Gas synchronous collection system

Abstract

The utility model provides a synchronous gas collection system which comprises a support frame, a sampling unit, a sample supply unit, a vacuum pump unit, a needle cylinder cleaning assembly, a chromatographic analysis unit, sampling pipelines and a sample delivery pipeline, and the sample supply unit is communicated with the vacuum pump unit and the sampling unit through a plurality of sampling pipelines. Comprising a plurality of sampling needle cylinders, a sampler lifting assembly and a sample feeding cylinder, the vacuum pump unit is used for providing power for the sampling pipeline; the cleaning needle cylinder assembly is connected with the path guider through a pipeline and is used for cleaning the sampling pipeline; and a path guider and a multi-path same-speed switch valve are also arranged on the sampling pipeline. Compared with the existing sampler, the gas synchronous acquisition system disclosed by the utility model has the characteristics of convenience in sampling, thorough cleaning and accuracy in sampling.

Description

Technical Field

[0001] The utility model relates to a gas synchronous sampling system, belonging to the technical field of gas measurement, and can be used for sampling and analyzing simulated environmental gases in an environmental wind tunnel laboratory. Background Art

[0002] In the environmental wind tunnel pollution diffusion test, the influence of real pollution sources in nature is simulated in a reduced scale in the test section of the wind tunnel for research and analysis and countermeasures are given. Conducting concentration sampling on the affected area during the test becomes an important means to master the distribution of pollutants, and a multi-point sampler becomes an important instrument for the laboratory to complete this work.

[0003] The working principle of the sampling device is to extract and control the flow rate of the gas sample through a vacuum pump and a flow meter, control the opening and closing of the sampling through a switching valve, sample through a syringe, and send it to a chromatograph for chromatographic analysis.

[0004] As Figure 1 shown, the existing sampling device or sampler includes: a sample delivery cylinder 2, a sampling syringe 6, a sampling pipeline 7, a mechanical scanning valve, a multi-way switching gate valve 9, a sample delivery pipeline 10, and a vacuum pump 13.

[0005] The main problems existing in the existing sampler and the existing sampling method are as follows:

[0006] The sample pressing method of the existing sampler is to install a rotating cantilever controlled by a stepping motor above the sampler, and install a mechanical pressing head controlled by a stepping motor at the end of the cantilever; the rotating arm carries the pressing head, finds the position of the plunger of the sample storage syringe, presses down the pressing head, and sends it to the chromatograph for analysis through the scanning valve, with a relatively complex structure.

[0007] The existing sampling syringe is on a same-diameter pipeline and is simultaneously extracted with the vacuum pump under the condition of sample flow. As a result, the flow rate is accelerated, the collection port of the sampling point becomes larger, and the samples taken in the syringe are incoherent and uncertain.

[0008] The existing sampler is equipped with a scanning valve, which not only has a relatively high cost, but also there is a cleaning dead zone in the sample delivery pipeline led out from the four-way to the scanning valve during the operation process, and the sampling pipeline from the scanning valve to the chromatograph is even more a cleaning dead zone. When the new sample enters the chromatograph, it will surely carry the old sample, which has a great impact on the measurement result. As shown in Figure 1 shown, there are cleaning dead zones in both the front and rear sections of the scanning valve, where A represents the front-section cleaning dead zone; B represents the rear-section cleaning dead zone.

[0009] In the understanding and use of existing samplers, it is considered that by adjusting the flow rate of the flowmeter, the sampling speed can be controlled to match the test wind speed, and the sample can be collected during the sampling process. However, most of the wind speeds in pollution diffusion tests are within 0.5 m / s. Sampling and sample collection are carried out simultaneously in the same fine pipeline with the same diameter, which affects the accuracy of flow velocity sampling. Considering comprehensive factors, the sampling time of the syringe is set to 3 - 4 seconds, which is converted to a flow velocity of about 2 m / s in the sampling pipeline. With the extraction of the vacuum pump added during this period, the sampling environment has been completely changed, and it is meaningless to control the flow velocity of the sampling pipe with the flowmeter. Summary of the Invention

[0010] In view of the deficiencies of the existing technology, the present invention provides a gas synchronous sampling system.

[0011] The specific technical solution of the present invention is as follows:

[0012] A gas synchronous sampling system includes a support frame, a sampling unit, a sample supply unit, a vacuum pump unit, a cleaning syringe assembly, a chromatographic analysis unit, a sampling pipeline, and a sample delivery pipeline. The sample supply unit is connected to the vacuum pump unit through a plurality of sampling pipelines.

[0013] The sampling unit includes a plurality of sampling syringes. Each sampling syringe includes a syringe barrel and a plunger. The syringe barrels are arranged side by side on the support frame. The lower opening of each syringe barrel is connected to a sampling pipeline. The sampling pipelines are commonly connected to a sample delivery pipeline and are connected to the chromatographic analysis unit through the sample delivery pipeline. The sampling unit further includes a sampler lifting assembly and a sample delivery cylinder. The sampler lifting assembly is used to drive the lifting of the plunger to realize the cleaning of the sampling syringe and the sampling of the sample. The sample delivery cylinder is used to press down the plunger to press the sample in the syringe into the chromatographic analysis unit.

[0014] The vacuum pump unit is used to provide power for the sampling pipeline.

[0015] The cleaning syringe assembly is connected to the path guide through a pipeline and is used for cleaning the sampling pipeline.

[0016] It further includes a path guide, which is connected in the sampling pipeline and is respectively connected to the cleaning syringe assembly and the chromatographic analysis unit. It is used to control the simultaneous conduction of multiple sampling pipelines and the single - path conduction of one sampling syringe and the sample delivery pipeline, so as to realize multi - path simultaneous sampling and single - path sample delivery.

[0017] Furthermore, it further includes a multi - path same - speed switching valve, which is connected to the rear end of the sampling pipeline and is used to convert the connected multi - path sampling pipelines into one output pipeline. The output pipeline is connected to the vacuum pump unit.

[0018] Furthermore, it further includes a damping section for flow equalization, which is arranged between the output pipeline of the multi - path same - speed switching valve and the vacuum pump unit.

[0019] Further, the path guide includes a cylindrical guide body. The guide body has axially distributed annular through holes which are through holes, and each axially distributed hole is connected to a sampling pipeline; the axially distributed holes are arranged on one or more circumferences, and the axially distributed holes on each circumference are radially corresponding to each other along the guide body; a through central hole is provided at the central axis position of the guide body, and both ends of the central hole are connected to a cleaning syringe assembly and a chromatographic analysis unit through pipe connectors respectively; the guide body also has at least one radially distributed hole which is perpendicularly through to the central hole, the outer end of the radially distributed hole is closed, and each axially distributed hole is selectively communicated with one radially distributed hole, thus forming a structural form in which each axially distributed hole is communicated with the central hole through the radially distributed hole.

[0020] Further, in the path guide, there are multiple radially distributed holes which are arranged in layers, and two radially distributed holes arranged in a cross shape are arranged in each layer, and the radially distributed holes between layers are arranged in a staggered manner; a pressure relief hole is also communicated with the central hole, and the pressure relief hole is connected to a pressure relief valve; conversion connectors are respectively provided at the middle positions on both sides of the guide body, and an extended section of the central hole and an L-shaped pressure relief hole are provided on the conversion connectors, the extended section of the central hole is communicated with the central hole, one end of the pressure relief hole is communicated with the central hole, and the other end extends out of the guide body.

[0021] Further, the multi-way same-speed switching valve includes a fixed valve seat, a moving valve seat, a flow guiding conical weir, an air flow contraction shell and a housing. The fixed valve seat and the moving valve seat are both annularly and evenly provided with axially through holes along the circumferential direction. When the axially through holes on the moving valve seat and the fixed valve seat are aligned, the channel between them is conducted; the fixed valve seat and the moving valve seat are rotationally matched through a valve core assembly, the fixed valve seat is connected to the housing, the moving valve seat is rotatably installed in the housing, the front end of the moving valve seat is matched with the rear end of the fixed valve seat, a flow guiding conical weir is installed at the rear end of the moving valve seat, an air flow contraction shell is installed at the rear end of the housing, the flow guiding conical weir is correspondingly covered inside the air flow contraction shell, an annular channel is formed between the outer surface of the flow guiding conical weir and the air flow contraction shell, the axially through holes on the moving valve seat are arranged corresponding to the annular channel position, and an air outlet nozzle is provided at the rear end of the air flow contraction shell, and the air outlet nozzle is connected to a vacuum pump unit; controlling the rotation of the moving valve seat to adjust the misalignment or alignment of the axially through holes on the moving and fixed valve seats to realize the opening and closing of the rotary valve.

[0022] Further, the valve core assembly includes a fixed valve core and a moving valve core. The fixed valve core and the moving valve core are both annular and are provided with axially through holes for conducting with the axially through holes of the valve seat. The fixed valve core is installed on the fixed valve seat, and the moving valve core is installed on the moving valve seat; controlling the rotation of the moving valve seat and the moving valve core to adjust the misalignment or alignment of the axially through holes of the moving valve core and the fixed valve core to control the opening and closing of the rotary valve.

[0023] A notch is opened on the housing, and a rocker is arranged at the notch. The rocker is connected to the moving valve seat; driving the rocker to swing through an (electric push rod) to control the rotation of the moving valve core and the misalignment and alignment of the axially through holes on the moving valve core.

[0024] A positioning flower disc is provided between the fixed valve core and the fixed valve seat. The positioning flower disc is an annular structure adapted to the valve core. The positioning flower disc is provided with holes corresponding to the valve core, and tubular seals are installed at the holes of the positioning flower disc;

[0025] The axial through holes of the fixed valve seat and the moving valve seat, and the annular axial holes of the fixed valve core and the moving valve core are uniformly distributed on one or more circumferences; a gap is left on the mating surface between the fixed valve seat and the moving valve seat, and this gap is connected to the outside through the exhaust hole in the middle of the fixed valve seat;

[0026] Further, the outer shape of the diversion cone weir is conical, and the surface is a streamline structure; the annular channel between the diversion cone weir and the air flow contraction shell is a contraction curved surface structure with a gradually decreasing cross-sectional area;

[0027] Further, the cleaning syringe assembly includes a cleaning cylinder, a cleaning syringe, as well as pipelines and control valves. The cleaning syringe is connected to the pure air supply pipeline and the path guide respectively through a tee, and one-way valves are respectively provided on the pipelines connected to the two. At the same time, it is connected to the chromatographic analysis unit through the path guide and the sample delivery pipeline, and is used to press pure air into the chromatographic analysis unit through the sample delivery pipeline to clean the sample delivery pipeline and send the tail sample;

[0028] The sampler lifting assembly includes an upper pressure plate, a lower pressure plate, a sliding assembly, an electric push rod and a guiding assembly. The upper pressure plate presses on the top surface of the plungers of each sampling syringe. The lower pressure plate is sleeved on the plungers of each sampling syringe. The upper pressure plate is provided with sleeve holes corresponding to each plunger. The upper and lower pressure plates are also connected to the sliding assembly. The sliding assembly drives the upper pressure plate to slide, so that the sleeve holes of the upper pressure plate are also misaligned with the plungers and press on the top surface of the plungers, realizing the clamping of the upper and lower pressure plates and the plungers. The electric push rod drives the lifting of the upper and lower pressure plates and all the plungers to realize the cleaning of the sampling syringe and the sampling pipeline, as well as the sample extraction;

[0029] When there are multiple chromatographs in the chromatograph analysis unit, the gas sample is connected to each chromatograph through the sample distribution box respectively, and the gas sample is switched by the sample distribution box and sent to the chromatograph alternately;

[0030] The system is also provided with a first-stage safety valve, a second-stage safety valve and a one-way valve;

[0031] The sampling syringes are arranged in an array. Correspondingly, the sample delivery cylinders are also arranged in an array.

[0032] The gas synchronous collection method of the above system includes the following steps:

[0033] 1) System preparation,

[0034] 2) Primary cleaning: The sliding component drives the upper pressure plate to translate. The upper pressure plate presses on top of the plunger. Cooperating with the lower pressure plate to drive the plunger to reciprocate multiple times, the cleaning syringe is extracted. Then the plunger stays at the low position, and the upper pressure plate is reset by the sliding component.

[0035] 3) Sample extraction: Open the release tracer gas at the required flow rate, and at the same time monitor the model wind speed in the wind tunnel test section as the test wind speed. Open the multi-channel same-speed switching valve, and the vacuum pump switches to the sampling state. Sample for 1 - 2 minutes, close the multi-channel same-speed switching valve, close the tracer gas, and extract a sample containing the tracer gas from the extraction pipeline.

[0036] 4) Sample collection: Start the electric push rod to drive the lower pressure plate to drive the entire plunger to lift upward, inject the sample in the sampling pipeline into the syringe. Then the electric push rod pulls the lower pressure plate and the upper pressure plate downward. The plungers of all sampling syringes still stay at the high position. The sample is stored in the syringe and the pipeline from the sampling pipeline tee upwards to the syringe. The sample collection is completed.

[0037] 5) Secondary cleaning: Open the multi-channel same-speed switching valve, and the vacuum pump switches to the sampling state. Sample for 1 - 2 minutes to clean the sampling pipeline.

[0038] 6) Sample delivery: The piston of a sample delivery cylinder presses down. The sample stored in the syringe is sent to the chromatograph through the reverse path of the sampling pipeline through the path guide channel. When the sample in the first sampling syringe is pressed out, the cleaning component will press pure air into the upstream interface of the path guide to enter the chromatograph following the tail sample, completing the tail sample delivery and cleaning of the sampling pipeline. Sample delivery is carried out one by one until the last sample is sent.

[0039] The utility model has the following beneficial effects compared with the prior art:

[0040] The gas synchronous collection system of the utility model has the characteristics of convenient sampling, thorough cleaning, and accurate sampling compared with the existing samplers.

[0041] The sample injection path and method of the utility model are different from the existing methods. The sample stored in the sampling syringe enters the path guide through the reverse path of the sampling pipeline. The sample enters the sample delivery pipeline through the vertical hole in the middle of the path guide and then enters the injection port of the chromatograph. The structural design is ingenious.

[0042] The utility model adopts a multi-channel same-speed switching valve and a sampling method with multiple actions. During the sampling process, the sample is first collected into the sampling pipeline and then into the sampling syringe. The samples collected by this sampling method ensure that the collected samples are continuous standard samples at the same moment, with the same flow rate, the same volume, and the same pressure.

[0043] The utility model independently sets up a group of cleaning syringe assemblies, which can not only remove the sample residues in the sample feeding pipeline during operation, but also complete the cleaning of the sample feeding pipeline, preparing for the passage of the next sample.

[0044] In the utility model, the sampling syringes are arranged in a square matrix, and the upper sample feeding cylinder corresponds to each of them one by one, with a compact structure and a volume reduced by one-half compared with the existing sampler.

[0045] In the utility model, the upper pressure plate covers the top surface of the plunger in a sliding manner, and the electric push rod lifting system moves up and down three times to clean the syringe, with a reasonable structure and convenient control. Description of the Drawings

[0046] Figure 1 is a structural schematic diagram of the existing sampler;

[0047] Figure 2 is a structural schematic diagram of the gas synchronous sampling system of the utility model;

[0048] Figure 3 is a schematic diagram of the sampling state of the gas synchronous sampling system;

[0049] Figure 4 is a schematic diagram of the sample pressing state of the gas synchronous sampling system;

[0050] Figure 5 is an installation schematic diagram of the electric control box and the cleaning syringe;

[0051] Figure 6 is Figure 4 the A-A sectional view of;

[0052] Figure 7 is a schematic diagram of the matrix arrangement of the sample feeding cylinders;

[0053] Figure 8 is a cross-sectional view of the path guide;

[0054] Figure 9 is Figure 1 the side view of;

[0055] Figure 10 is a structural schematic of the path guide;

[0056] Figure 11 is Figure 10 the bottom view of;

[0057] Figure 12 is Figure 10 the partial enlarged view at I in;

[0058] Figure 13 is corresponding to Figure 10 the cross-sectional view of layers a, b, c, and d in;

[0059] Figure 14 is Figure 13 A-A sectional view of layer a in

[0060] Figure 15 is Figure 13 B-B sectional view of layer b in

[0061] Figure 16 is Figure 13 C-C sectional view of layer c in

[0062] Figure 17 is Figure 13 D-D sectional view of layer d in

[0063] Figure 18 is the structural schematic of a multi-way same-speed switching valve;

[0064] Figure 19 is Figure 18 the partial enlarged view at I in

[0065] Figure 20 is Figure 18 the right view of

[0066] Figure 21 is Figure 18 the left view of

[0067] Figure 22 is Figure 18 the A-A direction view of

[0068] Figure 23 is Figure 22 the K direction view of

[0069] Figures 1 - 7 In

[0070] D1 - check valve; D2 - check valve; D3 - check valve; D4 - main pressure relief valve; D5 - main pressure relief valve; D6 - secondary pressure relief valve; D7 - normally closed solenoid valve;

[0071] Figures 8 - 17Middle: 801-introducer body; 802-conversion column; 803-axial channel; 804-center channel; 805-radial channel; 806-pressure relief hole; 807-extension section; C6-pipe joint;

[0072] Figures 18 - 23 In: 901-fixed valve seat; 902-moving valve seat; 903-housing; 904-guide cone weir; 905-airflow contraction shell; 906-threaded gland; 907-positioning disc; 908-fixed valve core; 909-moving valve core; 910-rocker; 911-sealing ring; 912-adjusting bolt; 913-flat key; 914-exhaust hole; C1-sampling needle; C2-bearing; C3-cylindrical pin; C4-tubular gasket; C5-O-ring. DETAILED DESCRIPTION

[0073] The utility model is further described below in conjunction with the accompanying drawings:

[0074] Embodiment 1:

[0075] like Figure 2 , Figure 3 As shown, this example provides a gas synchronous collection system, including a support frame, a sampling unit, a sample supply unit, a vacuum pump unit 13, a cleaning syringe assembly, a chromatographic analysis unit 11, a sampling pipeline 7 and a sample delivery pipeline 10, and the sample supply unit is connected to the vacuum pump unit 13 via a plurality of sampling pipelines 7.

[0076] The sampling unit includes a plurality of sampling syringes, wherein the sampling syringe 6 includes a syringe and a plunger, and each syringe is arranged side by side on a syringe fixing plate 22; the lower opening of each syringe is connected to a sampling pipeline, and each sampling pipeline 7 is connected to a sample delivery pipeline 10, and is connected to a chromatographic analysis unit 11 through the sample delivery pipeline 10; the sampling unit also includes a sampler lifting assembly 3 and a sample delivery cylinder 2, wherein the sampler lifting assembly 3 is used to drive the lifting and lowering of the plunger to realize the cleaning of the sampling syringe and the sampling of the sample; the sample delivery cylinder 2 is used to press the plunger downward to press the sample in the syringe into the chromatographic analysis unit 11;

[0077] A vacuum pump unit 13, used to provide power for the sampling pipeline 7;

[0078] A cleaning syringe assembly is connected to the path guide 8 via a pipeline and is used for tail sample delivery and sampling pipeline cleaning;

[0079] A path guide 8 is also provided on the sampling pipeline 7. The path guide 8 is connected in the sampling pipeline 7 and is respectively connected to the cleaning syringe assembly and the chromatographic analysis unit 11; it is used to control the simultaneous conduction of multiple sampling pipelines and the single conduction of one sampling syringe and the sample delivery pipeline, thereby realizing multi-channel simultaneous sampling and single-channel sample delivery.

[0080] Embodiment 2:

[0081] On the basis of the first embodiment, this example further includes a multi-way same-speed switching valve 9, which is connected to the rear end of the sampling pipeline and is used to convert the accessed multi-way sampling pipelines into a single output pipeline. The output pipeline is connected to the vacuum pump unit 13. It also includes a damping section 12 for rectification, which is arranged between the output pipeline of the multi-way same-speed switching valve 9 and the vacuum pump unit 13. The output end of the multi-way same-speed switching valve 9 is connected to the vacuum pump unit 13 through the damping section 12 and the bypass two-way valve 30.

[0082] Example 3:

[0083] In this example, the path guide 8 is further designed as Figures 8 - 17 shown. The path guide 8 includes a cylindrical guide body 801. The guide body 801 has axially distributed annular through holes 803, and the axially distributed through holes 803 are through holes. Each axially distributed through hole 803 is connected to one sampling pipeline 7; the axially distributed through holes are arranged on one or more circumferences, and the axially distributed through holes on each circumference are radially corresponding to each other along the guide body 801; a through central hole 804 is provided at the central axis position of the guide body 801, and both ends of the central hole 804 are connected to the cleaning syringe assembly and the chromatographic analysis unit 11 through pipe joints C5; the guide body 801 also has at least one radially distributed through hole 805 perpendicular to the central hole 804. The outer end of the radially distributed through hole 805 is closed and the inside is conducting. Each axially distributed through hole 803 is selectively connected to one radially distributed through hole 805, thereby forming a structural form in which each axially distributed through hole 803 is connected to the central hole 804 through the radially distributed through hole 805.

[0084] In this example, the path guide 8 is further designed. In the path guide 8, there are multiple radially distributed through holes 805 arranged in layers, and two radially distributed through holes arranged in a cross shape are arranged in each layer, and the radially distributed through holes between layers are arranged in a staggered manner; a pressure relief hole 806 is also connected to the central hole 804, and the pressure relief hole 806 is connected to a pressure relief valve; conversion connectors 802 are respectively provided at the middle positions on both sides of the guide body 801. An extended section 807 of the central hole and an L-shaped pressure relief hole 806 are provided on the conversion connector 802. The extended section 807 of the central hole is connected to the central hole 804, one end of the pressure relief hole 806 is connected to the central hole 804, and the other end extends out of the guide body 801.

[0085] As Figure 10 shown, there are 8 radially distributed through holes, which are arranged in 4 layers, with 2 arranged in a cross shape in each layer, and are arranged in a staggered manner at an angle of 22.5 degrees layer by layer. Layers a, b, c, and d are arranged at intervals.

[0086] Example 4:

[0087] The further design of this example is that the output end of the multi-way same-speed switch valve 9 is also provided with a damping section 12 for rectification, and multiple layers of stainless steel wire mesh are arranged inside the damping section 12 to form a uniform negative pressure area, which plays a rectifying role. The function of the damping section 12 is to eliminate the cyclone in the incoming flow and the vortex bubbles in the broken air flow, and improve the uniform distribution of the negative pressure field of the incoming flow.

[0088] Embodiment five:

[0089] This example is further designed in that, Figures 18 - 23 As shown, the multi-way same-speed switch valve 9 includes a fixed valve seat 901, a movable valve seat 902, a guide cone weir 904, an airflow contraction shell 905 and an outer shell 903. The fixed valve seat 901 and the movable valve seat 902 are evenly distributed with axial through holes in a circular shape along the circumferential direction. When the axial through holes on the movable valve seat 902 and the fixed valve seat 901 are aligned, the channel between the two is connected; the fixed valve seat 901 and the movable valve seat 902 are rotatably matched through the valve core assembly, the fixed valve seat 901 is connected to the outer shell 903, the movable valve seat 902 is rotatably installed in the outer shell 903, and the front end of the movable valve seat 902 is connected to the fixed valve seat 90 1, a guide cone weir 904 is installed at the rear end of the movable valve seat 902, and an airflow contraction shell 905 is installed at the rear end of the shell 903. The corresponding cover of the guide cone weir 904 is arranged inside the airflow contraction shell 905. An annular channel is formed between the outer surface of the guide cone weir 904 and the airflow contraction shell 905. The axial channel on the movable valve seat 902 is arranged corresponding to the position of the annular channel. An air outlet nozzle is provided at the rear end of the airflow contraction shell 905, and the air outlet nozzle is connected to the vacuum pump unit; the movable valve seat 902 is controlled to rotate, and the axial through holes on the movable and fixed valve seats are adjusted to be misaligned or aligned to realize the switch of the rotary valve.

[0090] The guide cone weir 904 has a conical shape and a streamlined surface. The annular channel between the guide cone weir 904 and the airflow contraction shell 905 is a contraction curved surface structure with a gradually decreasing cross-sectional area, thereby achieving uniform acceleration of the airflow.

[0091] Embodiment six:

[0092] This example is further designed in that, Figure 19 As shown, the valve core assembly of the multi-way same-speed switch valve includes a fixed valve core 908 and a moving valve core 909, both of which are annular and provided with an axial hole for communicating with the axial through hole of the valve seat, the fixed valve core 908 is installed on the fixed valve seat 901, and the moving valve core 909 is installed on the moving valve seat 902; the rotation of the moving valve seat 902 and the moving valve core 909 is controlled, and the misalignment or alignment of the moving valve core 909 with the axial hole of the fixed valve core 908 is adjusted to control the switch of the rotary valve;

[0093] There is a notch on the outer shell 903, and a rocker 910 is arranged at the notch. The rocker 910 is connected to the moving valve seat 902. The rocker 910 is driven by an electric push rod to swing, controlling the rotation and misalignment / alignment of the axial hole on the moving valve core 909. 14 indicates the rotation of the moving valve core, and the opening and closing of the multi-way same-speed switching valve are realized through the rotation of the moving valve core.

[0094] A positioning flower disc 907 is arranged between the fixed valve core 908 and the fixed valve seat 909. The positioning flower disc 907 is an annular structure adapted to the valve core. The positioning flower disc 907 is provided with holes corresponding to the valve core, and tubular seals C4 are installed at each hole of the positioning flower disc 907.

[0095] The axial through holes of the fixed valve seat 902 and the static valve 901, and the annular axial holes of the fixed valve core 908 and the moving valve core 909 are evenly distributed on one or more circumferences. There is a gap between the mating surfaces of the fixed valve seat 901 and the moving valve seat 902. This gap is connected to the outside through the exhaust hole 914 in the middle of the fixed valve seat to balance the internal and external pressures.

[0096] Example Seven:

[0097] The further design of this example is that, as Figure 5 shown, on the left is the electrical control box 1. The cleaning syringe assembly includes a cleaning cylinder 4, a cleaning syringe 5, as well as pipelines and control valves. The cleaning syringe 5 is respectively connected to the pure air supply pipeline and the path guide 8 through a tee. A one-way valve C2 is provided in the connecting pipeline between the pure air supply pipe and the cleaning syringe 5, and a one-way valve C2 is also provided in the connecting pipeline between the path guide 8 and the cleaning syringe 5. At the same time, it is connected to the chromatographic analysis unit via the path guide and the sampling pipeline, used to press pure air into the chromatographic analysis unit through the sampling pipeline to send in the tail sample and clean the sampling pipeline. One-way valves C1 are also provided at the front parts where the sampling pipeline 7 is connected to the path guide 8.

[0098] Example Eight:

[0099] The further design of this example is that, as Figure 4 shown, the sampler lifting assembly 3 includes an upper pressing plate 16, a lower pressing plate 17, a sliding assembly 18, a lifting electric push rod 19 and a guiding assembly. The guiding assembly includes a guide sleeve 20 and a guide rail 21. The upper pressing plate is pressed on the top surface of each sampling syringe plunger. The lower pressing plate is sleeved on the plungers of each sampling syringe. The upper pressing plate is provided with sleeve holes corresponding to each plunger. The upper and lower pressing plates are also connected to the sliding assembly. The sliding assembly drives the upper pressing plate to slide, so that the sleeve holes of the upper pressing plate are misaligned with the plungers and thus press on the top surface of the plungers, realizing the clamping of the upper and lower pressing plates and the plungers. The upper and lower pressing plates and all the plungers are driven by the lifting electric push rod to lift, realizing the cleaning of the sampling syringe and the sampling pipeline, as well as the sample extraction;

[0100] Example Nine:

[0101] The further design of this example is that, asFigure 6 As shown in the figure, multiple chromatographs can be provided. The gas samples are respectively connected to each chromatograph through the sample distribution box 15. The gas samples are switched by the sample distribution box 15 and sent to the chromatograph alternately. The system is also provided with a primary safety valve, a secondary safety valve and a check valve. The sampling syringes are arranged in an array. Correspondingly, the sample feeding cylinders 2 are also arranged in an array.

[0102] Example Ten:

[0103] As Figures 2 - 7 As shown in the figure, this example provides a gas synchronous sampling system, including a support frame, a sampling unit, a sample feeding unit, a path guide 8, a cleaning syringe assembly, a chromatographic analysis unit 11, a multi-channel same-speed switching valve 9, a damping section 12, a vacuum pump unit 13, a sampling pipeline 7 and a sample feeding pipeline 10.

[0104] The sampling unit includes a plurality of sampling syringes 6. The sampling syringe 6 includes a syringe barrel and a plunger. Each syringe barrel is arranged side by side on the support frame, specifically on the syringe barrel fixing plate 22. The lower opening of each syringe barrel is connected to a sampling pipeline.

[0105] The sampling pipeline 7 is connected between the sample feeding unit (such as the environmental wind tunnel test section) and the multi-channel same-speed switching valve 9. The multi-channel same-speed switching valve 9 is used to convert the accessed multi-channel sampling pipelines into one output pipeline for output. After the multi-channel same-speed switching valve 9, it is connected to the vacuum pump unit 13 through the damping section 12, the flowmeter 29 and the bypass two-way valve 30.

[0106] The damping section 12 is internally provided with multiple layers of stainless steel wire meshes to form a uniform negative pressure area, which plays a rectifying role. The function of the damping section 12 is to eliminate the air vortices in the incoming flow and the vortex bubbles in the broken air flow, and improve the uniform distribution of the incoming flow negative pressure field.

[0107] Each sampling pipeline 7 is commonly connected to a sample feeding pipeline through the path guide 8 and is connected to the chromatographic analysis unit 11 through the sample feeding pipeline.

[0108] This example has 48 sampling pipelines. The inlets of the sampling pipelines are arranged in the environmental wind tunnel test section, that is, the sample feeding unit. After being led out, a check valve C1 is provided and connected to the path guide 8. Then, the sampling pipeline 7 is respectively connected to the sampling syringe 6 and the multi-channel same-speed switching valve 9 through a tee. The lengths of each sampling pipeline 7 are the same. The pipelines connecting the sampling syringe 6 above the tee should also be of the same length. In this way, the amount of empty samples and real samples is the same during the sampling process, and the length is based on the farthest one. The pipelines above the tee can be arranged in the hose tray 31.

[0109] The sampling unit further includes a sampler lifting assembly 3 and a sample feeding cylinder 2. The sampler lifting assembly 3 is used to drive the lifting of the plunger to realize the cleaning of the sampling syringe and the sampling of the sample. The sample feeding cylinder 2 is used to press down the plunger to press the sample in the syringe into the chromatographic analysis unit. The vacuum pump unit is used to provide power for the sampling pipeline;

[0110] The cleaning syringe assembly is connected to the path guide 8 via a pipeline for cleaning the sampling pipeline; the cleaning syringe assembly includes a cleaning cylinder 4, a cleaning syringe 5, as well as pipelines and control valves. The cleaning syringe 5 is connected to the pure air supply pipeline and the air pressure reducing bottle 28 respectively via a tee, and to the path guide 8, and check valves are respectively provided on the pipelines connected to both, and at the same time, it is connected to the chromatographic analysis unit 11 via the path guide 8 and the sample delivery pipeline 10, for pressing pure air into the chromatographic analysis unit via the sample delivery pipeline to send the tail sample and clean the sample delivery pipeline.

[0111] The path guide 8 is connected in the sampling pipeline and is respectively connected to the cleaning syringe assembly and the chromatographic analysis unit; it is used to control the simultaneous conduction of multiple sampling pipelines and the single - path conduction of one sampling syringe and the sample delivery pipeline, so as to realize multi - path simultaneous sampling and single - path sample delivery.

[0112] The path guide 8 includes a cylindrical guide body. The guide body 801 has axially distributed holes 803 evenly distributed in a ring. The axially distributed holes in the ring are arranged on 3 circumferences, with 16 on each layer of the circumference, a total of 48. The axially distributed holes on each circumference are radially corresponding to each other along the radial direction of the guide body; a through - hole 804 runs through the center axis position of the guide body, and the guide body 8 also has 8 radially distributed holes 805 perpendicular to and communicating with the center hole. The 8 radially distributed holes are arranged in 4 layers, namely layer a, layer b, layer c, and layer d. Each layer is arranged with 2 radially distributed holes in a cross shape, and the radially distributed holes between layers are arranged in a staggered manner, with a 22.5 - degree angle stagger between adjacent layers.

[0113] A damping section 12 for rectification is also provided at the output end of the multi - path same - speed switching valve. The damping section 12 is internally provided with multiple layers of stainless steel wire meshes, forming a uniform negative pressure area to play a role in flow equalization. The role of the damping section is to eliminate the air vortices in the incoming flow and the vortex bubbles in the broken air flow, and improve the uniform distribution of the incoming flow negative pressure field.

[0114] The sampler lifting assembly 3 includes an upper pressure plate, a lower pressure plate, a sliding assembly, a lifting electric push rod, and a guiding assembly. The guiding assembly includes a guide sleeve 20 and a guide rail 21. The upper pressure plate 16 presses on the top surface of the plungers of each sampling syringe. The lower pressure plate 17 is sleeved on the plungers of each sampling syringe. The upper pressure plate 16 is provided with sleeve holes corresponding to each plunger. The upper and lower pressure plates are also connected to the sliding assembly 18. The sliding assembly 18 drives the upper pressure plate 16 to slide, so that the sleeve holes of the upper pressure plate 16 are misaligned with the plungers and then press on the top surface of the plungers, realizing the clamping of the upper and lower pressure plates and the plungers. The lifting of the upper and lower pressure plates and all the plungers is driven by the lifting electric push rod 19 to realize the cleaning of the sampling syringe and the sampling pipeline, as well as the sample extraction.

[0115] The chromatographic analysis sheet 11 is provided with multiple chromatographs. The gas sample is respectively connected to each chromatograph through the sample distribution box. The gas sample is switched by the sample distribution box and sent to different chromatographs alternately. The system is also provided with a primary safety valve and a secondary safety valve.

[0116] The sampling syringes are arranged in an array. Correspondingly, the sample delivery cylinders are also arranged in an array, so that the overall structure is compact.

[0117] Example XI:

[0118] The gas synchronous sampling method of the present utility model, as Figures 2 - 4 shown, based on the gas synchronous sampling system, includes the following steps:

[0119] 1) System preparation,

[0120] 2) Primary cleaning. The sliding component 18 drives the upper pressing plate to translate. The upper pressing plate 16 presses on the upper part of the plunger. Cooperating with the lower pressing plate 17 to drive the plunger to reciprocate multiple times, the cleaning syringe 5 is extracted. Then the plunger stays at the low position, and the upper pressing plate 16 is reset under the drive of the sliding component 18;

[0121] 3) Sample extraction. Open the release tracer gas (including tracer and helium) according to the required flow rate. At the same time, monitor the model wind speed in the wind tunnel test section as the test wind speed. Open the multi-channel same-speed switch valve 8. The vacuum pump switches to the sampling state and samples for 1-2 minutes. Close the multi-channel same-speed switch valve, close the tracer gas, and take the sample containing the tracer gas from the pipeline 7;

[0122] 4) Sample collection. Start the lifting electric push rod 19, push the lower pressing plate 17 to drive the plunger to lift upward as a whole, and inject the sample in the sampling pipeline 7 into the sampling syringe 6. Then the lifting electric push rod 19 pulls the lower pressing plate 17 and the upper pressing plate 16 downward. The plungers of all sampling syringes 6 still stay at the high position. The sample is stored in the syringe and the pipeline from the sampling pipeline tee above to the syringe. The sample collection is completed;

[0123] 5) Secondary cleaning. Open the multi-channel same-speed switch valve 9. The vacuum pump switches to the sampling state and samples for 1-2 minutes for cleaning the sampling pipeline;

[0124] 6) Sample delivery. The piston of a sample delivery cylinder presses down. The sample stored in the sampling syringe 6 is sent to the chromatograph through the reverse path of the sampling pipeline 7 through the channel of the path guide 8. When the sample in the first sampling syringe is pressed out, the cleaning component will press pure air into the upstream interface of the path guide 8 to enter the chromatographic analysis unit following the tail sample, completing the tail sample delivery and sampling pipeline cleaning; Deliver samples one by one in this way until the last sample is delivered.

[0125] Example XII:

[0126] The gas synchronous sampling method of the present utility model, asFigures 2 - 4 As shown in the figure, the specific steps are as follows:

[0127] 1. System preparation: Turn on the power supply to perform self-check of the equipment; input the number and serial number of chromatographs, input the number and serial number of sampling points, and automatically generate the corresponding number and serial number of sample delivery cylinders; establish working communication with the chromatographs; establish working communication with several electronic flow meters for controlling tracer release, and set the type and flow rate of the tracer according to the test requirements; adjust the pneumatic pressure of the pressure gauge of the electrical control box; prepare to enter the following sampling link.

[0128] 2. Primary cleaning: When the wind tunnel test meets the sampling conditions, first, the No. 1 push-pull electromagnet works, opens the multi-way same-speed switching valve 8, turns on the sampling vacuum pump, and adjusts the flow meter to control the sampling flow rate to match the test wind speed; the sampler currently extracts the air in the wind tunnel without releasing the tracer. The lifting electric push rod 19 works, pushes the lower pressure plate 17 upward to pull all the pistons of the sampling syringe 6 to the high position, and a pair of No. 2 push-pull electromagnets work to pull the upper pressure plate 16 to translate about 15 mm to the left. At this time, the solid part between the through holes of the upper pressure plate 16 moves above the piston of the syringe to press the piston. Subsequently, the upper and lower pressure plates drive all the pistons of the sampling syringe, and under the action of the lifting electric push rod 19, reciprocate up and down three times to extract and clean the syringe, and then the piston stays at the low position. The No. 1 push-pull electromagnet is powered off and returns to its original position under the action of the spring, and the switching valve is closed. The vacuum pump switches to bypass air intake and continues to operate. At the same time, the No. 2 push-pull electromagnet is also powered off, and the upper pressure plate 16 also returns to its original position under the action of the electromagnet spring, and the syringe cleaning operation is completed. The No. 1 push-pull electromagnet controls the switching valve to shut off, and the No. 2 push-pull electromagnet controls the upper pressure plate to return to its original position.

[0129] 3. Sample extraction: The electronic flow meters for communicating the tracer gas (including the tracer and helium) release the gas according to the flow rate required by the test, and monitor the changes in wind speed and flow rate with an electronic anemometer at the model release port in the wind tunnel test section. After obtaining the release confirmation, the No. 1 push-pull solenoid valve works, opens the multi-way same-speed switching valve 9, and the vacuum pump switches to the sampling state. At this time, the gas containing the tracer element is extracted. After extracting for 1 - 2 minutes, close the multi-way same-speed switching valve 9, and the vacuum pump switches to bypass operation to notify the electronic flow meters to close the tracer gas release, and the electronic anemometer monitors and confirms after the tracer stops. At this time, under the environment where the sampling flow rate matches the test wind speed, the standard sample obtained is retained in the 9 - 10-meter-long sampling tube, and the volume is about 28 - 31 ml.

[0130] 4. Sample collection: Start the lifting electric push rod 19, push the lower pressure plate 16 to drive all 48 pistons to lift upward, suck about 25 ml of the sample in the sampling pipeline into the syringe, and then the lifting electric push rod 19 pulls the lower pressure plate and the pressure plate to move downward, while the pistons of the 48 sampling syringes still stay at the high stretching position, and the sample is stored in the syringe and the pipeline from the tee to the syringe, and the sample storage operation is completed.

[0131] 5. Secondary cleaning: Start push-pull solenoid No. 1, open the multi-way same-speed switch valve 9, and switch the vacuum pump to the exhaust operation state. At this time, the air extracted does not contain tracer particles. Clean the sampling pipeline. After about 1 minute, the cleaning is completed, close the multi-way same-speed switch valve, and the vacuum pump is turned off and stopped.

[0132] 6. Sample delivery, communication with the chromatograph, sampling syringe 6 is ready to deliver samples; according to the number of chromatographs, the program setting is selected, and the sample delivery cylinder can be switched according to the number, sequence or through the sample distribution box 15, and alternately deliver samples to the chromatograph. The piston of the sample delivery cylinder is pressed down, and the sample stored in the syringe is delivered to the chromatograph through the path guide 8 channel in the reverse direction using the sampling pipeline 7. When the first sample is pressed out, the lower limit of the piston of the sample delivery cylinder 2 will send a signal to the cleaning component, and the syringe component of the cleaning cylinder 4 will press 20ml of industrial pure air into the upstream interface of the path guide to follow the sample and enter the chromatograph, both delivering the tail sample and timely cleaning the sampling pipeline shared by all samples, clearing the way for the next sample to pass; the chromatograph will send a detection completion signal after completing a sample detection, and the second sample will be pushed into the chromatograph by the corresponding cylinder piston for detection. After the second sample is pressed into the chromatograph, the lower limit of the cylinder piston will also send a signal to the cleaning component, and the cleaning cylinder syringe component will follow the second sample again to clean the sampling pipeline. This process continues until all samples are tested. When the last sample is tested, a buzzer sounds to remind you.

[0133] On the side of the electrical control box, a set of cleaning syringe assemblies is independently set up. The cleaning cylinder drives the cleaning syringe to draw industrial pure air stored in the pressure reducing bottle, and introduces it into the vertical channel in the middle of the path guide through a set of three-way, one-way valve and pipeline combination; when a sample is sent into the chromatograph, the lower limit of the sample delivery cylinder piston responds, and the cleaning cylinder drives the cleaning syringe plunger to promptly press 20ml of pure air into the chromatograph along with the sample. The pure air entering the chromatograph does not affect the analysis results, and also removes the sample residues in the sample delivery pipeline, thereby completing the cleaning of the sample delivery pipeline and preparing for the next sample to pass through.

[0134] Brief introduction to the functions and features of the utility model gas synchronous collection structure:

[0135] 1. The sampling syringes of this equipment are arranged in a square array with a compact structure; the pneumatic cylinder array corresponds to each other one by one, and the sample is pressed and delivered to the chromatograph accurately and reliably, and the control program is relatively simple.

[0136] 2. The lifter assembly can sample 48 sampling points at the same time, and the cylinder assembly can send samples to the chromatograph one by one (or in groups) according to the software options (if there are more than two chromatographs, a sample distribution box can be installed to reduce the sample detection time by several times);

[0137] 3. The valve unit composed of a path guide and a multi-way same-speed valve can ensure that the 48-tube gas samples collected are standard samples at the same moment, with the same flow rate, the same pressure, and the same volume under the rectifying action of the damping section on the secondary pressure air flow. After the sample collection is completed, the pneumatic cylinder array arranged corresponding to the syringe above will press the collected samples reversely through the central sampling pipeline of the path guide into the chromatograph for detection according to the program. After one sample is sent for inspection, the sampling pipeline cleaning component will promptly press 20 ml of industrial pure air into the central interface at the rear end of the path guide, enter the chromatograph through the sampling pipeline, and remove the residual gas samples in the sampling pipeline, laying a foundation for the next sample to be sent for inspection, thereby ensuring the accuracy and reliability of each detection result.

[0138] Taking 48 channels as an example, the synchronous sampling system of the present invention is compared with the existing sampler:

[0139] 1. The sampling syringe phalanx of the present invention is arranged in a phalanx, and the sample delivery pneumatic cylinders above correspond to it one by one. The structure is compact, and the volume is reduced by one-half compared with the existing sampler.

[0140] 2. The sampling method is the same as the principle of the existing sampler, that is, the gas sample is extracted and the flow rate is controlled through a vacuum pump and a flow meter, and the sampling is controlled by a switching valve. In the present invention, the multi-way same-speed switching valve guides the 48-way gas samples to run at the same speed through its internal contraction shell and diversion weir under the cooperation of the rectifying action of the damping section, which cannot be achieved by the switching valve of the existing sampler.

[0141] 3. The method of cleaning the syringe before sampling is the same as that of the existing sampler. The upper pressing plate of the plunger of the existing sampler rotates horizontally by an angle and covers the top surface of the annularly arranged plunger. The difference is that in the present invention, the upper pressing plate covers the top surface of the plunger by means of lateral sliding, and the syringe is cleaned three times up and down by the electric push rod lifting system.

[0142] 4. Sampling link: After the tracer gas is released from the wind tunnel model, the switching valve is opened and the vacuum pump extracts the sample.

[0143] In the existing sampler, on the same-diameter pipeline, when the sample is flowing, the sampling syringe and the vacuum pump extract simultaneously. As a result, the flow rate is accelerated, which is equivalent to the collection port of the sampling point becoming larger, and the surrounding unnecessary samples are also collected. Since the sampling syringe and the vacuum pump are sampling simultaneously, generally, the sampling speed of the sampling syringe is about 4 times that of the vacuum pump, resulting in the samples taken in the syringe being incoherent and unstable. The test requires that the test wind speed should match the sampling speed. The collected samples are not only the samples at the sampling point but also include the surrounding samples, thus causing measurement errors.

[0144] In the present utility model, when the multi-channel same-speed switching valve is opened and the vacuum pump operates to extract the sample (the sampling speed of the vacuum pump can match the test wind speed), after the operation becomes stable, the vacuum pump is turned off, the valve is closed, and the tracer and helium gas cylinders are closed. At this time, the sample stays in the sampling pipeline at a height of 9 - 10 meters, and the volume of this pipeline is 28 - 31 ml. Then, the lifting mechanism stretches the plunger of the sampling syringe to extract 25 ml of the sample stored in the sampling pipeline into the syringe. The sample collected in this way is a continuous standard sample at the same moment, with the same flow rate, the same volume, and the same pressure. This step-by-step sampling method ensures that the sampling speed matches the test wind speed.

[0145] 5. Sample delivery preparation and path: Open the switching valve, and the vacuum pump extracts the atmosphere without tracer particles in the test section to clean the sampling pipeline, which is the same as the existing sampler. After cleaning is completed, close the switching valve and the vacuum pump, and wait for the next sample injection step.

[0146] The existing sampler uses a four-way joint group to lead 48 φ3*2 mm sample delivery tubes through 48 reducing joints and connect them to the 48 needles at the inlet end of the scanning valve with φ2.5*1.5 mm thin tubes. A φ2.5*1.5 mm PTFE thin tube is led out from the downstream of the scanning valve and enters the injection port of the chromatograph.

[0147] The sample injection path and method in the present utility model are completely different. The sample stored in the syringe uses a path guide for the reverse entry of the sampling pipeline. The sample enters the sample delivery pipeline through the vertical channel in the middle of the path guide. The outlet joint is connected to a φ3*2 mm sample delivery tube, and near the chromatograph, a reducing joint is used to lead out a φ2.5*1.5 mm PTFE thin tube and enter the injection port of the chromatograph.

[0148] 6. Sample (pressure) injection link: The sample injection method of the existing sampler is to install a rotating cantilever controlled by a stepping motor above the sampler, and at the end of the cantilever, a mechanical pressure head controlled by a stepping motor is installed. The rotating arm carries the pressure head to find the position of the plunger of the sample storage syringe, and the pressure head is pressed down to send the sample into the chromatograph for analysis through the scanning valve. The gas synchronous sampling system of the present utility model uses cylinders corresponding to the sample storage syringes one by one above the sampler. According to the programmed serial number sequence, the pistons are extended to directly send the samples in the sample storage syringes into the chromatograph for analysis through the path guide, without using a scanning valve.

[0149] 7. New functions of the gas synchronous sampling system of the present utility model:

[0150] (1) Clean the sample delivery pipeline assembly

[0151] The origin of the idea is to observe the operation process of the existing sampler and find that the sample delivery pipeline led from the four-way joint to the scanning valve is a cleaning dead zone and cannot be cleaned. The sampling pipeline from the scanning valve to the chromatograph is an even more cleaning dead zone. There will always be old samples remaining in these two dead zones, and when the new sample enters the chromatograph, it will surely carry the old samples, which has a great impact on the measurement results.

[0152] Therefore, in the design of the gas synchronous acquisition system of the utility model, a path guide is designed and a cleaning syringe assembly is added. The specific method is: on the side of the electrical control box, a group of cleaning cylinders and cleaning syringes are independently set up to extract the industrial pure air stored in the pressure reducing bottle, and introduce it into the upstream center hole of the path guide through a set of three-way, one-way valve, and pipeline combination; when a sample is sent into the chromatograph, the lower limit limit of the sample cylinder piston responds, and the cleaning cylinder drives the cleaning syringe plunger to promptly press 20ml of pure air into the chromatograph along with the tail sample. The pure air enters the chromatograph, which does not affect the analysis results, but removes the sample residue in the sample delivery pipeline, thereby completing the cleaning of the sample delivery pipeline and preparing for the next sample to pass.

[0153] (2) Extended Attachments

[0154] If the laboratory is equipped with more than two chromatographs, an optional sample distribution box can be used. The software will assign the injection order according to the number of chromatographs checked by the user on the interface, which can shorten the duration of the entire test phase by several times.

[0155] (3) System pressure safety

[0156] The gas synchronous collection system of the present invention (excluding the safety valve of the pressure reducing bottle) is provided with a two-stage pressure safety structure, and two first-stage safety valves are provided at both ends of the path guide. If the switch valve is not opened (such as the switch valve solenoid fails), since the lengths of the various sections of the internal pipelines of the gas synchronous collection system of the present invention are relatively short, the electric push rod lifting mechanism carries 48 syringe plungers up and down, and the internal pressure of the pipeline will increase sharply, thereby damaging the sealing of the pipeline and components. The first-stage safety valve can release pressure in time when the pressure sensor alarm emergency shutdown fails to avoid equipment damage; the second-stage safety valve protects the sampling pipeline, and can release pressure in time if the solenoid valve of the sample distribution box fails and does not open during sampling.

[0157] 8. Several data and misunderstandings

[0158] In the understanding and use of existing samplers, it is believed that the sampling speed can be controlled to match the test wind speed by adjusting the flow rate of the flow meter, and samples are collected during the sampling process; however, the wind speed in most pollution diffusion tests is within 0.5m / s, and the sampling and sampling are in a very thin pipe of the same diameter, which is not the relationship between a big river and a small stream as understood. Moreover, based on comprehensive factors, the syringe sampling time is set to 3-4 seconds, which is converted into a sampling pipeline flow rate of about 2m / s. In addition, the vacuum pump is used for extraction, and the sampling environment has been completely changed. It is meaningless to control the sampling tube flow rate with a flowmeter.

[0159] The utility model gas synchronous collection system also adopts a flow meter to control the sampling speed in the sampling method. After the vacuum pump stops, the switch valve is closed, and then the electric push rod drives the syringe to collect the sample remaining in the sampling tube. At this time, sampling is no longer related to the sampling speed.

[0160] 9. The control program is relatively simple to compile, without complex calculations. The control nodes are all switch quantity sequential responses and running time settings; expansion is also easy to achieve.

[0161] Comparison table of residual samples entering the chromatograph from the existing sampler and the gas synchronous collection system of this application:

[0162]

[0163] In the table, the inner diameter, length, and cross-sectional area of the existing samplers are Figure 1 The inner diameter, length and cross-sectional area of the gas synchronous collection system in this application are the same as Figure 8 The radial channels of the A' section in the middle path guide correspond to each other, wherein the A' section is a longer cleaning dead zone, and the other sections are shorter.

[0164] From the table above, we can see that, assuming that the sample volume extracted from the sampling syringe is 25 ml, the residual sample generated by the cleaning dead zone accounts for the sample volume, which can be used to estimate the measurement accuracy. Figure 1 The volume ratio of residual samples in the existing sampler is 10.59%, while the volume ratio of residual samples in the gas synchronous collection system of the present application is less than 0.05%. Compared with the existing sampler, the sample volume error of the present application is smaller.

[0165] The main technical parameters, supporting equipment, and processing and installation instructions of the gas synchronous collection system in this application are as follows:

[0166] Main Technical Parameters

[0167] Number of Sampling Points (pcs) Volume of Single Tube (ml) Sampling Time (s) Model of Electric Push Rod Stroke of Push Rod (mm) Speed of Push Rod (mm / s) Thrust of Push Rod (N) Number of Pneumatic Cylinders (pcs) Stroke of Pneumatic Cylinder (mm) Speed of Pneumatic Cylinder (mm / s) 48 30 4 CE - LUILEC 70 20 1400 48+1 90,75 Adjustable .

Claims

1. A gas synchronous sampling system, comprising a support frame, a sampling unit, a sample supply unit, a vacuum pump unit, a cleaning syringe assembly, a chromatographic analysis unit, a sampling pipeline and a sample delivery pipeline. The sample supply unit is connected to the vacuum pump unit through a plurality of sampling pipelines. It is characterized in that The sampling unit includes a plurality of sampling syringes. Each sampling syringe includes a syringe barrel and a plunger. The syringe barrels are arranged side by side on the support frame. The lower opening of each syringe barrel is connected to a sampling pipeline. The sampling pipelines are commonly connected to a sample delivery pipeline and are connected to the chromatographic analysis unit through the sample delivery pipeline. The sampling unit further includes a sampler lifting assembly and a sample delivery cylinder. The sampler lifting assembly is used to drive the lifting of the plunger to realize the cleaning of the sampling syringe and the sampling of the sample. The sample delivery cylinder is used to press down the plunger to press the sample in the syringe into the chromatographic analysis unit. The vacuum pump unit is used to provide power for the sampling pipeline. The cleaning syringe assembly is connected to the path guide through a pipeline and is used for cleaning the sampling pipeline. It further includes a path guide, which is connected in the sampling pipeline and is respectively connected to the cleaning syringe assembly and the chromatographic analysis unit. It is used to control the simultaneous conduction of multiple sampling pipelines and the single-path conduction of one sampling syringe and the sample delivery pipeline, so as to realize multi-path simultaneous sampling and single-path sample delivery.

2. The gas synchronous acquisition system according to claim 1, characterized in that It further includes a multi-path same-speed switching valve, which is connected to the rear end of the sampling pipeline and is used to convert the connected multiple sampling pipelines into one output pipeline. The output pipeline is connected to the vacuum pump unit.

3. The gas synchronous acquisition system according to claim 2, wherein It further includes a damping section for flow equalization, which is arranged between the output pipeline of the multi-path same-speed switching valve and the vacuum pump unit.

4. The gas synchronous acquisition system according to claim 2, wherein The path guide includes a cylindrical guide body. The guide body has axially distributed annular and uniformly distributed axial channels. The axial channels are through channels. Each axial channel is connected to a sampling pipeline. The axially distributed annular channels are arranged on one or more circumferences. The axial channels on each circumference are radially corresponding and distributed along the guide body. A through central channel is provided at the central axis position of the guide body. The two ends of the central channel are respectively connected to the cleaning syringe assembly and the chromatographic analysis unit through pipe joints. The guide body further has at least one radially through channel perpendicular to the central channel. The outer end of the radially through channel is closed. Each axial channel is selectively connected to a radially through channel, thereby forming a structural form in which each axial channel is connected to the central channel through the radially through channel.

5. The gas synchronous acquisition system according to claim 4, characterized in that, In the path guide, there are multiple radially through channels and they are arranged in layers. Each layer is arranged with 2 radially through channels in a cross shape. The radially through channels between layers are arranged in a staggered manner. A pressure relief hole is also connected to the central channel. The pressure relief hole is connected to a pressure relief valve. Conversion connectors are respectively provided at the middle positions on both sides of the guide body. The conversion connectors are provided with an extension section of the central channel and an L-shaped pressure relief hole. The extension section of the central channel is connected to the central channel. One end of the pressure relief hole is connected to the central channel and the other end leads out of the guide body.

6. The gas synchronous acquisition system according to any one of claims 2-5, characterized in that, The multi-channel same-speed switching valve includes a fixed valve seat, a moving valve seat, a diversion cone weir, an air flow contraction shell and a housing. The fixed valve seat and the moving valve seat are both evenly distributed with axial through holes in the circumferential direction. When the axial through holes on the moving valve seat and the fixed valve seat are aligned, the channel between the two is conducted. The fixed valve seat and the moving valve seat are rotationally matched through a valve core assembly. The fixed valve seat is connected to the housing, and the moving valve seat is rotatably installed in the housing. The front end of the moving valve seat cooperates with the rear end of the fixed valve seat. A diversion cone weir is installed at the rear end of the moving valve seat, and an air flow contraction shell is installed at the rear end of the housing. The diversion cone weir is correspondingly covered inside the air flow contraction shell. An annular channel is formed between the outer surface of the diversion cone weir and the air flow contraction shell. The axial channel on the moving valve seat is arranged corresponding to the annular channel. An air outlet nozzle is provided at the rear end of the air flow contraction shell, and this air outlet nozzle is connected to the vacuum pump unit. By controlling the rotation of the moving valve seat, the misalignment or alignment of the axial through holes on the moving and fixed valve seats is adjusted to realize the opening and closing of the rotary valve.

7. The gas synchronous acquisition system according to claim 6, wherein The valve core assembly includes a fixed valve core and a moving valve core. Both the fixed valve core and the moving valve core are annular and are provided with axial holes for conducting with the axial through holes of the valve seat. The fixed valve core is installed on the fixed valve seat, and the moving valve core is installed on the moving valve seat. By controlling the rotation of the moving valve seat and the moving valve core, the misalignment or alignment of the axial holes of the moving valve core and the fixed valve core is adjusted to control the opening and closing of the rotary valve. A notch is opened on the housing, and a rocker is arranged at the notch. The rocker is connected to the moving valve seat. By driving the rocker to swing, the rotation of the moving valve core and the misalignment and alignment of the axial hole on the moving valve core are controlled. A positioning flower disc is arranged between the fixed valve core and the fixed valve seat. The positioning flower disc is an annular structure adapted to the valve core. The positioning flower disc is provided with holes corresponding to the valve core, and tubular seals are installed at each hole of the positioning flower disc. The axial through holes of the fixed valve seat and the moving valve seat and the annular axial holes of the fixed valve core and the moving valve core are evenly distributed on one or more circumferences. A gap is left on the mating surface of the fixed valve seat and the moving valve seat, and this gap is connected to the outside through the exhaust hole in the middle of the fixed valve seat.

8. The gas synchronous acquisition system according to claim 7, characterized in that, The outer shape of the diversion cone weir is conical, and the surface is a streamline structure. The annular channel between the diversion cone weir and the air flow contraction shell is a contraction curved surface structure with a gradually decreasing cross-sectional area.

9. The gas synchronous acquisition system according to claim 1, characterized in that The cleaning syringe assembly includes a cleaning cylinder, a cleaning syringe, as well as pipelines and control valves. The cleaning syringe is respectively connected to the pure air supply pipeline and the path guide through a tee, and one-way valves are respectively provided on the pipelines connected to the two. At the same time, it is connected to the chromatographic analysis unit through the path guide and the sample delivery pipeline, and is used to press pure air into the chromatographic analysis unit through the sample delivery pipeline to clean the sample delivery pipeline and send the tail sample.

10. The gas synchronous acquisition system according to claim 1, characterized in that, The sampler lifting assembly includes an upper pressure plate, a lower pressure plate, a sliding assembly, an electric push rod and a guiding assembly. The upper pressure plate presses on the top surface of the plungers of each sampling syringe. The lower pressure plate is sleeved on the plungers of each sampling syringe. The upper pressure plate is provided with sleeve holes corresponding to each plunger. The upper and lower pressure plates are also connected to the sliding assembly. The sliding assembly drives the upper pressure plate to slide, so that the sleeve holes of the upper pressure plate are also misaligned with the plungers and press on the top surface of the plungers to realize the clamping of the upper and lower pressure plates and the plungers. The electric push rod drives the lifting of the upper and lower pressure plates and all the plungers to realize the cleaning of the sampling syringe and the sampling pipeline, as well as the sample extraction.

11. The gas synchronous acquisition system according to claim 1, wherein, When there are multiple chromatographs in the chromatograph analysis unit, the gas sample is connected to each chromatograph through the sample distribution box respectively, and the gas sample is switched by the sample distribution box to send the sample to the chromatograph alternately; The system is also equipped with a first-stage safety valve, a second-stage safety valve and a check valve; The sampling syringes are arranged in an array, and correspondingly, the sample feeding cylinders are also arranged in an array.

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