multi-channel automatic water quality testing platform. Background Technology

[0002] Water is the source of life and a core resource for industrial production and agricultural irrigation. The content of heavy metals in water samples is directly related to human health and ecological environment safety. Heavy metals are characterized by their accumulative properties and high toxicity. Even low concentrations can accumulate through the food chain, causing serious problems such as damage to the nervous system and organ diseases. Therefore, establishing efficient and accurate methods for detecting heavy metals in water samples is a core requirement in fields such as environmental monitoring and drinking water safety assurance.

[0003] Currently, the mainstream technologies in the field of heavy metal detection in water samples include atomic absorption spectrometry, inductively coupled plasma mass spectrometry, traditional colorimetric methods, and single-channel electrochemical detection methods. Each method is applied to different scenarios due to its different characteristics.

[0004] Atomic absorption spectrometry: As one of the most widely used techniques, it calculates the concentration of heavy metals by measuring the amount of light absorbed at a specific wavelength. It has the advantage of being relatively simple to operate and is often used for routine laboratory testing.

[0005] Inductively coupled plasma mass spectrometry (ICP-MS) has a low detection limit and can analyze multiple elements simultaneously, but the equipment is expensive (usually over one million yuan) and has strict requirements for the operating environment. It is mainly used for high-precision scientific research testing.

[0006] Traditional colorimetric method: Based on chemical colorimetric reactions to determine heavy metal content, the equipment is inexpensive but the detection accuracy is low, and it is greatly affected by the colorimetric reagent. It is only suitable for semi-quantitative screening.

[0007] Single-channel electrochemical detection method: The concentration is analyzed through electrode reaction signals. The detection speed is relatively fast, but only one heavy metal can be detected at a time, and the electrode is easily contaminated.

[0008] Although existing methods have established a certain application system, their detection efficiency is low in actual monitoring and cannot meet the needs of multiple samples. Traditional atomic absorption spectrometry is mostly designed as a single channel, which can only detect one heavy metal at a time. If it is necessary to complete the detection of 8 common heavy metals, it is necessary to repeat the injection 8 times, and the detection time for a single water sample exceeds 1 hour. At the same time, most devices only support single water sample processing. When facing the needs of multiple batch detection of industrial wastewater, watershed water quality, etc., the efficiency improvement is limited and cannot meet the rapid response requirements of emergency monitoring.

[0009] Apart from high-end ICP-MS, most equipment requires manual operation of sample injection, cleaning, parameter adjustment, etc. For example, atomic absorption spectrometry requires manual replacement of hollow cathode lamps to adapt to different heavy metals. The injection process is prone to deviation in sample volume due to differences in operating force, and the human error rate can reach 5%-10%, which contrasts with the advantage of "full-process automated control" in this application. Summary of the Invention

[0010] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide a multi-channel automated water quality detection platform. This invention can perform a full-process detection of heavy metal content in multiple water samples, including sample loading, simultaneous detection, automatic cleaning, automatic sample replacement, cyclic detection, and data output. It can simultaneously detect the content of multiple heavy metals in the same water sample, improving the automation level and efficiency of heavy metal content detection.

[0011] The technical solution adopted by the invention to solve the problems existing in the prior art is:

[0012] Based on the multi-channel automatic water quality detection platform, the inside of the box is equipped with a multi-channel detection assembly consisting of 4 to 10 detection units, a liquid injector, a liquid injector control assembly, an argon gas supply and cleaning system, a liquid injector cleaning system, and a water sample storage and supply assembly. The outside of the box is equipped with a control and data processing module.

[0013] The detection unit includes a horizontally arranged heavy metal detection module, a characteristic light emission module, and a characteristic light detection module. The heavy metal detection module includes a graphite tube with a liquid inlet in the middle of the top of the graphite tube, an air inlet and an exhaust outlet on both sides of the liquid inlet at the top of the graphite tube, quartz windows at both ends of the graphite tube, and a resistance heating jacket wrapped around the outside of the graphite tube. The characteristic light emission module and the characteristic light detection module are coaxially arranged on both sides of the outside of the graphite tube.

[0014] Several detection units are arranged in a rectangular array at intervals. The injector control assembly drives the injector to move above the multi-channel detection assembly. The movement path is located directly above the liquid inlet of each graphite tube. The injector control assembly includes a lifting module, which drives the injector to move up and down.

[0015] The argon supply and cleaning system is connected to the inlet and outlet of the graphite tube via a pipeline equipped with an electrically controlled valve.

[0016] The injector cleaning system is used to clean the injector after injection.

[0017] The water sample storage and supply assembly includes up to two water storage boxes mounted on top of the injector control assembly. The water storage boxes are connected to the injector via a liquid filling pipe located at the bottom.

[0018] Furthermore, the detection unit includes a mounting plate with a fixed semi-circular arc groove that is open at the top. The mounting plate is equipped with a slide rail that is slidably connected to a sliding semi-circular arc groove. The fixed semi-circular arc groove and the sliding semi-circular arc groove are arranged opposite each other at intervals. The heavy metal detection module is installed between the fixed semi-circular arc groove and the sliding semi-circular arc groove. The fixed semi-circular arc groove and the sliding semi-circular arc groove are fixedly connected by at least two fastening bolts.

[0019] The characteristic light emission module and the characteristic light detection module are mounted on the mounting plate.

[0020] Furthermore, the graphite tube has an air inlet and an exhaust outlet connected to an air connector, and the graphite tube has a liquid inlet connector assembly connected to its liquid inlet.

[0021] The gas inlet connector is connected to the argon supply and cleaning system's inlet branch pipe, and the exhaust port connector is connected to the argon supply and cleaning system's exhaust branch pipe.

[0022] The liquid inlet connector assembly includes a liquid inlet pipe and a valve core, with the bottom of the liquid inlet pipe detachably connected to the liquid inlet.

[0023] The inner wall of the liquid inlet pipe is provided with a spiral guide groove with an open upper end. Inside the liquid inlet pipe, below the guide groove, are the valve core mounting cavity and the liquid collection cavity in sequence. The valve core is coaxially rotatably connected inside the valve core mounting cavity. The liquid inlet pipe is provided with a connecting channel that connects the valve core mounting cavity and the liquid collection cavity.

[0024] The valve core has a recessed middle cavity on its top surface, a drain hole at the bottom of the middle cavity, and a second slot with an open upper end recessed on the inner wall of the middle cavity. In the initial state, the drain hole and the connecting channel are arranged alternately.

[0025] Furthermore, the injector includes an outlet section and a reservoir section that are slidably connected vertically.

[0026] The liquid outlet section includes a liquid outlet pipe, with several first through holes at the top of the outer wall of the liquid outlet pipe, a slider protruding in the middle of the outer wall of the liquid outlet pipe, and a second insert block protruding at the bottom of the outer wall of the liquid outlet pipe, the second insert block being inserted into a second slot.

[0027] The liquid storage section includes a liquid storage tube with a second through hole at the top. A sliding cavity is connected through the bottom of the liquid storage tube. The inner diameter of the sliding cavity is smaller than the inner diameter of the liquid storage tube. A spring cavity and a third slot are recessed in the inner wall of the sliding cavity. The liquid outlet tube is slidably disposed inside the sliding cavity. The slider is slidably disposed inside the third slot. A first spring is disposed inside the spring cavity and sleeved outside the liquid outlet tube. The upper and lower ends of the first spring abut against the top surface of the spring cavity and the slider, respectively. A lower support sleeve and an upper support sleeve are fixed inside the liquid storage tube. A third pressure ring and a third insert are fixed outside the liquid storage tube. The third pressure ring is spaced below the third insert. A protrusion is provided at the bottom of the outer wall of the sliding cavity. The protrusion ring is slidably connected to the guide groove.

[0028] A lower blocking plate is provided above the bottom of the liquid storage tube and the through-hole of the sliding cavity. A sliding rod is fixed above the lower blocking plate. The sliding rod passes through the lower support sleeve. A second spring is sleeved on the sliding rod. The upper and lower ends of the second spring abut against the bottom surface of the lower support sleeve and the top surface of the lower blocking plate, respectively.

[0029] Inside the liquid storage tube, below the second through hole, there is an upper blocking plate. An upper sliding rod is fixed to the bottom of the upper blocking plate. The upper sliding rod passes through the upper support sleeve. A third spring is sleeved on the upper sliding rod. The upper and lower ends of the third spring abut against the bottom surface of the upper blocking plate and the top surface of the upper support sleeve, respectively.

[0030] The outer diameters of the lower support sleeve, upper support sleeve, lower plug plate, and upper plug plate are all smaller than the inner diameter of the liquid storage tube.

[0031] Furthermore, the injector control assembly includes a collar, a telescopic cylinder, and an electric linear module.

[0032] The collar is fitted over the third pressure ring outside the liquid storage tube. The thickness of the collar is less than or equal to the distance between the third pressure ring and the third insert. The top surface of the collar is recessed with a second groove, which is inserted into and connected to the third insert.

[0033] The telescopic rod of the telescopic cylinder is arranged vertically and is fixedly connected to the connecting frame of the collar.

[0034] The telescopic cylinder is fixedly connected to the sliding part of the electric linear module.

[0035] Furthermore, the argon supply and cleaning system includes argon cylinders and exhaust gas collection boxes.

[0036] The argon cylinder is connected to a cylinder connecting pipe via an electronically controlled pressure regulating valve, and the cylinder connecting pipe is connected to each inlet branch pipe via the main inlet pipe.

[0037] The exhaust branch pipe is connected to the exhaust main pipe. The end of the exhaust main pipe is connected to the ash exhaust pipe with an electronically controlled valve, the cleaning exhaust pipe and the drying exhaust pipe. The end of the drying exhaust pipe is connected to the water tank pipe. The ash exhaust pipe and the cleaning exhaust pipe are connected to the exhaust gas collection box. The outside of the exhaust gas collection box is connected to the exhaust gas discharge pipe.

[0038] Furthermore, the ashing exhaust pipe and the purging exhaust pipe are respectively connected to the exhaust gas collection box through a detachable exhaust gas adsorption tank.

[0039] Furthermore, the injector cleaning system includes a cleaning fluid storage tank, a delivery pump, and a waste fluid collection tank.

[0040] The inlet of the delivery pump is connected to the cleaning fluid storage tank through the inlet pipe, and the outlet of the delivery pump is connected to a vertically arranged lower sleeve through a pipeline. Inside the lower sleeve, a sliding lower tube is provided, and a lower nut sleeve is fixed to the outside of the sliding lower tube.

[0041] Upper sliding tubes are arranged at intervals above the lower sliding tube. The upper sliding tubes are slidably installed inside the upper sleeve. The upper sleeve is connected to the waste liquid collection box through a pipeline. An upper nut sleeve is fixed to the outside of the upper sliding tube.

[0042] The lower nut sleeve and the upper nut sleeve are threadedly connected to two threaded areas with opposite helical directions on the double-ended stud, and the double-ended stud is connected to the output shaft of the servo motor.

[0043] The inner diameter of the sliding tube is equal to the outer diameter of the liquid storage tube, the outer diameter of the upper sliding tube is equal to the inner diameter of the second through hole, and several third through holes are provided on the outer wall of the upper sliding tube.

[0044] Furthermore, the inner wall of the sliding tube is provided with an abutment ring, the outer side of the upper sliding tube is provided with a fourth pressure ring, and the third through hole is provided on the outer wall of the upper sliding tube located below the fourth pressure ring.

[0045] Furthermore, each end of the multi-channel detection assembly is equipped with a set of injector cleaning systems, and the cleaning fluid storage tanks of the two sets of injector cleaning systems are filled with % nitric acid solution and deionized water, respectively.

[0046] The water tank pipe of the argon gas supply and cleaning system is connected to the waste liquid collection tank in the injector cleaning system filled with deionized water.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] (1) The multi-channel parallel and automated design significantly shortens the detection time of multiple parameters for a single water sample, and the detection cycle of a single water sample is shortened by more than 70% compared with the traditional method. It reduces labor and consumable consumption, and reduces the cost of batch water quality monitoring by 40%-60%, which helps to normalize and widely cover the monitoring of drinking water sources, industrial wastewater and other scenarios.

[0049] (2) The low detection limit of 0.1-1μg / L and the strict anti-interference design meet the strict monitoring requirements for heavy metals in national standards such as the "Surface Water Environmental Quality Standard". The data error is controlled within ±2%, providing accurate data support for environmental law enforcement and water quality management, and avoiding misjudgment caused by insufficient accuracy of traditional detection.

[0050] (3) The 10.1-inch touch screen and visualization data processing software enable non-professionals to complete the operation with simple training, breaking through the limitation of traditional equipment "relying on professional technicians" and is suitable for on-site testing needs in different scenarios such as grassroots environmental protection stations, industrial parks, and waterworks.

[0051] (4) Argon protection avoids oxidation loss of graphite tube 1, high temperature cleaning reduces residual corrosion, modular structure reduces maintenance difficulty, extends the service life of core components of equipment by more than 30%, and reduces the risk of monitoring interruption caused by equipment failure. Attached Figure Description

[0052] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0053] Figure 1 This is a structural diagram of the multi-channel automatic water quality monitoring platform proposed in this application.

[0054] Figure 2 This is a partial sectional view of the housing of the multi-channel automatic water quality monitoring platform of this application.

[0055] Figure 3 This is a diagram showing the internal structure of the multi-channel automatic water quality monitoring platform used in this application.

[0056] Figure 4 This is a structural diagram of the multi-channel detection assembly in the multi-channel automatic water quality detection platform of this application.

[0057] Figure 5 This is a structural diagram of the detection unit in the multi-channel automatic water quality detection platform of this application.

[0058] Figure 6 This is an exploded view of the heavy metal detection module in the detection unit.

[0059] Figure 7 This is a cross-sectional view of the heavy metal detection module.

[0060] Figure 8 This is a structural diagram of the light source module in the detection unit.

[0061] Figure 9 This is a structural diagram of the liquid inlet connector assembly for the heavy metal detection module.

[0062] Figure 10 for Figure 9 First sectional view,

[0063] Figure 11 for Figure 9 The second sectional view,

[0064] Figure 12 for Figure 9 The third sectional view,

[0065] Figure 13 for Figure 9 The fourth sectional view,

[0066] Figure 14 This is a structural diagram of the valve core in the inlet connector assembly.

[0067] Figure 15 This is a structural diagram showing the detection unit connected to the injector.

[0068] Figure 16 for Figure 15 A partial sectional view,

[0069] Figure 17 This is a structural diagram of the injector control assembly in the multi-channel automatic water quality testing platform of this application.

[0070] Figure 18 This is a structural diagram of the injector.

[0071] Figure 19 This is a cross-sectional view of the injector.

[0072] Figure 20 This is a structural diagram of the argon gas supply and cleaning system in the multi-channel automatic water quality detection platform of this application.

[0073] Figure 21 This is a structural diagram of the injector cleaning system in the multi-channel automatic water quality testing platform of this application.

[0074] Figure 22 This is a structural diagram of the injector cleaning system after it is connected to the injector.

[0075] Figure 23 for Figure 22 Sectional view,

[0076] Figure 24 for Figure 23 Enlarged view of a portion of point A in the middle.

[0077] Figure 25 for Figure 23 Enlarged view of a section at point B in the middle.

[0078] Figure 26 This is a structural diagram of the water sample storage and supply assembly in the multi-channel automatic water quality monitoring platform of this application.

[0079] Figure 27Diagram of the support frame structure in the water sample storage supply assembly.

[0080] Figure 28 Structural diagram of the water storage tank in the water sample storage assembly.

[0081] Figure 29 for Figure 28 Enlarged view of a section at point C.

[0082] In the diagram: 1-Graphite tube, 101-Liquid inlet, 102-Air inlet, 103-Exhaust outlet, 2-Quartz window, 201-First insert, 3-High-temperature sealing gasket, 4-Resistance heating sleeve, 5-Gas connector, 501-First pressure ring, 6-Liquid inlet pipe, 601-Second pressure ring, 602-Guide groove, 603-Liquid collection chamber, 604-Connecting channel, 605-First slot, 7-Valve core, 701-Intermediate cavity, 702-Drain hole, 703-Second slot, 8-Feature light emission module, 9-Feature light detection module, 10-Mounting plate, 1001-Slide rail, 11-Fixed semi-circular groove, 12-Sliding semi-circular groove, 13-Fastening bolt, 14 - Pressure plate, 1401- Fixing plate, 15- Liquid outlet, 1501- Liquid outlet pipe, 1502- First through hole, 1503- Slider, 1504- Second insert block, 16- Liquid storage part, 1601- Liquid storage pipe, 1602- Second through hole, 1603- Sliding cavity, 1604- Spring cavity, 1605- Third slot, 1606- Lower support sleeve, 1607- Upper support sleeve, 1608- Third pressure ring, 1609- Third insert block, 16010- Protrusion, 17- First spring, 18- Lower blocking plate, 1801- Slide rod, 19- Second spring, 20- Upper blocking plate, 2001- Upper slide rod, 21- Third spring, 22- Collar, 2201 - Second slot, 2202- Connecting frame, 23- Telescopic cylinder, 2301- Telescopic rod, 24- Electric linear module, 2401- Sliding part, 25- Detection unit support plate, 26- Inlet branch pipe, 27- Inlet main pipe, 28- Gas cylinder connecting pipe, 29- Exhaust branch pipe, 30- Exhaust main pipe, 31- Ashing exhaust pipe, 32- Cleaning exhaust pipe, 33- Drying exhaust pipe, 34- Water tank connecting pipe, 35- Argon cylinder, 36- Waste gas adsorption tank, 37- Tail gas collection box, 38- Waste gas discharge pipe, 39- Cleaning fluid storage tank, 40- Transfer pump, 41- Liquid inlet pipe, 42- Liquid outlet pipe, 43- Liquid outlet branch pipe, 44- Lower sleeve, 45- Slide pipe, 45 01-Abutting ring, 46-Lower nut sleeve, 47-Upper sliding tube, 4701-Third through hole, 4702-Fourth pressure ring, 48-Upper nut sleeve, 49-Upper sleeve, 50-Waste liquid pipe, 51-Waste liquid collection box, 5101-Waste liquid discharge pipe, 52-Double-ended stud, 53-Servo motor, 54-First support frame, 55-Water storage box, 56-Liquid filling pipe, 5601-Fourth through hole, 5602-Fifth pressure ring, 57-First top cover, 58-Second support frame, 5801-First mounting plate, 5802-Positioning plate, 5803-Second mounting plate, 5804-Connecting rod, 59-Box body, 60-Second top cover, 61-Control and data processing module. Detailed Implementation

[0083] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of this application belong. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application.

[0084] Furthermore, the specification and claims of this invention use terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," to describe various exemplary structural parts and elements of the invention. However, these terms are used herein merely for illustrative purposes and are determined based on the exemplary orientations shown in the accompanying drawings. Therefore, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0085] The following description, in conjunction with the accompanying drawings, provides a more detailed account of the multi-channel automatic water quality detection platform of the present invention.

[0086] Depend on Figures 1 to 29 As shown, the multi-channel automatic water quality testing platform includes a housing 59. Inside the housing 59 are a multi-channel testing assembly consisting of 4 to 10 testing units, a liquid injector, a liquid injector control assembly, an argon gas supply and cleaning system, a liquid injector cleaning system, and a water sample storage and supply assembly. Outside the housing 59 is a control and data processing module 61.

[0087] In this embodiment, eight detection units are used to detect Pb, Cd, Cu, Zn, and Cr, respectively. 6+ It detects eight common heavy metals, including Hg, As, and Ni, with detection limits ranging from 0.1 to 1 μg / L. The eight detection units are arranged in two rows of four and fixed together in the detection unit support plate 25, which is fixedly installed inside the housing 59.

[0088] The detection unit includes a horizontally arranged heavy metal detection module, a characteristic light emission module 8, and a characteristic light detection module 9. The heavy metal detection module includes a graphite tube 1 with a liquid inlet 101 at the top center. On either side of the liquid inlet 101, there are air inlets 102 and exhaust ports 103. Quartz windows 2 are sealed at both ends of the graphite tube 1. To improve the sealing effect, a first insert 201 is provided at the end of the quartz window 2 facing the graphite tube 1. The outer diameter of the first insert 201 is the same as the inner diameter of the graphite tube 1, and the first insert 201 is inserted into the graphite tube 1. A high-temperature sealing gasket 3 is also provided at the contact point between the quartz window 2 and the graphite tube 1. A resistance heating sleeve 4 surrounds the graphite tube 1. The characteristic light emission module 8 and the characteristic light detection module 9 are coaxially arranged on both sides of the outside of the graphite tube 1.

[0089] The water sample to be tested is injected into the graphite tube 1 through the inlet 101. Impurities are removed by heating, and the heavy metal ions in the water sample are converted into ground-state atomic vapor. The characteristic light emission module 8 includes a hollow cathode lamp and a monochromator. The hollow cathode lamp emits characteristic wavelength light of each heavy metal, such as 283.3 nm for Pb measurement and 228.8 nm for Cd measurement. After the monochromator filters out stray light, a pure characteristic beam is formed.

[0090] When the characteristic beam of light passes through the ground-state atomic vapor inside the graphite tube 1, some of the light is absorbed by the ground-state atoms. The amount of absorption is proportional to the atomic concentration, that is, "the higher the concentration, the more light is absorbed".

[0091] The characteristic light detection module 9 includes a photomultiplier tube and a signal amplifier. The photomultiplier tube converts the light signal into a dot pattern, and the signal amplifier amplifies the electrical signal. The combination of the two can effectively reduce detection errors. The characteristic light detection module 9 detects the characteristic light beam passing through the graphite tube 1, and receives the unabsorbed residual characteristic light, converting it into an electrical signal. The control and data processing module 61 calculates the concentration values ​​of each heavy metal using the Lambert-Beer Law (A = εbc, A = absorbance, ε = molar absorptivity, b = optical path length, c = concentration), achieving synchronous quantitative analysis.

[0092] The injector control assembly moves the injector above the multi-channel detection assembly, with the movement path directly above the inlet 101 of each graphite tube 1. The injector control assembly includes a lifting module that moves the injector up and down. Under the control of the injector control assembly, the injector sequentially injects water samples from the water sample storage and supply assembly into each graphite tube 1.

[0093] The argon supply and cleaning system is connected to the inlet 102 and outlet 103 of the graphite tube 1 through a pipeline with an electrically controlled valve. It provides protective gas to the graphite tube 1 to prevent the atomized vapor from being oxidized, and also cleans the graphite tube 1.

[0094] The injector cleaning system is used to clean the injectors after injection, preventing cross-contamination and affecting the test results when performing automated heavy metal content analysis on multiple water samples.

[0095] The water sample storage and supply assembly includes 2 to 5 water storage boxes 55 mounted above the injector control assembly. The water storage boxes 55 are connected to the injector via a liquid filling pipe 56 located at the bottom. Each water storage box 55 can be filled with one type of water sample to be tested, enabling the multi-channel automatic water quality analyzer to analyze the heavy metal content of multiple water samples.

[0096] Specifically, in this embodiment, the detection unit includes a mounting plate 10, a feature light emission module 8, and a feature light detection module 9 disposed on the mounting plate 10.

[0097] The mounting plate 10 has a fixed semi-circular groove 11 with an open upper end. A slide rail 1001 is provided on the mounting plate 10, and a sliding semi-circular groove 12 is slidably connected to the slide rail 1001. The fixed semi-circular groove 11 and the sliding semi-circular groove 12 are arranged at intervals opposite to each other. The heavy metal detection module is engaged between the fixed semi-circular groove 11 and the sliding semi-circular groove 12. The fixed semi-circular groove 11 and the sliding semi-circular groove 12 are fixedly connected by at least two fastening bolts 13. Loosening the fastening bolts 13 can increase the distance between the fixed semi-circular groove 11 and the sliding semi-circular groove 12, thereby releasing the engagement of the metal detection module and facilitating the replacement of the graphite tube 1.

[0098] The graphite tube 1 has an air inlet 102 and an exhaust outlet 103 connected to an air connector 5, and the graphite tube 1 has a liquid inlet 101 connected to a liquid inlet connector assembly.

[0099] The gas inlet 102 is connected to the gas inlet branch pipe 26 in the argon gas supply and cleaning system via the gas connector 5, and the exhaust port 103 is connected to the exhaust branch pipe 29 in the argon gas supply and cleaning system via the gas connector 5. The liquid inlet assembly includes a liquid inlet pipe 6 and a valve core 7, and the bottom of the liquid inlet pipe 6 is detachably connected to the liquid inlet 101.

[0100] Since the graphite tube 1 is not easy to machine, such as by machining threads or other structures that facilitate connection, in this embodiment, the air connector 5 and the liquid inlet connector 6 are both connected to the air inlet 102, the exhaust port 103, and the liquid inlet 101 by crimping.

[0101] To improve the sealing performance of the connection, in this embodiment, a first pressure ring 501 is fixedly connected to the outside of the air connector 5, and a second pressure ring 602 is fixedly connected to the outside of the liquid inlet pipe 6. A pressure plate 14 is provided above both the first pressure ring 501 and the second pressure ring 602. The pressure plate 14 is detachably connected to the mounting plate 10 via a bottom fixing plate 1401. The pressure plate 14 presses down on the first pressure ring 501 and the second pressure ring 602 to seal the air connector 5 and the liquid inlet pipe 6 to the corresponding openings of the graphite tube 1.

[0102] To further improve the sealing effect, the bottom surface of the liquid inlet pipe 6 is recessed with an annular first groove 605, and the port of the tubular liquid inlet 101 is inserted into the first groove 605.

[0103] The inner wall of the liquid inlet pipe 6 is provided with a spiral guide groove 602 with an open upper end. Inside the liquid inlet pipe 6, below the guide groove 602, are a valve core mounting cavity and a liquid collection cavity 603. The valve core 7 is coaxially rotatably connected inside the valve core mounting cavity. The liquid inlet pipe 6 is provided with a connecting channel 604 that connects the valve core mounting cavity and the liquid collection cavity 603.

[0104] The valve core 7 has a recessed intermediate cavity 701 on its top surface, a drain hole 702 at the bottom of the intermediate cavity 701, and a second slot 703 with an open upper end recessed on the inner wall of the intermediate cavity 701. In the initial state, the drain hole 702 and the connecting channel 604 are arranged alternately.

[0105] The injector includes a liquid outlet section 15 and a liquid storage section 16 that are slidably connected vertically. The liquid outlet section 15 includes a liquid outlet tube 1501. The top of the outer wall of the liquid outlet tube 1501 is provided with a plurality of first through holes 1502. A slider 1503 protrudes from the middle of the outer wall of the liquid outlet tube 1501. A second insert 1504 protrudes from the bottom of the outer wall of the liquid outlet tube 1501. The second insert 1504 is inserted into the second slot 703.

[0106] The liquid storage section 16 includes a liquid storage tube 1601. A second through hole 1602 is provided at the top of the liquid storage tube 1601. A sliding cavity 1603 is connected through the bottom of the liquid storage tube 1601. The inner diameter of the sliding cavity 1603 is smaller than the inner diameter of the liquid storage tube 1601. A spring cavity 1604 and a third slot 1605 are recessed in the inner wall of the sliding cavity 1603. The liquid outlet tube 1501 is slidably disposed inside the sliding cavity 1603. The slider 1503 is slidably disposed inside the third slot 1605. A first spring 17 is provided inside the spring cavity 1604. Sleeve over the outside of the liquid outlet tube 1501, the upper and lower ends of the first spring 17 abut against the top surface of the spring cavity 1604 and the slider 1503 respectively. The inside of the liquid storage tube 1606 is fixed with a lower support sleeve 1606 and an upper support sleeve 1607. The outside of the liquid storage tube 1606 is fixed with a third pressure ring 1607 and a third insert block 1609. The third pressure ring 1607 is spaced below the third insert block 1609. The bottom of the outer wall of the sliding cavity 1603 is provided with a protrusion 16010. The protrusion ring 16010 is inserted into and slidably connected with the guide groove 602.

[0107] A lower blocking plate 18 is provided above the bottom of the liquid storage tube 1601 and the opening of the sliding cavity 1603. A sliding rod 1801 is fixed above the lower blocking plate 18. The sliding rod 1801 passes through the lower support sleeve 1606. A second spring 19 is sleeved on the sliding rod 1801. The upper and lower ends of the second spring 19 abut against the bottom surface of the lower support sleeve 1606 and the top surface of the lower blocking plate 18, respectively.

[0108] Inside the liquid storage tube 1601, below the second through hole 1602, there is an upper blocking plate 20. The bottom of the upper blocking plate 20 is fixed with an upper sliding rod 2001. The upper sliding rod 2001 passes through the upper support sleeve 1607. A third spring 21 is sleeved on the upper sliding rod 2001. The upper and lower ends of the third spring 21 abut against the bottom surface of the upper blocking plate 20 and the top surface of the upper support sleeve 1607, respectively.

[0109] The outer diameters of the lower support sleeve 1606, the upper support sleeve 1607, the lower blocking plate 18, and the upper blocking plate 20 are all smaller than the inner diameter of the liquid storage tube 1601.

[0110] In this embodiment, the valve core 7 is provided with three drain holes 702 spaced 120° apart, and the inlet pipe 6 is also provided with three connecting channels 604 arranged opposite to the drain holes 702. The included angle between the top and bottom of the guide groove 602 is 30° to 90°.

[0111] Pushed by the first spring 17, the slider 1503 slides to the bottom of the third slot 1605. When the injector is connected to the inlet connector assembly, the bottom of the outlet pipe 1501 is inserted into the intermediate cavity 701 of the valve core 7 through the top opening of the inlet pipe 6, while the second insert 1504 is inserted into the second slot 703. When the second insert 1504 abuts against the bottom surface of the second slot 703, there is a certain height gap between the bottom surface of the outlet pipe 1501 and the bottom surface of the intermediate cavity 701.

[0112] As the injector continues to move downwards, the outlet pipe 1501 is blocked by the second slot 703, causing the reservoir 16 to move downwards against the thrust of the first spring 17, shortening the length of the outlet pipe 1501 that leaks to the outside of the reservoir 16. As the reservoir 16 moves downwards, the protrusion 16010 inserts into the guide groove 602. Under the guidance of the guide groove 602, the moving injector rotates, simultaneously causing the valve core 7 to rotate. When the protrusion 16010 slides to the bottom of the guide groove 602, the angle of rotation of the valve core 7 is such that the drain hole 702 and the connecting channel 604 are arranged opposite to each other and connected.

[0113] During the retraction of the liquid storage tube 1501, the lower blocking plate 18 is pushed upward to open the through-hole between the liquid storage tube 1601 and the sliding cavity 1603. At the same time, the top of the liquid outlet tube 1501 extends into the interior of the liquid storage tube 1601, and the first through hole 1502 on the liquid outlet tube 1501 is connected to the interior of the liquid storage tube 1601.

[0114] The water sample stored inside the storage tube 1601 flows into the outlet tube 1501 through the first through hole 1502, and then flows into the collection chamber 603 through the gap between the bottom surface of the outlet tube 1501 and the bottom surface of the intermediate cavity 701, the drain hole 702, and the connecting channel 604. Finally, it flows into the graphite tube 1 through the inlet 101, completing the addition of water sample to the graphite tube 1.

[0115] After the water sample is added to the graphite tube 1, the injector moves upward. During the upward movement, under the action of the guide slide 602, the injector rotates in the opposite direction, which in turn drives the valve core 7 to rotate, so that the drain hole 702 and the connecting channel 604 are arranged alternately, thereby achieving the sealing of the inlet port 101 of the graphite tube 1 by the inlet connector assembly.

[0116] The injector control assembly includes a collar 22, a telescopic cylinder 23, and an electric linear module 24.

[0117] The collar 22 is sleeved above the third pressure ring 1608 outside the liquid storage tube 1601. The thickness of the collar 22 is less than or equal to the distance between the third pressure ring 1608 and the third insert 1609. The top surface of the collar 22 is recessed with a second slot 2201, which is inserted and connected to the third insert 1609.

[0118] The telescopic rod 2301 of the telescopic cylinder 23 is arranged vertically and is fixedly connected to the connecting frame 2202 of the collar 22. The telescopic cylinder 23 is fixedly connected to the sliding part 2401 of the electric linear module 24.

[0119] The collar 22 ensures that the syringe injector will not rotate after leaving the inlet connector assembly. Specifically, since the collar 22 cannot rotate, the third insert 1609 is initially inserted into the second slot 2201. Because the bottom of the second slot 2201 is sealed, the syringe will not slip out. The downward movement of the syringe injector is controlled by the up-and-down movement of the collar 22.

[0120] After the outlet tube 1501 of the injector is inserted into the intermediate cavity 701 of the valve core 7, the downward-moving collar 22 will first disengage from the third insert 1609 and then abut against the third pressure ring 1608 before it can continue to push the reservoir 16 downward. After the downward-moving reservoir 16 rotates, the third insert 1609 and the second slot 2201 are arranged alternately.

[0121] When the injector moves upward, the top surface of the collar 22 first abuts against the bottom surface of the third insert 1609. Pushing the third insert 1609 causes the reservoir 16 to move upward. During this upward movement, the reservoir 16 rotates in the opposite direction. When the protrusion 16010 leaves the guide groove 602, the third insert 1609 is positioned directly above the second slot 2201. The upward-moving collar 22 causes the third insert 1609 to insert into the second slot 2201, preventing further rotation of the injector and ensuring the positions of the protrusion 16010 and the second insert 1504. To optimize this effect, the upper end of the guide groove 602 is provided with a straight groove of a certain length.

[0122] In this embodiment, two sets of injector control assemblies are arranged side by side, and the two sets of injector control assemblies are mounted directly above the two rows of detection units.

[0123] The argon gas supply and cleaning system includes an argon gas cylinder 35 and a tail gas collection box 37.

[0124] The argon cylinder 35 is connected to a cylinder connecting pipe 28 via an electronically controlled pressure regulating valve. The cylinder connecting pipe 28 is connected to each inlet branch pipe 26 via an inlet main pipe 27.

[0125] The exhaust branch pipe 29 is connected to the exhaust main pipe 30. The exhaust main pipe 30 is connected to the ashing exhaust pipe 31 with an electric control valve, the cleaning exhaust pipe 32 and the drying exhaust pipe 33. The drying exhaust pipe 33 is connected to the water tank pipe 34. The ashing exhaust pipe 31 and the cleaning exhaust pipe 32 are connected to the exhaust gas collection box 37. The exhaust gas collection box 37 is connected to the outside of the exhaust gas collection box 37 with the exhaust gas discharge pipe 38.

[0126] The ashing exhaust pipe 31 and the purging exhaust pipe 32 are respectively connected to the exhaust gas collection box 37 through a detachable waste gas adsorption tank 36.

[0127] The injector cleaning system includes a cleaning fluid storage tank 39, a delivery pump 40, and a waste liquid collection tank 51. In this embodiment, a set of injector cleaning systems is provided at each end of the multi-channel detection assembly, and the cleaning fluid storage tanks 39 of the two sets of injector cleaning systems are respectively filled with 5% nitric acid solution and deionized water.

[0128] The water tank pipe 34 of the argon gas supply and cleaning system is connected to the waste liquid collection tank 51 of the injector cleaning system filled with deionized water.

[0129] The inlet of the delivery pump 40 is connected to the cleaning fluid storage tank 39 through the inlet pipe 41. The outlet of the delivery pump 40 is connected to two drainage branch pipes 43 with electrically controlled valves through the drain pipe 42. The end of the drainage branch pipe 43 is connected to a vertically arranged lower sleeve 44. The lower sleeve 44 has a sliding lower tube 45 inside which slides up and down. The lower nut sleeve 46 is fixed outside the sliding lower tube 45.

[0130] Above the sliding tube 45, there are spaced upper sliding tubes 47. The upper sliding tubes 47 are slidably disposed inside the upper sleeve 49. The upper sleeve 49 is connected to the waste liquid collection box 51 through the waste liquid pipe 50. The outside of the waste liquid collection box 51 is connected to the waste liquid discharge pipe 5101 with an electric control valve.

[0131] An upper nut sleeve 48 is fixed to the outside of the upper slide tube 47. The lower nut sleeve 46 and the upper nut sleeve 48 are threadedly connected to two threaded areas with opposite helical directions on the double-ended stud 52, which is connected to the output shaft of the servo motor 53.

[0132] The inner diameter of the sliding tube 45 is equal to the outer diameter of the liquid storage tube 1501, the outer diameter of the upper sliding tube 47 is equal to the inner diameter of the second through hole 1602, and several third through holes 4701 are provided on the outer wall of the upper sliding tube 47.

[0133] The inner wall of the sliding tube 45 is provided with an abutment ring 4501, the outer side of the upper sliding tube 47 is provided with a fourth pressure ring 4702, and the third through hole 4701 is provided on the outer wall of the upper sliding tube 47 located below the fourth pressure ring 4702.

[0134] The lower sleeve 44, the upper sleeve 49, the double-ended stud 52, and the servo motor 53 are all supported by the first support frame 54, which is fixedly connected to the cleaning fluid storage tank 39 or the waste liquid collection tank 51.

[0135] The electric linear module 24 moves the injector, which has completed the water sample addition to the graphite tube 1, to between the lower slide tube 45 and the upper slide tube 47, with all three arranged coaxially. Then, the servo motor 53 drives the double-headed stud 52 to rotate, causing the lower slide tube 45 and the upper slide tube 47 to move together towards the injector, compressing the outlet section 15 and the storage section 16. The bottom of the outlet tube 1501 is inserted into the lower slide tube 45 and abuts against the abutment ring 4501. The upper slide tube 47 is inserted into the second through hole 1602 and pushes the upper plug plate 20 downwards, connecting the third through hole 4701 to the inside of the storage tube 1601. Then, the delivery pump 40 injects 5% nitric acid solution from the bottom of the outlet tube 1501 to clean it, and then recovers it to the waste collection tank 51 through the upper slide tube 47 and the waste tube 50. After cleaning with 5% nitric acid solution, the injector is reset, and then transferred to the injector cleaning system at the other end for cleaning with deionized water. After cleaning, move it into the water storage box 55 and fill it with another water sample.

[0136] The water sample storage and supply assembly includes two opposing second support frames 58, which are fixedly connected to the inner wall of the housing 59 via connecting rods 5804.

[0137] The second support frame 58 includes a first mounting plate 5801 and a second mounting plate 5803. Several positioning plates 5802 are fixed on the first mounting plate 5801 at intervals. The water storage box 55 is placed on the first mounting plate 5801 of the second support frame 58, and the water storage box 55 is positioned by the positioning plates 5802.

[0138] A through hole is provided on the top surface of the housing 59 at a position corresponding to the water storage box 55. A second cover 60 is provided on the through hole. After opening the second cover 60, the water storage box 55 can be taken out through the through hole to complete the cleaning and water sample storage work.

[0139] The electric linear module 24 is mounted on the second mounting plate 5803, and the two are detachably connected by bolts.

[0140] Two liquid filling pipes 56 are provided at the bottom of the water storage box 55, and the two liquid filling pipes 56 are arranged corresponding to the two liquid injectors controlled by the two liquid injector control assemblies. The liquid filling pipes 56 are connected to the water storage box 55 through an electric control valve. The liquid filling pipes 56 are provided with a fifth pressure ring 5602 and a fourth through hole 5601, which is the same as the structure of the upper sliding pipe 47. When the liquid injector moves upward, the liquid filling pipe 56 is inserted into the second through hole 1602, and the corresponding electric control valve is opened, and the water sample inside the water storage box 55 is injected into the liquid storage pipe 1601.

[0141] The water storage box 55 has a water inlet on the top, and a first top cover 57 is provided over the water inlet.

[0142] The control and data processing module 61 includes an embedded main control unit, a touch screen, data processing software, and an alarm system. The embedded main control unit uses a quad-core processor to control the collaborative operation of each module; the touch screen uses a 10.1-inch capacitive screen to visualize parameters and view real-time data; the data processing software supports functions such as automatic standard curve plotting, automatic concentration calculation, data export, and historical data query, converting detector signals into "heavy metal concentration values" and generating test reports; the alarm system uses audible and visual alarms and has a fault code display function to promptly alert to abnormalities and prevent equipment damage or data deviation.

[0143] The steps for detecting heavy metal content in the water sample inside graphite tube 1 are as follows:

[0144] S01, Drying:

[0145] The resistance heating jacket 4 heats the graphite tube 1 to 80-120℃ to remove free water from the water sample and prevent sample splashing caused by boiling water in the subsequent high-temperature stage.

[0146] During the drying stage, the moisture in the water sample is converted into water vapor under heating, and then discharged from the graphite tube 1 by argon gas purging. The water vapor eventually flows into the waste liquid collection tank 51 through the drying exhaust pipe 33 and the water tank connection pipe 34, where it is re-condensed.

[0147] A pyrolytic graphite coating is attached to the inner wall of graphite tube 1 to make its surface smooth and non-absorbent, reducing moisture adsorption and ensuring that more than 99% of the moisture is completely discharged.

[0148] S02, Ashing:

[0149] The resistance heating jacket 4 heats the graphite tube 1 to 300-800℃, and removes organic matter such as humic acid and protein, as well as matrix impurities such as salts from the water sample through high-temperature oxidation and decomposition, so as to avoid these substances competing with heavy metals for the absorption of characteristic light in the subsequent atomization stage.

[0150] During the ashing stage, organic matter undergoes two transformations, leaving almost no solid residue:

[0151] (1) Easily decomposable organic matter, such as carbohydrates: decomposes into gaseous products such as CO2, H2O, and N2 at 300-500℃, and is discharged with argon gas purging. After discharge, it is discharged into the waste gas adsorption tank 36 through the ashing exhaust pipe 31 for adsorption by activated carbon, etc., and then enters the tail gas collection box 37. After passing the test, it is discharged through the waste gas discharge tank 38.

[0152] (2) Aromatic compounds and other difficult-to-decompose organic matter: further oxidized into small molecule gaseous products at 600-800℃. At the same time, the pyrolytic graphite coating of graphite tube 1 has extremely low adsorption, which can prevent organic matter from adhering to the tube wall after carbonization. It will also be blown away with argon gas.

[0153] S03, Atomization:

[0154] The resistance heating jacket 4 heats the graphite tube 1 to 1500-2500℃, removing residual heavy metal ions, such as Pb, after ashing. 2 +、Cd 2+ When these atoms are converted into ground-state atomic vapor, they have specific electronic energy levels and can selectively absorb characteristic wavelengths of light corresponding to heavy metals, which is a key prerequisite for detection.

[0155] After graphite tube 1 reaches the target temperature, the residual heavy metal salts after ashing undergo thermal dissociation at high temperature. Taking lead nitrate as an example, the reaction is as follows:

[0156] Residue after ashing: Pb(NO3)2→Pb 2+ +2NO3 -

[0157] Ground-state atomic vapor formation: Pb 2+ →Pb 0

[0158] The generated ground-state atomic vapor is uniformly distributed in the internal cavity of the graphite tube, forming an atomic vapor cloud, the concentration of which is proportional to the initial concentration of heavy metals in the water sample.

[0159] After atomization, the characteristic light emission module 8 and the characteristic light detection module 9 work together to detect the content of a certain heavy metal in the water sample.

[0160] S04, Clear:

[0161] After the test is completed, the resistance heating jacket 4 heats the graphite tube 1 to 2800℃ to thoroughly remove any remaining heavy metal atoms and salt impurities inside the graphite tube, preventing contamination of the next sample. The ultra-high temperature of 2800℃ vaporizes all remaining heavy metal atoms and salt impurities inside the tube into gaseous particles. Then, the argon gas flow rate is increased to purge the inside of the graphite tube 1.

[0162] The blown-out gaseous residue enters the corresponding exhaust gas adsorption tank 36 through the exhaust pipe 32. After the heavy metal gaseous particles are adsorbed by the activated carbon and chelating resin inside the exhaust gas adsorption tank 36, they enter the exhaust gas collection box 37.

[0163] The usage method of the multi-channel automatic water quality monitoring platform is as follows:

[0164] Step 1: Preparations before powering on

[0165] Add 5% nitric acid and deionized water to the two cleaning fluid storage tanks 39 of the injector cleaning system, respectively, until they reach the "maximum liquid level line" marked on the liquid level observation window on the outside of the tank 59; open the first top cover 57 of the water storage box 55, and inject the water sample to be tested into 2-5 water storage boxes 55 respectively. Each water storage box 55 should be filled with only one type of water sample. After filling, tighten the first top cover 57 to prevent contamination.

[0166] Step 2: Powering on and setting parameters

[0167] Turn on the main power supply of the device, press the power button of the control and data processing module 61, the embedded main control unit starts, the touch screen lights up and enters the operation interface, and waits for the system to complete the initialization of each module.

[0168] On the touchscreen, tap "Parameter Settings" and configure the following parameters in sequence:

[0169] Detection unit selection: Select the corresponding heavy metal (Pb, Cd, etc.) according to the item to be detected, and the system will automatically match the wavelength of the hollow cathode lamp of the characteristic light emission module 8;

[0170] Heating parameter settings: Set the drying temperature to 80-120℃, ashing temperature to 300-800℃, atomization temperature to 1500-2500℃, and purging temperature to 2800℃ according to the testing process. Adjust the holding time for each stage according to the type of water sample.

[0171] Argon parameters: Argon supply pressure is set to 0.2 MPa, flow rate is set to 50 mL / min for the drying / ashing stage, 10 mL / min for the atomization stage, and 100 mL / min for the purging stage.

[0172] Water sample parameters: Enter the water storage box number 55 and the corresponding water sample name, and set the test order. By default, the tests will start from water storage box number 1.

[0173] Standard curve calibration: Click the "Calibration" function on the operation interface. The system will automatically prompt you to inject a standard concentration water sample, such as 1 μg / L Pb standard solution. The standard solution will be injected into the graphite tube 1 of the corresponding detection unit through the injector control assembly. After calibration, the data processing software will automatically draw the standard curve. After the calibration is qualified, the interface will display "Calibration complete".

[0174] Step 3: Water Sample Testing Procedure

[0175] Clicking "Start Detection" causes the electric linear module 24 of the injector control assembly to move the injector below the target water storage box 55. The telescopic cylinder 23 drives the injector to move upward, so that the filling tube 56 is inserted into the second through hole 1602 of the injector. The electric control valve of the filling tube 56 is opened, and the water sample flows into the storage tube 1601 of the storage section 16 through the third through hole 4701 of the upper sliding tube 47. After the filling is completed, the electric control valve closes, and the injector moves downward to reset.

[0176] The electric linear module 24 moves the injector to the top of the inlet pipe 6 of the corresponding detection unit. The telescopic cylinder 23 drives the injector to move down. The bottom of the outlet pipe 1501 is inserted into the middle cavity 701 of the valve core 7. The second insert block 1504 is inserted into the second slot 703. The injector continues to move down. The liquid storage part 16 moves down against the thrust of the first spring 17. The protrusion 16010 slides along the guide groove 602 to drive the valve core 7 to rotate, so that the drain hole 702 is connected to the connecting channel 604. The water sample flows into the graphite tube 1 from the inlet 101 through the collection chamber 603. The single tube injection volume is 5-10μL. After injection, the injector moves up and the valve core 7 resets to achieve sealing of the inlet.

[0177] The heating and testing stages of graphite tube 1 are as follows:

[0178] Drying stage: The resistance heating jacket 4 is started, the graphite tube 1 is heated to the set temperature, the water in the water sample is converted into water vapor, and the argon gas is sent to the waste liquid collection box 51 for condensation and recovery through the exhaust port 103, exhaust branch pipe 29 and drying exhaust pipe 33.

[0179] Ashing stage: The temperature is raised to the ashing temperature, and the organic matter is decomposed into gaseous products such as CO2. These products are then introduced into the waste gas adsorption tank 36 through the argon ash exhaust pipe 31 and sent to the tail gas collection box 37 after being adsorbed by activated carbon.

[0180] Atomization and Detection: The graphite tube 1 is rapidly heated to the atomization temperature, and the heavy metal ions are converted into ground-state atomic vapor. The characteristic light beam emitted by the characteristic light emission module 8 passes through the graphite tube 1, and part of the light is absorbed by the ground-state atoms. The photomultiplier tube of the characteristic light detection module 9 converts the remaining light signal into an electrical signal, which is then amplified by the signal amplifier and transmitted to the control and data processing module 61. The heavy metal concentration is calculated using the Lambert-Beer law (A = εbc).

[0181] Removal stage: The temperature is raised to 2800℃, and the residual heavy metals and impurities are vaporized. A large flow of argon gas is sent to the waste gas adsorption tank 36 (chelating resin adsorbs heavy metal particles) through the removal exhaust pipe 32. Finally, the waste gas is discharged in compliance with standards through the waste gas discharge pipe 38.

[0182] The two sets of injector control assemblies correspond to two columns of detection units, enabling the simultaneous operation of four detection units. After completing one set of detections, the system automatically switches to the next set until all water samples from the 55 water storage tanks have been tested. The detection data is displayed in real time on the touch screen, including the concentration values ​​of each heavy metal, absorbance values, and detection time.

[0183] After each water sample test in a storage tank is completed, the injector is transferred to the injector cleaning system by the electric linear module 24. The servo motor 53 drives the double-headed stud 52 to rotate, so that the sliding tube 45 covers the outlet tube 1501 and the upper sliding tube 47 is inserted into the second through hole 1602. First, the delivery pump 40 is started to inject 5% nitric acid solution for cleaning for 30 seconds. The waste liquid flows into the waste liquid collection tank 51 through the waste liquid pipe 50. Then, the system switches to deionized water for cleaning for 60 seconds. After completion, the injector is reset and ready for the next filling.

[0184] Step 4: Post-detection processing

[0185] After the test is completed, click "Data Processing" on the operation interface. The data processing software will automatically generate a test report, which includes water sample information, concentration of each heavy metal, detection limit and pass / fail criteria (compared to national standards). It supports exporting data in Excel format via USB interface or printing the report directly.

[0186] Close all the electrically controlled valves of the water storage box 55, remove the water storage box 55, clean and dry it, and put the first top cover 57 back on for later use.

[0187] Click "System Cleaning". The argon supply and cleaning system will purge all graphite tubes 1 for 5 minutes. The injector cleaning system will flush the pipeline twice with deionized water.

[0188] If the graphite tube 1 needs to be replaced, loosen the fastening bolts 13 of the fixed semi-circular groove 11 and the sliding semi-circular groove 12, remove the old graphite tube, align the air inlet 102 and the exhaust port 103 of the new graphite tube with the air connector 5, press the quartz window 2 and tighten the fastening bolts 13.

[0189] Close the main valve of argon cylinder 35 and the delivery pump 40 of the liquid injector cleaning system in sequence. Click "Shut Down" in the control and data processing module 61. After the system completes the reset of each component (argon pipeline depressurization and heating jacket cooling), cut off the main power supply and close the side door of the box 59.

[0190] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A multi-channel automatic water quality detection platform, characterized in that: The box (59) is equipped with a multi-channel detection assembly consisting of 4 to 10 detection units, a liquid injector, a liquid injector control assembly, an argon gas supply and cleaning system, a liquid injector cleaning system, and a water sample storage and supply assembly. The box (59) is equipped with a control and data processing module (61) on the outside. The detection unit includes a horizontally arranged heavy metal detection module, a characteristic light emission module (8), and a characteristic light detection module (9). The heavy metal detection module includes a graphite tube (1). The graphite tube (1) has a liquid inlet (101) in the middle of its top. The top of the graphite tube (1) has an air inlet (102) and an exhaust outlet (103) on both sides of the liquid inlet (101). The graphite tube (1) has quartz windows (2) at both ends. The graphite tube (1) is wrapped with a resistance heating sleeve (4). The characteristic light emission module (8) and the characteristic light detection module (9) are coaxially arranged on both sides of the graphite tube (1). Several detection units are arranged in a rectangular array at intervals. The injector control assembly drives the injector to move above the multi-channel detection assembly. The moving path is located directly above the inlet (101) of each graphite tube (1). The injector control assembly includes a lifting module, which drives the injector to move up and down. The argon supply and cleaning system is connected to the inlet (102) and outlet (103) of the graphite tube (1) through a pipeline with an electrically controlled valve; The injector cleaning system is used to clean the injector after injection. The water sample storage and supply assembly includes 2 to 5 water storage boxes (55) mounted on top of the injector control assembly. The water storage boxes (55) are connected to the injector through a liquid filling pipe (56) at the bottom.

2. The multi-channel automatic water quality detection platform according to claim 1, characterized in that: The detection unit includes a mounting plate (10), a fixed semi-circular arc groove (11) with an open upper end is fixed on the mounting plate (10), a slide rail (1001) is provided on the mounting plate (10), a sliding semi-circular arc groove (12) is slidably connected to the slide rail (1001), the fixed semi-circular arc groove (11) and the sliding semi-circular arc groove (12) are arranged opposite to each other at intervals, the heavy metal detection module is installed between the fixed semi-circular arc groove (11) and the sliding semi-circular arc groove (12), and the fixed semi-circular arc groove (11) and the sliding semi-circular arc groove (12) are fixedly connected by at least two fastening bolts (13); The characteristic light emission module (8) and the characteristic light detection module (9) are mounted on the mounting plate (10).

3. The multi-channel automatic water quality detection platform according to claim 2, characterized in that: The graphite tube (1) has an air inlet (102) and an exhaust outlet (103) connected to an air connector (5), and the graphite tube (1) has a liquid inlet (101) connected to a liquid inlet assembly. The gas connector (5) of the inlet (102) is connected to the inlet branch pipe (26) in the argon supply and cleaning system, and the gas connector (5) of the outlet (103) is connected to the outlet branch pipe (29) in the argon supply and cleaning system. The liquid inlet connector assembly includes a liquid inlet pipe (6) and a valve core (7), and the bottom of the liquid inlet pipe (6) is detachably connected to the liquid inlet (101); The inner wall of the liquid inlet pipe (6) is provided with a spiral guide groove (602) with an open upper end. The inside of the liquid inlet pipe (6) below the guide groove (602) are the valve core mounting cavity and the liquid collection cavity (603) respectively. The valve core mounting cavity is coaxially rotatably connected to the valve core (7). The inside of the liquid inlet pipe (6) is provided with a connecting channel (604) that connects the valve core mounting cavity and the liquid collection cavity (603) through. The valve core (7) has a recessed intermediate cavity (701) on its top surface. The bottom of the intermediate cavity (701) has a drain hole (702). The inner wall of the intermediate cavity (701) has a recessed second slot (703) with an open upper end. In the initial state, the drain hole (702) and the connecting channel (604) are arranged alternately.

4. The multi-channel automatic water quality detection platform according to claim 3, characterized in that: The injector includes an outlet section (15) and a reservoir section (16) that are slidably connected vertically. The liquid outlet section (15) includes a liquid outlet pipe (1501), the top of the outer wall of the liquid outlet pipe (1501) is provided with a plurality of first through holes (1502), the middle of the outer wall of the liquid outlet pipe (1501) is provided with a slider (1503), the bottom of the outer wall of the liquid outlet pipe (1501) is provided with a second insert (1504), and the second insert (1504) is inserted into the second slot (703); The liquid storage section (16) includes a liquid storage tube (1601), a second through hole (1602) at the top of the liquid storage tube (1601), and a sliding cavity (1603) connected through the bottom of the liquid storage tube (1601). The inner diameter of the sliding cavity (1603) is smaller than the inner diameter of the liquid storage tube (1601). A spring cavity (1604) and a third slot (1605) are recessed in the inner wall of the sliding cavity (1603). The liquid outlet tube (1501) is slidably disposed inside the sliding cavity (1603), and the slider (1503) is slidably disposed inside the third slot (1605). A first spring (17) is disposed inside the spring cavity (1604). 7) The first spring (17) is sleeved on the outside of the liquid outlet pipe (1501). The upper and lower ends of the first spring (17) abut against the top surface of the spring cavity (1604) and the slider (1503) respectively. The lower support sleeve (1606) and the upper support sleeve (1607) are fixed inside the liquid storage pipe (1606). The third pressure ring (1607) and the third insert block (1609) are fixed outside the liquid storage pipe (1606). The third pressure ring (1607) is spaced below the third insert block (1609). The bottom of the outer wall of the sliding cavity (1603) is provided with a protrusion (16010). The protrusion ring (16010) is inserted into the guide slide groove (602) for sliding connection. A lower blocking plate (18) is provided above the bottom of the liquid storage tube (1601) and the through opening of the sliding cavity (1603). A sliding rod (1801) is fixed above the lower blocking plate (18). The sliding rod (1801) passes through the lower support sleeve (1606). A second spring (19) is sleeved on the sliding rod (1801). The upper and lower ends of the second spring (19) abut against the bottom surface of the lower support sleeve (1606) and the top surface of the lower blocking plate (18), respectively. Inside the liquid storage tube (1601), below the second through hole (1602), there is an upper blocking plate (20). The bottom of the upper blocking plate (20) is fixed with an upper sliding rod (2001). The upper sliding rod (2001) passes through the upper support sleeve (1607). A third spring (21) is sleeved on the upper sliding rod (2001). The upper and lower ends of the third spring (21) abut against the bottom surface of the upper blocking plate (20) and the top surface of the upper support sleeve (1607) respectively. The outer diameters of the lower support sleeve (1606), upper support sleeve (1607), lower plug plate (18), and upper plug plate (20) are all smaller than the inner diameter of the liquid storage tube (1601).

5. The multi-channel automatic water quality detection platform according to claim 4, characterized in that: The injector control assembly includes a collar (22), a telescopic cylinder (23), and an electric linear module (24); The collar (22) is sleeved above the third pressure ring (1608) outside the liquid storage tube (1601). The thickness of the collar (22) is less than or equal to the distance between the third pressure ring (1608) and the third insert (1609). The top surface of the collar (22) is recessed with a second slot (2201), and the second slot (2201) and the third insert (1609) are inserted and connected. The telescopic rod (2301) of the telescopic cylinder (23) is arranged vertically and is fixedly connected to the connecting frame (2202) of the collar (22); The telescopic cylinder (23) is fixedly connected to the sliding part (2401) of the electric linear module (24).

6. The multi-channel automatic water quality detection platform according to claim 5, characterized in that: The argon supply and cleaning system includes an argon cylinder (35) and a tail gas collection box (37); The argon cylinder (35) is connected to a cylinder connecting pipe (28) via an electronically controlled pressure regulating valve. The cylinder connecting pipe (28) is connected to each inlet branch pipe (26) via an inlet main pipe (27). The exhaust branch pipe (29) is connected to the exhaust main pipe (30). The exhaust main pipe (30) is connected to the end of the ashing exhaust pipe (31) with an electric control valve, the cleaning exhaust pipe (32) and the drying exhaust pipe (33). The drying exhaust pipe (33) is connected to the end of the water tank pipe (34). The ashing exhaust pipe (31) and the cleaning exhaust pipe (32) are connected to the exhaust gas collection box (37). The exhaust gas collection box (37) is connected to the outside of the exhaust gas collection box (37) with the exhaust gas discharge pipe (38).

7. The multi-channel automatic water quality detection platform according to claim 6, characterized in that: The ashing exhaust pipe (31) and the purging exhaust pipe (32) are respectively connected to the exhaust gas collection box (37) through a detachable exhaust gas adsorption tank (36).

8. The multi-channel automatic water quality detection platform according to claim 6 or 7, characterized in that: The injector cleaning system includes a cleaning fluid storage tank (39), a delivery pump (40), and a waste fluid collection tank (51); The inlet of the delivery pump (40) is connected to the cleaning fluid storage tank (39) through the inlet pipe (41), and the outlet of the delivery pump (40) is connected to a vertically arranged lower sleeve (44) through a pipeline. The lower sleeve (44) has a sliding lower tube (45) inside, and a lower nut sleeve (46) is fixed outside the sliding lower tube (45). An upper sliding tube (47) is arranged at intervals above the lower sliding tube (45). The upper sliding tube (47) is slidably installed inside the upper sleeve (49). The upper sleeve (49) is connected to the waste liquid collection box (51) through a pipeline. An upper nut sleeve (48) is fixed to the outside of the upper sliding tube (47). The lower nut sleeve (46) and the upper nut sleeve (48) are threadedly connected to two threaded areas with opposite helical directions on the double-ended stud (52), and the double-ended stud (52) is connected to the output shaft of the servo motor (53); The inner diameter of the sliding tube (45) is equal to the outer diameter of the liquid storage tube (1501), the outer diameter of the upper sliding tube (47) is equal to the inner diameter of the second through hole (1602), and several third through holes (4701) are provided on the outer wall of the upper sliding tube (47).

9. The automatic water quality detection platform based on a multi-channel according to claim 8, characterized in that: The inner wall of the sliding tube (45) is provided with an abutment ring (4501), the outer side of the upper sliding tube (47) is provided with a fourth pressure ring (4702), and the third through hole (4701) is provided on the outer wall of the upper sliding tube (47) located below the fourth pressure ring (4702).

10. The automatic water quality detection platform based on a multi-channel according to claim 8, characterized in that: The multi-channel detection assembly is equipped with a set of injector cleaning systems at both ends. The cleaning solution storage tanks (39) of the two sets of injector cleaning systems are filled with 5% nitric acid solution and deionized water, respectively. The water tank connector (34) of the argon gas supply and cleaning system is connected to the waste liquid collection tank (51) of the injector cleaning system filled with deionized water.

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