Automatic sample injector for fully automatic thermal desorber and working method thereof and fully automatic thermal desorber

Abstract

The present invention relates to the technical field of volatile organic compound detection, and discloses an automatic sample injector for a fully automatic thermal desorber, a working method thereof, and a fully automatic thermal desorber, that is, on the one hand, by arranging a Z-axis assembly, an X-axis assembly, and a Y-axis assembly, an adsorption tube grabbing and sample delivery action and an adsorption tube putting back action can be performed in the upper area of ​​a tray assembly, and on the other hand, by arranging a crossbeam assembly, a cap removal assembly, a loading assembly, and a valve island assembly, the adsorption tubes delivered for sample delivery can be sequentially handed over, cap removal, loading, unloading, capping, and returning, etc., so that they are particularly suitable for fully automatic thermal desorbers, greatly reducing manual workload, saving time and labor. In addition, the automatic sample injector also has the advantages of convenient loading / unloading, high grab success rate, automatic error detection, simple structure, and easy implementation, which is convenient for practical application and promotion.

Description

Technical Field

[0001] The present invention belongs to the technical field of volatile organic compound detection, and the industries involved include environmental monitoring and occupational health, and specifically relates to an automatic sample injector for a fully automatic thermal desorber, a working method thereof, and a fully automatic thermal desorber. Background Art

[0002] Thermal desorption is mainly used to analyze VOCs (Volatile Organic Compounds, which refers to organic compounds with a saturated vapor pressure greater than 133.32Pa at room temperature, a boiling point below 50-260℃ at a standard atmospheric pressure of 101.3kPa, and an initial boiling point equal to 250 degrees Celsius, or any volatile organic solid or liquid at room temperature and pressure). It refers to the use of solid-phase adsorbents at room temperature or low temperature to adsorb, fix, and enrich the analyte in the gas, and then heat the solid-phase adsorbent to desorb the adsorbed analyte from it and be carried away by the carrier gas. The thermal desorption method has commercial thermal desorbers, which are generally used in conjunction with gas chromatographs to heat and desorb the analyte adsorbed by the solid-phase adsorbent, and then enter the gas chromatograph for separation and detection. Since thermal desorption technology itself has few disadvantages, it is also the most mainstream method for detecting volatile organic compounds. The so-called disadvantages mainly depend on the design of each product model itself.

[0003] The internal standard method is also a commonly used method for detecting volatile organic compounds. It refers to adding a substance with a fixed concentration, which will never exist in the sample and has properties similar to the substance to be tested, to the sample to be tested. Then, the sample containing the internal standard is subjected to chromatographic analysis, and the peak area (or peak height) and relative correction factor of the internal standard and the component to be tested are measured respectively. The concentration of the component to be tested in the sample can be calculated according to the formula. The internal standard method is a relatively accurate quantitative method in chromatographic analysis. When using a mass spectrometer, the internal standard method is usually used for quantification.

[0004] There are many thermal desorption equipment on the market, but there are two companies with the most competitive products in terms of performance: PERKINELMER Company of the United States (hereinafter referred to as PE Company) and MARKES Company of the United Kingdom.

[0005] The main deficiencies of PE company's thermal desorption products are as follows:

[0006] (11) Basically, it can only analyze VOCs in adsorption tubes (stainless steel tubes or quartz tubes of about 6mm×9cm, filled with solid adsorbents, which can efficiently adsorb VOCs in the gas; after the collection is completed, the adsorption tubes are sent back to the laboratory and placed in a thermal desorber to analyze the VOCs in them), but cannot "cross-border" analyze sampling cans (the cans are evacuated before sampling, and the gas samples are drawn into and sealed during sampling, and sent back to the laboratory for online detection of the VOCs content in the gas; the method of analyzing sampling cans at home and abroad used to mainly use liquid nitrogen condensation to enrich VOCs, which is broadly classified as thermal desorption. Few people usually classify it as thermal desorption, so the term "cross-border" is used);

[0007] (12) When analyzing the adsorption tube, the sample cannot be automatically injected, that is, the sample tube filled with the solid phase adsorbent cannot be automatically loaded and unloaded, resulting in low detection efficiency and a large amount of manual work;

[0008] (13) There is no built-in dehydration module. When the water content of the collected sample is high, it cannot be effectively dehydrated, which can easily affect the accuracy of the measurement results and even cause damage to the instrument;

[0009] (14) The system is not highly inert and cannot analyze highly active volatile organic compounds (such as methyl mercaptan);

[0010] (15) The split flow control is inaccurate, and the VOCs content in the adsorption tube sample cannot be accurately calculated or reversed by the difference in split ratio;

[0011] (16) The additional internal standard filling module uses a quantitative loop (1 mL) for sample injection. Due to its small volume, a high concentration of internal standard gas is required. In the process of filling the quantitative loop, the excess internal standard gas will be exhausted and cause pollution. In addition, the flow rate of the internal standard gas is uncontrollable, resulting in high consumption and obvious waste.

[0012] The thermal desorption products of MARKES have the following main shortcomings:

[0013] (21) Although it is possible to cross-border collect samples in sampling cans and to select dehydration capabilities, these are independent optional instruments (independent devices, not modules or components inside the instrument), which not only take up space and reduce the integrity of the instrument, but also have the disadvantage of high cost;

[0014] (22) The actual insulation effect of the heating component of the adsorption tube is poor, and the upper temperature limit is generally just over 300°C, which is much lower than the claimed 450°C. In addition, the heating zone will naturally cool down between the analysis of the samples before and after, and will not start to heat up until the next sample is analyzed. If the set temperature is 300°C or above, it will take about 10 minutes to heat up, which affects the analysis efficiency. In addition, when the current sample is being analyzed, the next sample (adsorption tube) is also waiting near the heating zone, which can easily cause the waiting adsorption tube to heat up (usually 5-15°C). If the VOCs enriched in the adsorption tube contain substances that are difficult to capture and easy to diffuse, these substances can only be barely adsorbed and fixed on the solid adsorbent at room temperature. After the adsorption tube is heated, they are easily desorbed and lost.

[0015] (23) When the adsorption tube is placed on the automatic sampler, the MARKES patented DiffLok sealing caps must be installed at both ends of the tube. This sealing cap adopts a one-way ventilation design, but in fact the sealing effect is poor. After the adsorption tube is installed with the DiffLok cap and before analysis, the adsorbed VOCs are easily lost (for the reasons mentioned above), and it is easy to introduce contamination;

[0016] (24) Similar to the products of PE companies, the diversion flow control is not accurate, and even the standard configuration is to manually adjust the diversion flow, making it difficult to switch between high and low concentration curves.

[0017] In addition to the above two foreign manufacturers, there are also many domestic thermal desorber manufacturers, most of which imitate PE to varying degrees. Although some manufacturers have made some improvements based on PE, they have the defects of PE caused by the imitation design itself to varying degrees, and the workmanship is obviously different from PE equipment, and the stability of the components is not as good. Therefore, their performance and stability are difficult to exceed PE. Summary of the invention

[0018] In order to solve the problems of the existing thermal desorber that cannot automatically load and unload adsorption tubes and the large manual workload, the present invention aims to provide an automatic sample injector for a fully automatic thermal desorber and a working method thereof and a fully automatic thermal desorber.

[0019] The technical solution adopted by the present invention is:

[0020] An automatic sample injector for a fully automatic thermal desorber, comprising a main body support, a tray assembly, a Z-axis assembly, an X-axis assembly, a Y-axis assembly, a beam assembly, a cover removal assembly, a loading assembly and a valve island assembly, wherein the Z-axis is a vertical axis, the X-axis is a horizontal horizontal axis, and the Y-axis is a horizontal longitudinal axis;

[0021] The tray assembly is arranged on the tray station of the main support and is used to hold a plurality of adsorption tubes;

[0022] The Z-axis assembly is arranged on the main support and located above the tray assembly, and is used to vertically extract the adsorption tube from the tray assembly, and vertically place the adsorption tube into the tray assembly;

[0023] The X-axis assembly is arranged on the main support and located above the tray assembly, and is used to drive the Z-axis assembly to perform horizontal reciprocating motion in the area above the tray assembly;

[0024] The Y-axis assembly is arranged on the main support and located above the tray assembly, and is used to drive the X-axis assembly to perform horizontal and longitudinal reciprocating motion in the upper area of ​​the tray assembly, and to enable the Z-axis assembly to reach the handover position of the main support;

[0025] The crossbeam assembly is arranged on the main support and includes a crossbeam stepper motor, a first belt, a crossbeam ball screw, a two-claw lifting cylinder and a two-claw cylinder, wherein the crossbeam stepper motor is connected to the crossbeam ball screw through the first belt transmission, and is used to drive the movable part of the crossbeam ball screw to perform horizontal and lateral reciprocating motion, and to make the movable part of the crossbeam ball screw pass through the handover station, the cover removal station, the loading station and the waiting station of the main support in a single trip, the two-claw lifting cylinder is arranged on the movable part of the crossbeam ball screw, and the two-claw cylinder is arranged on the movable part of the two-claw lifting cylinder, and is used to drive the two-claw cylinder to perform vertical reciprocating motion, and the two-claw cylinder is arranged with two claw fingers for clamping or releasing the middle part of the adsorption tube;

[0026] The cap removal assembly is arranged at the cap removal station of the main support, and is used to remove the caps located at both ends of the adsorption tube in the vertical direction, and to cover the caps on the corresponding ends;

[0027] The loading assembly is arranged on the loading station of the main frame and includes an air circuit upper joint, an air circuit lower joint and a loading cylinder, wherein the air circuit upper joint and the air circuit lower joint are arranged opposite to each other up and down, and the air circuit lower joint is arranged on the movable part of the loading cylinder for driving the air circuit lower joint to perform vertical reciprocating motion;

[0028] The valve island assembly is arranged on the main body support and is used to supply air to each cylinder.

[0029] Optimally, the pallet assembly includes a fixed plate, a pallet driving cylinder and a pallet, wherein the pallet driving cylinder is arranged on the fixed plate, and the pallet is arranged on the movable part of the pallet driving cylinder for driving the pallet to perform horizontal linear reciprocating motion between the pallet station to the loading station, and the pallet is used to hold a plurality of the adsorption tubes.

[0030] Further optimized, the tray assembly also includes a plurality of pipe-lifting cylinders corresponding to each adsorption tube loading position, wherein the pipe-lifting cylinders are arranged at the bottom of the tray and are used to lift up the corresponding adsorption tubes through the movable part.

[0031] Optimized, the Z-axis assembly includes a Z-axis assembly mounting plate, a three-claw lifting cylinder and a three-claw cylinder, wherein the three-claw lifting cylinder is arranged on the Z-axis assembly mounting plate, the three-claw cylinder is arranged on the movable part of the three-claw lifting cylinder, and is used to drive the three-claw cylinder to perform vertical reciprocating motion, and the three-claw cylinder is arranged with three claws for grasping the upper end of the adsorption tube.

[0032] Optimized, the X-axis assembly includes an X-axis stepper motor, a second belt and an X-axis ball screw, wherein the X-axis stepper motor is connected to the X-axis ball screw through the second belt transmission, and is used to drive the active part of the X-axis ball screw to perform horizontal lateral reciprocating motion, and the Z-axis assembly is arranged on the active part of the X-axis ball screw.

[0033] Optimized, the Y-axis assembly includes a Y-axis stepper motor, a third belt and a Y-axis ball screw, wherein the Y-axis stepper motor is connected to the Y-axis ball screw through the third belt transmission, and is used to drive the active part of the Y-axis ball screw to perform horizontal and longitudinal reciprocating motion, and the X-axis assembly is arranged on the active part of the Y-axis ball screw.

[0034] Optimally, a laser beam switch is arranged below the handover station, wherein the laser beam switch comprises a transmitter and a receiver for detecting whether a lower end cap of the adsorption tube is present.

[0035] Another technical solution adopted by the present invention is:

[0036] A working method of an automatic sampler, wherein the automatic sampler is the automatic sampler for a fully automatic thermal desorber as described above, including an automatic adsorption tube installation process, wherein the automatic adsorption tube installation process includes the following steps:

[0037] S101. Grasping the adsorption tube: moving the Z-axis assembly to the top of the target adsorption tube loading position through the X-axis assembly and the Y-axis assembly, and then extracting the adsorption tube at the target adsorption tube loading position vertically from the tray assembly through the Z-axis assembly;

[0038] S102. Handover of the adsorption tube: Move the Z-axis assembly and the adsorption tube to the handover station through the X-axis assembly and the Y-axis assembly, and then move the two-claw lifting cylinder and the two-claw cylinder to the handover station through the crossbeam stepper motor and the crossbeam ball screw, and then make the two claws in a clamping state and clamp the middle of the adsorption tube through the two-claw cylinder, and then release the adsorption tube from the Z-axis assembly, and finally move the two-claw cylinder and the adsorption tube downward through the two-claw lifting cylinder, so that the adsorption tube is out of the grasping range of the Z-axis assembly;

[0039] S103. Remove the cap of the adsorption tube: Move the two-claw lifting cylinder and the two-claw cylinder and the adsorption tube to the cap removal station through the crossbeam stepper motor and the crossbeam ball screw, and then remove the cap of the adsorption tube and the caps at both ends of the vertical direction by removing the cap assembly;

[0040] S104. Loading of the adsorption tube: Move the two-claw lifting cylinder, the two-claw cylinder and the adsorption tube to the loading station through the crossbeam stepper motor and the crossbeam ball screw, then lift the two-claw cylinder and the adsorption tube through the two-claw lifting cylinder, insert the upper joint of the air path into the upper port of the adsorption tube, then lift the lower joint of the air path through the loading cylinder, insert the lower joint of the air path into the lower port of the adsorption tube, then release the two claws through the two-claw cylinder, finally move the two-claw lifting cylinder and the two-claw cylinder to the waiting station through the crossbeam stepper motor and the crossbeam ball screw.

[0041] Optimally, after the adsorption tube automatic installation process, an adsorption tube automatic unloading process is also included, wherein the adsorption tube automatic unloading process includes the following steps:

[0042] S201. Unloading of the adsorption tube: Move the two-claw lifting cylinder, the two-claw cylinder and the adsorption tube to the loading station through the crossbeam stepper motor and the crossbeam ball screw, and then use the two-claw cylinder to make the two claws in a clamping state and clamp the middle of the adsorption tube, and then move the lower joint of the air circuit downward through the loading cylinder to pull out the lower port of the adsorption tube, and then move the two-claw cylinder and the adsorption tube downward through the two-claw lifting cylinder to pull out the upper port of the adsorption tube through the air circuit joint;

[0043] S202. Capping the adsorption tube: The two-claw lifting cylinder and the two-claw cylinder and the adsorption tube are moved to the cap-taking station by the crossbeam stepper motor and the crossbeam ball screw, and then the cap is covered on both ends of the adsorption tube vertically by the cap-taking assembly;

[0044] S203. Return of the adsorption tube: Move the two-claw lifting cylinder and the two-claw cylinder and the adsorption tube to the handover station through the crossbeam stepper motor and the crossbeam ball screw, and then move the Z-axis assembly to the handover station through the X-axis assembly and the Y-axis assembly, and then lift the two-claw cylinder and the adsorption tube through the two-claw lifting cylinder, so that the adsorption tube is in the grasping range of the Z-axis assembly, and then grasp the upper end of the adsorption tube through the Z-axis assembly, and finally release the two claws through the two-claw cylinder;

[0045] S204. Putting back the adsorption tube: Move the Z-axis assembly and the adsorption tube to the top of the target adsorption tube loading position through the X-axis assembly and the Y-axis assembly, and then vertically place the adsorption tube into the tray assembly through the Z-axis assembly, and finally release the adsorption tube through the Z-axis assembly.

[0046] Another technical solution adopted by the present invention is:

[0047] A fully automatic thermal desorber, comprising the automatic sample injector for the fully automatic thermal desorber as described above, and also comprising a gas circuit assembly and a circuit assembly arranged on the main body support;

[0048] The gas circuit assembly includes a nitrogen connector, a first mass flow controller, a second mass flow controller, a multi-way switching valve, a first solenoid switching valve, a second solenoid switching valve, a first drain connector, a second drain connector, a third drain connector, a sample recovery tube, an eight-way switching valve, a temperature-controlled dehydration tube, a temperature-controlled focusing tube, a carrier gas inlet and outlet pipeline, a proportional valve and a pressure sensor;

[0049] The nitrogen connector is connected to the input port of the first mass flow controller, the output port of the first mass flow controller is respectively connected to the second interface of the multi-way switching valve, the normally closed port of the first electromagnetic switching valve and the normally open port of the second electromagnetic switching valve, the normally open port of the first electromagnetic switching valve is connected to the first emptying connector, the common port of the first electromagnetic switching valve is connected to one of the upper connector on the gas circuit and the lower connector on the gas circuit, the other of the upper connector on the gas circuit and the lower connector on the gas circuit is connected to the first interface of the multi-way switching valve, and the third interface of the multi-way switching valve is respectively connected to the first port of the sample recovery tube and the first interface of the eight-way switching valve;

[0050] The second port of the sample recovery tube is connected to the input port of the proportional valve, the air pressure sensor is arranged in the air path between the second port of the sample recovery tube and the input port of the proportional valve, and the output port of the proportional valve is connected to the second drain connector;

[0051] The second interface of the eight-way switching valve is connected to the first port of the temperature-controlled dehydration tube, the second port of the temperature-controlled dehydration tube is connected to the eighth interface of the eight-way switching valve, the seventh interface of the eight-way switching valve is connected to the first port of the temperature-controlled focusing tube, the second port of the temperature-controlled focusing tube is connected to the fourth interface of the eight-way switching valve, the fifth interface of the eight-way switching valve is connected to the inlet pipeline of the carrier gas inlet and outlet pipelines, the sixth interface of the eight-way switching valve is connected to the outlet pipeline of the carrier gas inlet and outlet pipelines, and the third interface of the eight-way switching valve is connected to the common port of the second electromagnetic switching valve;

[0052] The normally closed port of the second electromagnetic switching valve is connected to the input port of the second mass flow controller, and the output port of the second mass flow controller is connected to the third drain connector;

[0053] The circuit assembly includes an adsorption tube temperature control assembly arranged on the loading station and used for temperature controlling the adsorption tube.

[0054] Optimized, the adsorption tube temperature control assembly includes a temperature control assembly mounting plate, an ultra-thin cylinder and an electric heating block, wherein the ultra-thin cylinder is arranged on the temperature control assembly mounting plate, the electric heating block is arranged on the movable part of the ultra-thin cylinder for driving the electric heating block to perform horizontal transverse reciprocating motion, and the electric heating block is arranged with a U-shaped groove for semi-enclosing the adsorption tube.

[0055] The beneficial effects of the present invention are:

[0056] (1) The invention provides a novel automatic mechanism and working method for automatically injecting and discharging adsorption tubes in a fully automatic thermal desorber by combining electric and pneumatic methods. That is, on the one hand, by arranging the Z-axis assembly, the X-axis assembly and the Y-axis assembly, the adsorption tube grabbing and sample delivery actions and the adsorption tube putting back actions can be performed in the upper area of ​​the tray assembly. On the other hand, by arranging the crossbeam assembly, the cap removal assembly, the loading assembly and the valve island assembly, the adsorption tubes delivered can be successively handled, capped, loaded, unloaded, capped and returned. The complete injection and sample discharging actions are particularly suitable for fully automatic thermal desorbers, greatly reducing the manual workload, saving time and labor;

[0057] (2) It can provide up to 120 adsorption tubes with automatic injection capacity, saving manpower to the maximum extent: the maximum injection position of thermal desorbers of other manufacturers is 100, and most of them do not exceed 50. Generally speaking, the average analysis time of a sample is 25-45 minutes. Based on an average of 35 minutes, it takes 70 hours to analyze 120 samples. If a unit gets off work at 17:00 on Friday and returns to work at 9:00 on Monday, there will be a 64-hour unmanned period in between, which can basically ensure that "people rest, but instruments do not rest" to achieve the highest efficiency.

[0058] (3) The automatic sampler also has the advantages of convenient loading / unloading, high grabbing success rate, automatic error detection, simple structure and easy implementation, which is convenient for practical application and promotion;

[0059] (4) In addition to achieving the purpose of fully automatic sampling and thermal desorption analysis, a new thermal desorber structure is provided that can be used with a gas chromatograph to complete volatile organic compound analysis and detection. In the desorption stage, two mass flow controllers and a proportional valve are opened, and the flow rates of the two mass flow controllers are set according to the target split ratio, and the ratio of the flow rate of the proportional valve to the flow rate of the evacuation mass flow controller is controlled to meet the target split ratio, so that VOCs can be quantitatively adsorbed in the focusing tube and the sample recovery tube according to the target split ratio. Then, a purge stage and a sampling analysis stage are performed. In this way, not only accurate split control can be achieved, but also the analysis results can be converted to each other under different split ratios, so that the analysis results of the sample recovery tube can be qualitatively and quantitatively analyzed, which greatly increases the fault tolerance of the thermal desorber, thereby avoiding repeated sampling, facilitating the detection of volatile organic compounds, and further facilitating practical application and promotion.

[0060] (5) The fully automatic thermal desorber can analyze adsorption tubes, sampling cans (i.e., Suma cans) or air bags, achieving the purpose of multiple uses of one device, so that it can respond to and analyze all VOCs listed in the thermal desorption method standards (including organic sulfur and n-hexadecane), and can also analyze all VOCs in the volatile organic compound monitoring program for key areas promulgated by the state. That is, the former is the application of adsorption tubes, and the latter is the application of sampling cans. Both of them basically cover all VOCs at home and abroad. It is a comprehensive design, which greatly expands the scope of application of the fully automatic thermal desorber;

[0061] (6) The built-in temperature-controlled dehydration pipe can effectively eliminate the influence of moisture, and compared with the independent dehydration equipment solution adopted by the British MARKES company, it is simpler and more convenient to use;

[0062] (7) Since the temperature-controlled dehydration tube and the temperature-controlled focusing tube both use electronic refrigeration technology, no liquid nitrogen or other refrigerants are required, which is economical and affordable. That is, if a VOCs pre-concentrator (analysis sampling tank) is used for liquid nitrogen refrigeration, there is obviously a problem of high cost of use. 1,200 yuan of liquid nitrogen can only analyze about 50 samples, and the liquid nitrogen tank also costs thousands to more than 10,000 yuan. In comparison, electronic refrigeration components only consume electricity and the power is not high. In addition, liquid nitrogen replenishment and replacement are more troublesome, and it is easy to fail to replace it in time, resulting in delays in sample analysis time. Some third- and fourth-tier cities do not even have liquid nitrogen manufacturers;

[0063] (8) Due to the fully inert and temperature-controlled VOCs flow path, it can ensure the minimum VOCs residue;

[0064] (9) It can be used with a sampling tank automatic sampler or an internal standard gas tank with an internal standard gas level to collect the internal standard gas, so as to achieve the purpose of using the internal standard method or the external standard method for detection and analysis, further expanding the scope of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0066] Figure 1 It is a schematic diagram of the split structure of the main body support and the tray assembly, the Z-axis assembly, the X-axis assembly and the Y-axis assembly in the automatic sample injector provided by the present invention.

[0067] Figure 2 It is a schematic diagram of the split structure of the main body support and beam assembly, cover removal assembly, loading assembly, valve island assembly and adsorption tube temperature control assembly in the automatic sample injector provided by the present invention.

[0068] Figure 3 The present invention is a schematic flow chart of the working method of the automatic sample injector provided by the present invention.

[0069] Figure 4 The present invention is a schematic diagram of the structure of the gas path assembly and peripheral equipment in the fully automatic thermal desorption instrument.

[0070] In the above drawings: 1-nitrogen connector; 201-first mass flow controller; 202-second mass flow controller; 3-multi-way switching valve; 402-first electromagnetic switching valve; 402-second electromagnetic switching valve; 403-third electromagnetic switching valve; 501-first emptying connector; 502-second emptying connector; 503-third emptying connector; 6-adsorption tube; 7-sample recovery tube; 8-eight-way switching valve; 9-temperature-controlled dehydration tube; 10-temperature-controlled focusing tube; 11-carrier gas inlet and outlet pipeline; 12-proportional valve; 13-pressure sensor; 141-adsorption tube temperature control assembly; 1411-temperature control assembly mounting plate; 1412-ultra-thin cylinder; 1413-electric heating block; 142-dehydration tube port temperature control unit; 143-focusing tube port temperature control unit; 144-central temperature control unit; 145-carrier temperature control unit; 146-intake temperature control unit; 15-intake connector; 16-air pump; 17-internal standard intake connector; 18-solenoid valve; 19-first storage box; 20-second storage box; 21-first speed control valve; 22-second speed regulating valve; 23-trap; 24-three-way connector; 30-compressed air connector; 50-connecting vessel; 100-main frame; 110-tray assembly; 1101-fixing plate; 1102-tray drive cylinder; 1103-tray; 120-Z axis assembly; 1201-Z axis assembly mounting plate; 1202-three-claw lifting cylinder; 1203-three-claw cylinder; 130-X axis assembly; 1301-X axis stepping motor; 1303-X axis ball screw; 140- Y-axis assembly; 1401-Y-axis stepper motor; 1403-Y-axis ball screw; 150-crossbeam assembly; 1501-crossbeam stepper motor; 1503-crossbeam ball screw; 1504-two-claw lifting cylinder; 1505-two-claw cylinder; 160-cap removal assembly; 170-loading assembly; 1702-gas line lower connector; 1703-loading cylinder; 180-valve island assembly; 200-nitrogen bottle; 300-gas chromatograph; 400-sampling tank automatic sampler; 500-compressed air bottle. DETAILED DESCRIPTION

[0071] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that although the description of these embodiments is used to help understand the present invention, it does not constitute a limitation of the present invention. The specific structures and functional details disclosed herein are only used to describe the exemplary embodiments of the present invention. However, the present invention can be embodied in many alternative forms, and it should not be understood that the present invention is limited to the embodiments set forth herein.

[0072] It should be understood that although the terms first, second, etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another unit. For example, a first unit can be referred to as a second unit, and similarly, a second unit can be referred to as a first unit without departing from the scope of the exemplary embodiments of the present invention.

[0073] It should be understood that the term "and / or" that may appear in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" that may appear in this article describes another type of association object relationship, indicating that two relationships may exist. For example, A / and B can represent two situations: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0074] It should be understood that when an element is referred to herein as being "connected," "connected," or "coupled" to another element, it can be directly connected or coupled to the other element, or intermediate elements can exist. Conversely, when an element is referred to herein as being "directly connected" or "directly coupled" to another element, no intermediate elements are present. Additionally, other words used to describe the relationship between elements (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.) should be interpreted in a similar manner.

[0075] It should be understood that the terms used herein are only used to describe specific embodiments and are not intended to limit the exemplary embodiments of the present invention. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that when the terms "include", "comprises", "includes", and / or "comprising" are used herein, they specify the existence of the claimed features, integers, steps, operations, units, and / or components, and do not exclude the existence or addition of one or more other features, quantities, steps, operations, units, components, and / or their combinations.

[0076] It should be understood and also noted that in some alternative embodiments, the functions / actions that appear may be different from the order in which the figures appear. For example, depending on the functions / actions involved, two figures shown in succession may actually be performed substantially concurrently, or may sometimes be performed in the reverse order.

[0077] It should be understood that in the following description, specific details are provided to facilitate a complete understanding of the example embodiments. However, it should be understood by those of ordinary skill in the art that the example embodiments can be implemented without these specific details. For example, the system can be shown in a block diagram to avoid obscuring the example with unnecessary details. In other examples, well-known processes, structures, and techniques may not be shown in unnecessary detail to avoid obscuring the example embodiments.

[0078] Embodiment 1

[0079] like Figures 1 to 3As shown, the automatic sample injector for the fully automatic thermal desorber provided in this embodiment includes a main support 100, a tray assembly 110, a Z-axis assembly 120, an X-axis assembly 130, a Y-axis assembly 140, a crossbeam assembly 150, a cover removal assembly 160, a loading assembly 170 and a valve island assembly 180, wherein the Z-axis is a vertical axis, the X-axis is a horizontal horizontal axis, and the Y-axis is a horizontal longitudinal axis; the tray assembly 110 is arranged on the tray station of the main support 100, and is used to hold a plurality of adsorption tubes 6; the Z-axis assembly 120 is arranged on the main support 100 and is located above the tray assembly 110, and is used to vertically extract the adsorption tube 6 from the tray assembly 110, and vertically place the adsorption tube 6 into the tray assembly 110. The tray assembly 110; the X-axis assembly 130 is arranged on the main support 100 and is located above the tray assembly 110, and is used to drive the Z-axis assembly 120 to perform horizontal lateral reciprocating motion in the upper area of ​​the tray assembly 110; the Y-axis assembly 140 is arranged on the main support 100 and is located above the tray assembly 110, and is used to drive the X-axis assembly 130 to perform horizontal longitudinal reciprocating motion in the upper area of ​​the tray assembly 110, and enable the Z-axis assembly 120 to reach the handover station of the main support 100; the crossbeam assembly 150 is arranged on the main support 100 and includes a crossbeam stepping motor 1501, a first belt, a crossbeam ball screw 1503, and two claw lifting Cylinder 1504 and two-claw cylinder 1505, wherein the crossbeam stepper motor 1501 is connected to the crossbeam ball screw 1503 through the first belt transmission, and is used to drive the active part of the crossbeam ball screw 1503 to perform horizontal lateral reciprocating motion, and to make the active part of the crossbeam ball screw 1503 pass through the handover station, cover removal station, loading station and waiting station of the main support 100 in one direction, the two-claw lifting cylinder 1504 is arranged on the active part of the crossbeam ball screw 1503, and the two-claw cylinder 1505 is arranged on the active part of the two-claw lifting cylinder 1504, and is used to drive the two-claw cylinder 1505 to perform vertical reciprocating motion, and the two-claw cylinder 1505 is arranged with a pneumatic device for clamping or releasing The two claws are placed in the middle of the adsorption tube 6; the cover removal assembly 160 is arranged on the cover removal station of the main support 100, and is used to remove the caps of the adsorption tube 6 and located at the two vertical ends, and to cover the caps on the corresponding ends; the loading assembly 170 is arranged on the loading station of the main support 100 and includes an upper air circuit joint, a lower air circuit joint 1702 and a loading cylinder 1703, wherein the upper air circuit joint and the lower air circuit joint 1702 are arranged opposite to each other up and down, and the lower air circuit joint 1702 is arranged on the movable part of the loading cylinder 1703, which is used to drive the lower air circuit joint 1702 to perform vertical reciprocating motion; the valve island assembly 180 is arranged on the main support 100, and is used to supply air to each cylinder.

[0080] like Figures 1-2 As shown, in the specific structure of the automatic sampler, the main frame 100 is used as the reference frame of the entire fully automatic thermal desorber, and is used to install and support the tray assembly 110, the Z-axis assembly 120, the X-axis assembly 130, the Y-axis assembly 140, the beam assembly 150, the cover removal assembly 160, the loading assembly 170, the valve island assembly 180, and other assemblies of the fully automatic thermal desorber, such as the gas circuit assembly and the circuit assembly. The tray assembly 110 is used to hold a plurality of the adsorption tubes 6 so that they can be grabbed by the Z-axis assembly 120. For example, 120 adsorption tube holding positions can be provided, so as to realize automatic sampling and thermal desorption detection of 120 adsorption tubes 6 in batches. The Z-axis assembly 120 is used to achieve the purpose of grabbing and putting back the adsorption tubes. The X-axis assembly 130 and the Y-axis assembly 140 are used to horizontally move the Z-axis assembly 120 and the adsorption tube 6 between the adsorption tube loading position and the handover station, so that the Z-axis assembly 120 can perform the adsorption tube handover operation with the crossbeam assembly 150 at the handover station.

[0081] The crossbeam assembly 150 is used to horizontally and linearly move the two-claw lifting cylinder 1504 and the two-claw cylinder 1505 / and the adsorption tube 6 between the handover station, the capping station, the loading station and the waiting station through the crossbeam stepper motor 1501 and the crossbeam ball screw 1503, so as to perform the adsorption tube handover action with the Z-axis assembly 120 at the handover station, perform the adsorption tube capping or capping action through the capping assembly 160 at the capping station, perform the adsorption tube loading or unloading action through the loading assembly 170 at the loading station, and wait for the completion of thermal desorption method detection at the waiting station. In the specific structure of the crossbeam assembly 150, the linear drive mechanism composed of the crossbeam stepper motor 1501, the first belt and the crossbeam ball screw 1503 is an existing conventional structure, and the two-claw lifting cylinder 1504 is used to lift or move the two-claw cylinder 1505 and the adsorption tube 6 downward, so as to remove the adsorption tube 6 from the Z-axis assembly 120 or lift it to the Z-axis assembly 120, and insert or withdraw the joint on the air path into the upper port of the adsorption tube 6; the two-claw lifting cylinder 1504 can be, but not limited to, an existing rodless cylinder or a slide cylinder. The two-claw cylinder 1505 is used to switch the working state of the two claws: clamping state and loosening state, so as to complete the corresponding actions at the handover station and the loading station; the two-claw cylinder 1505 can also be implemented by an existing cylinder structure.

[0082] The capping assembly 160 is used to open / close the two vertical ports of the adsorption tube 6 at the capping station, so that the two vertical ports of the adsorption tube 6 are connected to the gas line joint and the gas line lower joint 1702 respectively at the loading station, which can be realized by the existing capping mechanism. The loading assembly 170 is used to load the adsorption tube 6 into the gas line assembly of the fully automatic thermal desorber at the loading station, or to unload the adsorption tube 6 from the gas line assembly, wherein the gas line joint and the gas line lower joint 1702 are connected to the corresponding ports of the gas line assembly respectively, and the loading cylinder 1703 is used to lift or move the gas line lower joint 1702 downward, so that the gas line lower joint 1702 is inserted into or pulled out of the lower port of the adsorption tube 6; the loading cylinder 1703 can be, but is not limited to, an existing rodless cylinder or a slide cylinder. The valve island assembly 180 is used to connect to an external compressed air bottle, so as to supply air to each cylinder and drive them to complete corresponding actions. Specifically, the valve island assembly 180 includes a low-pressure valve island and a high-pressure valve island, wherein the air supply output end of the low-pressure valve island is connected to the air supply input end of the loading cylinder 1703, and the air supply output end of the high-pressure valve island is respectively connected to the air supply input ends of the two-claw lifting cylinder 1504 and the two-claw cylinder 1505.

[0083] Thus, through the detailed structural description of the aforementioned automatic sample injector, a new type of automation mechanism is provided which combines electric and pneumatic methods to realize automatic sample injection and sample removal of adsorption tubes in a fully automatic thermal desorber, that is, on the one hand, by arranging the Z-axis assembly 120, the X-axis assembly 130 and the Y-axis assembly 140, the adsorption tube grabbing and sample delivery actions and the adsorption tube putting back actions can be performed in the upper area of ​​the tray assembly 110, and on the other hand, by arranging the crossbeam assembly 150, the cap removal assembly 160, the loading assembly 170 and the valve island assembly 180, the adsorption tubes delivered can be sequentially subjected to complete sample injection and sample removal actions such as handover, cap removal, loading, unloading, capping and handing back, so that it is particularly suitable for a fully automatic thermal desorber, greatly reduces the manual workload, saves time and effort, and is convenient for practical application and promotion.

[0084] Further optimized, the specific working method of the automatic sample injector includes an automatic installation process of the adsorption tube and an automatic unloading process of the adsorption tube in sequence.

[0085] The optimized automatic adsorption tube installation process may include but is not limited to the following steps S101 to S104: S101. Grasping the adsorption tube: Move the Z-axis assembly 120 to the top of the target adsorption tube loading position (corresponding to the X-axis coordinate, the Y-axis coordinate and the Z-axis coordinate) through the X-axis assembly 130 and the Y-axis assembly 140, and then vertically extract the adsorption tube 6 at the target adsorption tube loading position from the tray assembly 110 through the Z-axis assembly 120; S102. Handover of the adsorption tube: Move the Z-axis assembly 120 to the top of the target adsorption tube loading position (corresponding to the X-axis coordinate, the Y-axis coordinate and the Z-axis coordinate) through the X-axis assembly 130 and the Y-axis assembly 140; S103. 30 and Y-axis assembly 140 move Z-axis assembly 120 and adsorption tube 6 to the handover station, and then move two-claw lifting cylinder 1504 and two-claw cylinder 1505 to the handover station through crossbeam stepper motor 1501 and crossbeam ball screw 1503, and then make two claws in a clamping state and clamp the middle of adsorption tube 6 through two-claw cylinder 1505, and then make Z-axis assembly 120 release adsorption tube 6, and finally move two-claw cylinder 1505 and adsorption tube 6 downward through two-claw lifting cylinder 1504 to make adsorption tube 6 detached The grasping range of the Z-axis assembly 120; S103. Removing the cap of the adsorption tube: The two-claw lifting cylinder 1504, the two-claw cylinder 1505 and the adsorption tube 6 are moved to the cap removal station by the crossbeam stepper motor 1501 and the crossbeam ball screw 1503, and then the caps of the adsorption tube 6 and located at both ends of the vertical direction are removed by the cap removal assembly 160; S104. Loading the adsorption tube: The two-claw lifting cylinder 1504, the two-claw cylinder 1505 and the adsorption tube 6 are moved to the loading station by the crossbeam stepper motor 1501 and the crossbeam ball screw 1503. The two-claw cylinder 1505 and the adsorption tube 6 are then lifted by the two-claw lifting cylinder 1504, so that the upper joint of the air circuit is inserted into the upper port of the adsorption tube 6; the lower joint 1702 of the air circuit is lifted by the loading cylinder 1703, so that the lower joint 1702 of the air circuit is inserted into the lower port of the adsorption tube 6; the two-claw cylinder 1505 is used to release the two claws; finally, the two-claw lifting cylinder 1504 and the two-claw cylinder 1505 are moved to the waiting position by the crossbeam stepper motor 1501 and the crossbeam ball screw 1503. Regardless of whether the fully automatic thermal desorber is in thermal desorption mode or sampling tank mode (i.e., VOCs detection with the Suma tank automatic sampler), the aforementioned steps S101 to S104 can be used to load the adsorption tube (in thermal desorption mode at this time) or the empty tube (i.e., when the sampling tank mode is started, the empty tube is loaded into the gas circuit assembly as the adsorption tube) into the gas circuit assembly, so that the fully automatic thermal desorber can normally perform VOCs detection in the corresponding mode. In addition, before the step S102, the two-claw lifting cylinder 1504 needs to be returned to the following position: lift the two-claw cylinder 1505; and the two-claw cylinder 1505 needs to be returned to the following position: release the two claws.

[0086] The automatic unloading process of the adsorption tube can be optimized in detail, but is not limited to the following steps: S201. Unloading of the adsorption tube: Move the two-claw lifting cylinder 1504 and the two-claw cylinder 1505 and the adsorption tube 6 to the loading station through the crossbeam stepper motor 1501 and the crossbeam ball screw 1503, and then use the two-claw cylinder 1505 to make the two claws in a clamping state and clamp the middle of the adsorption tube 6, and then move the lower joint 170 of the air circuit downward through the loading cylinder 1703. 2. Make the lower joint 1702 of the air circuit pull out the lower end of the adsorption tube 6, and then move the two-claw cylinder 1505 and the adsorption tube 6 downward through the two-claw lifting cylinder 1504, so that the upper joint of the air circuit pulls out the upper end of the adsorption tube 6; S202. Capping the adsorption tube: Move the two-claw lifting cylinder 1504 and the two-claw cylinder 1505 and the adsorption tube 6 to the capping station through the crossbeam stepping motor 1501 and the crossbeam ball screw 1503, and then cover the cap on the adsorption tube through the capping assembly 160 6 at both ends of the vertical; S203. Return of the adsorption tube: Move the two-claw lifting cylinder 1504 and the two-claw cylinder 1505 and the adsorption tube 6 to the handover station through the crossbeam stepper motor 1501 and the crossbeam ball screw 1503, and then move the Z-axis assembly 120 to the handover station through the X-axis assembly 130 and the Y-axis assembly 140, and then lift the two-claw cylinder 1504 and the adsorption tube 6 through the two-claw lifting cylinder 1505, so that the adsorption tube 6 is in the grasping position of the Z-axis assembly 120 Take the range, then grab the upper end of the adsorption tube 6 through the Z-axis assembly 120, and finally release the two claws through the two-claw cylinder 1505; S204. Put back the adsorption tube: move the Z-axis assembly 120 and the adsorption tube 6 to the top of the target adsorption tube loading position through the X-axis assembly 130 and the Y-axis assembly 140, and then vertically put the adsorption tube 6 into the tray assembly 110 through the Z-axis assembly 120, and finally release the adsorption tube 6 by the Z-axis assembly 120. Regardless of whether the fully automatic thermal desorber is in the thermal desorption mode or the sampling tank mode (i.e., VOCs detection is performed in conjunction with the Suma tank automatic sampler), the aforementioned steps S201 to S204 can be used to unload the adsorption tube (in the thermal desorption mode at this time) or the empty tube (i.e., when the sampling tank mode is ended, the empty tube is unloaded from the gas circuit assembly as the adsorption tube) from the gas circuit assembly, so that the fully automatic thermal desorber can normally end the VOCs detection in the corresponding mode.

[0087] Optimally, the tray assembly 110 includes a fixed plate 1101, a tray driving cylinder 1102 and a tray 1103, wherein the tray driving cylinder 1102 is arranged on the fixed plate 1101, and the tray 1103 is arranged on the movable part of the tray driving cylinder 1102, which is used to drive the tray 1103 to perform horizontal linear reciprocating motion between the tray station and the loading station, and the tray 1103 is used to hold a plurality of the adsorption tubes 6. Figure 1As shown, the tray driving cylinder 1102 is used to horizontally move the tray 1103 between the tray station and the loading station, so as to manually load and remove the adsorption tubes in batches at the loading station, which is convenient for loading and unloading; the tray driving cylinder 1102 can be, but is not limited to, an existing rodless cylinder or a slide cylinder. In addition, the air supply input end of the tray driving cylinder 1102 is connected to the air supply output end of the high-pressure valve island.

[0088] Further optimized, the tray assembly 110 also includes a plurality of pipe-pushing cylinders corresponding to each adsorption tube loading position, wherein the pipe-pushing cylinder is arranged at the bottom of the tray 1103, and is used to lift up the corresponding adsorption tube 6 through the movable part. By arranging the pipe-pushing cylinder (not shown in the attached figure), before the Z-axis assembly 120 grabs the adsorption tube at the target adsorption tube loading position, the corresponding adsorption tube can be lifted up through the movable part for grabbing, thereby avoiding the dragging of the grabbing process and improving the success rate of grabbing; and before the adsorption tube is put back, the movable part of the pipe-pushing cylinder needs to be moved down to its position so that the adsorption tube can return unimpeded; the pipe-pushing cylinder can also be implemented by using the existing cylinder structure. In addition, specifically, the air supply input end of the pipe-pushing cylinder is connected to the air supply output end of the high-pressure valve island.

[0089] Optimally, the Z-axis assembly 120 includes a Z-axis assembly mounting plate 1201, a three-claw lifting cylinder 1202 and a three-claw cylinder 1203, wherein the three-claw lifting cylinder 1202 is arranged on the Z-axis assembly mounting plate 1201, and the three-claw cylinder 1203 is arranged on the movable part of the three-claw lifting cylinder 1202 for driving the three-claw cylinder 1203 to perform vertical reciprocating motion, and the three-claw cylinder 1203 is arranged with three claws for grabbing the upper end of the adsorption tube 6. Figure 1 As shown, the three-claw lifting cylinder 1202 is used to lift or move the three-claw cylinder 1203 and the adsorption tube 6 downward, so as to vertically extract the adsorption tube 6 from the tray assembly 110, and vertically place the adsorption tube 6 into the tray assembly 110; the three-claw lifting cylinder 1202 can be, but is not limited to, an existing rodless cylinder or a slide cylinder, etc. The three-claw cylinder 1203 is used to switch the working states of the three claws: clamping state and releasing state, so as to complete the corresponding actions above the target adsorption tube loading position and the handover station; the three-claw cylinder 1203 can also be implemented with an existing cylinder structure. In addition, specifically, the air supply input ends of the three-claw lifting cylinder 1202 and the three-claw cylinder 1203 are respectively connected to the air supply output end of the low-pressure valve island.

[0090] To be more specific, the aforementioned Z-axis assembly 120 can, but is not limited to, vertically extract the adsorption tube 6 at the target adsorption tube filling position from the tray assembly 110 in the following steps: S1011. After the Z-axis assembly 120 moves to directly above the target adsorption tube filling position, the three claws are released by the three-claw cylinder 1203; S1012. The three-claw lifting cylinder 1202 moves the three-claw cylinder 1203 downward; S1013. The three claws are clamped by the three-claw cylinder 1203 and clamp the upper end of the adsorption tube 6; S1014. The three-claw lifting cylinder 1202 lifts the three-claw cylinder 1203 and the adsorption tube 6 to vertically extract the adsorption tube at the target adsorption tube filling position from the tray assembly 110.

[0091] To be more specific, the aforementioned Z-axis assembly 120 can, but is not limited to, vertically place the adsorption tube 6 into the tray assembly 110 according to the following steps: S2041. After the Z-axis assembly 120 and the adsorption tube 6 are moved to directly above the target adsorption tube loading position, the three-claw lifting cylinder 1202 is used to move the three-claw cylinder 1203 and the adsorption tube 6 downward to vertically place the adsorption tube 6 into the target adsorption tube loading position of the tray assembly 110; S2042. The three claws are released by the three-claw cylinder 1203; S2043. The three-claw lifting cylinder 1202 lifts the three-claw cylinder 1203.

[0092] Optimally, the X-axis assembly 130 includes an X-axis stepper motor 1301, a second belt and an X-axis ball screw 1303, wherein the X-axis stepper motor 1301 is connected to the X-axis ball screw 1303 through the second belt transmission, and is used to drive the active part of the X-axis ball screw 1303 to perform horizontal transverse reciprocating motion, and the Z-axis assembly 120 is arranged on the active part of the X-axis ball screw 1303. Figure 1 As shown, the linear drive mechanism composed of the X-axis stepper motor 1301, the second belt and the X-axis ball screw 1303 is an existing conventional structure, which can achieve the purpose of horizontally moving the Z-axis assembly 120.

[0093] Optimally, the Y-axis assembly 140 includes a Y-axis stepper motor 1401, a third belt and a Y-axis ball screw 1403, wherein the Y-axis stepper motor 1401 is connected to the Y-axis ball screw 1403 through the third belt transmission, and is used to drive the active part of the Y-axis ball screw 1403 to perform horizontal and longitudinal reciprocating motion, and the X-axis assembly 130 is arranged on the active part of the Y-axis ball screw 1403. Figure 1As shown, the linear drive mechanism composed of the Y-axis stepper motor 1401, the third belt and the Y-axis ball screw 1403 is an existing conventional structure, which can achieve the purpose of horizontally and longitudinally moving the X-axis assembly 130 and the Z-axis assembly 120.

[0094] Optimally, a laser beam switch is arranged below the handover station, wherein the laser beam switch includes a transmitter and a receiver for detecting whether the lower end cap of the adsorption tube 6 exists. By arranging the laser beam switch (not shown in the accompanying drawings), when the Z-axis assembly 120 hands over the adsorption tube (i.e., step S102 or step S203), it can be determined whether there is an adsorption tube on the Z-axis assembly 120 by detecting whether the lower end cap exists. If so, proceed to the next step, otherwise stop the corresponding process, and trigger an error signal to the control center to further improve the degree of automation. In addition, the control center is a host computer and software that controls the entire automatic sampler and each controlled module in the entire fully automatic thermal desorber (such as the valve island assembly and each stepping motor, etc.), wherein the software can provide a human-machine interface, workflow control, and cap detection algorithm, etc.

[0095] In summary, the automatic sample injector for a fully automatic thermal desorber and the working method thereof provided in this embodiment have the following technical effects:

[0096] (1) This embodiment provides a novel automated mechanism and working method for automatically injecting and discharging adsorption tubes in a fully automatic thermal desorber by combining electric and pneumatic methods. That is, on the one hand, by arranging the Z-axis assembly, the X-axis assembly and the Y-axis assembly, the adsorption tube grabbing and sample delivery actions and the adsorption tube putting back actions can be performed in the upper area of ​​the tray assembly. On the other hand, by arranging the crossbeam assembly, the cap removal assembly, the loading assembly and the valve island assembly, the adsorption tubes delivered can be sequentially transferred, capped, loaded, unloaded, capped and returned. The complete injection and sample discharging actions are particularly suitable for fully automatic thermal desorbers, greatly reducing the manual workload and saving time and effort.

[0097] (2) The automatic sampler also has the advantages of convenient loading / unloading, high grasping success rate, automatic error detection, simple structure and easy implementation, which is convenient for practical application and promotion.

[0098] Embodiment 2

[0099] like Figure 1 , 2As shown in and 4, this embodiment further provides a new type of fully automatic thermal desorber on the basis of Example 1, including the automatic sample injector for the fully automatic thermal desorber as described in Example 1, and also including a gas circuit assembly and a circuit assembly arranged on the main support 100; the gas circuit assembly includes a nitrogen connector 1, a first mass flow controller 201, a second mass flow controller 202, a multi-way switching valve 3, a first electromagnetic switching valve 401, a second electromagnetic switching valve 402, a first emptying connector 501, a second emptying connector 502, a third emptying connector 503, a sample recovery tube 7, an eight-way switching valve 8, a temperature-controlled dehydration tube 9, a temperature-controlled focusing tube 10, a carrier gas inlet and outlet pipeline 11, a proportional valve 12 and a pressure sensor 13; The nitrogen connector 1 is connected to the input port of the first mass flow controller 201, and the output port of the first mass flow controller 201 is respectively connected to the second interface P32 of the multi-way switching valve 3, the normally closed port of the first electromagnetic switching valve 401 and the normally open port of the second electromagnetic switching valve 402, the normally open port of the first electromagnetic switching valve 401 is connected to the first emptying connector 501, the common port of the first electromagnetic switching valve 401 is connected to one of the upper connector on the gas line and the lower connector 1702 on the gas line, the other of the upper connector on the gas line and the lower connector 1702 on the gas line is connected to the first interface P31 of the multi-way switching valve 3, and the third interface P33 of the multi-way switching valve 3 is respectively connected to the upper connector on the gas line and the lower connector 1702 on the gas line. The first port of the sample recovery tube 7 is connected to the first interface P81 of the eight-way switching valve 8; the second port of the sample recovery tube 7 is connected to the input port of the proportional valve 12, the air pressure sensor 13 is arranged in the air path between the second port of the sample recovery tube 7 and the input port of the proportional valve 12, and the output port of the proportional valve 12 is connected to the second emptying joint 502; the second interface P82 of the eight-way switching valve 8 is connected to the first port of the temperature-controlled dehydration tube 9, the second port of the temperature-controlled dehydration tube 9 is connected to the eighth interface P88 of the eight-way switching valve 8, the seventh interface P87 of the eight-way switching valve 8 is connected to the first port of the temperature-controlled focusing tube 10, and the temperature-controlled focusing tube 10 is The second port is connected to the fourth interface P84 of the eight-way switching valve 8, the fifth interface P85 of the eight-way switching valve 8 is connected to the air inlet pipeline in the carrier gas inlet and outlet pipeline 11, the sixth interface P86 of the eight-way switching valve 8 is connected to the air outlet pipeline in the carrier gas inlet and outlet pipeline 11, and the third interface P83 of the eight-way switching valve 8 is connected to the common port of the second electromagnetic switching valve 402; the normally closed port of the second electromagnetic switching valve 402 is connected to the input port of the second mass flow controller 202, and the output port of the second mass flow controller 202 is connected to the third drain joint 503; the circuit assembly includes an adsorption tube temperature control assembly 141 arranged on the loading station and used to temperature control the adsorption tube 6.

[0100] like Figure 4 As shown, in the specific gas circuit assembly structure of the fully automatic thermal desorber, the nitrogen connector 1 is used to connect the external nitrogen bottle 200, so as to introduce dry nitrogen required for cleaning, desorption and purging into the relevant pipelines inside the instrument. The first mass flow controller 201 is used to accurately control the flow rate of the introduced nitrogen; the second mass flow controller 202 is used to accurately control the flow rate of the derived gas, and both the first mass flow controller 201 and the second mass flow controller 202 can be implemented by existing electronic mass flow controllers. The multi-way switching valve 3 is used to realize the gas circuit switching in the following two states: in the A position state, the first interface P31 is connected to the third interface P33, and the second interface P32 is cut off; in the B position state, the first interface is connected to the second interface P32, and the third interface P33 is cut off; the multi-way switching valve 3 can be specifically a three-way or more switching valve; in addition, the gas supply input end of the multi-way switching valve 3 is connected to the gas supply output end of the high-pressure valve island in the valve island assembly 180, so that the gas circuit switching is driven by the high-pressure valve island. The first electromagnetic switching valve 401 and the second electromagnetic switching valve 402 are respectively used to realize the gas path switching of the following two states through electromagnetic control: when the power is off, the common port is connected to the normally closed port, and the normally open port is cut off; when the power is on, the common port is connected to the normally open port, and the normally closed port is cut off (the "normally closed" and "normally open" in this specification are similar to the meanings of "normally open contact" and "normally closed contact" in the circuit, that is, "open" means "the passage is disconnected and cut off", and "closed" means "the passage is closed and turned on", and other names can also be used according to this meaning). The first drain connector 501, the second drain connector 502 and the third drain connector 503 are respectively used to discharge the gas in the internal pipeline of the instrument.

[0101] The adsorption tube 6 is used as a sample collection part to adsorb and store the VOCs to be detected. It can generally be a stainless steel tube or a quartz tube of about 6mm×9cm, filled with a solid adsorbent for adsorbing VOCs; at the same time, the adsorption tube 6 can be automatically loaded and unloaded through the automatic sample injector provided in Example 1, so as to achieve the purpose of automatically replacing samples. Since the temperature of the adsorption tube plays a key role in the adsorption and desorption processes of VOCs, the temperature of the adsorption tube can be heated, cooled and maintained by arranging the adsorption tube temperature control assembly 141. Specifically, the adsorption tube temperature control assembly 141 includes a temperature control assembly mounting plate 1411, an ultra-thin cylinder 1412 and an electric heating block 1413, wherein the ultra-thin cylinder 1412 is arranged on the temperature control assembly mounting plate 1411, and the electric heating block 1413 is arranged on the movable part of the ultra-thin cylinder 1412 for driving the electric heating block 1413 to perform horizontal transverse reciprocating motion, and the electric heating block 1413 is arranged with a U-shaped groove for semi-enclosing the adsorption tube 6. Figure 2As shown, the ultra-thin cylinder 1412 is used to horizontally move the electric heating block 1413 on the loading station, so that the electric heating block 1413 is close to and semi-surrounds the adsorption tube 6 to achieve the purpose of heating, and the electric heating block 1413 is away from and withdrawn from the adsorption tube 6 to achieve the purpose of temporarily stopping heating; in addition, the air supply input end of the ultra-thin cylinder 1412 is connected to the air supply output end of the high-pressure valve island in the valve island assembly 180, so as to reciprocate through the high-pressure valve island. In detail, the electric heating block 1413 can be, but is not limited to, an aluminum heat block. In addition, since the electric heating block 1413 is generally not powered off after starting up, in order to achieve temporary temperature control, an adsorption tube air cooling component (not shown in the drawings) can also be arranged on the adsorption tube temperature control assembly 141, so that the adsorption tube temperature is maintained at room temperature by opening the adsorption tube air cooling component at the same time, for example, before the desorption link, it is necessary to maintain room temperature to ensure that VOCs in the tube are not desorbed. In detail, the adsorption tube air-cooling component may be specifically a heat dissipation fan.

[0102] The sample recovery tube 7 is used to recover and adsorb VOCs that pass through during diversion, as well as a very small amount of VOCs that pass through during thermal cleaning and may remain on the temperature-controlled dehydration tube 9 and the temperature-controlled focusing tube 10. Therefore, when the adsorption tube 6 fails to detect, the sample recovery tube 7 can be used as the adsorption tube (the sample recovery tube 7 needs to use the same tube body structure as the adsorption tube 6) for re-analysis; in addition, when diversion detection is not performed (for example, when the VOCs content in the adsorption tube 6 is low), the sample recovery tube 7 can be replaced with an empty tube without recovery and adsorption function to keep the pipeline connected. The eight-way switching valve 8 is used to realize the gas circuit switching in the following two states: in the A position state, the first interface P81 is connected to the eighth interface P88, the second interface P82 is connected to the third interface P83, the fourth interface P84 is connected to the fifth interface P85, and the sixth interface P86 is connected to the seventh interface P87; in the B position state, the first interface P81 is connected to the second interface P82, the third interface P83 is connected to the fourth interface P84, the fifth interface P85 is connected to the sixth interface P86, and the seventh interface P87 is connected to the eighth interface P88; in addition, the gas supply input end of the eight-way switching valve 8 is connected to the gas supply output end of the high-pressure valve island in the valve island assembly 180, so as to drive the gas circuit switching through the high-pressure valve island. In addition, in order to prevent the gas from having condensation residue due to low temperature when flowing through the pipeline between the adsorption tube 6 and the eight-way switching valve 8 and inside the multi-way switching valve 3 and the eight-way switching valve 8, as shown in FIG. Figure 4 As shown, a central temperature control unit 144 with shared heating may be arranged in the pipeline area between the adsorption tube 6 and the eight-way switching valve 8, the installation position of the multi-way switching valve 3 and the installation position of the eight-way switching valve 8. For example, the central temperature control unit 144 may be specifically an aluminum thermal plate.

[0103] The temperature-controlled dehydration tube 9 is used to remove moisture by freezing the water in the gas flowing through it at low temperature (generally below zero degrees Celsius) during desorption, so that most of the VOCs enter the temperature-controlled focusing tube 10. Since the temperature of the dehydration tube needs to be low during desorption and high during purging and thermal cleaning, it is necessary to arrange a temperature control unit around the dehydration tube body to increase, decrease and maintain the temperature of the dehydration tube; Figure 4 As shown, dehydration tube port temperature control units 142 are respectively arranged at the ports on both sides of the temperature-controlled dehydration tube 9; in order to facilitate temperature control and reduce temperature control costs, the low-temperature or normal-temperature control method of the temperature-controlled dehydration tube 9 can preferentially adopt existing electronic refrigeration technology, thereby eliminating the need for liquid nitrogen refrigeration, greatly reducing refrigeration costs, and being convenient and practical; and when heated to high temperatures, conventional heating wires can be used for winding heating.

[0104] The temperature-controlled focusing tube 10 is used to focus and adsorb VOCs in the gas flowing through it at a lower temperature (generally below -20 degrees Celsius) during desorption and purging, using the internal solid adsorbent to achieve the purpose of serving as a temporary transfer station for VOCs. Since the focusing tube temperature needs to be low during desorption and purging, and high during sampling and thermal cleaning, it is necessary to arrange a temperature control unit around the focusing tube body to increase, decrease, and maintain the temperature of the focusing tube; Figure 4 As shown, a focusing tube port temperature control unit 143 is arranged at the port of the temperature-controlled focusing tube 10; in order to facilitate temperature control and reduce temperature control costs, the low-temperature or normal-temperature control method of the temperature-controlled focusing tube 10 can also preferentially adopt the existing electronic refrigeration technology; and when heated to a high temperature, a conventional heating wire can be used for winding and heating. In addition, the internal volume of the temperature-controlled focusing tube 10 can be significantly smaller than that of the adsorption tube 6, so that in a low-temperature environment, the diffusion area of ​​VOCs can be smaller, thereby effectively focusing VOCs, which is beneficial to obtaining a chromatogram with a high peak quality during subsequent separation and analysis, and ensuring the effect of quantitative analysis.

[0105] The carrier gas inlet and outlet pipeline 11 is used to connect the carrier gas output pipe and the carrier gas return pipe of the gas chromatograph 300, so that the volatile organic compounds in the temperature-controlled focusing tube 10 can be introduced into the gas chromatograph 300 along with the carrier gas to achieve the purpose of sampling and separation analysis; in order to avoid the phenomenon of residual VOCs in the flow pipeline due to too low a carrier gas temperature, such as Figure 4 As shown, a carrier gas temperature control unit 145 may also be arranged on the carrier gas inlet and outlet pipeline 11 to appropriately heat the gas flowing through the carrier gas inlet and outlet pipeline 11. For example, the carrier gas temperature control unit 145 may be specifically a heating pipeline.

[0106] The proportional valve 12 is also used to accurately control the flow rate, and the effect is similar to that of two mass flow controllers. Then, by controlling the flow rate of the proportional valve 12 and the flow rate of the second mass flow controller 202 to meet the target split ratio, VOCs can be quantitatively adsorbed in the temperature-controlled focusing tube 10 and the sample recovery tube 7 according to the target split ratio. The air pressure sensor 13 is used to collect the air pressure data in the tube between the second port of the sample recovery tube 7 and the input port of the proportional valve 12, so as to monitor the internal air pressure of the pipeline; it can be implemented by an existing pressure sensor or air pressure sensor. Figure 4 As shown, in an optimized manner, the proportional valve 12, the air pressure sensor 13 and the three-way connector 24 together constitute an integral element structure, wherein the first port of the three-way connector 24 is connected to the second port of the sample recovery tube 7, the second port of the three-way connector 24 is connected to the input port of the proportional valve 12, and the third port of the three-way connector 24 is connected to the air inlet port of the air pressure sensor 13, thereby not only achieving the aforementioned purpose, but also integrating multiple components for convenient matching and use.

[0107] In addition, the gas circuit assembly may also include a compressed air connector 30 whose two ends are respectively connected to the valve island assembly 180 and the external compressed air bottle 500, and may also include a connecting vessel 50 (such as a three-way connector, a four-way connector, etc.) for connecting multiple components. In addition, in the internal pipelines of the instrument of the gas circuit assembly, the pipelines through which VOCs flow are made of inert materials (generally referring to inert stainless steel, such as silanized stainless steel, which is a kind of inert stainless steel), and cold spots or cold areas are minimized in these pipelines to avoid adsorption losses of VOCs, while other pipelines can generally use stainless steel pipes; the nitrogen connector 1, the first drain connector 501, the second drain connector 502, the third drain connector 503 and the compressed air connector 30 can be specifically through-plate connectors that pass through the main support 100.

[0108] The working principle of the fully automatic thermal desorber is: first in the desorption stage, by turning on the first mass flow controller 201, the second mass flow controller 202 and the proportional valve 12, and setting the flow of the first mass flow controller 201 and the flow of the second mass flow controller 202 according to the target split ratio, and controlling the ratio of the flow of the proportional valve 12 to the flow of the second mass flow controller 202 to meet the target split ratio, VOCs can be quantitatively adsorbed in the temperature-controlled focusing tube 10 and the sample recovery tube 7 according to the target split ratio, and then the purge stage and the sample injection analysis stage are carried out to achieve the purpose of completing VOCs analysis and detection in combination with the gas chromatograph 300. Therefore, through the detailed description of the aforementioned specific structure and working principle, in addition to achieving the purpose of fully automatic sampling and thermal desorption analysis, a new thermal desorber structure is provided that can be used with a gas chromatograph to complete volatile organic compound analysis and detection. It can not only realize precise diversion control, but also facilitate the conversion of analysis results to each other under different diversion ratios, so that the analysis results of the sample recovery tube can be qualitatively and quantitatively analyzed, greatly increasing the fault tolerance of the thermal desorber, thereby avoiding repeated sampling, facilitating the detection of volatile organic compounds, and further facilitating practical application and promotion.

[0109] The optimization also includes an air inlet connector 15 and an air pump 16, wherein the air inlet connector 15 is used to connect to the common outlet of the sampling tank automatic sample injector 400; the air inlet connector 15 is connected to the first interface P81 of the eight-way switching valve 8, the input port of the air pump 16 is connected to the output port of the second mass flow controller 202, and the output port of the air pump 16 is connected to the third exhaust connector 503. Figure 4 As shown, the air inlet connector 15 is used to introduce sample gas, nitrogen or internal standard gas from a sampling can automatic sampler 400 (an existing sampling can automatic sampler device, the basic structure of which is a multi-way selection valve connecting different sampling cans, and when switching to a certain sampling position, the common outlet of the multi-way selection valve is connected to the corresponding sampling can; in addition, one of the ways of the multi-way selection valve needs to be connected to a nitrogen bottle, and another way needs to be blocked), so as to achieve the purpose of "cross-border" matching and analyzing the sampling can; in addition, when the fully automatic thermal desorber has a main bracket 100, the air inlet connector 15 can also be specifically a through-plate connector that passes through the main bracket 100; in addition, as Figure 4As shown, in order to avoid too low intake temperature, an intake air temperature control unit 146 can also be arranged at the installation position of the intake connector 15, so as to appropriately heat the gas flowing through the intake connector 15. For example, the carrier air temperature control unit 146 can also be specifically a heating pipeline. The air pump 16 is used to provide extraction power for the gas flow in the internal pipeline of the instrument when starting, so that the sample gas, nitrogen or internal standard gas from the sampling tank automatic sampler 400 can be normally introduced. Therefore, through the above-mentioned component configuration, the sampling tank (i.e., Suma tank) or air bag can also be analyzed to achieve the purpose of one device with multiple uses, so that it can respond to and analyze all VOCs listed in the thermal desorption method standards (including organic sulfur and n-hexadecane), and can also analyze all VOCs in the volatile organic compound monitoring program for key areas promulgated by the state, that is, the former is the application of the adsorption tube, and the latter is the application of the sampling tank. Both basically cover all VOCs at home and abroad, and are the design of the master, which greatly expands the scope of application of the fully automatic thermal desorber. In addition, the internal standard gas can be introduced into the internal pipeline of the instrument through a sampling tank automatic sampler equipped with an internal standard gas position (that is, one of the multiple selection valves is connected to the internal standard gas tank), thereby achieving the purpose of internal standard method measurement and analysis and further expanding the scope of application.

[0110] The optimized one further comprises an internal standard air intake connector 17 and a solenoid valve 18, wherein the internal standard air intake connector 17 is connected to the input port of the solenoid valve 18, and the output port of the solenoid valve 18 is connected to the first interface P81 of the eight-way switching valve 8. Figure 4 As shown, the internal standard gas inlet connector 17 is used to connect to the internal standard gas tank (not shown in the figure), so that when the solenoid valve 18 is controlled to be turned on, the internal standard gas can be introduced into the internal pipeline of the instrument to achieve the purpose of internal standard method measurement and analysis, further expanding the scope of application. Figure 4 As shown, when the air inlet connector 15, the internal standard air inlet connector 17 and the solenoid valve 18 are included at the same time, the third interface P33 of the multi-way switching valve 3, the first port of the sample recovery tube 7, the first interface P81 of the eight-way switching valve 8, the air inlet connector 15 and the solenoid valve 18 can be interconnected in pairs through a combination structure of an inert three-way and an inert four-way.

[0111] The optimized one further comprises a first housing box 19 for housing the temperature-controlled dehydration tube 9, a second housing box 20 for housing the temperature-controlled focusing tube 10, an on-off valve 403, a first speed regulating valve 21 and a second speed regulating valve 22; the first port of the on-off valve 403 is connected to the nitrogen connector 1, the second port of the on-off valve 403 is connected to the input port of the first speed regulating valve 21 and the input port of the second speed regulating valve 22 respectively, the output port of the first speed regulating valve 21 is connected to the inner cavity of the first housing box 19, and the output port of the second speed regulating valve 22 is connected to the inner cavity of the second housing box 20. Figure 4The first container box 19 and the second container box 20 are approximately sealed boxes, which can be made of, but not limited to, oxynitride glass fiber. The on-off valve 403 can be, but not limited to, an electromagnetic switching valve (which is used to achieve the following two states of gas path switching through electromagnetic control: in the power-off state, the common port is connected to the normally closed port, and the normally open port is cut off; in the power-on state, the common port is connected to the normally open port, and the normally closed port is cut off) or an electromagnetic switch valve, etc.; Figure 4 As shown, when the on-off valve 403 adopts an electromagnetic switching valve, the normally closed port of the electromagnetic switching valve is blocked, the normally open port is used as the first port to connect to the nitrogen connector 1, and the common port is used as the second port to connect to the input port of the first speed regulating valve 21 and the input port of the second speed regulating valve 22. The first speed regulating valve 21 and the second speed regulating valve 22 are respectively used to adjust the air flow speed so that the nitrogen can be blown into the corresponding containing box at a uniform speed. Therefore, through the above-mentioned structural design, the purpose of blowing nitrogen into the first containing box 19 and the second containing box 20 at a uniform speed can be achieved by energizing the on-off valve 403 and opening the first speed regulating valve 21 and the second speed regulating valve 22, thereby ensuring that the temperature-controlled dehydration tube 9 and the temperature-controlled focusing tube 10 are filled with dry nitrogen, thereby avoiding the phenomenon that the presence of oxygen and moisture affects accessories such as heating wires (oxygen easily reduces the life of the heating wires) or electronic refrigeration components (moisture will freeze on the electronic refrigeration components, and in severe cases damage the hardware), thereby extending the service life of the temperature control unit, etc., and is particularly suitable for nitrogen blowing protection when thermally cleaning the temperature-controlled dehydration tube 9 and the temperature-controlled focusing tube 10.

[0112] The optimized method further includes a trap 23, wherein the input port of the trap 23 is connected to the second port of the sample recovery tube 7, and the output port of the trap 23 is connected to the input port of the proportional valve 12. Figure 4 As shown, the trap 23 is used to adsorb volatile organic compounds in the exhaust gas to achieve the purpose of protecting the environment. It can be specifically a quartz tube or a stainless steel tube filled with activated carbon.

[0113] In summary, the fully automatic thermal desorber provided in this embodiment has the following technical effects based on the technical effects of the first embodiment:

[0114] (1) In addition to achieving the purpose of fully automatic sampling and thermal desorption analysis, this embodiment also provides a new thermal desorber structure that can be used in conjunction with a gas chromatograph to complete volatile organic compound analysis and detection. In the desorption stage, the two mass flow controllers and the proportional valve are opened, and the flow rates of the two mass flow controllers are set according to the target split ratio, and the ratio of the flow rate of the proportional valve to the flow rate of the evacuation mass flow controller is controlled to meet the target split ratio, so that VOCs can be quantitatively adsorbed in the focusing tube and the sample recovery tube according to the target split ratio. Then, the purge stage and the sampling analysis stage are performed. In this way, not only accurate split control can be achieved, but also the analysis results can be converted to each other under different split ratios, so that the analysis results of the sample recovery tube can be qualitatively and quantitatively analyzed, which greatly increases the fault tolerance of the thermal desorber, thereby avoiding repeated sampling, facilitating the detection of volatile organic compounds, and further facilitating practical application and promotion.

[0115] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention is described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0116] Finally, it should be noted that the present invention is not limited to the above optional implementations, and anyone can derive other various forms of products under the enlightenment of the present invention. The above specific implementations should not be understood as limiting the scope of protection of the present invention. The scope of protection of the present invention should be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. An automatic sample injector for a fully automatic thermal desorber, characterized in that: It comprises a main frame (100), a tray assembly (110), a Z-axis assembly (120), an X-axis assembly (130), a Y-axis assembly (140), a crossbeam assembly (150), a cover removal assembly (160), a loading assembly (170) and a valve island assembly (180), wherein the Z-axis is a vertical axis, the X-axis is a horizontal horizontal axis, and the Y-axis is a horizontal longitudinal axis; The tray assembly (110) is arranged on a tray station of the main frame (100) and is used to hold a plurality of adsorption tubes (6); The Z-axis assembly (120) is arranged on the main support (100) and is located above the tray assembly (110), and is used to vertically extract the adsorption tube (6) from the tray assembly (110), and vertically place the adsorption tube (6) into the tray assembly (110); The X-axis assembly (130) is arranged on the main frame (100) and is located above the tray assembly (110), and is used to drive the Z-axis assembly (120) to perform horizontal reciprocating motion in the area above the tray assembly (110); The Y-axis assembly (140) is arranged on the main frame (100) and is located above the tray assembly (110), and is used to drive the X-axis assembly (130) to perform horizontal and longitudinal reciprocating motion in the area above the tray assembly (110), and to enable the Z-axis assembly (120) to reach the handover position of the main frame (100); The crossbeam assembly (150) is arranged on the main support (100) and includes a crossbeam stepper motor (1501), a first belt, a crossbeam ball screw (1503), a two-claw lifting cylinder (1504) and a two-claw cylinder (1505), wherein the crossbeam stepper motor (1501) is connected to the crossbeam ball screw (1503) through the first belt transmission, and is used to drive the active part of the crossbeam ball screw (1503) to perform horizontal and lateral reciprocating motion, and to make the crossbeam ball screw (1503) ) passes through the handover station, cover removal station, loading station and waiting station of the main support (100) in one direction in sequence, the two-claw lifting cylinder (1504) is arranged on the movable part of the crossbeam ball screw (1503), the two-claw cylinder (1505) is arranged on the movable part of the two-claw lifting cylinder (1504), and is used to drive the two-claw cylinder (1505) to make vertical reciprocating motion, and the two-claw cylinder (1505) is arranged with two claws for clamping or releasing the middle part of the adsorption tube (6); The cap removal assembly (160) is arranged on the cap removal station of the main support (100) and is used to remove the caps located at both ends of the adsorption tube (6) in the vertical direction and to cover the caps on the corresponding ends; The loading assembly (170) is arranged on the loading station of the main support (100) and comprises an upper gas circuit joint, a lower gas circuit joint (1702) and a loading cylinder (1703), wherein the upper gas circuit joint and the lower gas circuit joint (1702) are arranged opposite to each other up and down, and the lower gas circuit joint (1702) is arranged on the movable part of the loading cylinder (1703) for driving the lower gas circuit joint (1702) to perform vertical reciprocating motion; The valve island assembly (180) is arranged on the main body support (100) and is used to supply air to each cylinder.

2. An automatic sample injector for a fully automatic thermal desorber according to claim 1, characterized in that: The tray assembly (110) includes a fixed plate (1101), a tray driving cylinder (1102) and a tray (1103), wherein the tray driving cylinder (1102) is arranged on the fixed plate (1101), and the tray (1103) is arranged on the movable part of the tray driving cylinder (1102) for driving the tray (1103) to perform horizontal linear reciprocating motion between the tray station and the loading station, and the tray (1103) is used to hold a plurality of the adsorption tubes (6).

3. An automatic sample injector for a fully automatic thermal desorber as claimed in claim 2, characterized in that: The tray assembly (110) further comprises a plurality of pipe-lifting cylinders corresponding one-to-one to each adsorption tube containing position, wherein the pipe-lifting cylinders are arranged at the bottom of the tray (1103) and are used to lift up the corresponding adsorption tube (6) through a movable portion.

4. The automatic sample injector for a fully automatic thermal desorber according to claim 1, characterized in that: The Z-axis assembly (120) includes a Z-axis assembly mounting plate (1201), a three-claw lifting cylinder (1202) and a three-claw cylinder (1203), wherein the three-claw lifting cylinder (1202) is arranged on the Z-axis assembly mounting plate (1201), and the three-claw cylinder (1203) is arranged on the movable part of the three-claw lifting cylinder (1202) for driving the three-claw cylinder (1203) to perform vertical reciprocating motion, and the three-claw cylinder (1203) is arranged with three claws for grasping the upper end of the adsorption tube (6).

5. The automatic sample injector for a fully automatic thermal desorber according to claim 1, characterized in that: The X-axis assembly (130) comprises an X-axis stepper motor (1301), a second belt and an X-axis ball screw (1303), wherein the X-axis stepper motor (1301) is connected to the X-axis ball screw (1303) via the second belt transmission, and is used to drive the active part of the X-axis ball screw (1303) to perform horizontal lateral reciprocating motion, and the Z-axis assembly (120) is arranged on the active part of the X-axis ball screw (1303).

6. The automatic sample injector for a fully automatic thermal desorber according to claim 1, characterized in that: The Y-axis assembly (140) comprises a Y-axis stepper motor (1401), a third belt and a Y-axis ball screw (1403), wherein the Y-axis stepper motor (1401) is connected to the Y-axis ball screw (1403) via the third belt transmission, and is used to drive the active part of the Y-axis ball screw (1403) to perform horizontal and longitudinal reciprocating motion, and the X-axis assembly (130) is arranged on the active part of the Y-axis ball screw (1403).

7. The automatic sample injector for a fully automatic thermal desorber according to claim 1, characterized in that: A laser beam switch is arranged below the handover station, wherein the laser beam switch comprises a transmitter and a receiver, and is used to detect whether a cap at the lower end of the adsorption tube (6) is present.

8. A method for operating an automatic sample injector, characterized in that: The automatic sample injector is an automatic sample injector for a fully automatic thermal desorber according to any one of claims 1 to 7, comprising an automatic adsorption tube installation process, wherein the automatic adsorption tube installation process comprises the following steps: S101. Grasping the adsorption tube: moving the Z-axis assembly (120) to the top of the target adsorption tube loading position through the X-axis assembly (130) and the Y-axis assembly (140), and then vertically extracting the adsorption tube (6) at the target adsorption tube loading position from the tray assembly (110) through the Z-axis assembly (120); S102. Handover of the adsorption tube: Move the Z-axis assembly (120) and the adsorption tube (6) to the handover station through the X-axis assembly (130) and the Y-axis assembly (140), and then move the two-claw lifting cylinder (1504) and the two-claw cylinder (1505) to the handover station through the crossbeam stepper motor (1501) and the crossbeam ball screw (1503), and then use the two-claw cylinder (1505) to make the two claws in a clamping state and clamp the middle of the adsorption tube (6), and then make the Z-axis assembly (120) release the adsorption tube (6), and finally move the two-claw cylinder (1505) and the adsorption tube (6) downward through the two-claw lifting cylinder (1504), so that the adsorption tube (6) is out of the grasping range of the Z-axis assembly (120); S103. Remove the cap of the adsorption tube: Move the two-claw lifting cylinder (1504) and the two-claw cylinder (1505) and the adsorption tube (6) to the cap removal station through the crossbeam stepper motor (1501) and the crossbeam ball screw (1503), and then remove the caps of the adsorption tube (6) and the caps located at both ends of the vertical direction through the cap removal assembly (160); S104. Loading of the adsorption tube: Move the two-claw lifting cylinder (1504), the two-claw cylinder (1505) and the adsorption tube (6) to the loading station through the crossbeam stepper motor (1501) and the crossbeam ball screw (1503), then lift the two-claw cylinder (1505) and the adsorption tube (6) through the two-claw lifting cylinder (1504), so that the air circuit joint is inserted into the upper port of the adsorption tube (6), and then lift the air circuit lower joint (1702) through the loading cylinder (1703), so that the air circuit lower joint (1702) is inserted into the lower port of the adsorption tube (6), and then the two claws are released by the two-claw cylinder (1505), and finally move the two-claw lifting cylinder (1504) and the two-claw cylinder (1505) to the waiting station through the crossbeam stepper motor (1501) and the crossbeam ball screw (1503).

9. The working method of an automatic sample injector according to claim 8, characterized in that: After the adsorption tube automatic installation process, an adsorption tube automatic unloading process is also included, wherein the adsorption tube automatic unloading process includes the following steps: S201. Unloading of the adsorption tube: the two-claw lifting cylinder (1504), the two-claw cylinder (1505) and the adsorption tube (6) are moved to the loading station by the crossbeam stepper motor (1501) and the crossbeam ball screw (1503), and then the two claws are placed in a clamping state and the middle of the adsorption tube (6) are clamped by the two-claw cylinder (1505), and then the lower joint (1702) of the air circuit is moved downward by the loading cylinder (1703), so that the lower joint (1702) of the air circuit is pulled out of the lower port of the adsorption tube (6), and then the two-claw lifting cylinder (1504) is moved downward by the two-claw cylinder (1505) and the adsorption tube (6), so that the upper joint of the air circuit is pulled out of the upper port of the adsorption tube (6); S202. Capping the adsorption tube: The two-claw lifting cylinder (1504) and the two-claw cylinder (1505) and the adsorption tube (6) are moved to the capping station by the crossbeam stepper motor (1501) and the crossbeam ball screw (1503), and then the cap is covered on both ends of the adsorption tube (6) vertically by the capping assembly (160); S203. Return of the adsorption tube: Move the two-claw lifting cylinder (1504) and the two-claw cylinder (1505) and the adsorption tube (6) to the handover station through the crossbeam stepper motor (1501) and the crossbeam ball screw (1503), then move the Z-axis assembly (120) to the handover station through the X-axis assembly (130) and the Y-axis assembly (140), and then lift the two-claw cylinder (1505) and the adsorption tube (6) through the two-claw lifting cylinder (1504) to make the adsorption tube (6) within the grasping range of the Z-axis assembly (120), and then grasp the upper end of the adsorption tube (6) through the Z-axis assembly (120), and finally make the two claws in a loose state through the two-claw cylinder (1505); S204. Putting back the adsorption tube: Move the Z-axis assembly (120) and the adsorption tube (6) to the top of the target adsorption tube loading position through the X-axis assembly (130) and the Y-axis assembly (140), and then vertically place the adsorption tube (6) into the tray assembly (110) through the Z-axis assembly (120), and finally release the adsorption tube (6) through the Z-axis assembly (120).

10. A fully automatic thermal desorber, characterized in that: It comprises the automatic sample injector for a fully automatic thermal desorber according to any one of claims 1 to 7, and also comprises a gas circuit assembly and a circuit assembly arranged on the main support (100); The gas circuit assembly comprises a nitrogen connector (1), a first mass flow controller (201), a second mass flow controller (202), a multi-way switching valve (3), a first electromagnetic switching valve (401), a second electromagnetic switching valve (402), a first drain connector (501), a second drain connector (502), a third drain connector (503), a sample recovery tube (7), an eight-way switching valve (8), a temperature-controlled dehydration tube (9), a temperature-controlled focusing tube (10), a carrier gas inlet and outlet pipeline (11), a proportional valve (12) and a gas pressure sensor (13); The nitrogen connector (1) is connected to the input port of the first mass flow controller (201), the output port of the first mass flow controller (201) is respectively connected to the second interface (P32) of the multi-way switching valve (3), the normally closed port of the first electromagnetic switching valve (401) and the normally open port of the second electromagnetic switching valve (402), the normally open port of the first electromagnetic switching valve (401) is connected to the first emptying connector (501), the common port of the first electromagnetic switching valve (401) is connected to one of the upper connector on the gas circuit and the lower connector on the gas circuit (1702), the other of the upper connector on the gas circuit and the lower connector on the gas circuit (1702) is connected to the first interface (P31) of the multi-way switching valve (3), and the third interface (P33) of the multi-way switching valve (3) is respectively connected to the first port of the sample recovery tube (7) and the first interface (P81) of the eight-way switching valve (8); The second port of the sample recovery tube (7) is connected to the input port of the proportional valve (12), the air pressure sensor (13) is arranged in the air path between the second port of the sample recovery tube (7) and the input port of the proportional valve (12), and the output port of the proportional valve (12) is connected to the second drain connector (502); The second interface (P82) of the eight-way switching valve (8) is connected to the first port of the temperature-controlled dehydration tube (9), the second port of the temperature-controlled dehydration tube (9) is connected to the eighth interface (P88) of the eight-way switching valve (8), the seventh interface (P87) of the eight-way switching valve (8) is connected to the first port of the temperature-controlled focusing tube (10), the second port of the temperature-controlled focusing tube (10) is connected to the fourth interface (P84) of the eight-way switching valve (8), the fifth interface (P85) of the eight-way switching valve (8) is connected to the inlet pipeline of the carrier gas inlet and outlet pipeline (11), the sixth interface (P86) of the eight-way switching valve (8) is connected to the outlet pipeline of the carrier gas inlet and outlet pipeline (11), and the third interface (P83) of the eight-way switching valve (8) is connected to the common port of the second electromagnetic switching valve (402); The normally closed port of the second electromagnetic switching valve (402) is connected to the input port of the second mass flow controller (202), and the output port of the second mass flow controller (202) is connected to the third drain connector (503); The circuit assembly comprises an adsorption tube temperature control assembly (141) arranged on the loading station and used for temperature controlling the adsorption tube (6).

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