CN215493377U - Headspace balance gas sample introduction device - Google Patents

Abstract

The utility model discloses a headspace balance gas sampling device which comprises a four-port selector valve, a pressure gauge, a micro vacuum pump, a mass flow meter, a quantitative ring, a gas pipeline, a six-way two-position valve, a digital pump, a first three-way electromagnetic valve, a second three-way electromagnetic valve and a straight-through electromagnetic valve; the four-port selection valve is connected with the six-way two-position valve through the straight-through electromagnetic valve and the mass flow meter, two interfaces of the six-way two-position valve are connected through the quantitative ring, three interfaces of the first three-way electromagnetic valve are respectively connected with the six-position selection valve, the digital pump and the headspace balancer, two interfaces of the second three-way electromagnetic valve are respectively connected with the six-way two-position valve and the micro vacuum pump, and the other interface gives out air. According to the utility model, by adding functional components such as the electromagnetic valve and optimizing the control signal and program, the automatic operation of the device is realized, the repeatability, the operability and the stability of the sample introduction process are improved, and the accuracy and the precision of the measured data are improved.

Description

Headspace balance gas sample introduction device

Technical Field

The utility model relates to the field of gas sampling, in particular to a headspace balance gas sampling device.

Background

During gas phase analysis, a plurality of samples cannot be directly injected, and need to be subjected to pretreatment and then indirectly injected, so that headspace injection belongs to the pretreatment method, gas is used for extracting sample components in headspace injection, and compared with the traditional solid-liquid extraction, liquid-liquid extraction and other modes, the method has the advantages of lower experiment cost and smaller interference factor, and is widely applied to gas analysis.

The existing headspace balance gas sampling device is shown in fig. 1 and comprises a manual four-port selector valve V6, manual three-way ball valves V7 and V9, a manual straight-through ball valve V8, a mass flow meter M, a micro vacuum pump B, a pressure gauge P, a quantitative ring L and the like. During the process of implementing the standard gas sequence and the headspace balance gas sample injection, each valve needs to be manually operated to change the flow direction of the gas path. The method has low automation degree, the repeatability of the sample volume is difficult to control, and the precision and the accuracy of data measurement are greatly influenced by manual operation instability.

The full-automatic headspace sampling device disclosed in Chinese patent document, with publication number CN206420837U and publication date 2017-08-18, comprises a sampling needle, a six-way valve, a gas quantitative ring, a pressure control valve, an emptying control valve, an air inlet and outlet interface and a controller, and reduces manual operation by controlling the whole headspace sampling process through the controller. But it bears sample gas through the ration ring, and in the sampling process, ration ring and unloading control valve intercommunication, in the in-process that reaches atmospheric pressure balance, the external gas can mix in the sample gas in ration ring and its surrounding gas circuit pipeline in a small amount through the control valve to influence follow-up accuracy and the accuracy to sample gas analysis.

SUMMERY OF THE UTILITY MODEL

The utility model provides a headspace balance gas sampling device, which aims to solve the problems that the gas sampling repeatability is difficult to master and the precision and accuracy of measured data are insufficient in the prior art, can realize automatic control, is simple and convenient to operate, and greatly improves the repeatability of a gas sampling process and the precision and accuracy of measured data.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a headspace balance gas sampling device comprises a four-port selector valve V2, a pressure gauge, a micro vacuum pump, a mass flow meter, a quantitative ring and a gas pipeline, and is characterized by further comprising a six-way two-position valve V1, a digital pump, a first three-way electromagnetic valve V3, a second three-way electromagnetic valve V5 and a straight-way electromagnetic valve V4; four-port selector valve V2 gas outlets link to each other through No. three blow vents of direct-flow solenoid valve V4 and mass flow meter and six lead to two position valve V1, No. two blow vents and No. five blow vents of six lead to two position valve V1 pass through the ration ring is connected, the third port that first three-way solenoid valve V3 is connected to a six lead to two position valve V1's a gas port, and first port and digital pump of first three-way solenoid valve V3 link to each other, and the second port of first three-way solenoid valve V3 is balanced gaseous introduction port, and No. one gas vent is connected to No. four blow vents of six lead to two position valve V1, and No. six lead to two position valve V1's No. six blow vents pass through the pressure gauge and are connected with the first port of second three-way solenoid valve V5, and No. three gas vents are connected through miniature vacuum pump to the third port of second three-way solenoid valve V5, and No. two gas vents are connected to the second three-way solenoid valve V5's second port.

And the digital pump is used for extracting headspace balance gas from the headspace balancer or injecting the headspace balance gas into the gas circuit at regular time and quantity according to a preset program, so that high-precision sampling repeatability is ensured. The first three-way electromagnetic valve is used for pumping headspace balance gas by a digital pump when automatically switching to the A-B communication state according to a preset program; when the automatic switching is in the A-C communication state, the digital pump is used for conveying headspace balance gas to the gas circuit and the measuring instrument. The six-way two-position valve switches the air inlet line of standard gas or headspace balance gas according to a preset program. The four-port selector valve realizes the one-by-one gas intake of four different concentration standard gases according to a preset program. The through electromagnetic valve controls the on-off state of the standard gas path according to a preset program. The pressure gauge is used for displaying the air pressure inside the air passage in real time. The micro vacuum pump is used for extracting gas in the gas circuit, the amount of headspace balance gas is limited generally, for reducing the gas circuit dead volume and flushing the required headspace balance gas, before the headspace balance gas is introduced into a sample, the micro vacuum pump is utilized in advance to pump the sample gas circuit to the negative pressure, so that the consumption of headspace balance gas can be effectively reduced, and the gas circuit flushing efficiency is improved. The second three-way electromagnetic valve is used for vacuumizing the gas path when the A-C are communicated according to a preset program; when the A and the B are communicated, the device is used for flushing headspace balance gas sample injection.

Preferably, the digital pump further comprises an airtight syringe.

The airtight injector is used for temporarily storing headspace balance gas extracted by the digital pump, and after the micro vacuum pump pumps the gas circuit into negative pressure, the headspace balance gas is discharged into the gas circuit, so that repeatability of sample injection operation and accuracy of sample injection each time can be ensured.

Preferably, four air inlets of the four-port selector valve are respectively and correspondingly connected with four standard gases with different concentrations.

The sampling of four kinds of different concentration standard gases can be realized, and the standard gas connected with each gas inlet can be replaced, so that the sampling operation of more kinds of standard gases is realized.

Preferably, the six-way two-position valve V1 has two states of opening and closing, when in the opening state, the first vent hole is communicated with the sixth vent hole, the second vent hole is communicated with the third vent hole, and the fourth vent hole is communicated with the fifth vent hole; when the valve is in a closed state, the first vent hole is communicated with the second vent hole, the third vent hole is communicated with the fourth vent hole, and the fifth vent hole is communicated with the sixth vent hole.

According to the six-way two-position valve, the flow direction of the gas path is changed by switching the opening state and the closing state, residual gas in the six-way two-position valve can be isolated before switching, the gas in the gas path after switching cannot be influenced, and the influence of the residual gas in the valve on experimental operation can be reduced compared with a method of changing the flow direction of the gas path by rotating the six-way valve.

Preferably, the gas sampling device further comprises a first glass rotameter and a second glass rotameter, wherein the first glass rotameter is connected with a fourth vent and a first exhaust port of a six-way two-position valve V1, and the second glass rotameter is connected with a second vent and a second exhaust port of a second three-way electromagnetic valve V5. The glass rotameter is arranged at the tail end of the sample injection gas circuit and used for monitoring whether the sample injection gas circuit is smooth or not.

Preferably, the gas sampling device further comprises a box body, and the box body is loaded with various components of the gas sampling device. The box provides the integrated fixed carrier for other functional assembly, makes the device be orderly overall state, also makes things convenient for the removal of whole device.

Preferably, the gas sampling device further comprises a headspace balancer, and the headspace balancer is connected with the second vent of the first three-way electromagnetic valve V3. The gas and liquid in the headspace balancer reach an equilibrium state, and the upper part of gas is headspace balance gas extracted in the experiment.

Preferably, each component in the gas sampling device is connected through a gas pipeline. The selected gas circuit pipeline is not easy to be attached with gas and is not easy to be corroded by the gas flowing through the pipeline, so that the accuracy and the precision of the test are improved.

The novel use has the following beneficial effects: new functional components such as an electromagnetic valve and the like are added, and control signals and programs are integrated and optimized, so that the automatic operation of the sample feeding device is realized, the manual operation difficulty is reduced, and the repeatability is improved; the digital pump and the airtight injector are added, so that the repeatability of sample injection quantification is improved, and the quality and the efficiency of measured data are greatly improved.

Drawings

FIG. 1 is a diagram of a headspace balanced gas sampling device in the prior art.

FIG. 2 is a diagram of a headspace balanced gas injection device of the present invention.

FIG. 3 is a schematic diagram of the standard gas injection state of the present invention.

FIG. 4 is a schematic diagram of the headspace equilibrium gas injection state of the present invention.

In the figure: 1. the device comprises a mass flowmeter, 2, a headspace balancer, 3, a quantitative ring, 4, a digital pump, 5, a pressure gauge, 6, a micro vacuum pump, 7, a second glass rotameter, 8, a first glass rotameter, 9, a gas pipeline, 10 and a box body.

Detailed Description

The utility model is further described with reference to the following detailed description and accompanying drawings.

As shown in fig. 2, a headspace balance gas sampling device comprises a four-port selector valve V2, a straight-through solenoid valve V4, a mass flow meter 1, a six-way two-position valve V1, a first three-way solenoid valve V3, a digital pump 4, a pressure gauge 5, a second three-way solenoid valve V5, a micro vacuum pump 6, a first glass rotameter 8, a second glass rotameter 7, a gas pipeline 9, a box body 10, a quantitative ring 3 and a headspace balancer 2; the air outlet s of the four-port selector valve V2 is connected with a third vent hole C of a six-port two-position valve V1 through a through electromagnetic valve V4 and a mass flow meter 1, a second vent hole B and a fifth vent hole e of the six-port two-position valve V1 are connected through the quantifying ring 3, a third C vent hole of a first three-way electromagnetic valve V3 is connected with a first vent hole a of the six-port two-position valve V1, a first A vent hole of a first three-way electromagnetic valve V3 is connected with the digital pump 4, a second B vent hole of the first three-way electromagnetic valve V3 is a balance gas inlet connected with the headspace balancer 2, a fourth vent hole d of the six-port two-position valve V1 is connected with a first vent hole out1 through a glass rotameter 8, a sixth vent hole f of the six-port two-position valve V1 is connected with a first vent hole A vent hole of a second three-way electromagnetic valve V5 through a micro vacuum pump 8, a third C vent hole of the second three-port V5 is connected with a third vent hole out3 through a micro vacuum pump 6, the second B port of the second three-way solenoid valve V5 is connected to the second exhaust port out2 via the second glass rotameter 7.

The digital pump 4 extracts the headspace balance gas from the headspace balancer 2 or samples the headspace balance gas into the gas circuit at regular time and quantity according to a preset program, so that high-precision sampling repeatability is ensured. The digital pump 4 also comprises an airtight injector which is used for temporarily storing the headspace balance gas extracted by the digital pump 4, and after the micro vacuum pump 6 pumps the gas path into negative pressure, the headspace balance gas is discharged into the gas path, so that the repeatability of sample injection operation and the accuracy of each sample injection can be ensured.

The first three-way electromagnetic valve V3 is used for pumping headspace balance gas by the digital pump 4 when automatically switching to the A-B communication state according to a preset program; when automatically switched to the A-C communication state, the digital pump 4 is used for conveying headspace balance gas to the gas circuit and the measuring instrument. The second three-way electromagnetic valve V5 is used for vacuumizing the gas path when the A-C are communicated according to a preset program; when the A and the B are communicated, the device is used for flushing headspace balance gas sample injection.

The six-way two-position valve V1 switches the air inlet circuit of standard gas or headspace balance gas according to a preset program. The six-way two-position valve V1 has two states of Opening (ON) and closing (OFF), when in the ON state, the first vent hole a is communicated with the sixth vent hole f, the second vent hole b is communicated with the third vent hole c, and the 4 vent hole d is communicated with the fifth vent hole e; when in OFF state, the first vent hole a and the second vent hole b are communicated, the third vent hole c and the fourth vent hole d are communicated, and the fifth vent hole e and the sixth vent hole f are communicated. The six-way two-position valve V1 changes the flow direction of the gas path through the switching of ON and OFF states, residual gas in the six-way two-position valve V1 before switching can be isolated after switching, the gas in the gas path after switching cannot be influenced, and the influence of the residual gas in the valve ON experimental operation can be reduced compared with a method of changing the flow direction of the gas path by rotating the six-way valve.

The four-port selector valve V2 realizes the one-by-one air intake of the four standard gases with different concentrations std1, std2, std3 and std4 according to a preset program. The four air inlets o, p, q and r of the four-port selector valve V2 are respectively and correspondingly connected with four standard gases with different concentrations, and meanwhile, the connected standard gases can be replaced by each air inlet, so that the sampling operation of more types of standard gases is realized.

The through electromagnetic valve V4 controls the on-off state of the standard gas path according to a preset program.

The pressure gauge 5 is used for displaying the pressure inside the gas path in real time.

A glass rotameter 8 and a glass rotameter 7 are respectively installed at the tail ends of a standard gas sample introduction gas circuit and a headspace balance gas sample introduction gas circuit and used for monitoring whether the sample introduction measuring gas circuit is smooth or not.

The micro vacuum pump 6 is used for extracting gas in the gas circuit, the amount of headspace balance gas is limited generally, for reducing the gas circuit dead volume to wash the required headspace balance gas, before the headspace balance gas is introduced into the sample, the micro vacuum pump 6 is utilized in advance to pump the sample gas circuit to the negative pressure, the consumption of headspace balance gas can be effectively reduced, and the gas circuit washing efficiency is improved.

The components in the gas sampling device are connected through a gas pipeline 9. The selected gas line 9 should be less prone to gas adhesion and corrosion by the gas flowing through the line, thereby improving the accuracy and precision of the test.

The box 10 is loaded with each part of the gas sampling device, and provides an integrated and fixed carrier for other functional components, so that the device is in an ordered integral state, and the movement of the whole device is facilitated.

The gas and liquid in the headspace balancer 2 reach an equilibrium state, and the upper part of the gas is the headspace balance gas extracted in the experiment.

The utility model is mainly used for automatic sample injection control of a standard gas sequence and headspace balance gas, and simultaneously, the concentration of a component to be detected in the headspace balance gas is quantified by utilizing standard gas sample injection measurement. The specific experimental process is as follows:

the first stage is shown in fig. 3 and belongs to a standard gas injection stage. Firstly, according to a preset program, a four-port selector valve V2 sequentially selects standard gases std1, std2, std3 or std4 which are correspondingly connected through valve ports o, p, q or r, a straight-through electromagnetic valve V4 is switched to be in an open state, a six-way two-position valve V1 is switched to be in an ON state, so that the standard gases enter a third vent hole c of the six-way two-position valve V1 through the mass flow meter 1, then enter a quantitative ring 3 of a measuring instrument through a second vent hole b of the six-way two-position valve V1, then return to a fifth vent hole e of the six-way two-position valve V1, and finally flow out from a fourth vent hole d of the six-way two-position valve V1 and are emptied through a first glass rotameter 8. According to the preset program, the device automatically finishes gas path flushing and standard gas sample injection by 30 seconds.

The second stage is shown in fig. 4, and belongs to a headspace equilibrium gas sample introduction stage, and comprises the following two steps:

the first step is the preparation of the headspace balance gas for injection. According to a preset program, the three-way electromagnetic valve V3 is switched to be in an A-B communication state, the six-way switching valve V1 is switched to be in an OFF state, and the three-way electromagnetic valve V5 is switched to be in an A-C communication state. At this point, the digital pump 4 is started to draw headspace balance gas into the airtight syringe of the digital pump 4 (since headspace balance gas is drawn, the water sample in the syringe without the handle automatically flows into the headspace balancer 2, keeping the internal pressure consistent with the ambient pressure). Meanwhile, the micro vacuum pump 6 is automatically powered on, so that the inside of the air passage from the third port C of the three-way electromagnetic valve V3 to the micro vacuum pump 6 is pumped to negative pressure, and the pressure value is directly displayed by the pressure gauge 5. According to the preset program, the device completes the procedures of headspace balance gas transfer and gas circuit vacuumizing by 30 seconds.

The second step is the formal sampling of the headspace balance gas. The micro vacuum pump 6 stops running, and simultaneously the three-way electromagnetic valve V3 is switched to the A-C communication state. The digital pump 4 is started, headspace balance gas in the airtight injector is injected into the gas path, enters the quantitative ring 3 through the first vent port a and the second vent port B of the six-way two-position valve V1, returns to the fifth vent port e of the six-way two-position valve V1 and flows out from the sixth vent port f, and the three-way electromagnetic valve V5 is switched to the A-B communication state, so that the headspace balance gas flows through the second glass rotameter 7 and is discharged. According to the preset program, the device automatically completes the sample injection of the headspace balance gas by 30 seconds.

The foregoing is considered as illustrative and exemplary embodiments of the present invention, and not as limiting thereof, and it is understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the utility model.

Claims (8)

1. A headspace balance gas sample introduction device comprises a four-port selector valve V2, a pressure gauge (5), a micro vacuum pump (6), a mass flow meter (1), a quantitative ring (3) and a gas circuit pipeline (9), and is characterized by further comprising a six-way two-position valve V1, a digital pump (4), a first three-way electromagnetic valve V3, a second three-way electromagnetic valve V5 and a straight-way electromagnetic valve V4; the air outlet of the four-port selector valve V2 is connected with a third air port of a six-port two-position valve V1 through a straight-through electromagnetic valve V4 and a mass flow meter (1), the second air port and the fifth air port of the six-way two-position valve V1 are connected through the quantitative ring (3), a gas port of six-way two-position valve V1 connects the third port of first three-way solenoid valve V3, first three-way solenoid valve V3's first port links to each other with digital pump (4), first three-way solenoid valve V3's second port is balanced gas introduction port, No. one gas vent is connected to six-way two-position valve V1's No. four gas vents, pressure gauge (5) and the first port of second three-way solenoid valve V5 are passed through to six-way two-position valve V1's No. six gas vents, No. three gas vents are connected through micro vacuum pump (6) to second three-way solenoid valve V5's third port, No. two gas vents are connected to second three-way solenoid valve V5's second port.

2. The headspace balanced gas sampling device according to claim 1, wherein said digital pump (4) further comprises a gas-tight injector.

3. The headspace balanced gas sampling device according to claim 1, wherein four gas inlets of the four-port selector valve V2 are respectively and correspondingly connected with four standard gases with different concentrations.

4. The headspace balanced gas sampling device according to claim 1, wherein the six-way two-position valve V1 has two states of open and closed, and when in the open state, the first vent is communicated with the sixth vent, the second vent is communicated with the third vent, and the fourth vent is communicated with the fifth vent; when the valve is in a closed state, the first vent hole is communicated with the second vent hole, the third vent hole is communicated with the fourth vent hole, and the fifth vent hole is communicated with the sixth vent hole.

5. The headspace balanced gas sampling device according to claim 1, further comprising a first glass rotameter (8) and a second glass rotameter (7), wherein the first glass rotameter (8) is connected with a fourth vent and a first exhaust of a six-way two-position valve V1, and the second glass rotameter (7) is connected with a second vent and a second exhaust of a second three-way electromagnetic valve V5.

6. A headspace balanced gas injection device according to any of claims 1 to 5, further comprising a housing (10), said housing (10) carrying the components of the gas injection device.

7. The headspace balanced gas sampling device according to claim 1, further comprising a headspace balancer (2), wherein the headspace balancer (2) is connected to the second vent of the first three-way solenoid valve V3.

8. A headspace balanced gas injection device according to claim 1, wherein the components of the gas injection device are connected by gas lines (9).

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