CN114699876B

CN114699876B - Mixed gas separation device

Info

Publication number: CN114699876B
Application number: CN202210615369.8A
Authority: CN
Inventors: 王铁; 毛钢钢; 张凯林; 燕昊
Original assignee: Tianjin University of Technology
Current assignee: Beijing Huaerda Technology And Trade Co ltd
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2022-12-23
Anticipated expiration: 2042-06-01
Also published as: CN114699876A

Abstract

The invention relates to the technical field of gas separation detection, in particular to a mixed gas separation device, wherein the IPC classification number is B01D, and the mixed gas separation device comprises a passage main board, an annular induction heating device and an airflow circulation passage, wherein the annular induction heating device is arranged in the passage main board, and the airflow circulation passage is arranged in the annular induction heating device; the airflow circulation path comprises a main path and a side path, the main path and the side path are mutually intersected and communicated, an intersection deceleration structure is formed at the intersection between the main path and the side path, an adsorption material is filled in the main path, the side path consists of two arc transition paths, and the carrier airflow in the side path can reversely converge into the main path; one end of the passage main board is provided with an airflow sample inlet. The invention improves the separation and analysis effects on volatile organic compounds; the convergent needle point sampling nozzle at the sampling port can effectively improve the speed of carrier gas flow and improve the subsequent ionization yield.

Description

Mixed gas separation device

Technical Field

The invention relates to the technical field of gas separation and detection, in particular to a mixed gas separation device, wherein IPC (International patent application for Industrial control) is B01D.

Background

At present, chromatographic analysis refers to a method of separating and analyzing substances according to the difference in partition coefficients between a stationary phase and a mobile phase. It can be classified into liquid chromatography, gas chromatography, supercritical fluid chromatography, etc. according to the molecular aggregation state of the mobile phase. According to the separation principle, the separation method can be divided into a plurality of categories such as adsorption, distribution, space exclusion, ion exchange, affinity and chiral chromatography. According to the operating principle, the method can be classified into column chromatography, plate chromatography and the like. The chromatographic analysis is widely applied in the fields of analytical chemistry, organic chemistry, biochemistry and the like, and the gas chromatographic analysis refers to a chromatographic analysis method with a gas as a mobile phase, and samples such as gas, liquid or solid which is easy to volatilize and the like can be separated and measured by the gas chromatographic analysis.

In the existing gas chromatography separation technology in the prior art, special materials are filled or sprayed in a chromatographic column, and the special materials have different attractions to different gas molecules, so that the flow rates of different gases are slowly changed in the flowing process of mixed gas in a pipeline, the different gases are gradually separated after flowing through a longer pipeline, the chromatographic column is separated by the different flowing speeds of the different gases in the pipeline, and the long-path chromatographic column can reduce the content of certain samples to be measured, so that the measurement accuracy is influenced.

There is therefore a need for a mixed gas separation device that can solve the above problems.

Disclosure of Invention

The invention provides a mixed gas separation device, which utilizes the effect of a reverse Tesla valve on fluid deceleration to enable mixed gas to slowly flow out of a separation valve, and converts the idea of separating each component of the mixed gas by using space length in the traditional gas chromatography into time length. The carrier gas in the side passage is injected into the main passage to reduce the flow speed of the main passage, the carrier gas and the carrier gas are combined to form a local flow effect similar to a ring, so that the flow speed of the fluid is reduced, the mixed gas can be fully absorbed by the adsorption coating material in the valve body, based on the basic principle of gas capillary column chromatographic separation technology, molecules with low gasification temperature flow out of the valve body firstly along with the rise of temperature, the molecules with high gasification temperature are retained in the valve body for a longer time, and finally the separation of different component substances in the mixed gas is realized.

The technical scheme adopted by the invention for solving the technical problems is as follows: a mixed gas separation device comprises a passage main board, an annular induction heating device and an airflow circulation passage, wherein the annular induction heating device is arranged inside the passage main board, and the airflow circulation passage is arranged inside the annular induction heating device;

the airflow circulation path comprises a main path and a side path, the main path and the side path are mutually intersected and communicated, an intersection deceleration structure is formed at the intersection between the main path and the side path, an adsorption material is filled in the main path, the side path consists of two arc transition paths, and the carrier airflow in the side path can reversely converge into the main path;

one end of the passage main board is provided with an airflow sample inlet which is communicated with the input end of the main passage, the other side of the passage main board is provided with a sample outlet nozzle which is communicated with the output end of the main passage;

the annular induction heating device is internally provided with an annular heating resistance wire for heating the mixed gas in the airflow circulation passage, and is provided with a plurality of patch electrode interfaces for connecting the heating resistance wire with a control circuit so as to control the heating temperature of the resistor.

Further, the adsorbing material filled in the main channel is any one of polysiloxane, polyethylene glycol or alumina, the thickness of the film is 1.2-1.8 mu m, and the inner diameter is 0.1mm-0.5mm.

Furthermore, the annular induction heating device is connected with a temperature sensor, and the temperature sensor is used for detecting the temperature of the temperature sensitive resistor layer in the annular induction heating device.

Furthermore, the shape of the sample outlet nozzle is in a needle point convergence shape and is used for enabling the carrier gas flow to be in a beam-shaped diffusion state.

Furthermore, the upper end and the lower end of the path mainboard are fixedly connected with fixing pieces, and screw holes are formed in the fixing pieces.

Furthermore, a sealing gasket is sleeved outside the annular induction heating device.

The invention has the advantages that: the invention provides a mixed gas separation device, which has the following advantages:

1. compared with the chromatographic column with the traditional structure, the invention can carry out multi-stage speed reduction on the carrier gas flow with the volatile organic compounds through the gas flow circulation passage consisting of the main passage and the side passage; because the gas circulates for many times in the main channel and the side channel, the volatile organic compounds can be fully adsorbed by using a shorter chromatographic column, and the loss of trace components in the thermal adsorption process of organic molecules is avoided; the device can be fully separated and analyzed in the main passage, and can facilitate subsequent qualitative and quantitative detection.

2. The side passage in the invention has the effects of providing deceleration and gradual decompression for the carrier gas flow, and the speed of the volatile organic compounds moving in the main passage is limited, so that the integral separation time is prolonged, all components in the carrier gas flow can be fully circulated, the separation effect is improved, and good conditions are provided for further analysis and detection.

3. The sampling nozzle structure with the convergent shape can endow a relatively high outflow speed to the carrier gas flow after multistage speed reduction. The sample outlet structure is a needle tip nozzle which is gradually narrowed in an exponential convergence mode and can enable carrier gas flow to be in a beam-shaped diffusion state; the method is more favorable for ionizing the molecules of the sample compound, improves the ionization yield and can obtain better signals in further detection.

Drawings

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

FIG. 1 is a schematic view of the structure of the present invention;

FIG. 2 is an enlarged schematic view of a sample outlet nozzle according to the present invention;

FIG. 3 is a left side view of the present invention;

FIG. 4 is a schematic left side view of the annular induction heating apparatus of the present invention;

FIG. 5 is a schematic top view of the structure of FIG. 4;

wherein:

1. an airflow sample inlet; 2. A path main board; 3. A main path;

4. a fixing sheet; 5. A junction deceleration structure; 6. A side passage;

7. an annular induction heating device; 8. A temperature sensor; 9. A patch electrode interface;

10. a sample outlet nozzle; 11. A sealing gasket; 12. Heating resistance wires;

13. and a screw hole.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that unless otherwise explicitly specified or limited, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on those illustrated in the drawings, and are merely for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance, and the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1:

fig. 1 is a schematic structural view of the present invention, and the mixed gas separation device shown in fig. 1 includes a passage main plate 2, an annular induction heating device 7 and an airflow circulation passage, in the present invention, fixing plates 4 are fixedly connected to both upper and lower ends of the passage main plate 2, screw holes 13 are formed on the fixing plates 4, the whole device can be connected and fixed through four symmetrical bolts via the screw holes 13, and at the same time, the screw holes 13 also have a function of positioning the whole device; the invention is located in the chromatograph, the chromatographic column part is provided with the annular induction heating device 7 for heating the carrier gas flow, and the volatile organic compounds in the carrier gas flow are separated due to the difference of polarity, boiling point and adsorption property; the Tesla valve-like structure side passage 6 can provide speed reduction and gradual pressure reduction effects for the carrier gas flow. By limiting the movement speed of the volatile organic compounds in the main channel 3, the integral separation time is prolonged, all components in the carrier gas flow can be fully circulated, the separation effect is improved, and good conditions are provided for further analysis and detection;

the gas flow circulation path comprises a main path 3 and a side path 6, the main path 3 and the side path 6 are communicated with each other in an intersecting manner, an intersecting speed reduction structure 5 is formed at the intersection between the main path 3 and the side path 6, one end of a path main board 2 is provided with a gas flow injection port 1, the gas flow injection port 1 is communicated with the input end of the main path 3, an adsorption material is filled in the main path 3, the adsorption material in the main path 3 can select and use polysiloxane according to the type of a target analyte, the thickness of a film is 1.4 mu m, the inner diameter is 0.25mm, and under proper conditions, different stationary phases can be selected according to the difference of detection conditions or sample types to obtain the optimal separation and analysis effect; the side passage 6 is composed of two arc transition passages, the carrier gas flow in the side passage 6 can reversely flow into the main passage 3, and the Tesla valve-like structure shown in the attached figure 1 of the specification has no moving parts, so that the mechanical wear and fatigue damage are eliminated. Under the action of carrier gas, volatile organic compounds to be separated and detected enter a main passage 3 of a serpentine structure through an airflow sample inlet 1, the airflow is divided at an intersection speed reduction structure 5 between the main passage 3 and side passages 6, and the airflow entering each stage of side passages 6 reversely and re-enters the main passage 3, so that the carrier gas in the main passage 3 is blocked;

the side passage 6 in the invention is composed of two arc transition passages, wherein one bent branch passage is a spiral section, and the other arc passage is a trunk section; wherein the realization of the circulation flow requires a pressure drop in the reverse flow direction of the side passage 6 to be larger than that in the forward flow direction of the main passage 3. The fluid flow behavior is not caused by external mechanisms, but rather by changes that result in a pressure drop Δ P between forward and reverse flows, with the formula Di =

To describe; wherein, the delta Pr is the reverse total pressure drop, and the delta Pf is the forward total pressure drop. Δ P produces Di (degrees of diode) due to the inertial and viscous forces of the fluid, the losses of inertial force being proportional to the square of the velocity, and the viscous forces being proportional to the velocity and they become significant in laminar flow, the Di value being degrees of diode, a criterion for evaluating the performance of the valve, a parameter describing the difference in the effect of the forward and reverse flows; the air can flow normally in the forward direction, the flow effect is greatly limited in the reverse direction, and when Di is larger than 1, the air flow of the main channel 3 can keep moving in the forward direction. The air flow in the side passage 6 is converged into the main section, and when the two air flows are converged, a fine-crushing turbulent flow is formed and generates a vortex-shaped air flow, so that the forward movement of the air flow in the main passage 3 is blocked;

compared with the chromatographic column with the traditional structure, the capillary chromatographic column with the snake-shaped path and the Tesla-like valve structure side passage 6 can carry out multi-stage speed reduction on carrier gas flow with volatile organic compounds; because the gas circulates for many times in the Tesla separation valve, the volatile organic compounds can be fully adsorbed by a shorter chromatographic column, and the loss of trace components in the thermal adsorption process of organic molecules is avoided; the separation and analysis can be fully carried out in the main channel 3, and the subsequent qualitative and quantitative detection can be conveniently carried out; after the carrier gas flow with the volatile organic compounds is decelerated in multiple stages, the gas flow speed is slower and slower, and a better separation effect can be obtained after long-time circulating separation; when the carrier gas flow leaves the capillary chromatographic column through the needle point sampling nozzle 10 with the convergent shape, the gas flow is in a beam-shaped diffusion state, which is beneficial to ionizing a sample compound in the next step and can obviously improve the ionization yield of the sample.

The invention carries out filling of a fixed phase or vacuum coating treatment in a main passage 3 with a snake-shaped structure; the carrier gas flows mostly in the forward direction through the main passage 3; part of the carrier gas flow is accelerated by the side passage 6 and then reversely merged into the main passage 3, and the gas flow in the main passage 3 is subjected to stepped speed reduction; the reverse airflow in the side passages 6 increases the movement resistance of the airflow in the main passage 3, so that the speed and the pressure of the airflow in the main passage 3 are gradually reduced, and when the reverse airflow in each side passage 6 is converged into the main passage 3, a vortex-shaped airflow is formed to block the forward movement speed of the airflow in the main passage 3, so that the airflow in the following circulating main passage 3 is reduced, and the speed is reduced.

The side passage 6 with the Tesla valve-like structure has compact layout and adaptability to various functions. The flow rate and the gas pressure of the carrier gas flow can be controlled and adjusted, and the flow rate and the gas pressure of the carrier gas flow with the volatile organic compounds can be adjusted to a suitable range by increasing or decreasing the number of the side passages 6.

Fig. 2 is an enlarged schematic structural diagram of a sample outlet nozzle in the present invention, as shown in fig. 2 of the specification, a sample outlet nozzle 10 is provided on the other side of a main channel plate 2, the sample outlet nozzle 10 is communicated with an output end of the main channel 3, the sample outlet nozzle 10 in the present invention is in a needle point convergent shape for making a carrier gas flow in a beam-shaped diffusion state, and the carrier gas flow in the main channel 3 finally flows out of the main channel 3 from the needle point sample outlet nozzle 10 in the convergent shape after multistage speed reduction through a side channel 6; the airflow may then spread in a bundle. The airflow in the scattering state is more beneficial to the next step of ionizing the molecules of the sample compounds, and the reliability of the detection result is improved by improving the ionization rate of organic molecules.

Fig. 3 is a schematic left-view structural diagram of the present invention, fig. 4 is a schematic left-view structural diagram of the annular induction heating device of the present invention, fig. 5 is a schematic top-view structural diagram of fig. 4, and as shown in fig. 3, fig. 4 and fig. 5, an annular heating resistance wire 12 is disposed inside the annular induction heating device 7 of the present invention, and is used for uniformly heating the mixed gas in the airflow circulation passage, so as to accelerate separation of organic matter molecules in the mixed gas, and a corresponding preset heating gear can be selected according to different sample types, so as to ensure that an optimal separation effect can be achieved on the samples; the annular induction heating device 7 is provided with a plurality of patch electrode interfaces 9, the patch electrode interfaces 9 are used for connecting a heating resistance wire 12 with a control circuit, so that the heating temperature of a resistor is controlled, a sealing gasket 11 is sleeved outside the annular induction heating device 7, a good sealing effect is achieved, the annular induction heating device 7 is connected with a temperature sensor 8, the temperature sensor 8 is used for detecting the temperature of a temperature-sensitive resistance layer, the temperature signal output end of the temperature sensor 8 can be externally connected with a display, the display displays the temperature signal of the temperature sensor 8, and the function is to accurately monitor the temperature of mixed gas in a passage; the temperature sensor 8 can also be connected with a control circuit, and the heating gear is adjusted through the temperature fed back by the sensor.

The invention improves the separation and analysis effects of volatile organic compounds; the convergent needle tip sampling spout 10 at the sampling outlet can effectively improve the speed of carrier gas flow and can improve the subsequent ionization yield.

The working principle is as follows: the degree of diode Di, which measures the performance of the device, is due to the difference in the connection angle between the two portions of the tesla-like valve, the resistance being greater in the reverse direction compared to the forward direction. The carrier gas flow in each level of side passage 6 can continuously and reversely flow into the main passage 3, and the carrier gas flow in the main passage 3 is obviously hindered; when the reverse airflow of each stage of side passage 6 is converged into the main passage 3, vortex-shaped airflow is formed to block the forward movement of the carrier gas of the main passage 3, so that the airflow to the rear circulating main passage 3 is less and less, and the speed of the whole carrier gas flow is lower and less; therefore, the gas flow has a longer residence time in the device, volatile organic compounds in the carrier gas can be fully circulated in the main passage 3 filled with the adsorbing material and absorbed by the adsorbing material, the heating device can start heating after the gas is fully absorbed, small molecular substances with lower gasification temperature can be released earlier, and macromolecular substances have a longer retention time in the valve body, so that the separation and analysis effects on various volatile organic compounds can be improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and these modifications or substitutions do not depart from the spirit of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A mixed gas separation device comprises a passage main board (2), an annular induction heating device (7) and an airflow circulation passage, wherein the annular induction heating device (7) is arranged inside the passage main board (2), and the airflow circulation passage is arranged inside the annular induction heating device (7);

the method is characterized in that: the airflow circulation path comprises a main path (3) and a side path (6), the main path (3) and the side path (6) are mutually intersected and communicated, an intersection deceleration structure (5) is formed at the intersection between the main path (3) and the side path (6), an adsorption material is filled in the main path (3), the side path (6) is composed of two arc transition paths, and the carrier airflow in the side path (6) can be reversely converged into the main path (3);

an airflow sample inlet (1) is formed in one end of the path main board (2), the airflow sample inlet (1) is communicated with the input end of the main path (3), a sample outlet nozzle (10) is formed in the other side of the path main board (2), the sample outlet nozzle (10) is communicated with the output end of the main path (3), and the shape of the sample outlet nozzle (10) is in a needle point convergence state and is used for enabling carrier airflow to be in a beam-shaped diffusion state;

the main passage (3) is of a snake-shaped structure, wherein a stationary phase is filled; the carrier gas flow flows in a forward direction through the main passage (3); part of carrier gas flow is accelerated by the side passage (6) and then reversely flows into the main passage (3), and the stepped speed reduction is carried out on the gas flow in the main passage (3); the reverse airflow in the side passages (6) is used for increasing the movement resistance of the airflow in the main passage (3) and gradually reducing the speed and the air pressure of the airflow in the main passage (3), the reverse airflow in each side passage (6) is converged into the main passage (3) to form vortex-shaped airflow which is used for hindering the forward movement speed of the airflow in the main passage (3) and reducing the airflow in the circulating main passage (3) and slowing down the speed;

the mixed gas separation device is positioned inside a gas chromatograph and is used for gas chromatographic analysis.

2. The mixed gas separation device according to claim 1, wherein a ring-shaped heating resistance wire (12) is arranged inside the ring-shaped induction heating device (7) and used for heating the mixed gas in the airflow circulation path, a plurality of patch electrode interfaces (9) are arranged on the ring-shaped induction heating device (7), and the patch electrode interfaces (9) are used for connecting the heating resistance wire (12) with a control circuit, so as to control the heating temperature of the resistance.

3. The mixed gas separation device according to claim 1, wherein the adsorption material filled in the main passage (3) is any one of polysiloxane, polyethylene glycol or alumina, the thickness of a film formed by the adsorption material is 1.2 to 1.8 μm, and the inner diameter of the film formed by the adsorption material is 0.1mm to 0.5mm.

4. A mixed gas separating device according to claim 1, wherein a temperature sensor (8) is connected to the annular induction heating device (7), and the temperature sensor (8) is used for detecting the temperature of the temperature sensitive resistor layer in the annular induction heating device (7).

5. The mixed gas separating device according to claim 1, wherein the upper and lower ends of the passage main plate (2) are fixedly connected with fixing plates (4), and screw holes (13) are formed on the fixing plates (4).

6. A mixed gas separating device according to claim 1, wherein the annular induction heating means (7) is externally provided with a sealing gasket (11).