Fully automatic multi-channel needle-type gas sampling device and automatic online gas dilution method

Abstract

The present invention discloses a fully automatic multi-channel needle-type gas sampling device and an automatic online gas dilution method, comprising a turret body, a controller, a needle-type sampling module, and a sample tray sampling module, a dilution module, and an exhaust module composed of an injection connection unit; the needle-type sampling module is fixedly arranged on the turret body, and the sample tray sampling module, the dilution module, and the exhaust module are respectively arranged on the movement stroke of the needle-type sampling module on the turret body. The present invention arranges a constant temperature needle-type sampling module, a sample injection tray, a standard gas sampling module, a dilution module, an exhaust module and other modules on the turret mechanism to realize fully automatic multi-channel needle-type gas sampling, completely solves the problem of mutual cross-contamination between high- and low-concentration samples, and can change the gas injection volume at any time according to the difference in sample concentration, and can automatically and continuously perform dynamic dilution on high-concentration samples or standard gases, significantly improving the precision and accuracy of gas sample detection.

Description

Technical Field

[0001] The invention relates to the technical field of instrument analysis sampling, and in particular to a full-automatic multi-channel needle-type gas sampling device and an automatic online gas dilution method. Background Art

[0002] With the strengthening of environmental pollutant gas monitoring and analysis, the direct analysis of gas samples by chromatography is becoming more and more common. Compared with liquid samples, gas samples are large in volume and highly diffusive. Using a traditional manual gas syringe to directly extract samples and inject them at the chromatographic injection port often encounters many problems such as adsorption on the inner wall of the syringe, high recoil pressure on the chromatographic column head, and gas leakage during operation that endangers the health of the test personnel. This makes the quantitative analysis of gas samples inaccurate and the repeatability of the measurement results poor. Especially when the sample concentration is high and dilution injection or preparation of a standard gas curve is required, the manual dilution and preparation results have greater errors.

[0003] At present, domestic and foreign instrument manufacturers all use six-way valve gas samplers. Its valve body belongs to a plane rotating valve. A certain volume of sample is measured with a quantitative loop, and the sample is pushed into the chromatographic column quickly and accurately with the help of power or chromatographic carrier gas. Most valve-type fully automatic gas sampling devices use a sampling valve with multiple channels (10-way valve, 12-way valve) to connect the gas sampling bag or other gas sampling storage device. The other end of the valve is connected to the quantitative loop. A stepper motor or a multi-way electromagnetic switch is used to switch between different samples, and a vacuum pump is used to transfer the sample into the quantitative loop. However, the valve-type fully automatic gas sampling device has the following significant disadvantages: 1. The injection volume is fixed (quantitative loop volume), and the injection volume cannot be changed with the sample concentration; 2. There is a common channel when different samples are extracted, especially a one-way multi-channel sampling valve, and there is significant cross-contamination between high and low concentration samples; 3. It is impossible to automatically and continuously dilute high-concentration samples or standard gases dynamically online; 4. The gas sample in the quantitative loop cannot be automatically injected into the chromatographic column, and the gas path of the chromatographic instrument needs to be modified, and the chromatographic carrier gas is introduced into the chromatographic column. Summary of the invention

[0004] The purpose of the present invention is to provide a fully automatic multi-channel needle-type gas injection device and an automatic online gas dilution method, which can avoid the dependence of the traditional valve-type injection device on the transmission line and / or the quantitative loop, completely solve the problem of cross-contamination between high- and low-concentration samples, and can change the gas injection volume at any time according to the difference in sample concentration, and can automatically and continuously dilute the high-concentration sample or standard gas online, significantly improving the precision and accuracy of gas sample detection. The instrument adopts a gas-tight injection needle injection method, and does not need to modify the carrier gas path of the chromatographic instrument, thereby ensuring the reliability of the chromatographic analysis instrument.

[0005] The technical solution adopted by the present invention is:

[0006] A fully automatic multi-channel needle-type gas sampling device comprises a turret body, a controller, a needle-type sampling module, and a sample tray sampling module, a dilution module, and an exhaust module formed by an injection connection unit; the needle-type sampling module is fixedly arranged on the turret body, and the sample tray sampling module, the dilution module, and the exhaust module are respectively arranged on the movement stroke of the needle-type sampling module on the turret body; the injection connection unit comprises, from top to bottom, a sampling needle guide port, a sealing gasket, and a connecting pipe for cooperating with the injection needle of the needle-type sampling module for injection, the lower end of the sampling needle guide port and the upper end of the connecting pipe are respectively sealed with the sealing gasket, and the sampling needle guide port and the connecting pipe are coaxially arranged;

[0007] A plurality of first injection connection units are vertically fixedly arranged on the sample tray of the sample tray injection module, and the lower end of the connecting pipe of each first injection connection unit is respectively connected to the gas outlet of a gas storage device such as a gas sampling bag or a syringe;

[0008] The dilution module comprises a third sample injection connection unit and an inert gas source, and the lower end of the connecting pipe of the third sample injection connection unit is used to communicate with the gas outlet of the inert gas source;

[0009] The exhaust module comprises a fourth sample injection connection unit and a filter assembly, and the lower end of the connecting pipe of the fourth sample injection connection unit is used to communicate with the air inlet of the filter assembly.

[0010] The filter assembly comprises an exhaust gas pipe and a filter adsorption tube, one end of the exhaust gas pipe is connected to the lower end of the connecting pipe of the fourth sample injection connection unit, and the other end is connected to the air inlet of the filter adsorption tube.

[0011] It also includes a cleaning port and a heating module. The cleaning port is opened on the side wall of the upper end of the needle cavity of the gas sampling needle of the needle sampling module, and when the needle rod of the gas sampling needle is at the highest position of the needle cavity, the cleaning port is connected with the needle cavity, and the cleaning port is connected with the gas outlet of the inert gas source. The heating module is covered and arranged on the outside of the needle cavity for heating the needle cavity.

[0012] It also includes a standard gas sampling module, which includes a plurality of second sampling connection units, which are vertically arranged on a standard sampling station through a fixed bracket, and the lower ends of the connecting tubes of the plurality of second sampling connection units are respectively used to connect with the standard gas cylinders, and the standard sampling station is arranged on the movement stroke of the needle sampling module on the turret automatic control structure.

[0013] It also includes a pressure regulating control structure, the output end of the controller is connected to the input end of the pressure regulating control structure, and the pressure regulating control structure includes a pressure reducing valve and an electromagnetic switch valve, which are sequentially arranged between the inert gas source and the connecting pipe and the air inlet of the third sample injection connection unit.

[0014] The sample injection tray module includes a base, a sample tray, a slide rail, a sensor and a stepper motor. The base is provided with a slider that cooperates with the slide rail. The base is connected to the output shaft of the stepper motor and is used to make reciprocating motion along the slide rail under the drive of the stepper motor. The multiple first injection connection units are evenly arranged into multiple arc structures, and the centers of the multiple arc structures coincide with the axes of the rotating shaft of the turret automatic control mechanism on the same horizontal plane as the first injection connection units. The control input ends of the sensor and the stepper motor are connected to the output end of the controller. The sensor is used to monitor the actual position of the sample tray.

[0015] The automatic online gas dilution method based on a fully automatic multi-channel needle-type gas injection device comprises the following steps:

[0016] Step A: First, clean the sampling needle through the cleaning port and heating module:

[0017] The controller controls the turret body to rotate to the station where the exhaust module is located. The needle sampling module inserts the syringe sampling needle into the sampling needle guide port of the fourth injection connection unit and passes through the sealing gasket. Then, the syringe needle rod moves up to above the upper cleaning port of the syringe. The controller controls the opening of the first electromagnetic switch valve. After the gas from the inert gas source is opened through the first electromagnetic switch valve, it enters the internal space of the syringe. At the same time, the controller controls the heating module to heat up according to the set temperature. The heated inert gas cleans the inside of the syringe. After the cleaning time set by the controller is reached, the controller sends a control signal to the heating module to turn off the heating. After the syringe returns to room temperature, the controller sends a control signal to the first electromagnetic switch valve to close the first electromagnetic switch valve. The controller sends a control signal to the turret body to move the syringe needle rod down to the zero scale to complete the cleaning of the sampling needle.

[0018] Step B: Fill the cleaned sampling needle pipeline, discharge the inert gas in the pipeline, and fill the entire pipeline and sampling needle with the sample to improve the accuracy of subsequent sampling;

[0019] Step C: Sampling through the sampling needle after the pipeline is filled:

[0020] The controller extracts samples according to the volume of gas sample or standard gas to be extracted calculated by the software;

[0021] Step D: Dilute the sample in the sample tube as needed:

[0022] The controller controls the turret body to lift up, pull out the sampling needle, and the turret body is transferred to the gradient dilution station where the dilution module is located, and inserted downward into the third injection connection unit, and the controller controls the second electromagnetic switch valve to open, and the controller controls the turret body to extract the inert gas for dilution according to the value calculated by the software;

[0023] Step E: Equilibrate the diluted sample:

[0024] After the inert gas for dilution is extracted, the turret body does not move, but stands for a certain period of time, and waits for the diluted sample or standard gas to be completely mixed according to the set gas mixing time;

[0025] Step F: Quantitatively set the balanced sample so that the sample volume in the sampling needle is consistent with the set required value:

[0026] Step G: After the controller controls the turret body to rotate to the injection position, injection is completed:

[0027] Pull the syringe out of the exhaust port, turn the turret to the injection port position of the chromatographic host, and push the sample into the chromatographic system for analysis according to the injection volume set by the program.

[0028] The step B specifically includes: the controller controls the turret body to rotate to the sample sampling port or the standard gas sampling port, the sampling needle is inserted into the sampling position at a set height, generally 5 mm, the syringe needle moves up to the set scale, the sampling needle is pulled out, the turret rotates to the exhaust port position of the cleaning-waste discharge module, the gas is discharged, and the gas is discharged repeatedly so that the sample or standard gas completely fills the transmission pipeline.

[0029] The step F specifically includes: the controller controls the turret body to pull the syringe out of the cleaning port, the turret body rotates to the station where the exhaust module is located, and the syringe sampling needle is lowered and inserted through the fourth sampling connection unit of the exhaust module through the corresponding sealing gasket, and the controller controls the syringe needle rod to descend to discharge excess mixed sample or standard gas.

[0030] In step F, if the dilution ratio exceeds the maximum single dilution amount, steps DF may be repeated until the dilution ratio set by the program is reached.

[0031] The present invention is to set a constant temperature needle sampling module, a sample injection plate, a standard gas sampling module, a dilution module, an exhaust module and other modules on a fully automatic turret mechanism to realize fully automatic multi-channel needle gas injection, avoid the dependence of the traditional valve injection device on the transmission line and / or the quantitative loop, completely solve the problem of cross contamination between high and low concentration samples, and can change the gas injection volume at any time according to the difference in sample concentration, and can automatically and continuously dilute the high concentration sample or standard gas online, significantly improving the precision and accuracy of gas sample detection. The instrument adopts a gas-tight injection needle injection method, and does not need to modify the carrier gas path of the chromatographic instrument, thereby ensuring the reliability of the chromatographic analysis instrument. Further, the present invention refers to the national standard for gas injection detection, designs and discloses an automatic online gas dilution method, which can automatically prepare a gas standard curve, automatically perform dynamic dilution of high concentration samples, and avoid the environmental and personnel errors generated when manually preparing the standard curve and diluting the high concentration sample, thereby reducing the workload of the inspection and detection personnel and improving the efficiency of the inspection and detection work. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 It is a structural schematic diagram of the present invention;

[0034] Figure 2 It is a structural schematic diagram of the sample injection connection unit of the present invention;

[0035] Figure 3 It is a schematic diagram of the structure of the dilution module and the exhaust module of the present invention;

[0036] Figure 4 This is a schematic structural diagram of the sample tray injection module of the present invention;

[0037] Figure 5 This is a schematic diagram of the structure of the standard gas sampling module of the present invention;

[0038] Figure 6 This is a schematic diagram of the structure of the constant temperature needle sampling module of the present invention;

[0039] Figure 7 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] like Figure 1 , 2 As shown in Figure 3, the present invention includes a turret body 1, a controller, a needle sampling module 6, and a sample tray sampling module 4, a dilution module 3, and an exhaust module 2 composed of an injection connection unit; the needle sampling module 6 is fixedly arranged on the turret body 1, and the sample tray sampling module 4, the dilution module 5 and the exhaust module 2 are respectively arranged on the rotational movement stroke of the needle sampling module 6 on the turret body 1; the injection connection unit includes, from top to bottom, a sampling needle guide port 13, a sealing gasket 14 and a connecting pipe for cooperating with the injection needle of the needle sampling module, the lower end of the sampling needle guide port 13 and the upper end of the connecting pipe are respectively sealed with the sealing gasket 14, and the sampling needle guide port 13 and the connecting pipe are coaxially arranged. Specifically, the turret mechanism includes a turret and a turret base. The turret is provided with a power mechanism, a sampling mechanism mounting plate and a needle sampling module with heating, constant temperature and inert gas cleaning functions. Since the turret structure body itself is existing technology, it only needs to provide rotation, stepping and lifting, so its specific structure will not be described here.

[0042] The needle sampling module moves up and down under the action of the power mechanism through the sampling mechanism mounting plate; the sample injection tray is detachably arranged on one side of the turret mechanism, and a standard gas sampling module is arranged on the side of the turret base adjacent to the sample injection tray for standard gas collection, and a dilution module and an exhaust module are arranged on the other side of the turret base corresponding to the side adjacent to the sample injection tray. The dilution module and the exhaust module are fixedly arranged on the gradient dilution station of the turret automatic sampler body base, and are used for automatic continuous dynamic online dilution of high-concentration samples or standard gases as needed. An injection module for connecting to the inlet of a chromatographic instrument is arranged on the side of the turret base opposite to the sample injection tray.

[0043] The sampling needle guide port 13 has an inverted cone at the top and a cylindrical through hole at the bottom that matches the outer diameter of the injection needle core, which is used to guide the injection needle core into the sampling port. The T-shaped sealing gasket 14 is a cylinder connected to each other from top to bottom, with a thicker diameter at the top that is consistent with the outer thread diameter at the bottom of the guide port, and a thinner diameter at the bottom that is consistent with the total boss diameter in the through hole. The lower part of the T-shaped sealing gasket 14 and the upper part of the plastic blade ring 15 have a cylindrical through hole with a thinner diameter, and the diameter matches the outer diameter of the injection needle core. The top of the injection needle core is inserted into this area for gas sample extraction. The setting of the cylindrical through hole can prevent the sampling needle from directly contacting the upper end of the connecting tube, thereby avoiding the problem of contact wear between the two and reduced sealing.

[0044] A plurality of first sample injection connection units 34 are vertically fixedly arranged on the sample tray 17 of the sample tray injection module 4, and the lower end of the connecting pipe 27 of each first sample injection connection unit 34 is respectively connected to the gas outlet of a gas sampling bag or a syringe or other gas sample storage device;

[0045] The dilution module comprises a third sample injection connection unit 9 and an inert gas source (not shown in the figure). The lower end of the connecting pipe of the third sample injection connection unit 9 is used to communicate with the gas outlet of the inert gas source. Figure 3 As shown, the inert gas inlet pipe 7 is connected to the lower end of the connecting pipe.

[0046] The exhaust module includes a fourth sample injection connection unit 10 and a filter assembly, and the lower end of the connecting pipe of the fourth sample injection connection unit 10 is used to communicate with the air inlet of the filter assembly. The filter assembly includes an exhaust pipe 11 and a filter adsorption tube 12, one end of the exhaust pipe 11 is connected to the lower end of the connecting pipe of the fourth sample injection connection unit 10, and the other end is connected to the air inlet of the filter adsorption tube 12. In actual use, since the above two modules are relatively small, they can be set together according to actual needs, but they are still different workstations. The outer shells of the two can be made of semi-circular aluminum or plastic, the lower part is a cylindrical base, and the upper part has two small cylinders connected to each other, and the base and the upper cylinder are made of the same material. There is a cylindrical through hole in the middle of the two upper cylinders. The through hole is located on the arc swept by the turret injection needle. The internal structure of the through hole is consistent with the sampling port in the sample tray. The lower part is connected through a pipe, one of which is connected to the inert gas for cleaning, and the other is connected to the filter adsorption module for exhaust gas adsorption to prevent laboratory pollution. The program can be adjusted according to different connections to achieve different functions.

[0047] The cleaning port and the heating module are also included. The cleaning port is opened on the side wall of the upper end of the needle cavity of the gas sampling needle of the needle sampling module. When the needle rod 30 of the gas sampling needle is at the highest position of the needle cavity, the cleaning port is connected with the needle cavity. The cleaning port is connected with the gas outlet of the inert gas source. The heating module is covered and arranged outside the needle cavity for heating the needle cavity. Figure 6 As shown, the sampling needle module includes a gas injection needle rod 30, an upper nut 31, an upper fixing block 32, a shell 33, a lower nut 36, a lower fixing block 37, an extension tube screw 38, a flanged air pipe 39, a copper heat pipe 40, and a heating film 41. The extension tube screw 38 fixes the flanged air pipe 39 on the cleaning port to connect with the inert gas source. At the same time, the heating film 41 and the copper heat pipe 40 are sequentially covered on the outside of the needle cavity to provide a heating environment for the needle cavity.

[0048] The shell 33 of the heating thermostatic module in the present invention has two parts, front and back, which are connected by a slot. The front half is a rectangular groove with guide grooves for connection on both sides, and the protruding outer part of the rear half is provided with a slot plate and a positioning column. After the two parts are connected, a cylindrical through hole is formed in the middle of the interior. There is an annular slot on the upper and lower parts of the through hole, which is used to fix the upper and lower fixing blocks of the metal heat-conducting pipe; a square hole is opened in the middle of the protruding slot plate of the rear half, and the wiring of the heating pipe and the temperature probe is connected to the control circuit from here. The lower fixing block 32 is a T-shaped cylinder, and the lower small cylinder is provided with an external thread, which matches the internal thread of the lower nut 36, thereby locking the two parts of the heating thermostatic module shell; there is a through hole in the middle, and the diameter is directly matched with the outer diameter of the metal heat-conducting pipe.

[0049] In actual use, the cleaning port can be installed and fixed by a gas introduction module. The gas introduction module is integrated with the upper fixing block 32 for fixing the metal heat pipe. The gas introduction module is a T-shaped cylinder with a circular groove at the bottom, which matches the upper slot of the heating constant temperature module; there is a circular through hole in the horizontal direction in the middle part, which is the cleaning port. There is a thread inside the cleaning port, which matches the external thread of the extension tube screw 38 of the inert gas connecting pipeline for cleaning; the upper part is a small cylinder with an external thread, which matches the internal thread of the upper nut 31, thereby locking the gas injector.

[0050] The copper heat pipe 40 is a cylinder with a through hole inside. The inner diameter matches the outer diameter of the gas injector and is coated on the outside of the gas injector, i.e., the outside of the needle cavity. The copper heat pipe 40 is wrapped with a heating film 41. The diaphragm is embedded with a heating wire and a temperature probe. The diaphragm is wrapped with thermal insulation material for constant temperature insulation.

[0051] The gas syringe type injection needle is an existing technology, and the specific structure will not be repeated. It is an airtight injection needle. There is a circular horizontal through hole, i.e., a cleaning port, on the upper part of the glass needle rod. The outside of the through hole matches the horizontal through hole on the gas introduction module. The gas connecting pipeline after flanging is sealed with an extension tube screw and the glass needle rod through hole, which is convenient for cleaning the gas syringe.

[0052] like Figure 5 As shown, it also includes a standard gas sampling module, which includes a plurality of second sampling connection units 35, which are vertically arranged on the standard sampling station through a fixed bracket 28, and the lower ends of the connecting pipes of the plurality of second sampling connection units 35 are respectively used to connect with the standard gas cylinder through the standard gas connection pipe 29, and the standard sampling station is arranged on the movement stroke of the needle sampling module on the turret automatic control structure. The standard gas sampling module is made of semi-circular aluminum or plastic, and the upper part of the standard gas sampling module has a row of upper and lower through holes with the arc swept by the turret injection needle as the axis, and the structure is consistent with the sampling port in the sample tray.

[0053] It also includes a pressure regulating control structure, the output end of the controller is connected to the input end of the pressure regulating control structure, and the pressure regulating control structure includes a pressure reducing valve and an electromagnetic switch valve, which are sequentially arranged between the inert gas source and the connecting pipe and the air inlet of the third injection connection unit, wherein the valves arranged between the inert gas source and the air inlet are marked as the first pressure reducing valve and the first electromagnetic switch valve, and the valves arranged between the inert gas source and the connecting pipe of the third injection connection unit are marked as the second pressure reducing valve and the second electromagnetic switch valve.

[0054] The sample injection tray module includes a base 18, a sample tray 17, a slide rail 22, a sensor and a stepper motor 24. The base 18 is provided with a slider 21 that cooperates with the slide rail. The base 18 is connected to the output shaft of the stepper motor 24 and is used to make reciprocating motion along the slide rail under the drive of the stepper motor. The multiple first injection connection units 34 are evenly arranged into multiple arc structures, and the centers of the multiple arc structures coincide with the axis of the rotating shaft of the turret automatic control mechanism on the same horizontal plane as the first injection connection unit 34. The control input end of the stepper motor 24 is connected to the output end of the controller, and the output end of the sensor is connected to the input end of the controller, which is used to locate the position of the sample tray in real time. Figure 4 As shown, in actual use, the sample plate 17 is fixed on the top of the base 18 by the column 19, the slider 21 is fixed on the bottom of the base 18 by the slider connecting block 20, and the sensor adopts an optical coupler sensor 23, an optical coupler sensor shading plate 26, and a screw nut 25.

[0055] In actual use, the sample tray and the sample tray base are slidably connected through the guide rail and the lead screw nut on the same track of the stepper motor, which is used to match sample trays of different sizes; the optical coupling sensor shading plate is arranged on the upper part of the connecting plate, and a slider connecting block is arranged at the lower part of the connecting plate, and a lead screw nut is embedded in the middle of the slider connecting block, and there are linear sliding shafts with a 1 / 4 opening corresponding to the slide rail on both sides, which are used for the sample tray to move horizontally on the slide. By setting the optical coupling sensor 23 and the optical coupling sensor shading plate 26, the current actual position of the sample tray base can be determined, so that the turret mechanism can be better cooperated for precise sampling.

[0056] The sample tray described in the present invention is made of semicircular aluminum or plastic. The upper part of the sample tray is provided with multiple rows of upper and lower through holes with the arc swept by the turret injection needle as the axis. The upper part of the through hole is provided with an internal thread, which is connected to the corresponding sampling needle guide port 13 with an external thread at the lower part. The sampling needle guide port 13 is provided with a sealing gasket 14, which is T-shaped here, so that the sealing can be more tightly matched; the lower part of the through hole of the sample tray is provided with an internal thread, which matches the external thread of the tube screw connected to the sample tube, and the upper part of the sample tube screw 16 is provided with a conical sealing plastic blade ring 15, and the inside of the opening of the sample tube is provided with a stainless steel liner tube. The conical sealing plastic blade ring 15 seals and locks the sample tube equipped with the stainless steel liner tube.

[0057] like Figure 7 As shown, an automatic online gas dilution method based on the fully automatic multi-channel needle-type gas injection device comprises the following steps:

[0058] Step A: First, clean the sampling needle through the cleaning port and heating module:

[0059] The controller controls the turret body 1 to rotate to the station where the exhaust module is located, and the needle sampling module 6 inserts the syringe sampling needle into the sampling needle guide port of the fourth injection connection unit 10 and passes through the sealing gasket, and then moves the syringe needle rod 30 upward to above the upper cleaning port of the syringe, and the controller controls the opening of the first electromagnetic switch valve. After the gas of the inert gas source is opened through the first electromagnetic switch valve, it enters the internal space of the syringe, and at the same time, the controller controls the heating module to heat up according to the set temperature, and the heated inert gas cleans the inside of the syringe; after the cleaning time set by the controller is reached, the controller sends a control signal to the heating module to turn off the heating, and after the syringe returns to room temperature, the controller sends a control signal to the first electromagnetic switch valve to close the first electromagnetic switch valve, and the controller sends a control signal to the turret body to move the syringe needle rod down to the zero scale to complete the cleaning of the sampling needle;

[0060] Step B: Fill the cleaned sampling needle pipeline, exhaust the inert gas in the pipeline, fill the entire pipeline and sampling needle with the sample, and improve the accuracy of subsequent sampling:

[0061] The controller controls the turret body to rotate to the sample sampling port or the standard gas sampling port, and the sampling needle is inserted into the sampling position at the set height, generally 5mm. The syringe needle moves up to the set scale, and the sampling needle is pulled out. The turret rotates to the exhaust port position of the cleaning-waste discharge module to discharge the gas. Repeat the gas discharge several times to make the sample or standard gas completely fill the transmission pipeline;

[0062] Step C: Sampling through the sampling needle after the pipeline is filled:

[0063] The controller extracts samples according to the volume of gas sample or standard gas to be extracted calculated by the software;

[0064] Step D: Dilute the sample in the sample tube as needed:

[0065] The controller controls the turret body to lift up, pull out the sampling needle, and the turret body is transferred to the gradient dilution station where the dilution module is located, and inserted downward into the third sample injection connection unit, and the controller controls the second electromagnetic switch valve to open, and the controller controls the turret body to extract the inert gas for dilution according to the calculated value;

[0066] Step E: Equilibrate the diluted sample:

[0067] After the inert gas for dilution is extracted, the turret body does not move, but stands for a certain period of time, and waits for the diluted sample or standard gas to be completely mixed according to the set gas mixing time;

[0068] Step F: Quantitatively set the balanced sample so that the sample volume in the sampling needle is consistent with the set required value:

[0069] The controller controls the turret body to pull the syringe out of the cleaning port, the turret body is rotated to the position where the exhaust module is located, and the syringe sampling needle is lowered to be inserted through the fourth injection connection unit of the exhaust module and through the corresponding sealing gasket, and the controller controls the syringe needle rod to descend to discharge the excess mixed sample or standard gas;

[0070] Among them, if the dilution ratio exceeds the maximum single dilution amount, the turret can be rotated to the exhaust position, and a certain amount of gas can be discharged according to the volume for re-dilution calculated by the software, and steps DF are repeated until the dilution ratio set by the program is reached. Since the volume of the sampling needle is fixed, the initial suction volume can be controlled, and the maximum proportion dilution can be performed according to demand. Since the maximum proportion dilution still cannot meet the demand at this time, it can be repeated many times until the required dilution ratio is reached.

[0071] Step G: After the controller controls the turret body to rotate to the injection position, injection is completed:

[0072] Pull the syringe out of the exhaust port, turn the turret to the injection port position of the chromatographic host, and push the sample into the chromatographic system for analysis according to the injection volume set by the program.

[0073] The present invention arranges a thermostatic needle sampling module, a sample injection plate, a standard gas sampling module, a dilution module, an exhaust module and other modules on a fully automatic turret mechanism to realize fully automatic multi-channel needle gas injection, avoids the dependence of the traditional valve injection device on the transmission line and / or the quantitative loop, completely solves the problem of cross contamination between high and low concentration samples, and can change the gas injection volume at any time according to the difference in sample concentration, and can automatically and continuously dilute the high concentration sample or standard gas dynamically, significantly improving the precision and accuracy of gas sample detection. The instrument adopts a gas-tight injection needle injection method, does not need to modify the carrier gas path of the chromatographic instrument, and ensures the reliability of the chromatographic analysis instrument.

[0074] Referring to the national standards for gas detection, the company has designed and published an automatic online gas dilution method that can automatically prepare a gas standard curve and automatically perform dynamic dilution of high-concentration samples, thus avoiding environmental and human errors caused by manual preparation of standard curves and dilution of high-concentration samples. The specific implementation is as follows:

[0075] The present invention discloses an automatic online gas dilution method. The sample or standard gas position and dilution ratio are set in the sampling program of the instrument software. The sampler software automatically calculates the amount of gas sample or standard gas to be extracted, and at the same time calculates the amount of inert gas used for dilution, so as to achieve the dilution ratio of the standard gas or high-concentration sample, and obtain standard gas or samples of various concentrations. During the sampling, the syringe cooperates with the solenoid valve and the constant temperature heating module to ensure the cleanliness of the sampling pipeline and the sampling syringe, and ensure the precision and accuracy of the measurement results of the diluted samples.

[0076] Workflow: Use the gas sampling storage device to extract high-concentration samples or standard gases of known concentration, connect the standard gas to the standard gas sampling channel, and connect the sample to the sample tray sampling channel. Set the position and dilution ratio of the standard gas or sample. After the settings are completed, press the start button. The gas sampling device automatically runs the process: needle cleaning - pipeline filling - sampling - dilution - balance - quantitative - injection. Analyze each diluted sample or standard gas according to the program set by the host. Each diluted sample or standard gas can be repeatedly analyzed according to the set number of injections until the set program ends.

[0077] In the description of the present invention, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions and positional relationships based on the directions or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the present invention.

[0078] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0079] Note that the above are only preferred embodiments of the present invention and the principles of the application technology. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the specific embodiments described herein, and may include more other effective embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. Fully automatic multi-channel needle-type gas injection device, characterized by: It comprises a turret body, a controller, a needle sampling module, and a sample tray sampling module, a dilution module, and an exhaust module formed by an injection connection unit; the needle sampling module is fixedly arranged on the turret body, and the sample tray sampling module, the dilution module, and the exhaust module are respectively arranged on the movement stroke of the needle sampling module on the turret body; the injection connection unit comprises, from top to bottom, a sampling needle guide port, a sealing gasket, and a connecting pipe for cooperating with the injection needle of the needle sampling module for injection, the lower end of the sampling needle guide port and the upper end of the connecting pipe are respectively sealed with the sealing gasket, and the sampling needle guide port and the connecting pipe are coaxially arranged; A plurality of first injection connection units are vertically fixedly arranged on the sample tray of the sample tray injection module, and the lower end of the connecting pipe of each first injection connection unit is respectively connected to the gas outlet of a gas storage device such as a gas sampling bag or a syringe; The dilution module comprises a third sample injection connection unit and an inert gas source, and the lower end of the connecting pipe of the third sample injection connection unit is used to communicate with the gas outlet of the inert gas source; The exhaust module includes a fourth sampling connection unit and a filter assembly, and the lower end of the connecting pipe of the fourth sampling connection unit is used to connect with the air inlet of the filter assembly; it also includes a cleaning port and a heating module, the cleaning port is opened on the side wall of the upper end of the needle cavity of the gas sampling needle of the needle sampling module, and when the needle rod of the gas sampling needle is at the highest position of the needle cavity, the cleaning port is connected with the needle cavity, the cleaning port is connected with the air outlet of the inert gas source, and the heating module is covered and arranged on the outside of the needle cavity for heating the needle cavity; it also includes a standard gas sampling module, the standard gas sampling module includes a plurality of second sampling connection units, the plurality of second sampling connection units are vertically arranged on the standard sampling station through a fixed bracket, and the lower ends of the connecting pipes of the plurality of second sampling connection units are respectively used to connect with the standard gas cylinder, and the standard sampling station is arranged on the movement stroke of the needle sampling module on the turret automatic control structure.

2. The fully automatic multi-channel needle-type gas injection device according to claim 1, characterized in that: The filter assembly comprises an exhaust gas pipe and a filter adsorption tube, one end of the exhaust gas pipe is connected to the lower end of the connecting pipe of the fourth sample injection connection unit, and the other end is connected to the air inlet of the filter adsorption tube.

3. The fully automatic multi-channel needle-type gas injection device according to claim 1, characterized in that: It also includes a pressure regulating control structure, the output end of the controller is connected to the input end of the pressure regulating control structure, and the pressure regulating control structure includes a pressure reducing valve and an electromagnetic switch valve, which are sequentially arranged between the inert gas source and the connecting pipe and the air inlet of the third sample injection connection unit.

4. The fully automatic multi-channel needle-type gas injection device according to any one of claims 1 to 3, characterized in that: The sample tray injection module includes a base, a sample tray, a slide rail, a sensor and a stepper motor. The base is provided with a slider that cooperates with the slide rail. The base is connected to the output shaft of the stepper motor and is used to make reciprocating motion along the slide rail under the drive of the stepper motor. The multiple first injection connection units are evenly arranged into multiple arc structures, and the centers of the multiple arc structures coincide with the axes of the rotating shaft of the turret automatic control mechanism on the same horizontal plane as the first injection connection units. The control input ends of the sensor and the stepper motor are connected to the output end of the controller. The sensor is used to monitor the actual position of the sample tray.

5. The automatic online gas dilution method based on the fully automatic multi-channel needle-type gas injection device according to any one of claims 1 to 3, characterized in that: The steps include: Step A: First, clean the sampling needle through the cleaning port and heating module: The controller controls the turret body to rotate to the station where the exhaust module is located, and the needle sampling module inserts the syringe sampling needle into the sampling needle guide port of the fourth injection connection unit and passes through the sealing gasket, and then moves the syringe needle rod up to above the upper cleaning port of the syringe, and the controller controls the opening of the first electromagnetic switch valve, and the gas of the inert gas source enters the internal space of the syringe after the first electromagnetic switch valve is opened. At the same time, the controller controls the heating module to heat up according to the set temperature, and the heated inert gas cleans the inside of the syringe; after the cleaning time set by the controller is reached, the controller sends a control signal to the heating module to turn off the heating, and after the syringe returns to room temperature, the controller sends a control signal to the first electromagnetic switch valve to close the first electromagnetic switch valve, and the controller sends a control signal to the turret body to move the syringe needle rod down to the zero scale to complete the cleaning of the sampling needle; Step B: Fill the cleaned sampling needle pipeline, discharge the inert gas in the pipeline, and fill the entire pipeline and sampling needle with the sample to improve the accuracy of subsequent sampling; Step C: Sampling through the sampling needle after the pipeline is filled: The controller extracts samples according to the volume of gas sample or standard gas to be extracted calculated by the software; Step D: Dilute the sample in the sample tube as needed: The controller controls the turret body to lift up, pull out the sampling needle, and the turret body is transferred to the gradient dilution station where the dilution module is located, and inserted downward into the third injection connection unit, and the controller controls the second electromagnetic switch valve to open, and the controller controls the turret body to extract the inert gas for dilution according to the value calculated by the software; Step E: Equilibrate the diluted sample: After the inert gas for dilution is extracted, the turret body does not move, but stands for a certain period of time, and waits for the diluted sample or standard gas to be completely mixed according to the set gas mixing time; Step F: Quantitatively set the balanced sample so that the sample volume in the sampling needle is consistent with the set required value: Step G: After the controller controls the turret body to rotate to the injection position, injection is completed: Pull the syringe out of the exhaust port, turn the turret to the injection port position of the chromatographic host, and push the sample into the chromatographic system for analysis according to the injection volume set by the program.

6. The online gas dilution method according to claim 5, characterized in that: The step B specifically includes: the controller controls the turret body to rotate to the sample sampling port or the standard gas sampling port, the sampling needle is inserted into the sampling position at a set height, generally 5 mm, the syringe needle moves up to the set scale, the sampling needle is pulled out, the turret rotates to the exhaust port position of the cleaning-waste discharge module, the gas is discharged, and the gas is discharged repeatedly so that the sample or standard gas completely fills the transmission pipeline.

7. The online gas dilution method according to claim 6, characterized in that: The step F specifically includes: the controller controls the turret body to pull the syringe out of the cleaning port, the turret body rotates to the station where the exhaust module is located, and the syringe sampling needle is lowered and inserted through the fourth sampling connection unit of the exhaust module through the corresponding sealing gasket, and the controller controls the syringe needle rod to descend to discharge excess mixed sample or standard gas.

8. The online gas dilution method according to claim 7, characterized in that: In step F, if the dilution ratio exceeds the maximum single dilution amount, steps DF may be repeated until the dilution ratio set by the program is reached.

Images