CN110988229A - Automatic sample injector for full-automatic thermal desorption instrument, working method of automatic sample injector and full-automatic thermal desorption instrument - Google Patents

Abstract

The invention relates to the technical field of volatile organic compound detection, and discloses an automatic sample injector for a full-automatic thermal desorption instrument, a working method thereof and the full-automatic thermal desorption instrument, namely on one hand, an adsorption tube grabbing and sample feeding action and an adsorption tube placing action can be carried out in an upper area of a tray assembly by arranging a Z-axis assembly, an X-axis assembly and a Y-axis assembly, and on the other hand, complete sample injection and sample discharge actions such as handing over, cap taking, loading, unloading, cap covering and handing over can be carried out on the adsorption tube fed with a sample in sequence by arranging a beam assembly, a cap taking assembly, a loading assembly and a valve island assembly, so that the full-automatic thermal desorption instrument is particularly suitable for the full-automatic thermal desorption instrument, the manual workload is greatly reduced, and the time and the labor are saved. In addition, the automatic sample injector has the advantages of convenience in loading/unloading, high grabbing success rate, capability of automatically detecting errors, simple structure, easiness in implementation and the like, and is convenient for practical application and popularization.

Description

Automatic sample injector for full-automatic thermal desorption instrument, working method of automatic sample injector and full-automatic thermal desorption instrument

Technical Field

The invention belongs to the technical field of volatile organic compound detection, relates to industries including environmental monitoring, occupational health and the like, and particularly relates to an automatic sample injector for a full-automatic thermal desorption instrument, a working method of the automatic sample injector and the full-automatic thermal desorption instrument.

Background

The thermal desorption method is mainly used for analyzing VOCs (Volatile Organic Compounds, which refer to Organic Compounds having a saturated vapor pressure of more than 133.32Pa at normal temperature, a boiling point of 50-260 ℃ below under a standard atmospheric pressure of 101.3kPa, and an initial boiling point of 250 ℃, or any Volatile Organic solid or liquid at normal temperature and normal pressure), and refers to adsorbing, fixing and enriching an object to be detected in a gas by using a solid phase adsorbent at normal temperature or low temperature, and then heating the solid phase adsorbent to desorb the adsorbed object to be detected from the solid phase adsorbent and take the desorbed object away by a carrier gas. The thermal desorption method is a commercial thermal desorption apparatus, which is generally used in combination with a gas chromatograph, and heats and desorbs the substance to be detected adsorbed by the solid phase adsorbent, and then enters the gas chromatograph for separation and detection. The thermal desorption technology is the most mainstream volatile organic compound detection method at present because of its few defects, and the so-called defects are mainly the design of each product model.

The internal standard method is also a commonly used volatile organic compound detection method, and is characterized in that a substance with fixed concentration, absolutely no sample and close property to a substance to be detected is taken as an internal standard substance and added to the substance to be detected, then the sample containing the internal standard substance is subjected to chromatographic analysis, peak areas (or peak heights) and relative correction factors of the internal standard substance and the substance to be detected are respectively measured, and the concentration of the substance to be detected in the sample can be obtained according to a formula. The internal standard method is a relatively accurate quantitative method in chromatographic analysis, and when a mass spectrum detector is used, the internal standard method is generally adopted for quantification.

There are also many thermal desorption devices on the market today, but the most competitive products in terms of performance are two: PERKINELMER company (hereinafter referred to as PE company) in the United states and MARKES company in the United kingdom.

The thermal desorption products of PE company mainly suffer from the following disadvantages:

(11) the method is characterized in that the method can only analyze VOCs in adsorption tubes (stainless steel tubes or quartz tubes of about 6mm multiplied by 9cm, solid adsorbents are filled in the adsorption tubes, the adsorbents can efficiently adsorb VOCs in gas, after collection is completed, the adsorption tubes are returned to a laboratory and placed in a thermal desorption instrument to analyze the VOCs in the adsorption tubes), but cannot analyze VOCs in a sampling tank in a cross-boundary way (the tank is vacuumized before sampling, a gas sample is pumped and sealed during sampling, and the gas sample is returned to the laboratory to detect the content of the VOCs in the gas in an online way;

(12) when the adsorption tube is analyzed, automatic sample introduction, namely the sample tube filled with the solid phase adsorbent, cannot be automatically assembled and disassembled, so that the detection efficiency is low, and the manual workload is large;

(13) the device is not provided with a built-in dehydration module, and when the moisture content in the collected sample is high, effective dehydration cannot be realized, so that the accuracy of a measurement result is easily influenced, and even an instrument is damaged;

(14) the inertization degree of the system is not high, and volatile organic compounds (such as methyl mercaptan) with higher activity cannot be analyzed;

(15) the flow control of the split flow is inaccurate, and the content of VOCs in the adsorption tube sample can not be accurately calculated or inversely calculated through the difference of the split flow ratio;

(16) the added internal standard filling module adopts a quantitative ring (1mL) for sample injection, needs high-concentration internal standard gas due to small volume, and in the process of filling the quantitative ring, redundant internal standard gas can be emptied to cause pollution, the flow rate of the internal standard gas is uncontrollable, the consumption is large, and the waste is obvious.

The thermal desorption products from the company marker have mainly the following disadvantages:

(21) although the sample in the sampling tank can be collected across the boundary, and the dehydration capacity can be matched, the sampling tank and the dehydration capacity are independent matching instruments (independent equipment, not modules or elements inside the instrument), the space is not occupied, the integrity of the instrument is reduced, and the defect of high cost is caused;

(22) the heating component of the adsorption tube has poor actual heat insulation effect, the upper limit temperature is generally 300 ℃ out of the head and is far lower than the alleged 450 ℃; between the samples before and after analysis, the heating area is naturally cooled, and the temperature is raised before the next sample is analyzed, if the set temperature is 300 ℃ or above, the temperature rise time is about 10min, and the analysis efficiency is influenced; when the current sample is analyzed, the next sample (adsorption tube) also waits near the heating area, the temperature of the adsorption tube which is easy to wait is increased (generally, the temperature can be increased by 5-15 ℃), if VOCs enriched in the adsorption tube have substances which are difficult to trap and easy to diffuse, the substances can be only barely adsorbed and fixed on a solid adsorbent at normal temperature, and after the temperature of the adsorption tube is increased, the substances are easy to desorb and lose;

(23) the adsorption tube is arranged on the automatic sample injector, the DiffLok sealing caps of MARKES patents are required to be arranged at two ends of the adsorption tube, the sealing caps adopt a one-way ventilation design, but the sealing effect is poor in practice, and after the adsorption tube is arranged on the DiffLok sealing caps and before analysis, the adsorbed VOCs are easy to lose (for the reasons mentioned above) and pollution is easy to introduce;

(24) similar to the products of PE company, the flow distribution control is inaccurate, and even the flow distribution is manually adjusted in standard matching, so that the switching between high and low concentration curves is difficult.

Besides the two foreign manufacturers, a plurality of thermal desorption instrument manufacturers exist in China, most of the thermal desorption instrument manufacturers imitate PE to different degrees, although some manufacturers do some improvement on the basis of the PE, the imitation design causes the defects of the PE, the thermal desorption instrument manufacturers exist to different degrees, the working degree and the PE equipment are obviously different, and the element stability is not good. Therefore, their properties, stability, etc. are difficult to exceed those of PE.

Disclosure of Invention

The invention aims to solve the problems that an adsorption tube cannot be automatically assembled and disassembled and the manual workload is large in the existing thermal desorption instrument, and provides an automatic sample injector for a full-automatic thermal desorption instrument, a working method of the automatic sample injector and the full-automatic thermal desorption instrument.

The technical scheme adopted by the invention is as follows:

an automatic sample injector for a full-automatic thermal desorption instrument comprises a main body support, a tray assembly, a Z-axis assembly, an X-axis assembly, a Y-axis assembly, a cross beam assembly, a cover taking assembly, a loading assembly and a valve island assembly, wherein the Z-axis is a vertical axis, the X-axis is a horizontal cross axis, and the Y-axis is a horizontal longitudinal axis;

the tray assembly is arranged on a tray station of the main body bracket and is used for containing a plurality of adsorption tubes;

the Z-axis assembly is arranged on the main body support and positioned above the tray assembly, and is used for vertically extracting the adsorption tube from the tray assembly and vertically placing the adsorption tube into the tray assembly;

the X-axis assembly is arranged on the main body bracket and positioned above the tray assembly and is used for driving the Z-axis assembly to horizontally and transversely reciprocate in an area above the tray assembly;

the Y-axis assembly is arranged on the main body support and positioned above the tray assembly and used for driving the X-axis assembly to horizontally and longitudinally reciprocate in an area above the tray assembly and enabling the Z-axis assembly to reach a handover station of the main body support;

the cross beam assembly is arranged on the main body support and comprises a cross beam stepping motor, a first belt, a cross beam ball screw, a two-jaw lifting cylinder and two-jaw cylinders, wherein the cross beam stepping motor is in transmission connection with the cross beam ball screw through the first belt and is used for driving a movable part of the cross beam ball screw to horizontally and transversely reciprocate and enabling the movable part of the cross beam ball screw to sequentially pass through a cross-connecting station, a cover taking station, a loading station and a waiting station of the main body support in a single-pass manner;

the cover taking assembly is arranged on a cover taking station of the main body bracket and used for taking down the cover caps of the adsorption tube and positioned at the two vertical ends and covering the cover caps on the corresponding ends;

the loading assembly is arranged on a loading station of the main body support and comprises an air path upper joint, an air path lower joint and a loading cylinder, wherein the air path upper joint and the air path lower joint are arranged in an up-down opposite mode, and the air path lower joint is arranged on a movable part of the loading cylinder and used for driving the air path lower joint to do vertical reciprocating motion;

the valve island assembly is arranged on the main body support and used for supplying air to each air cylinder.

Preferably, the tray assembly drives actuating cylinder and tray including fixed plate, tray, wherein, the tray drives actuating cylinder and arranges on the fixed plate, it has arranged on the movable part that the tray drove actuating cylinder the tray for the drive the tray is in be horizontal straight reciprocating motion between tray station to the position of feeding, the tray is used for the splendid attire a plurality of adsorption tube.

Further preferably, the tray assembly further comprises a plurality of pipe jacking cylinders corresponding to the adsorption pipe containing positions one by one, wherein the pipe jacking cylinders are arranged at the bottom of the tray and used for jacking the corresponding adsorption pipes through the movable parts.

The Z-axis assembly comprises a Z-axis assembly mounting plate, a three-jaw lifting cylinder and a three-jaw cylinder, wherein the three-jaw lifting cylinder is arranged on the Z-axis assembly mounting plate, the three-jaw cylinder is arranged on a movable part of the three-jaw lifting cylinder and used for driving the three-jaw cylinder to do vertical reciprocating motion, and three jaw fingers used for grabbing the upper end part of the adsorption tube are arranged on the three-jaw cylinder.

Preferably, the X-axis assembly comprises an X-axis stepping motor, a second belt and an X-axis ball screw, wherein the X-axis stepping motor is in transmission connection with the X-axis ball screw through the second belt and used for driving a movable part of the X-axis ball screw to horizontally reciprocate, and the Z-axis assembly is arranged on the movable part of the X-axis ball screw.

Preferably, the Y-axis assembly comprises a Y-axis stepping motor, a third belt and a Y-axis ball screw, wherein the Y-axis stepping motor is in transmission connection with the Y-axis ball screw through the third belt and is used for driving a movable part of the Y-axis ball screw to do horizontal longitudinal reciprocating motion, and the X-axis assembly is arranged on the movable part of the Y-axis ball screw.

Preferably, a laser correlation switch is arranged below the cross-connecting station, wherein the laser correlation switch comprises a transmitter and a receiver and is used for detecting whether a lower end cover cap of the adsorption tube exists or not.

The other technical scheme adopted by the invention is as follows:

the working method of the automatic sample injector is that the automatic sample injector is used for the full-automatic thermal desorption instrument, and comprises an automatic adsorption tube installation process, wherein the automatic adsorption tube installation process comprises the following steps:

s101, grabbing of an adsorption tube: moving the Z-axis assembly to a position right above a target adsorption tube containing position through the X-axis assembly and the Y-axis assembly, and vertically extracting the adsorption tube at the target adsorption tube containing position from the tray assembly through the Z-axis assembly;

s102, connection of adsorption tubes: moving the Z-axis assembly and the adsorption tube to an intersection station through the X-axis assembly and the Y-axis assembly, then moving the two-claw lifting cylinder and the two-claw cylinder to the intersection station through the beam stepping motor and the beam ball screw, then enabling the two claw fingers to be in a clamping state through the two-claw cylinder and clamping the middle part of the adsorption tube, then enabling the Z-axis assembly to release the adsorption tube, and finally enabling the adsorption tube to be separated from the grabbing range of the Z-axis assembly through the two-claw lifting cylinder to move the two-claw cylinder and the adsorption tube downwards;

s103, taking a cap of the adsorption tube: moving the two-jaw lifting cylinder, the two-jaw cylinder and the adsorption tube to a cap taking station through a beam stepping motor and a beam ball screw, and then taking down the caps of the adsorption tube which are positioned at the two vertical ends through a cap taking assembly;

s104, loading of the adsorption tube: the two-jaw lifting cylinder, the two-jaw cylinder and the adsorption pipe are moved to a loading station through the beam stepping motor and the beam ball screw, then the two-jaw cylinder and the adsorption pipe are lifted through the two-jaw lifting cylinder, the upper joint of the air circuit is inserted into the upper port of the adsorption pipe, then the lower joint of the air circuit is lifted through the loading cylinder, the lower joint of the air circuit is inserted into the lower port of the adsorption pipe, then the two jaw fingers are in a loosening state through the two-jaw cylinder, and finally the two-jaw lifting cylinder and the two-jaw cylinder are moved to a waiting station through the beam stepping motor and the beam ball screw.

Preferably, the method further comprises an automatic adsorption tube unloading process after the automatic adsorption tube installation process, wherein the automatic adsorption tube unloading process comprises the following steps:

s201, unloading of the adsorption pipe: moving a two-claw lifting cylinder, a two-claw cylinder and an adsorption tube to a loading station through a beam stepping motor and a beam ball screw, enabling two claw fingers to be in a clamping state through the two-claw cylinder and clamping the middle part of the adsorption tube, then moving a lower joint of a gas circuit downwards through the loading cylinder, enabling the lower joint of the gas circuit to be drawn out of a lower port of the adsorption tube, and then moving the two-claw cylinder and the adsorption tube downwards through the two-claw lifting cylinder, enabling an upper joint of the gas circuit to be drawn out of an upper port of the adsorption tube;

s202, covering a cap of an adsorption tube: moving the two-jaw lifting cylinder, the two-jaw cylinder and the adsorption tube to a cap taking station through a beam stepping motor and a beam ball screw, and covering caps on two vertical ends of the adsorption tube through a cap taking assembly;

s203, returning of the adsorption pipe: moving a two-jaw lifting cylinder, a two-jaw cylinder and an adsorption tube to an intersection station through a beam stepping motor and a beam ball screw, then moving a Z-axis assembly to the intersection station through an X-axis assembly and a Y-axis assembly, then lifting the two-jaw cylinder and the adsorption tube through the two-jaw lifting cylinder to enable the adsorption tube to be in a grabbing range of the Z-axis assembly, grabbing the upper end part of the adsorption tube through the Z-axis assembly, and finally enabling two jaw fingers to be in a loosening state through the two-jaw cylinder;

s204, putting back the adsorption tube: and moving the Z-axis assembly and the adsorption tube to the position right above the target adsorption tube containing position through the X-axis assembly and the Y-axis assembly, vertically placing the adsorption tube into the tray assembly through the Z-axis assembly, and finally loosening the adsorption tube through the Z-axis assembly.

The other technical scheme adopted by the invention is as follows:

a full-automatic thermal desorption instrument comprises the automatic sample injector for the full-automatic thermal desorption instrument, and further comprises a gas circuit assembly and a circuit assembly which are arranged on a main body bracket;

the gas path assembly comprises a nitrogen connector, a first mass flow controller, a second mass flow controller, a multi-way switching valve, a first electromagnetic switching valve, a second electromagnetic switching valve, a first exhaust connector, a second exhaust connector, a third exhaust connector, a sample recovery pipe, an eight-way switching valve, a temperature control dehydration pipe, a temperature control focusing pipe, a carrier gas inlet and outlet pipeline, a proportional valve and a gas pressure sensor;

the nitrogen connector is communicated with an input port of the first mass flow controller, an output port of the first mass flow controller is respectively communicated with a second interface of the multi-way switching valve, a normally closed port of the first electromagnetic switching valve and a normally open port of the second electromagnetic switching valve, the normally open port of the first electromagnetic switching valve is communicated with the first exhaust connector, a common port of the first electromagnetic switching valve is communicated with one of the gas path upper connector and the gas path lower connector, the other of the gas path upper connector and the gas path lower connector is communicated with a first interface of the multi-way switching valve, and a third interface of the multi-way switching valve is respectively communicated with a first port of the sample recovery pipe and a first interface of the eight-way switching valve;

the second port of the sample recovery pipe is communicated with the input port of the proportional valve, the air pressure sensor is arranged in an air path between the second port of the sample recovery pipe and the input port of the proportional valve, and the output port of the proportional valve is communicated with the second emptying joint;

the second interface of the eight-way switching valve is communicated with the first port of the temperature control dehydration pipe, the second port of the temperature control dehydration pipe is communicated with the eighth interface of the eight-way switching valve, the seventh interface of the eight-way switching valve is communicated with the first port of the temperature control focusing pipe, the second port of the temperature control focusing pipe is communicated with the fourth interface of the eight-way switching valve, the fifth interface of the eight-way switching valve is communicated with an air inlet pipeline in the carrier gas inlet and outlet pipeline, the sixth interface of the eight-way switching valve is communicated with an air outlet pipeline in the carrier gas inlet and outlet pipeline, and the third interface of the eight-way switching valve is communicated with the common port of the second electromagnetic switching valve;

the normally closed port of the second electromagnetic switching valve is communicated with the input port of the second mass flow controller, and the output port of the second mass flow controller is communicated with the third emptying joint;

the circuit assembly comprises an adsorption tube temperature control assembly which is arranged on the loading station and used for controlling the temperature of the adsorption tube.

Optimized, adsorption tube control by temperature change assembly mounting panel, ultra-thin cylinder and electric heat piece, wherein, ultra-thin cylinder arranges on the control by temperature change assembly mounting panel, arranged on the movable part of ultra-thin cylinder the electric heat piece is used for the drive horizontal transverse reciprocating motion is done to the electric heat piece, it is used for semi-surrounding to arrange on the electric heat piece the U-shaped groove of adsorption tube.

The invention has the beneficial effects that:

(1) the invention provides a novel automatic mechanism and a working method for realizing automatic sample introduction and sample discharge of an adsorption tube in a full-automatic thermal desorption instrument by combining an electric mode and a pneumatic mode, namely on one hand, the adsorption tube can be grabbed and sent out and placed back in the upper area of a tray assembly by arranging a Z-axis assembly, an X-axis assembly and a Y-axis assembly, and on the other hand, the adsorption tube sent out can be sequentially subjected to complete sample introduction and sample discharge actions such as cross joint, cap taking, loading, unloading, cap covering and cross-over by arranging a cross beam assembly, a cap taking assembly, a loading assembly and a valve island assembly, so that the novel automatic mechanism is particularly suitable for the full-automatic thermal desorption instrument, the manual workload is greatly reduced, and the time and the labor are saved;

(2) can provide the adsorption tube autoinjection ability up to 120, furthest saves the manpower: the maximum sample introduction digit of the thermal desorption instrument of other manufacturers is 100 digits, and most of the maximum sample introduction digits do not exceed 50 digits; generally speaking, the average analysis time of one sample is 25-45min, and the average 35min is used, the analysis of 120 samples needs 70h, if a certain unit is 17:00 off duty on a friday and 9:00 on a monday, the middle unattended period is 64h, and the highest efficiency can be basically realized by 'people and instruments are not in rest';

(3) the automatic sample injector also has the advantages of convenient loading/unloading, high grabbing success rate, automatic error detection, simple structure, easy realization and the like, and is convenient for practical application and popularization;

(4) besides the purpose of realizing the analysis of full-automatic sample introduction and thermal desorption method, the novel thermal desorption instrument structure which can complete the analysis and detection of volatile organic compounds by matching with a gas chromatograph is provided, the novel thermal desorption instrument structure can firstly open two mass flow controllers and a proportional valve in a desorption link, set the flow of the two mass flow controllers according to a target flow dividing ratio, and control the flow ratio of the proportional valve and the flow of the emptying mass flow controller to meet the target flow dividing ratio, so that VOCs can be quantitatively absorbed in a focusing pipe and a sample recovery pipe according to the target flow dividing ratio, then a purging link and a sample introduction analysis link are carried out, thereby not only realizing accurate flow dividing control, but also being beneficial to carrying out mutual conversion on analysis results under the condition of different flow dividing ratios, leading the analysis results of the sample recovery pipe to be qualitatively and quantitatively analyzed and greatly increasing the fault-tolerant rate of the thermal desorption instrument, thereby avoiding repeated sampling, facilitating the detection of volatile organic compounds, and further being beneficial to practical application and popularization

(5) The full-automatic thermal desorption instrument can analyze an adsorption tube, can also analyze a sampling tank (namely a suma tank) or an air bag, achieves the aim of multiple purposes, can respond and analyze VOCs (including organic sulfur and n-hexadecane) listed in all standards of a thermal desorption method, and can analyze all VOCs in a monitoring scheme of volatile organic compounds in key areas issued by the country, namely the adsorption tube is applied, the sampling tank is applied, the sampling tube and the sampling tank basically contain all VOCs at home and abroad, the full-automatic thermal desorption instrument is designed by an integrated person, and the application range of the full-automatic thermal desorption instrument is greatly expanded;

(6) the temperature control dehydration pipe is arranged in the dehydration device, so that the influence of moisture can be effectively eliminated, and the dehydration device is simpler and more convenient to use compared with an independent dehydration device scheme adopted by MARKES company in England;

(7) because the temperature control dehydration pipe and the temperature control focusing pipe both adopt an electronic refrigeration technology, liquid nitrogen and other refrigerants are not needed, and the device is economical and practical, namely if a VOCs preconcentrator (analysis sampling tank) refrigerated by liquid nitrogen is used, the problem of high use cost obviously exists, 1200-element liquid nitrogen can only analyze about 50 samples, and the liquid nitrogen tank also needs thousands to ten thousand of prices, compared with the prior art, the device only consumes electricity and has low power; in addition, liquid nitrogen is more troublesome to supply and replace, the situation of untimely replacement is easy to occur, the delay of sample analysis time is caused, and some three-four-line cities even have no liquid nitrogen manufacturers;

(8) due to the fact that the VOCs flow path is fully inert and fully temperature-controlled, the minimum residual VOCs can be guaranteed;

(9) the internal standard gas collection device can be matched with a sampling tank automatic sampler with an internal standard gas level or an internal standard gas tank to realize internal standard gas collection, so that the purpose of detection and analysis by using an internal standard method or an external standard method is realized, and the application range is further expanded.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a disassembled structure of a main body support and tray assembly, a Z-axis assembly, an X-axis assembly and a Y-axis assembly in an automatic sample injector provided by the invention.

FIG. 2 is a schematic diagram of a disassembled structure of a main body support and beam assembly, a cover-removing assembly, a loading assembly, a valve island assembly and an adsorption tube temperature control assembly in the automatic sample injector provided by the invention.

Fig. 3 is a schematic flow chart of a working method of the automatic sampler provided by the present invention.

Fig. 4 is a schematic structural diagram of a gas circuit assembly and peripheral equipment in the full-automatic thermal desorption apparatus provided by the invention.

In the above drawings, 1-nitrogen joint; 201-a first mass flow controller; 202-a second mass flow controller; 3-a multi-way switching valve; 402-a first electromagnetic switching valve; 402-a second electromagnetic switching valve; 403-a third electromagnetic switching valve; 501-a first emptying joint; 502-second drain connection; 503-a third evacuation connection; 6-an adsorption tube; 7-sample recovery tube; 8-eight-way switching valve; 9-temperature control dehydration pipe; 10-temperature control focusing tube; 11-carrier gas inlet and outlet pipeline; 12-a proportional valve; 13-a barometric pressure sensor; 141-adsorption tube temperature control assembly; 1411-temperature control assembly mounting plate; 1412-ultra-thin cylinder; 1413-an electric heating block; 142-a dehydration tube port temperature control unit; 143-focus tube port temperature control unit; 144-a central temperature control unit; 145-carrier gas temperature control unit; 146-an intake air temperature control unit; 15-an air inlet joint; 16-an air pump; 17-internal standard gas inlet joint; 18-a solenoid valve; 19-a first containment box; 20-a second containment box; 21-a first speed valve; 22-a second speed valve; 23-a trap; 24-a three-way connector; 30-compressed air joint; 50-a connector; 100-a body support; 110-a tray assembly; 1101-a fixed plate; 1102-a pallet drive cylinder; 1103-a tray; a 120-Z axis assembly; 1201-Z axis assembly mounting plate; 1202-three-jaw lifting cylinder; 1203-three-jaw cylinder; 130-X axis assembly; 1301-X axis stepper motor; 1303-X axis ball screw; 140-Y axis assembly; 1401-Y axis stepper motors; 1403-Y axis ball screw; 150-a beam assembly; 1501-beam stepper motor; 1503-beam ball screw; 1504-two-jaw lifting cylinder; 1505-two jaw cylinder; 160-cover taking assembly; 170-a loading assembly; 1702-gas path lower joint; 1703-a loading cylinder; 180-a valve island assembly; 200-nitrogen gas cylinder; 300-gas chromatography; 400-sample tank autosampler; 500-compressed air bottle.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. Specific structural and functional details disclosed herein are merely illustrative of example embodiments of the invention. This invention may, however, be embodied in many alternate forms and should not be construed as limited to the embodiments set forth herein.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments of the present invention.

It should be understood that, for the term "and/or" as may appear herein, it is merely an associative relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, B exists alone, and A and B exist at the same time; for the term "/and" as may appear herein, which describes another associative object relationship, it means that two relationships may exist, e.g., a/and B, may mean: a exists independently, and A and B exist independently; in addition, for the character "/" that may appear herein, it generally means that the former and latter associated objects are in an "or" relationship.

It will 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 intervening elements may be present. Conversely, if a unit is referred to herein as being "directly connected" or "directly coupled" to another unit, it is intended that no intervening units are present. In addition, other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between … …" versus "directly between … …", "adjacent" versus "directly adjacent", etc.).

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and/or groups thereof.

It should also be noted that, in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed substantially concurrently, or the figures may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

It should be understood that specific details are provided in the following description to facilitate a thorough understanding of example embodiments. However, it will be understood by those of ordinary skill in the art that the example embodiments may be practiced without these specific details. For example, systems may be shown in block diagrams in order not to obscure the examples in unnecessary detail. In other instances, well-known processes, structures and techniques may be shown without unnecessary detail in order to avoid obscuring example embodiments.

Example one

As shown in fig. 1 to 3, the autosampler for a full-automatic thermal desorption apparatus provided in this embodiment includes a main body support 100, a tray assembly 110, a Z-axis assembly 120, an X-axis assembly 130, a Y-axis assembly 140, a cross beam assembly 150, a cover removing assembly 160, a loading assembly 170, and a valve island assembly 180, where the Z-axis is a vertical axis, the X-axis is a horizontal axis, and the Y-axis is a horizontal vertical axis; the tray assembly 110 is arranged on a tray station of the main body bracket 100 and is used for containing a plurality of adsorption tubes 6; the Z-axis assembly 120 is disposed on the main body support 100 above the tray assembly 110, and is used for vertically extracting the suction pipe 6 from the tray assembly 110 and vertically putting the suction pipe 6 into the tray assembly 110; the X-axis assembly 130 is disposed on the main body bracket 100 and above the tray assembly 110, and is configured to drive the Z-axis assembly 120 to horizontally and horizontally reciprocate in an area above the tray assembly 110; the Y-axis assembly 140 is disposed on the main body support 100 and above the tray assembly 110, and is used for driving the X-axis assembly 130 to perform horizontal and longitudinal reciprocating motion in an area above the tray assembly 110, and enabling the Z-axis assembly 120 to reach a handover station of the main body support 100; the traverse assembly 150 is disposed on the body frame 100 and includes a traverse stepping motor 1501, a first belt, a traverse ball screw 1503, a two-jaw lifting cylinder 1504 and a two-jaw cylinder 1505, wherein the beam stepping motor 1501 is in transmission connection with the beam ball screw 1503 through the first belt, is used for driving the movable part of the cross beam ball screw 1503 to do horizontal and transverse reciprocating motion, and enables the movable part of the cross beam ball screw 1503 to pass through the handing-over station, the cover taking station, the loading station and the waiting station of the main body bracket 100 in sequence in a single pass, the two-claw lift cylinder 1504 is disposed on the movable portion of the cross beam ball screw 1503, the two-claw cylinder 1505 is disposed on the movable portion of the two-claw lift cylinder 1504, the two-claw cylinder 1505 is driven to do vertical reciprocating motion, and two claw fingers used for clamping or releasing the middle part of the adsorption pipe 6 are arranged on the two-claw cylinder 1505; the cover removing assembly 160 is arranged at a cover removing station of the main body bracket 100, and is used for removing the cover caps of the adsorption pipe 6 at two vertical ends and covering the cover caps at the corresponding ends; the loading assembly 170 is arranged at a loading station of the main body bracket 100 and includes an air path upper joint, an air path lower joint 1702 and a loading cylinder 1703, wherein the air path upper joint and the air path lower joint 1702 are arranged in an up-down opposite manner, and the air path lower joint 1702 is arranged on a movable portion of the loading cylinder 1703 and used for driving the air path lower joint 1702 to make a vertical reciprocating motion; the valve island assembly 180 is disposed on the main body frame 100 for supplying air to each cylinder.

As shown in fig. 1 to 2, in a specific structure of the auto-sampler, the main body support 100 is used as a reference frame of the full-automatic thermal desorption apparatus, and is used for mounting and supporting the tray assembly 110, the Z-axis assembly 120, the X-axis assembly 130, the Y-axis assembly 140, the cross beam assembly 150, the cover-removing assembly 160, the loading assembly 170, the valve island assembly 180, and other assemblies of the full-automatic thermal desorption apparatus, such as an air circuit assembly and a circuit assembly. The tray assembly 110 is used for containing a plurality of the adsorption tubes 6 so as to be grabbed by the Z-axis assembly 120, for example, 120 adsorption tube containing positions can be provided, so that automatic sample feeding and thermal desorption detection of 120 adsorption tubes 6 in batch can be realized. The Z-axis assembly 120 is used for grabbing and replacing the adsorption tube. The X-axis assembly 130 and the Y-axis assembly 140 are used for horizontally moving the Z-axis assembly 120 and/or the adsorption tube 6 between a position above a tube loading position and a transfer position, so that the Z-axis assembly 120 performs a tube transfer operation with the cross beam assembly 150 at the transfer position.

The beam assembly 150 is configured to horizontally and linearly move the two-jaw lift cylinder 1504 and the two-jaw cylinder 1505/the adsorption tube 6 between a handover station, a cap removing station, a loading station, and a waiting station through the beam stepper motor 1501 and the beam ball screw 1503, so as to perform an adsorption tube handover operation with the Z-axis assembly 120 at the handover station, perform an adsorption tube cap removing or cap covering operation through the cap removing assembly 160 at the cap removing station, perform an adsorption tube loading or unloading operation through the loading assembly 170 at the loading station, and wait for completion of thermal desorption detection at the waiting station. In the specific structure of the traverse assembly 150, the linear driving mechanism composed of the traverse stepping motor 1501, the first belt and the traverse ball screw 1503 is a conventional structure, and the two-jaw lifting cylinder 1504 is used for lifting or lowering the two-jaw cylinder 1505 and/or the suction tube 6 so as to remove or lift the suction tube 6 from or to the Z-axis assembly 120 and insert or withdraw the gas path connector into or from the upper port of the suction tube 6; the two-jaw lifting cylinder 1504 may be, but is not limited to, an existing rodless cylinder or a sliding table cylinder. The two-claw cylinder 1505 is used for switching the working states of two claws: a clamping state and a releasing state so as to complete corresponding actions at a transfer station and a loading station; the two-jaw cylinder 1505 may also be implemented using existing cylinder configurations.

The cap removing assembly 160 is configured to open/close the two vertical ports of the adsorption tube 6 at a cap removing station, so that the two vertical ports of the adsorption tube 6 are respectively communicated with the upper air path connector 1702 and the lower air path connector 1702 at a loading station, and can be implemented by using an existing cap removing mechanism. The loading assembly 170 is used for loading the adsorption tube 6 into an air channel assembly of the full-automatic thermal desorption instrument at a loading station, or unloading the adsorption tube 6 from the air channel assembly, wherein the air channel upper connector and the air channel lower connector 1702 are respectively communicated with corresponding ports of the air channel assembly, and the loading cylinder 1703 is used for lifting or moving down the air channel lower connector 1702 so as to insert or extract the air channel lower connector 1702 into or out of the lower port of the adsorption tube 6; the loading cylinder 1703 may be, but is not limited to, an existing rodless cylinder or a slide cylinder. The valve island assembly 180 is used for communicating with an external compressed air bottle so as to supply air to each cylinder and drive the cylinders to complete corresponding actions. Specifically, the valve island assembly 180 includes a low-pressure valve island and a high-pressure valve island, wherein an air supply output end of the low-pressure valve island is communicated with an air supply input end of the loading cylinder 1703, and an air supply output end of the high-pressure valve island is respectively communicated with air supply input ends of the two-jaw lifting cylinder 1504 and the two-jaw cylinder 1505.

Therefore, through the detailed structural description of the automatic sample injector, a novel automatic mechanism for realizing automatic sample introduction and sample outlet of the adsorption tube in the full-automatic thermal desorption instrument by combining an electric mode and a pneumatic mode is provided, namely, on one hand, through arranging the Z-axis assembly 120, the X-axis assembly 130 and the Y-axis assembly 140, the adsorption tube grabbing sample feeding action and the adsorption tube returning action can be carried out in the upper area of the tray assembly 110, and on the other hand, through arranging the beam assembly 150, the cover taking assembly 160, the loading assembly 170 and the valve island assembly 180, complete sample introduction and sample outlet actions such as cross-connecting, cap taking, loading, unloading, cap covering, cross-connecting and the like can be sequentially carried out on the adsorption tube from which the sample is sent, so that the automatic sample injector is particularly suitable for the full-automatic thermal desorption instrument, the artificial workload is greatly reduced, time and labor are saved, and practical application and popularization.

Further preferably, the specific working method of the automatic sample injector sequentially comprises an automatic adsorption tube installation process and an automatic adsorption tube unloading process.

In detail, the automatic installation process of the adsorption pipe may include, but is not limited to, the following steps S101 to S104: s101, grabbing of the adsorption tube: moving the Z-axis assembly 120 to a position right above a target adsorption tube containing position (corresponding to an X-axis coordinate, a Y-axis coordinate and a Z-axis coordinate) 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 containing position from the tray assembly 110 through the Z-axis assembly 120; s102, connection of adsorption tubes: moving the Z-axis assembly 120 and the adsorption tube 6 to an intersection station through the X-axis assembly 130 and the Y-axis assembly 140, then moving the two-claw lifting cylinder 1504 and the two-claw cylinder 1505 to the intersection station through the beam stepping motor 1501 and the beam ball screw 1503, then enabling the two claw fingers to be in a clamping state and clamp the middle part of the adsorption tube 6 through the two-claw cylinder 1505, then enabling the Z-axis assembly 120 to loosen the adsorption tube 6, and finally moving the two-claw cylinder 1505 and the adsorption tube 6 downwards through the two-claw lifting cylinder 1504 to enable the adsorption tube 6 to be separated from the clamping range of the Z-axis assembly 120; s103, taking a cap of the adsorption tube: moving a two-jaw lifting cylinder 1504, a two-jaw cylinder 1505 and the adsorption tube 6 to a cap taking station through a crossbeam stepping motor 1501 and a crossbeam ball screw 1503, and then taking down the caps of the adsorption tube 6 which are positioned at the two vertical ends through a cap taking assembly 160; s104, loading of the adsorption tube: the two-claw lifting cylinder 1504, the two-claw cylinder 1505 and the adsorption tube 6 are moved to a loading station through the beam stepping motor 1501 and the beam ball screw 1503, then the two-claw cylinder 1505 and the adsorption tube 6 are lifted through the two-claw lifting cylinder 1504, an upper joint of an air path is inserted into an upper port of the adsorption tube 6, then the lower joint 1702 of the air path is lifted through the loading cylinder 1703, the lower joint 1702 of the air path is inserted into a lower port of the adsorption tube 6, then the two claw fingers are in a loose state through the two-claw cylinder 1505, and finally the two-claw lifting cylinder 1504 and the two-claw cylinder 1505 are moved to a waiting station through the beam stepping motor 1501 and the beam ball screw 1503. No matter the full-automatic thermal desorption appearance is in thermal desorption mode or sampling tank mode (promptly cooperate the detection that the suma jar automatic sample injector carried out VOCs), can all adopt aforementioned step S101 ~ S104 to load the gas circuit assembly with adsorption tube (being in thermal desorption mode this moment) or empty pipe (promptly when starting the sampling tank mode, load the air circuit assembly with the empty pipe as the adsorption tube in) to full-automatic thermal desorption appearance normally carries out the VOCs under the corresponding mode and detects. Before step S102, the two-claw lift cylinder 1504 needs to be returned to the following state: the two-claw cylinder 1505 is lifted; and the two-jaw cylinder 1505 needs to be in the following homing state: the two fingers are released.

In a detailed optimization, the automatic unloading process of the adsorption pipe may include, but is not limited to, the following steps: s201, unloading of the adsorption pipe: moving a two-claw lifting cylinder 1504, a two-claw cylinder 1505 and an adsorption tube 6 to a loading station through a crossbeam stepping motor 1501 and a crossbeam ball screw 1503, enabling two claw fingers to be in a clamping state through the two-claw cylinder 1505 and clamp the middle part of the adsorption tube 6, then moving a lower joint 1702 of an air path downwards through a loading cylinder 1703, enabling the lower joint 1702 of the air path to be drawn out of a lower port of the adsorption tube 6, and then moving the two-claw cylinder 1505 and the adsorption tube 6 downwards through the two-claw lifting cylinder 1504 to enable an upper joint of the air path to be drawn out of an upper port of the adsorption tube 6; s202, covering a cap of an adsorption tube: moving a two-claw lifting cylinder 1504, a two-claw cylinder 1505 and the adsorption tube 6 to a cap taking station through a crossbeam stepping motor 1501 and a crossbeam ball screw 1503, and then covering the cap on the two vertical ends of the adsorption tube 6 through a cap taking assembly 160; s203, returning of the adsorption pipe: moving a two-claw lifting cylinder 1504, a two-claw cylinder 1505 and an adsorption tube 6 to an intersection station through a beam stepping motor 1501 and a beam ball screw 1503, then moving a Z-axis assembly 120 to the intersection station through an X-axis assembly 130 and a Y-axis assembly 140, then lifting the two-claw cylinder 1505 and the adsorption tube 6 through the two-claw lifting cylinder 1504 to enable the adsorption tube 6 to be in the grabbing range of the Z-axis assembly 120, then grabbing the upper end part of the adsorption tube 6 through the Z-axis assembly 120, and finally enabling two claw fingers to be in a loose state through the two-claw cylinder 1505; s204, releasing the adsorption tube: the Z-axis assembly 120 and the suction tube 6 are moved to a position right above the target suction tube loading position by the X-axis assembly 130 and the Y-axis assembly 140, and then the suction tube 6 is vertically placed into the tray assembly 110 by the Z-axis assembly 120, and finally the suction tube 6 is released by the Z-axis assembly 120. No matter the full-automatic thermal desorption instrument is in the thermal desorption mode or the sampling tank mode (i.e. the detection of the VOCs is carried out by matching with the automatic Suma tank sample injector), the adsorption tube (in the thermal desorption mode at this time) or the empty tube (i.e. the empty tube is unloaded from the gas circuit assembly as the adsorption tube when the sampling tank mode is finished) can be unloaded from the gas circuit assembly by adopting the steps S201 to S204, so that the full-automatic thermal desorption instrument normally finishes the detection of the VOCs in the corresponding mode.

Preferably, the tray assembly 110 includes a fixing plate 1101, a tray driving cylinder 1102 and a tray 1103, wherein the tray driving cylinder 1102 is disposed on the fixing plate 1101, the tray 1103 is disposed on a movable portion of the tray driving cylinder 1102 and used 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 for containing a plurality of the adsorption tubes 6. As shown in fig. 1, the tray driving cylinder 1102 is used for horizontally moving the tray 1103 between the tray station and the loading position, so as to manually load and unload the adsorption tubes in batches at the loading position, thereby facilitating loading and unloading; the tray driving cylinder 1102 may be, but is not limited to, an existing rodless cylinder or a sliding table cylinder, etc. In addition, specifically, the air supply input end of the tray driving cylinder 1102 is communicated with the air supply output end of the high-pressure valve island.

Preferably, the tray assembly 110 further includes a plurality of pipe jacking cylinders corresponding to the adsorption pipe receiving positions one by one, wherein the pipe jacking cylinders are disposed at the bottom of the tray 1103 for jacking up the corresponding adsorption pipes 6 through the movable portions. By arranging the pipe-jacking cylinder (not shown in the drawings), before the Z-axis assembly 120 grabs the adsorption pipe on the target adsorption pipe containing position, the corresponding adsorption pipe is jacked up by the movable part for grabbing, so that the water is prevented from being dragged by the mud in the grabbing link, and the grabbing success rate is improved; before the adsorption pipe is put back, the movable part of the pipe jacking cylinder needs to be moved downwards to return, so that the adsorption pipe can return without obstacles; the pipe jacking cylinder can also be realized by adopting the existing cylinder structure. In addition, specifically, the air supply input end of the pipe jacking cylinder is communicated with the air supply output end of the high-pressure valve island.

Preferably, the Z-axis assembly 120 includes a Z-axis assembly mounting plate 1201, a three-jaw lifting cylinder 1202 and a three-jaw cylinder 1203, wherein the three-jaw lifting cylinder 1202 is disposed on the Z-axis assembly mounting plate 1201, the three-jaw cylinder 1203 is disposed on a movable portion of the three-jaw lifting cylinder 1202 and is used for driving the three-jaw cylinder 1203 to perform vertical reciprocating motion, and three fingers for gripping the upper end portion of the adsorption tube 6 are disposed on the three-jaw cylinder 1203. As shown in fig. 1, the three-jaw lifting cylinder 1202 is used for lifting or moving down the three-jaw cylinder 1203/and the suction tube 6, so as to vertically extract the suction tube 6 from the tray assembly 110 and vertically place the suction tube 6 into the tray assembly 110; the three-jaw lifting cylinder 1202 may be, but is not limited to, an existing rodless cylinder or a sliding table cylinder. The three-claw cylinder 1203 is used for switching the working states of three claws: the clamping state and the releasing state are convenient for completing corresponding actions above the target adsorption tube containing position and the handover station; the three-jaw cylinder 1203 can also be realized by adopting the existing cylinder structure. In addition, specifically, the air supply input ends of the three-jaw lifting cylinder 1202 and the three-jaw air cylinder 1203 are respectively communicated with the air supply output end of the low-pressure valve island.

More specifically, the Z-axis assembly 120 may, but is not limited to, vertically extract the suction tube 6 at the target suction tube loading position from the tray assembly 110 according to the following steps: s1011, after the Z-axis assembly 120 moves to a position right above the target adsorption tube containing position, enabling the three fingers to be in a loosening state through the three-jaw cylinder 1203; s1012, moving the three-jaw cylinder 1203 downwards through the three-jaw lifting cylinder 1202; s1013, enabling the three fingers to be in a clamping state and clamping the upper end part of the adsorption tube 6 through the three-jaw air cylinder 1203; s1014, the three-jaw cylinder 1203 and the adsorption tube 6 are lifted through the three-jaw lifting cylinder 1202, and the adsorption tube in the target adsorption tube containing position is vertically extracted from the tray assembly 110.

More specifically, the Z-axis assembly 120 may, but is not limited to, vertically place the suction tube 6 into the tray assembly 110 according to the following steps: s2041, after the Z-axis assembly 120 and the adsorption tube 6 move to a position right above a target adsorption tube containing position, the three-jaw cylinder 1203 and the adsorption tube 6 are moved downwards through the three-jaw lifting cylinder 1202, and the adsorption tube 6 is vertically placed on the target adsorption tube containing position of the tray assembly 110; s2042, enabling the three fingers to be in a released state through a three-jaw cylinder 1203; and S2043, lifting the three-jaw cylinder 1203 by the three-jaw lifting cylinder 1202.

Preferably, the X-axis assembly 130 includes an X-axis stepping motor 1301, a second belt and an X-axis ball screw 1303, wherein the X-axis stepping motor 1301 is connected to the X-axis ball screw 1303 through the second belt in a transmission manner, and is configured to drive a moving portion of the X-axis ball screw 1303 to horizontally and horizontally reciprocate, and the Z-axis assembly 120 is disposed on the moving portion of the X-axis ball screw 1303. As shown in fig. 1, the linear driving mechanism composed of the X-axis stepping motor 1301, the second belt, and the X-axis ball screw 1303 is a conventional structure, and can horizontally and laterally move the Z-axis assembly 120.

Preferably, the Y-axis assembly 140 includes a Y-axis stepping motor 1401, a third belt and a Y-axis ball screw 1403, wherein the Y-axis stepping motor 1401 is connected to the Y-axis ball screw 1403 through the third belt in a transmission manner, and is configured to drive a movable portion of the Y-axis ball screw 1403 to perform horizontal and longitudinal reciprocating motion, and the X-axis assembly 130 is disposed on the movable portion of the Y-axis ball screw 1403. As shown in fig. 1, the linear driving mechanism composed of the Y-axis stepping motor 1401, the third belt, and the Y-axis ball screw 1403 has a conventional structure, and can horizontally and vertically move the X-axis assembly 130 and the Z-axis assembly 120.

Preferably, a laser correlation switch is arranged below the transfer station, wherein the laser correlation switch comprises a transmitter and a receiver and is used for detecting whether a lower end cap of the adsorption tube 6 exists or not. By arranging the laser correlation switch (not shown in the drawings), when the Z-axis assembly 120 is connected with the adsorption tube (i.e., step S102 or step S203), whether the adsorption tube exists on the Z-axis assembly 120 can be determined by detecting whether the lower end cap exists, if so, the next step is continued, otherwise, the corresponding process is stopped, and an error signal is triggered to the control center, so that the automation degree is further improved. In addition, the control center is an upper computer and software for controlling the whole automatic sample injector and each controlled module (such as the valve island assembly, each stepping motor and the like) in the whole full-automatic thermal desorption instrument, wherein the software can provide a human-computer interface, work flow control, a cap detection algorithm and the like.

In summary, the automatic sample injector for the full-automatic thermal desorption instrument and the working method thereof provided by the embodiment have the following technical effects:

(1) the embodiment provides a novel automatic mechanism and a working method for realizing automatic sample introduction and sample discharge of an adsorption tube in a full-automatic thermal desorption instrument by combining an electric mode and a pneumatic mode, namely, on one hand, the adsorption tube can be subjected to sample grabbing and sending actions and adsorption tube replacement actions in an upper area of a tray assembly by arranging a Z-axis assembly, an X-axis assembly and a Y-axis assembly, and on the other hand, the adsorption tube subjected to sample sending can be subjected to complete sample introduction and sample discharge actions such as cross-connecting, cap taking, loading, unloading, cap covering and cross-connecting in sequence by arranging a beam assembly, a cap taking assembly, a loading assembly and a valve island assembly, so that the novel automatic mechanism is particularly suitable for the full-automatic thermal desorption instrument, the manual workload is greatly reduced, and the time and the labor are saved;

(2) the automatic sample injector also has the advantages of convenience in loading/unloading, high grabbing success rate, capability of automatically detecting errors, simple structure, easiness in implementation and the like, and is convenient for practical application and popularization.

Example two

As shown in fig. 1, 2 and 4, the present embodiment further provides a novel full-automatic thermal desorption apparatus on the basis of the first embodiment, including the autosampler for the full-automatic thermal desorption apparatus according to the first embodiment, and further including an air path assembly and a circuit assembly arranged on the main body support 100; the gas path 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 emptying connector 501, a second emptying connector 502, a third emptying connector 503, a sample recovery pipe 7, an eight-way switching valve 8, a temperature control dehydration pipe 9, a temperature control focusing pipe 10, a carrier gas inlet and outlet pipeline 11, a proportional valve 12 and a gas pressure sensor 13; the nitrogen connector 1 is communicated with an input port of the first mass flow controller 201, an output port of the first mass flow controller 201 is respectively communicated with a second port P32 of the multi-way switching valve 3, a normally closed port of the first electromagnetic switching valve 401 and a normally open port of the second electromagnetic switching valve 402, the normally open port of the first electromagnetic switching valve 401 is communicated with the first emptying connector 501, a common port of the first electromagnetic switching valve 401 is communicated with one of the gas path upper connector and the gas path lower connector 1702, the other of the gas path upper connector and the gas path lower connector 1702 is communicated with a first port P31 of the multi-way switching valve 3, and a third port P33 of the multi-way switching valve 3 is respectively communicated with a first port of the sample recovery tube 7 and a first port P81 of the eight-way switching valve 8; the second port of the sample recovery pipe 7 is communicated with the input port of the proportional valve 12, the air pressure sensor 13 is arranged in an air path between the second port of the sample recovery pipe 7 and the input port of the proportional valve 12, and the output port of the proportional valve 12 is communicated with the second emptying joint 502; the second port P82 of the eight-way switching valve 8 is communicated with the first port of the temperature-controlled dehydration pipe 9, the second port of the temperature-controlled dehydration pipe 9 is communicated with the eighth port P88 of the eight-way switching valve 8, the seventh port P87 of the eight-way switching valve 8 is communicated with the first port of the temperature-controlled focusing pipe 10, the second port of the temperature-controlled focusing pipe 10 is communicated with the fourth port P84 of the eight-way switching valve 8, the fifth port P85 of the eight-way switching valve 8 is communicated with the air inlet pipeline in the carrier gas inlet and outlet pipeline 11, the sixth port P86 of the eight-way switching valve 8 is communicated with the air outlet pipeline in the carrier gas inlet and outlet pipeline 11, and the third port P83 of the eight-way switching valve 8 is communicated with the common port of the second electromagnetic switching valve 402; the normally closed port of the second electromagnetic switching valve 402 is communicated with the input port of the second mass flow controller 202, and the output port of the second mass flow controller 202 is communicated with the third emptying joint 503; the circuit assembly comprises a suction tube temperature control assembly 141 which is arranged on the loading station and is used for controlling the temperature of the suction tube 6.

As shown in fig. 4, in the specific gas circuit assembly structure of the full-automatic thermal desorption instrument, the nitrogen connector 1 is used for communicating with an external nitrogen cylinder 200 so as to introduce dry nitrogen required for cleaning, desorption, purging and other operations into related pipelines inside the instrument. The first mass flow controller 201 is used for accurately controlling the flow of the introduced nitrogen; the second mass flow controller 202 is used for accurately controlling the flow of the derived gas, and both the first mass flow controller 201 and the second mass flow controller 202 can be implemented by using an existing electronic mass flow controller. The multi-way switching valve 3 is used for realizing the following two states of air path switching: in the A-bit state, the first port P31 is communicated with the third port P33, and the second port P32 is cut off; when the B position is in the state, the first interface is communicated with the second interface P32, and the third interface P33 is cut off; the multi-way switching valve 3 can be a three-way or more switching valve; in addition, specifically, the air supply input end of the multi-way switching valve 3 is communicated with the air supply output end of the high-pressure valve island in the valve island assembly 180, so that air path switching is performed through the high-pressure valve island. The first electromagnetic switching valve 401 and the second electromagnetic switching valve 402 are respectively used for realizing the following two states of air passage switching by an electromagnetic control mode: when the power is off, the common port is communicated with the normally closed port, and the normally open port is closed; in the energized state, the common port is connected with a normally open port, and the normally closed port is closed (in this specification, "normally closed" and "normally open" are used, meaning similar to "normally open contact" and "normally closed contact" in a circuit, that is, "open" means "open/close" means "close/open" of a path, and according to this meaning, other names can be named). The first evacuation connector 501, the second evacuation connector 502 and the third evacuation connector 503 are respectively used for exhausting gas in an internal pipeline of the instrument.

The adsorption tube 6 is used as a sample collecting piece for adsorbing and storing VOCs to be detected, generally can be a stainless steel tube or a quartz tube with the thickness of about 6mm multiplied by 9cm, and is internally filled with a solid adsorbent for adsorbing the VOCs; meanwhile, the automatic sample injector provided in the first embodiment can automatically load and unload the adsorption tubes 6, so as to achieve the purpose of automatically replacing the samples. Because the adsorption tube temperature plays critical effect to VOCs's adsorption process and desorption process, consequently through arranging adsorption tube temperature control assembly 141 can heat up, cool down and maintain control the adsorption tube temperature. Specifically, the adsorption tube temperature control assembly 141 comprises a temperature control assembly mounting plate 1411, an ultrathin cylinder 1412 and an electric heating block 1413, wherein the ultrathin cylinder 1412 is arranged on the temperature control assembly mounting plate 1411, the electric heating block 1413 is arranged on a movable part of the ultrathin cylinder 1412 and used for driving the electric heating block 1413 to horizontally and transversely reciprocate, and a U-shaped groove for semi-surrounding the adsorption tube 6 is arranged on the electric heating block 1413. As shown in fig. 2, the ultra-thin cylinder 1412 is used for horizontally and transversely moving the electric heating block 1413 at the loading station, so as to make the electric heating block 1413 close to and semi-surround the adsorption tube 6 for heating purpose, and make the electric heating block 1413 far away from and withdraw from the adsorption tube 6 for temporarily stopping heating purpose; in addition, specifically, the air supply input end of the ultra-thin air cylinder 1412 is communicated with the air supply output end of the high-pressure valve island in the valve island assembly 180, so that reciprocating driving is performed through the high-pressure valve island. In detail, the electric heating block 1413 may be, but is not limited to, an aluminum thermal block. In addition, since the electric heating block 1413 is generally not powered off after being powered on, in order to realize temporary temperature control, an adsorption tube air cooling component (not shown in the drawings) may be further disposed on the adsorption tube temperature control assembly 141, so as to maintain the temperature of the adsorption tube at a normal temperature state by simultaneously turning on the adsorption tube air cooling component, for example, the temperature of the adsorption tube needs to be maintained at the normal temperature state before the desorption step, so as to ensure that the VOCs in the tube are not desorbed. In detail, the adsorption pipe air cooling component may be a cooling fan.

The sample recovery pipe 7 is used for recovering VOCs passing through during shunting, and VOCs passing through during hot cleaning and possibly remaining on the temperature control dehydration pipe 9 and the temperature control focusing pipe 10 in a very small amount, so that when the detection of the adsorption pipe 6 fails, the sample recovery pipe 7 can be used as an adsorption pipe (the sample recovery pipe 7 needs to adopt the same pipe body structure as the adsorption pipe 6) for reanalysis; in addition, when the split detection is not performed (for example, in the case where the content of VOCs in the adsorption tube 6 is small), the sample recovery tube 7 may be replaced with an empty tube having no recovery adsorption function to keep the tubes in communication. The eight-way switching valve 8 is used for realizing the following two-state air path switching: in the A position state, the first port P81 is communicated with the eighth port P88, the second port P82 is communicated with the third port P83, the fourth port P84 is communicated with the fifth port P85, and the sixth port P86 is communicated with the seventh port P87; in the B position state, the first port P81 is communicated with the second port P82, the third port P83 is communicated with the fourth port P84, the fifth port P85 is communicated with the sixth port P86, and the seventh port P87 is communicated with the eighth port P88; in addition, the air supply input end of the eight-way switching valve 8 is communicated with the air supply output end of the high-pressure valve island in the valve island assembly 180, so that air path switching is carried out through the driving of the high-pressure valve island. In addition, in order to prevent the gas from remaining condensed due to a low temperature when flowing through the pipelines between the adsorption pipe 6 and the eight-way switching valve 8 and between the multi-way switching valve 3 and the eight-way switching valve 8, a central temperature control unit 144 for common heating may be disposed in a pipeline region between the adsorption pipe 6 and the eight-way switching valve 8, a mounting position of the multi-way switching valve 3, and a mounting position of the eight-way switching valve 8, as shown in fig. 4, and the central temperature control unit 144 may be specifically an aluminum hot plate, for example.

The temperature control dehydration tube 9 is used for freezing the moisture in the gas flowing through the temperature control dehydration tube in a low temperature mode (generally, the temperature is below zero degrees centigrade) during desorption to remove the moisture, so that most of VOCs enter the temperature control focusing tube 10. Because the temperature of the dehydration tube needs low temperature during desorption and high temperature during purging and hot cleaning, a temperature control unit is necessarily arranged around the dehydration tube body so as to conveniently carry out temperature rise, temperature reduction and maintenance control on the temperature of the dehydration tube; as shown in fig. 4, dehydration pipe port temperature control units 142 are respectively arranged at both side ports of the temperature controlled dehydration pipe 9; in order to facilitate temperature control and reduce temperature control cost, the low-temperature or normal-temperature control mode of the temperature control dehydration pipe 9 can preferentially adopt the existing electronic refrigeration technology, so that liquid nitrogen refrigeration is not needed, the refrigeration cost is greatly reduced, and the temperature control dehydration pipe is convenient and practical; and heating to high temperature, and winding and heating by using a conventional heating wire.

The temperature-controlled focusing pipe 10 is used for focusing and adsorbing the VOCs in the gas flowing through by using an internal solid adsorbent through a lower temperature mode (generally, the temperature is below-20 ℃) during desorption and purging, so that the aim of serving as a temporary VOCs transfer station is fulfilled. Because the temperature of the focusing tube needs low temperature during desorption and purging and high temperature during sample introduction and hot cleaning, a temperature control unit is also needed to be arranged around the focusing tube body so as to conveniently carry out temperature rise, temperature reduction and maintenance control on the temperature of the focusing tube; as shown in fig. 4, a focusing tube port temperature control unit 143 is arranged at a port of the temperature controlled focusing tube 10; in order to facilitate temperature control and reduce the temperature control cost, the low-temperature or normal-temperature control mode of the temperature control focusing tube 10 can also preferentially adopt the existing electronic refrigeration technology; and heating to high temperature, and winding and heating by using a conventional heating wire. In addition, the intraductal volume of control by temperature change focusing pipe 10 can be showing and be less than adsorption tube 6 to when low temperature environment, make VOCs's diffusion zone littleer, and then effectively focus VOCs, obtain the chromatogram of peak shape quality when doing benefit to follow-up separation and analysis, ensure quantitative analysis's effect.

The carrier gas inlet and outlet pipeline 11 is used for butting a carrier gas output pipe and a carrier gas return pipe of the gas chromatograph 300 so as to lead the volatile organic compounds in the temperature-controlled focusing pipe 10 into the gas chromatograph 300 along with the carrier gas, thereby realizing the purposes of sample introduction and separation analysis; in order to avoid the phenomenon of residual VOCs in the flow-through pipeline due to too low temperature of the carrier gas, as shown in fig. 4, a carrier gas temperature control unit 145 may also be disposed on the carrier gas inlet/outlet pipeline 11 so as to appropriately heat the gas flowing through the carrier gas inlet/outlet pipeline 11, for example, the carrier gas temperature control unit 145 may be a heating pipeline.

The proportional valve 12 is also used for accurately controlling the flow rate, the effect is similar to that of two mass flow controllers, and further, in a manner that the ratio of the flow of the proportional valve 12 to the flow of the second mass flow controller 202 is controlled to meet a target split ratio, the VOCs can be respectively and 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 for acquiring the air pressure data in the pipe between the second port of the sample recovery pipe 7 and the input port of the proportional valve 12 so as to monitor the internal air pressure of the pipe; in particular, it can be realized by an existing pressure sensor or an air pressure sensor. As shown in fig. 4, preferably, the proportional valve 12, the air pressure sensor 13 and the three-way connector 24 together constitute an integrated component structure, wherein a first port of the three-way connector 24 is communicated with a second port of the sample recovery tube 7, a second port of the three-way connector 24 is communicated with an input port of the proportional valve 12, and a third port of the three-way connector 24 is communicated with an air inlet port of the air pressure sensor 13, so that not only the foregoing objects can be achieved, but also multiple components can be integrated for convenient matching.

In addition, the air path assembly may further include a compressed air connector 30 having two ends respectively communicating with the valve island assembly 180 and the external compressed air bottle 500, and may further include a connector 50 (e.g., a three-way connector, a four-way connector, etc.) for interfacing with the multiplexing components. In addition, in the internal pipelines of the instrument of the gas circuit assembly, the pipelines through which the VOCs flow are made of an inerting material (generally, inerting stainless steel, such as silanized stainless steel, which is a kind of inerting stainless steel), and the cold spots or cold areas in the pipelines are reduced as much as possible so as to avoid the adsorption loss of the VOCs, while the other pipelines can be made of stainless steel pipes; the nitrogen connector 1, the first evacuation connector 501, the second evacuation connector 502, the third evacuation connector 503, and the compressed air connector 30 may be specifically through-plate connectors penetrating through the main body support 100.

The working principle of the full-automatic thermal desorption instrument is as follows: in the desorption step, the first mass flow controller 201, the second mass flow controller 202 and the proportional valve 12 are opened, the flow of the first mass flow controller 201 and the flow of the second mass flow controller 202 are set according to the target split ratio, and the ratio of the flow of the proportional valve 12 to the flow of the second mass flow controller 202 is controlled to meet the target split ratio, so that the 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 purging step and the sample injection analysis step are performed, so that the purpose of completing analysis and detection of the VOCs by matching the gas chromatograph 300 is achieved. From this through the detailed explanation of aforementioned concrete structure and theory of operation, except realizing full autoinjection and thermal desorption method analysis purpose, still provide a novel thermal desorption appearance structure that can arrange gas chromatograph and accomplish volatile organic compounds analysis and detection, it not only can realize accurate shunt control, can also be under the different split ratio circumstances, do benefit to converting each other the analysis result, the analysis result that makes sample recovery pipe can carry out qualitative and quantitative analysis, increase substantially the fault-tolerant rate of thermal desorption appearance, thereby can avoid the repeated sampling, conveniently carry out the detection of volatile organic compounds, further do benefit to practical application and popularization.

Optimally, the device also comprises an air inlet connector 15 and an air pump 16, wherein the air inlet connector 15 is used for being communicated with a common outlet of the sampling tank automatic sampler 400; the air inlet joint 15 is communicated with the first port P81 of the eight-way switching valve 8, the input port of the air pump 16 is communicated with the output port of the second mass flow controller 202, and the output port of the air pump 16 is communicated with the third emptying joint 503. As shown in FIG. 4, the air inlet connector 15 is used for introducing sample gas, nitrogen gas or internal standard gas from a sampling tank autosampler 400 (an existing sampling tank autosampler device, the basic structure is that a plurality of selector valves are communicated with different sampling tanks, when the sampling tank autosampler is switched to a certain sampling position, a common outlet of the plurality of selector valves is communicated with the corresponding sampling tank, besides, one path of the plurality of selector valves needs to be communicated with a nitrogen gas bottle, and the other path needs to be plugged), so as to realize the purpose of 'cross-boundary' collocation analysis of the sampling tanks; in addition, when the full-automatic thermal desorption instrument is provided with the main body support 100, the air inlet joint 15 can also be specifically a plate penetrating joint penetrating out of the main body support 100; in addition, as shown in fig. 4, in order to avoid the intake air temperature from being too low, an intake air temperature control unit 146 may be disposed at the installation position of the intake air connector 15 so as to appropriately heat the gas flowing through the intake air connector 15, for example, the carrier gas temperature control unit 146 may also be specifically a heating pipeline. The air pump 16 is used to provide pumping power for the gas flow in the internal piping of the instrument at start-up so that the sample gas, nitrogen gas, internal standard gas, or the like from the sample tank autosampler 400 can be introduced normally. Therefore, through the configuration of the elements, a sampling tank (namely a suma tank) or an air bag can be analyzed, the purpose of one device with multiple purposes is achieved, VOCs (including organic sulfur and n-hexadecane) listed in all thermal desorption method standards can be responded and analyzed, and all VOCs in volatile organic compound monitoring schemes in key areas issued by the country can be analyzed, namely the VOCs are applied to an adsorption tube and the VOCs are applied to a sampling tank, the VOCs basically encompass all VOCs at home and abroad, the device is designed by an integrated person, and the application range of the full-automatic thermal desorption instrument is greatly expanded. In addition, internal standard gas can be introduced into an internal pipeline of the instrument through a sampling tank automatic sampler provided with an internal standard gas level (namely, one path of the multi-path selection valve is communicated with an internal standard gas tank), so that the purpose of measurement and analysis by an internal standard method is realized, and the application range is further expanded.

Preferably, the eight-way switching valve further comprises an internal standard gas inlet joint 17 and a solenoid valve 18, wherein the internal standard gas inlet joint 17 is communicated with an input port of the solenoid valve 18, and an output port of the solenoid valve 18 is communicated with a first port P81 of the eight-way switching valve 8. As shown in fig. 4, the internal standard gas inlet joint 17 is used for communicating an internal standard gas tank (not shown in the figure), so that an internal standard gas can be introduced into an internal pipeline of the instrument when the electromagnetic valve 18 is controlled to be switched on, the purpose of measurement and analysis by an internal standard method is achieved, and the application range is further expanded. In addition, as shown in fig. 4, when the air inlet joint 15, the internal standard air inlet joint 17 and the electromagnetic valve 18 are included at the same time, the third port P33 of the multi-way switching valve 3, the first port of the sample collection pipe 7, the first port P81 of the eight-way switching valve 8, the air inlet joint 15 and the electromagnetic valve 18 can be communicated with each other by a combination structure of an inerting tee and an inerting four-way.

Preferably, the system also comprises a first containing box 19 for containing the temperature-controlled dehydration pipe 9, a second containing box 20 for containing the temperature-controlled focusing pipe 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 communicated with the nitrogen connector 1, the second port of the on-off valve 403 is respectively communicated with the input port of the first speed regulating valve 21 and the input port of the second speed regulating valve 22, the output port of the first speed regulating valve 21 is communicated with the inner cavity of the first accommodating box 19, and the output port of the second speed regulating valve 22 is communicated with the inner cavity of the second accommodating box 20. As shown in FIG. 4, the first and second containers 19 and 20 are approximately sealed boxes, which may be made of, but not limited to, a nitrogen-oxygen glass fiber material. The on-off valve 403 may be, but not limited to, an electromagnetic switching valve (which is used for implementing gas circuit switching in an electromagnetic control manner between a normally closed port and a normally open port in a power-off state, and a normally open port and a normally closed port in a power-on state, or an electromagnetic switch valve); as shown in fig. 4, when the on-off valve 403 is an electromagnetic switching valve, a normally closed port of the electromagnetic switching valve is blocked, a normally open port serves as a first port to communicate with the nitrogen gas connector 1, and a common port serves as a second port to communicate with the input port of the first speed regulation valve 21 and the input port of the second speed regulation valve 22, respectively. The first speed regulating valve 21 and the second speed regulating valve 22 are used for regulating the air flow speed respectively, so that nitrogen can be blown into the corresponding accommodating boxes at uniform speed. Therefore, through the structural design, the purpose of blowing nitrogen into the first accommodating box 19 and the second accommodating box 20 at uniform speed can be achieved by electrifying the on-off valve 403 and opening the first speed regulating valve 21 and the second speed regulating valve 22, dry nitrogen is fully filled around the temperature control dehydration pipe 9 and the temperature control focusing pipe 10, the phenomenon that accessories such as heating wires (the service life of the heating wires is easily reduced due to oxygen) or electronic refrigeration elements (water can freeze on the electronic refrigeration elements and damage hardware seriously) are influenced due to the existence of oxygen and moisture is avoided, the service life of a temperature control unit and the like is prolonged, and the temperature control dehydration pipe is particularly suitable for nitrogen blowing protection when the temperature control dehydration pipe 9 and the temperature control focusing pipe 10 are cleaned thermally.

Preferably, the sample recovery device further comprises a trap 23, wherein an input port of the trap 23 is communicated with the second port of the sample recovery pipe 7, and an output port of the trap 23 is communicated with an input port of the proportional valve 12. As shown in fig. 4, the trap 23 is used for adsorbing volatile organic compounds in the exhaust gas to protect the environment, and may be embodied as a quartz tube or a stainless steel tube filled with activated carbon.

To sum up, adopt the full-automatic thermal desorption appearance that this embodiment provided, on the technological effect basis of embodiment one, still have following technological effect:

(1) the embodiment provides a novel thermal desorption instrument structure which can complete analysis and detection of volatile organic compounds by matching with a gas chromatograph, besides the purpose of realizing analysis by full-automatic sample introduction and thermal desorption methods, the novel thermal desorption instrument structure can firstly open two mass flow controllers and a proportional valve in a desorption link, set the flow rates of the two mass flow controllers according to a target flow dividing ratio, and control the flow rate of the proportional valve and the flow rate of the mass flow controller for emptying to meet the target flow dividing ratio, so that VOCs can be quantitatively adsorbed in a focusing tube and a sample recovery tube according to the target flow dividing ratio, then a purging link and a sample introduction analysis link are carried out, thereby not only realizing accurate flow dividing control, but also being beneficial to mutually converting analysis results under the condition of different flow dividing ratios, and leading the analysis results of the sample recovery tube to be qualitatively and quantitatively analyzed, the fault tolerance of the thermal desorption instrument is greatly increased, so that repeated sampling can be avoided, the detection of volatile organic compounds is convenient, and the practical application and popularization are further facilitated.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: modifications of the technical solutions described in the embodiments or equivalent replacements of some technical features may still be made. And such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Finally, it should be noted that the present invention is not limited to the above alternative embodiments, and that various other forms of products can be obtained by anyone in light of the present invention. The above detailed description should not be taken as limiting the scope of the invention, which is defined in the claims, and which the description is intended to be interpreted accordingly.

Claims (10)

1. The automatic sample injector for the full-automatic thermal desorption instrument is characterized by comprising a main body support (100), a tray assembly (110), a Z-axis assembly (120), an X-axis assembly (130), a Y-axis assembly (140), a cross beam assembly (150), a cover taking 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 cross axis, and the Y axis is a horizontal longitudinal axis;

the tray assembly (110) is arranged on a tray station of the main body bracket (100) and is used for containing a plurality of adsorption tubes (6);

the Z-axis assembly (120) is arranged on the main body bracket (100) and is positioned above the tray assembly (110) and used for vertically extracting the adsorption tube (6) from the tray assembly (110) and vertically placing the adsorption tube (6) into the tray assembly (110);

the X-axis assembly (130) is arranged on the main body bracket (100) and is positioned above the tray assembly (110) and used for driving the Z-axis assembly (120) to horizontally and transversely reciprocate in an area above the tray assembly (110);

the Y-axis assembly (140) is arranged on the main body support (100) and is positioned above the tray assembly (110) and used for driving the X-axis assembly (130) to horizontally and longitudinally reciprocate in an upper area of the tray assembly (110) and enabling the Z-axis assembly (120) to reach a delivery station of the main body support (100);

the crossbeam assembly (150) is arranged on the main body bracket (100) and comprises a crossbeam stepping 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 stepping motor (1501) is in transmission connection with the crossbeam ball screw (1503) through the first belt and is used for driving a movable part of the crossbeam ball screw (1503) to horizontally and transversely reciprocate and enabling the movable part of the crossbeam ball screw (1503) to pass through a handing-over station, a cover taking-out station, a loading station and a waiting station of the main body bracket (100) in sequence in a single-pass manner, the two-claw lifting cylinder (1504) is arranged on the movable part of the crossbeam ball screw (1503), and the two-claw cylinder (1505) is arranged on the movable part of the two-claw lifting cylinder (1504) and is used for driving the two-claw cylinder (1505) to vertically reciprocate, two claw fingers used for clamping or releasing the middle part of the adsorption pipe (6) are arranged on the two claw cylinder (1505);

the cover taking assembly (160) is arranged on a cover taking station of the main body bracket (100) and is used for taking down the cover caps of the adsorption pipe (6) at two vertical ends and covering the cover caps at the corresponding ends;

the loading assembly (170) is arranged on a loading station of the main body support (100) and comprises an air path upper joint, an air path lower joint (1702) and a loading cylinder (1703), wherein the air path upper joint and the air path lower joint (1702) are arranged in an up-down opposite mode, and the air path lower joint (1702) is arranged on a movable part of the loading cylinder (1703) and used for driving the air path lower joint (1702) to do vertical reciprocating motion;

the valve island assembly (180) is disposed on the body frame (100) for supplying air to each cylinder.

2. The autosampler for full-automatic thermal desorption instrument according to claim 1, characterized in that the tray assembly (110) comprises a fixing plate (1101), a tray driving cylinder (1102) and a tray (1103), wherein the tray driving cylinder (1102) is arranged on the fixing plate (1101), the tray (1103) is arranged on the movable part of the tray driving cylinder (1102) for driving the tray (1103) to do horizontal linear reciprocating motion between the tray station to the loading station, and the tray (1103) is used for containing a plurality of adsorption tubes (6).

3. The autosampler for full-automatic thermal desorption instrument according to claim 2, wherein the tray assembly (110) further comprises a plurality of top tube cylinders corresponding to the adsorption tube loading positions one by one, wherein the top tube cylinders are arranged at the bottom of the tray (1103) for jacking up the corresponding adsorption tubes (6) through the movable portion.

4. The automatic sample injector for the full-automatic thermal desorption instrument according to claim 1, characterized in that the Z-axis assembly (120) comprises a Z-axis assembly mounting plate (1201), a three-jaw lifting cylinder (1202) and a three-jaw cylinder (1203), wherein the three-jaw lifting cylinder (1202) is arranged on the Z-axis assembly mounting plate (1201), the three-jaw cylinder (1203) is arranged on a movable part of the three-jaw lifting cylinder (1202) and used for driving the three-jaw cylinder (1203) to do vertical reciprocating motion, and three fingers for grabbing the upper end part of the adsorption tube (6) are arranged on the three-jaw cylinder (1203).

5. The autosampler for full-automatic thermal desorption instrument according to claim 1, wherein the X-axis assembly (130) comprises an X-axis stepping motor (1301), a second belt and an X-axis ball screw (1303), wherein the X-axis stepping motor (1301) is in transmission connection with the X-axis ball screw (1303) through the second belt, and is used for driving the movable part of the X-axis ball screw (1303) to horizontally and transversely reciprocate, and the Z-axis assembly (120) is arranged on the movable part of the X-axis ball screw (1303).

6. The autosampler for the fully automatic thermal desorption instrument according to claim 1, wherein the Y-axis assembly (140) comprises a Y-axis stepping motor (1401), a third belt and a Y-axis ball screw (1403), wherein the Y-axis stepping motor (1401) is connected with the Y-axis ball screw (1403) through the third belt for driving the movable part of the Y-axis ball screw (1403) to reciprocate horizontally and longitudinally, and the X-axis assembly (130) is arranged on the movable part of the Y-axis ball screw (1403).

7. The autosampler for a fully automatic thermal desorption apparatus according to claim 1, wherein a laser correlation switch is arranged below the hand-over station, wherein the laser correlation switch comprises a transmitter and a receiver for detecting whether the lower end cap of the adsorption tube (6) is present.

8. An operation method of an autosampler, characterized in that the autosampler is the autosampler for the full-automatic thermal desorption apparatus according to any one of claims 1 to 7, and comprises an automatic adsorption tube installation process, wherein the automatic adsorption tube installation process comprises the following steps:

s101, grabbing of an adsorption tube: moving the Z-axis assembly (120) to a position right above a target adsorption tube containing 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 containing position from the tray assembly (110) through the Z-axis assembly (120);

s102, connection of adsorption tubes: moving the Z-axis assembly (120) and the adsorption tube (6) to an intersection station through the X-axis assembly (130) and the Y-axis assembly (140), then moving the two-claw lifting cylinder (1504) and the two-claw cylinder (1505) to the intersection station through the crossbeam stepping motor (1501) and the crossbeam ball screw (1503), then enabling the two claw fingers to be in a clamping state through the two-claw cylinder (1505) and clamping the middle part of the adsorption tube (6), then enabling the Z-axis assembly (120) to release the adsorption tube (6), and finally enabling the adsorption tube (6) to be separated from the grabbing range of the Z-axis assembly (120) through the two-claw lifting cylinder (1504) to move the two-claw cylinder (1505) and the adsorption tube (6) downwards;

s103, taking a cap of the adsorption tube: moving a two-jaw lifting cylinder (1504), a two-jaw cylinder (1505) and an adsorption tube (6) to a cap taking station through a crossbeam stepping motor (1501) and a crossbeam ball screw (1503), and then taking down the caps of the adsorption tube (6) and positioned at the two vertical ends through a cap taking assembly (160);

s104, loading of the adsorption tube: the two-claw lifting cylinder (1504), the two-claw cylinder (1505) and the adsorption tube (6) are moved to a loading station through the beam stepping motor (1501) and the beam ball screw (1503), then the two-claw cylinder (1505) and the adsorption tube (6) are lifted through the two-claw lifting cylinder (1504), the upper joint of the air circuit is inserted into the upper port of the adsorption tube (6), then the lower joint (1702) of the air circuit is lifted through the loading cylinder (1703), the lower joint (1702) of the air circuit is inserted into the lower port of the adsorption tube (6), then the two claw fingers are in a loose state through the two-claw cylinder (1505), and finally the two-claw lifting cylinder (1504) and the two-claw cylinder (1505) are moved to a waiting station through the beam stepping motor (1501) and the beam ball screw (1503).

9. The method of claim 8, further comprising a sorbent tube auto-unload procedure after the sorbent tube auto-mount procedure, wherein the sorbent tube auto-unload procedure comprises the following steps:

s201, unloading of the adsorption pipe: moving a two-claw lifting cylinder (1504), a two-claw cylinder (1505) and an adsorption tube (6) to a loading station through a crossbeam stepping motor (1501) and a crossbeam ball screw (1503), enabling two claws to be in a clamping state through the two-claw cylinder (1505), clamping the middle part of the adsorption tube (6), moving a gas circuit lower joint (1702) downwards through a loading cylinder (1703), enabling the gas circuit lower joint (1702) to draw out a lower port of the adsorption tube (6), and moving the two-claw cylinder (1505) and the adsorption tube (6) downwards through the two-claw lifting cylinder (1504), enabling a gas circuit upper joint to draw out an upper port of the adsorption tube (6);

s202, covering a cap of an adsorption tube: moving a two-jaw lifting cylinder (1504), a two-jaw cylinder (1505) and an adsorption tube (6) to a cap taking station through a crossbeam stepping motor (1501) and a crossbeam ball screw (1503), and then covering caps at two vertical ends of the adsorption tube (6) through a cap taking assembly (160);

s203, returning of the adsorption pipe: moving a two-claw lifting cylinder (1504), a two-claw cylinder (1505) and an adsorption tube (6) to an intersection station through a crossbeam stepping motor (1501) and a crossbeam ball screw (1503), then moving a Z-axis assembly (120) to the intersection station through an X-axis assembly (130) and a Y-axis assembly (140), then lifting the two-claw cylinder (1505) and the adsorption tube (6) through the two-claw lifting cylinder (1504), enabling the adsorption tube (6) to be in the grabbing range of the Z-axis assembly (120), grabbing the upper end part of the adsorption tube (6) through the Z-axis assembly (120), and finally enabling two claw fingers to be in a loosening state through the two-claw cylinder (1505);

s204, putting back the adsorption tube: the Z-axis assembly (120) and the adsorption tube (6) are moved to the position right above a target adsorption tube containing position through the X-axis assembly (130) and the Y-axis assembly (140), then the adsorption tube (6) is vertically placed into the tray assembly (110) through the Z-axis assembly (120), and finally the adsorption tube (6) is loosened through the Z-axis assembly (120).

10. A full-automatic thermal desorption instrument, which is characterized by comprising the automatic sample injector for the full-automatic thermal desorption instrument according to any one of claims 1 to 7, and further comprising a gas circuit assembly and a circuit assembly which are arranged on the main body bracket (100);

the gas path 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 emptying connector (501), a second emptying connector (502), a third emptying connector (503), a sample recovery pipe (7), an eight-way switching valve (8), a temperature control dehydration pipe (9), a temperature control focusing pipe (10), a carrier gas inlet and outlet pipeline (11), a proportional valve (12) and a gas pressure sensor (13);

the nitrogen connector (1) is communicated with an input port of the first mass flow controller (201), the output port of the first mass flow controller (201) is respectively communicated with a 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 communicated with the first emptying joint (501), the common port of the first electromagnetic switching valve (401) is communicated with one of the air path upper joint and the air path lower joint (1702), the other one of the air path upper connector and the air path lower connector (1702) is communicated with a first interface (P31) of the multi-way switching valve (3), the third interface (P33) of the multi-way switching valve (3) is respectively communicated with 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 pipe (7) is communicated with the input port of the proportional valve (12), the air pressure sensor (13) is arranged in an air path between the second port of the sample recovery pipe (7) and the input port of the proportional valve (12), and the output port of the proportional valve (12) is communicated with the second emptying joint (502);

the second port (P82) of the eight-way switching valve (8) is communicated with the first port of the temperature control dehydration pipe (9), the second port of the temperature control dehydration pipe (9) is communicated with an eighth port (P88) of the eight-way switching valve (8), a seventh interface (P87) of the eight-way switching valve (8) is communicated with the first port of the temperature control focusing pipe (10), the second port of the temperature control focusing pipe (10) is communicated with a fourth port (P84) of the eight-way switching valve (8), a fifth interface (P85) of the eight-way switching valve (8) is communicated with an air inlet pipeline in the carrier gas inlet and outlet pipeline (11), a sixth port (P86) of the eight-way switching valve (8) is communicated with an air outlet pipeline in the carrier gas inlet and outlet pipeline (11), a third port (P83) of the eight-way switching valve (8) is communicated with a common port of the second electromagnetic switching valve (402);

the normally closed port of the second electromagnetic switching valve (402) is communicated with the input port of the second mass flow controller (202), and the output port of the second mass flow controller (202) is communicated with the third emptying joint (503);

the circuit assembly comprises a suction tube temperature control assembly (141) which is arranged on the loading station and is used for controlling the temperature of the suction tube (6).

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