CN114544275A

CN114544275A - Gas sampling device by air bag method

Info

Publication number: CN114544275A
Application number: CN202210324035.5A
Authority: CN
Inventors: 沙亚东; 秦铭磊; 丁泓皓; 刘奂
Original assignee: Jiangsu Xinrui Environmental Monitoring Co ltd
Current assignee: Jiangsu Xinrui Environmental Monitoring Co ltd
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2022-05-27

Abstract

The invention discloses an air bag method gas sampling device, which comprises a sampling box, wherein an air chamber and a placing cavity are arranged in the sampling box, an air bag is placed in the placing cavity, the placing cavity comprises a plurality of placing cavities, hollow holes communicated with the air chamber are formed in the plurality of placing cavities, the air chamber is connected with a pressure control device for boosting or reducing pressure, an air bag is placed in each placing cavity, an inlet of the air bag is fixed at the upper end of the placing cavity, the inlet of the air bag is connected with a branch pipe, the branch pipe is connected with a sampling pipe through a main pipe, a branch switch device for opening or closing the branch pipe is arranged on each branch pipe, an opening switch device for opening or closing the branch pipe is arranged between the main pipe and the sampling pipe, and a first electric heating device for heating the sampling gas is arranged on the sampling pipe; the device can gather the quartic by the time quantum, and it is loaded down with trivial details to have avoided the manual work bag of taking a breath, effectively reduces the factor that influences the result, improves sampling efficiency.

Description

Gas sampling device by air bag method

Technical Field

The invention relates to an air bag method gas sampling device, which is suitable for the field of gas sampling.

Background

The air bag sampling is to collect a certain gas for analysis and determination, the sampling mode is determined according to the sampling purpose and the field condition, and the sampled sample is representative to obtain reliable basic data; the prior air bag method gas sampling device comprises a sampling pipe, the tail end of the sampling pipe is connected with an air bag, the air bag is arranged in a sealed air chamber, the outlet of the air bag is fixed at the upper end of the air chamber and is communicated with the tail part of the sampling pipe, the air chamber is connected with an electric air pump which can be switched by positive pressure and negative pressure, an electric heating wire is arranged in the sampling pipe, is used for heating the sampled gas to ensure that the temperature of the sampled gas reaches 120 ℃, the gas in the air bag needs to be replaced before sampling, generally, the mode is adopted that an electric air pump is firstly opened to ensure that the gas is subjected to negative pressure, the internal pressure of an air chamber is reduced, thus, the pressure in the air bag expands outwards to increase the volume of the air bag, thereby pumping the gas into the air bag, then the electric air pump is switched to positive pressure, so that the pressure of the air chamber is increased, the air in the air bag can be pressed out, and the air can be replaced after the steps are repeated, however, the sampling device has the following defects: 1. when the gas bag is replaced, the gas in the gas bag is discharged from the sampling pipe, and the gas which is replaced and discharged cannot be completely discharged from the sampling pipe due to the small volume of the gas bag, so that the discharged gas is still in the sampling pipe, the gas which is sampled is not completely sampled, and the result is inaccurate; 2. the existing gas bag method sampling device can only collect gas once, but under normal conditions, gas needs to be collected four times at one sampling point, so that the collecting process is very complicated, the gas bag needs to be frequently taken out and installed, then gas is replaced, and the like, so that the degree of needing manual participation is high, and time and labor are wasted; 3. although the temperature of the current air bag method collecting device is heated to 120 ℃, moisture is changed into water vapor, the water vapor in the air bag is condensed into water in the later-stage conveying and transporting process due to the fact that the water vapor enters the air bag and is not provided with a heat preservation device, and the liquid water can dissolve target detection substances in the gas, for example, when gas VOC (volatile organic compound) detection sampling is carried out, components of partial VOC can be dissolved in the water, and therefore subsequent detection results are inaccurate.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the utility model provides a gas sampling device of air pocket method, the device can gather many times by the time quantum, has avoided the loaded down with trivial details of artifical trade air pocket, improves sampling efficiency.

In order to solve the technical problems, the technical scheme of the invention is as follows: the utility model provides a gaseous sampling device of air pocket method, includes the sampling box, be provided with the air chamber in the sampling box and place the chamber, the air pocket is placed in placing the intracavity, it includes a plurality of chambeies of placing to place the chamber, a plurality of fretwork holes that all are provided with on placing the chamber and communicate with the air chamber, the air chamber is connected with a pressure control device who is used for pressure boost or decompression, all placed one in every placing the chamber the air pocket, the entry of air pocket is fixed in the upper end of placing the chamber, a branch pipe is all connected to the air pocket entry, divide the pipe to be connected with the sampling pipe through house steward, every is provided with a branch switching device who is used for opening or closing branch pipe on dividing the pipe, be equipped with the entry switching device who opens or close between house steward and the sampling pipe, be provided with the first electric heater unit that heats sampling gas on the sampling pipe.

As a preferred scheme, sampling box includes box and apron, connect through buckle structure between apron and the box, be provided with the sealing strip between apron and the box, a plurality of chambers of placing set up between box and apron, the air chamber sets up in the below of placing the chamber.

As a preferable scheme, the other end of the main pipe is provided with an exhaust port, and an exhaust switch device for opening or closing the exhaust port is arranged at the exhaust port.

Preferably, a thermostatic device for keeping the air bag warm is further arranged on the chamber wall of the placing chamber.

As a preferable scheme, the chamber wall of the placing chamber is of a multilayer structure, the chamber wall of the placing chamber comprises an outer chamber wall, an inner chamber wall and heat insulation layers arranged on the outer chamber wall and the inner chamber wall, the constant temperature device is a second electric heating device arranged in the heat insulation layers, and a temperature sensor is arranged in the placing chamber.

As a preferable scheme, a filtering device for absorbing water vapor is arranged behind the inlet switch device, and the filtering device is a titanium filter element and a molecular sieve which are connected in series.

As a preferred scheme, the pressure control device is an electric air pump, the electric air pump is connected to the air chamber through an air path pipeline, and a pressure gauge convenient for pressure observation is arranged on the electric air pump.

After the technical scheme is adopted, the invention has the effects that: the gas sampling device adopting the air bag method comprises a sampling box, wherein an air chamber and a placing cavity are arranged in the sampling box, an air bag is placed in the placing cavity, the placing cavity comprises a plurality of placing cavities, hollow holes communicated with the air chamber are formed in the placing cavities, the air chamber is connected with a pressure control device for boosting or reducing pressure, one air bag is placed in each placing cavity, an inlet of the air bag is fixed at the upper end of the placing cavity, the inlet of the air bag is connected with a branch pipe, the branch pipe is connected with the sampling pipe through a main pipe, a branch switch device for opening or closing the branch pipe is arranged on each branch pipe, an opening and closing inlet switch device is arranged between the main pipe and the sampling pipe, and a first electric heating device for heating the sampled gas is arranged on the sampling pipe;

firstly, replacing an air bag, placing a sampling pipe in a required sampling point, starting a pressure control device, exhausting air from an air chamber and reducing pressure, communicating the air chamber with a placing cavity through a hollow hole, opening all branch switch devices and an inlet switch device, wherein the air pressure in the air chamber is smaller than the external air pressure, so that the air is sucked into a main pipe from the sampling pipe, enters each branch pipe connected with the main pipe, finally enters the air bag to expand the air bag, then, blowing air to pressurize the air chamber, wherein the internal air pressure is larger than the external air pressure, so that the air in the air bag is extruded out to enter each branch pipe, is collected into the main pipe by the branch pipes, is discharged from the sampling pipe, and after repeating for several times, closing the branch switch devices and the inlet switch device to finish replacement; then, starting sampling operation, heating the gas in the sampling pipe through a first electric heating device during first sampling, performing air exhaust and pressure reduction on the gas chamber through a pressure control device after the gas is heated to 120 degrees, only starting one of the branch switch devices and the inlet switch device at the moment, enabling the sampling gas to enter the main pipe from the sampling pipe, enabling the sampling gas to enter an air bag of the started branch pipe, then closing the corresponding branch switch device, and then waiting for second sampling; the device can gather the quartic by the time quantum in proper order, avoids the manual work to trade the loaded down with trivial details of bag, effectively reduces the factor that influences the result, improves sampling efficiency.

Because sampling box includes box and apron, connect through buckle structure between apron and the box, be provided with the sealing strip between apron and the box, a plurality of cavities of placing set up between box and apron, the air chamber sets up in the below of placing the cavity, through being equipped with buckle structure, can quick replacement when the air pocket is changed to needs to be equipped with the sealing strip and can effectively improve the leakproofness of placing the cavity.

And because the other end of the main pipe is provided with the exhaust port, the exhaust opening and closing device for opening or closing the exhaust port is arranged at the exhaust port, when gas is replaced, the gas enters the gas bag, the exhaust opening and closing device is closed, when the gas in the gas bag needs to be exhausted, the exhaust opening and closing device is opened, the gas can be exhausted from the exhaust port, so that the gas inlet and the gas outlet can be distinguished, the gas is required when the gas is replaced, and the sampling accuracy is improved.

And because the wall of the placing chamber is also provided with a constant temperature device for insulating the air bag, the heated air can be effectively insulated after entering the air bag, the air is prevented from generating vapor due to cooling, and the inaccuracy of subsequent detection is avoided.

The chamber wall of the placing chamber is of a multilayer structure, the chamber wall of the placing chamber comprises an outer chamber wall, an inner chamber wall and heat insulation layers arranged on the outer chamber wall and the inner chamber wall, the constant temperature device is a second electric heating device arranged in the heat insulation layers, a temperature sensor is arranged in the placing chamber, the multilayer structure is arranged, on one hand, heat can be prevented from being dissipated, and on the other hand, the problem caused by direct contact of the second electric heating device and the air bag is avoided.

And because the filtering device for absorbing water vapor is arranged behind the inlet switch device and is a titanium filter element and a molecular sieve which are mutually connected in series, the water vapor in the gas can be effectively filtered, fine particles can be filtered, target detection substances in the gas can be prevented from being dissolved by the water vapor, and the detection accuracy is ensured.

And because the pressure control device is an electric air pump which is connected to the air chamber through an air path pipeline, the electric air pump is provided with a pressure gauge which is convenient for observing the pressure, the pressure value in the air chamber can be changed through air exhaust or air blowing, and the pressure gauge can be used for visually observing, so that the next operation is convenient.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

in the drawings: 1. a sampling box; 2. a box body; 3. a cover plate; 4. a sealing strip; 5. an air chamber; 6. placing a chamber; 61. an outer chamber wall; 62. an inner chamber wall; 63. a heat-insulating layer; 64. a second electric heating device; 7. an air bag; 8. hollowing out holes; 9. pipe distribution; 10. a first solenoid valve; 11. a second solenoid valve; 12. a third electromagnetic valve; 13. a fourth solenoid valve; 14. a header pipe; 15. an exhaust port; 16. an exhaust switch device; 17. a sampling tube; 18. an inlet opening and closing device; 19. a first electric heating device; 20. a filtration device; 21. an electric air pump; 22. a pressure gauge; 23. a buckle structure.

Detailed Description

The present invention is described in further detail below with reference to specific examples.

As shown in figure 1, the gas sampling device by the air bag method comprises a sampling box 1, wherein a gas chamber 5 and a placing cavity are arranged in the sampling box 1, the air bag 7 is placed in a placing cavity, the placing cavity comprises a plurality of placing chambers 6, hollow holes 8 communicated with the air chamber 5 are arranged on the placing chambers 6, the air chamber 5 is connected with a pressure control device for increasing or reducing pressure, each placing chamber 6 is internally provided with an air bag 7, the inlets of the air bags 7 are fixed at the upper end of the placing cavity, the inlets of the air bags 7 are connected with a branch pipe 9, the branch pipes 9 are connected with a sampling pipe 17 through a main pipe 14, each branch pipe 9 is provided with a branch switch device for opening or closing the branch pipe 9, an inlet opening and closing device 18 which is opened or closed is arranged between the main pipe 14 and the sampling pipe 17, the sampling pipe 17 is provided with a first electric heating device 19 for heating the sampling gas.

In this embodiment, the placing cavity is internally provided with 4 air bags 7, so the placing cavity comprises 4 placing cavities 6, the 4 placing cavities 6 correspond to the 4 branch pipes 9, the pressure control device is an electric air pump 21, the electric air pump 21 is connected to the air chamber 5 through an air passage pipeline, the electric air pump 21 is provided with a pressure gauge 22 convenient for observing pressure, the electric air pump 21 can continuously pump air or blow air through electric power, so that the pressure in the air chamber 5 is reduced or increased, and the pressure gauge 22 on the electric air pump 21 can observe the pressure at the moment to determine subsequent operation, thereby improving safety; the first heating device adopts an electric heating wire, the electric heating wire is arranged in the sampling pipe 17, gas in the pipe is heated, the temperature is 120 +/-5 ℃, and water vapor in the pipe is effectively reduced; the inlet switch device 18 adopts a regulating valve which has the function of variable resistance in a pipeline, so that the size of the air flow can be regulated, and the flow rate of the air flowing in and out can be effectively controlled; of course, a valve such as a ball valve or a butterfly valve which can be controlled to open and close can be used.

Further sampling box 1 includes box 2 and apron 3, connect through buckle structure 23 between apron 3 and the box 2, be provided with sealing strip 4 between apron 3 and the box 2, buckle structure 23 is current structure, therefore does not describe in detail herein, 4 place cavity 6 and set up between box 2 and apron 3, air chamber 5 sets up in the below of placing cavity 6, be equipped with on the apron 3 with 4 air pocket 7 entry one-to-one apron 3 openings and with divide pipe 9 to be connected, divide switching device to adopt the solenoid valve, the solenoid valve includes first solenoid valve 10, second solenoid valve 11, third solenoid valve 12 and fourth solenoid valve 13, just so can each solenoid valve of remote control realize the switch of air pocket 7 through the circuit, raises the efficiency.

In the embodiment, the other end of the main pipe 14 is provided with an exhaust port 15, the exhaust port 15 is provided with an exhaust switch device 16 for opening or closing the exhaust port 15, the collecting pipe needs to be extended far, and then the main pipe 14 is connected so that gas is not exhausted from the pipeline when gas is replaced and is drawn back into the gas bag 7, so that the gas is impure, the exhaust port 15 is arranged at the other end of the main pipe 14, the exhaust port 15 is close to the position passing through the gas bag 7, when gas is replaced, the exhaust switch device 16 is closed when the gas bag 7 inhales, the gas enters the main pipe 14 from the sampling pipe 17 and enters the gas bag 7, and when the gas bag 7 exhausts, the exhaust switch device 16 is opened, the inlet switch device 18 is closed, and the gas is exhausted from the exhaust port 15; in the sampling process, the exhaust switch device 16 is in a closed state, the exhaust switch device 16 adopts a ball valve, and the gas is required to be exhausted as soon as possible when the device exhausts, so that the flow rate is not required to be controlled, and the gas enters the gas bag 7 from the main pipe 14 and is exhausted from the exhaust port 15, so that the purity of replacement of the gas bag 7 is ensured, and the detection accuracy is improved.

Further, a constant temperature device for insulating the air bag 7 is further arranged on the chamber wall of the placing chamber 6, the chamber wall of the placing chamber 6 is of a multilayer structure, the chamber wall of the placing chamber 6 comprises an outer chamber wall 61, an inner chamber wall 62 and an insulating layer 63 arranged on the outer chamber wall 61 and the inner chamber wall 62, the constant temperature device is a second electric heating device 64 arranged in the insulating layer 63, a temperature sensor is arranged in the placing chamber 6, the multilayer structure is adopted to effectively reduce heat dissipation, potential safety hazards caused by direct contact between the air bag 7 and the second electric heating device 64 are avoided in the air suction expansion process of the air bag 7, the second electric heating device 64 also adopts an electric heating wire, and after the air enters the air bag 7, the air bag is heated by the second heating device to avoid condensation of the air in the storage process, and subsequent detection is influenced.

Be equipped with the filter equipment 20 who is used for absorbing steam behind the entry switching device 18, filter equipment 20 includes titanium filter core and molecular sieve, the molecular sieve is the material that has the hole of even size, and these pore sizes are similar with chemical micromolecule in, therefore the macromolecule can not get into the molecular sieve or be adsorbed, and the micromolecule can, titanium filter core is formed by titanium metal sintering, has fine filtering quality, and titanium filter core has advantages such as long service life, high temperature resistant, separation efficiency height, consequently can effectively dry the moisture in the air current and filter tiny particulate matter, guarantees the degree of dryness of air current, reduces the disappearance of the target detection material that dissolves in water, makes the testing result accurate.

The working principle of the invention is as follows: firstly, replacing gas in 4 air bags 7, placing sampling pipes 17 in sampling points, starting all electromagnetic valves and inlet switch devices 18, opening an electric air pump 21, pumping air to the air chamber 5 for decompression, communicating the air chamber 5 with a placing chamber 6 through a hollow hole 8, enabling the air pressure in the air chamber 5 to be smaller than the external air pressure, pumping the gas into a main pipe 14 from the sampling pipes 17, then entering each branch pipe 9 connected with the main pipe 14, finally entering the air bags 7 to expand the air bags 7, closing the inlet switch devices 18 when the 4 air bags 7 are in contact with an inner chamber wall 62, enabling the electric air pump 21 to blow and pressurize the air chambers 5, enabling the internal air pressure in the air bags 7 to be larger than the external air pressure, extruding the gas in the air bags 7 to enter the respective branch pipes 9, starting exhaust switch devices 16, exhausting the gas from an exhaust port 15, repeating for several times, and finally exhausting the gas from the air bags 7, and (3) closing the exhaust switch device 16, all the electromagnetic valves and the electric air pump 21, starting the first electromagnetic valve 10 and the inlet switch device 18 after the first sampling time is reached, starting the electric air pump 21 to pump air and reduce pressure of the air chamber 5, enabling the air to enter the main pipe 14 from the sampling pipe 17 and then enter the branch pipe 9 for starting the first electromagnetic valve 10, finally entering the air bag 7, waiting for the air bag 7 to expand to be in contact with the inner layer chamber wall 62, closing the first electromagnetic valve 10, finishing the first sampling, and then sequentially waiting for repeating the sampling operation at the next subsequent sampling time node, so that the air sequentially enters the remaining 3 air bags 7, and finishing the sampling.

The above-mentioned embodiments are merely descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and alterations made to the technical solution of the present invention without departing from the spirit of the present invention are intended to fall within the scope of the present invention defined by the claims.

Claims

1. The utility model provides a gaseous sampling device of air pocket method, includes the sampling box, be provided with the air chamber in the sampling box and place the chamber, the air pocket is placed in placing the intracavity, its characterized in that: the utility model discloses a sampling pipe, including placing the chamber, place the chamber and include a plurality of chambeies of placing, a plurality of fretwork holes that all are provided with on placing the chamber and communicate with the air chamber, the air chamber is connected with a pressure control device who is used for pressure boost or decompression, every is placed and all has been placed one in the chamber the air pocket, the entry of air pocket is fixed in the upper end of placing the chamber, the air pocket entry all connects a branch pipe, divide the pipe to be connected with the sampling pipe through house steward, every is provided with a branch switching device who is used for opening or closing branch pipe on dividing the pipe, be equipped with the entry switching device who opens or close between house steward and the sampling pipe, be provided with the first electric heater unit that heats sampling gas on the sampling pipe.

2. An air bag gas sampling assembly as defined in claim 1 wherein: the sampling box comprises a box body and an cover plate, the cover plate is connected with the box body through a buckle structure, a sealing strip is arranged between the cover plate and the box body, a plurality of placing cavities are arranged between the box body and the cover plate, and an air chamber is arranged below the placing cavities.

3. An air bag gas sampling apparatus as defined in claim 2, wherein: the other end of the main pipe is provided with an exhaust port, and an exhaust switch device for opening or closing the exhaust port is arranged at the exhaust port.

4. An air bag gas sampling assembly as defined in claim 3 wherein: the chamber wall of the placing chamber is also provided with a constant temperature device for insulating the air bag.

5. An air bag gas sampling apparatus as defined in claim 4, wherein: the chamber wall of the placing chamber is of a multilayer structure, the chamber wall of the placing chamber comprises an outer chamber wall, an inner chamber wall and heat insulation layers arranged on the outer chamber wall and the inner chamber wall, the constant temperature device is a second electric heating device arranged in the heat insulation layers, and a temperature sensor is arranged in the placing chamber.

6. An air bag gas sampling apparatus as defined in claim 5, wherein: and a filtering device for absorbing water vapor is arranged behind the inlet switch device, and the filtering device is a titanium filter element and a molecular sieve which are mutually connected in series.

7. An air bag gas sampling apparatus as defined in claim 6, wherein: the pressure control device is an electric air pump, the electric air pump is connected to the air chamber through an air path pipeline, and a pressure gauge convenient for pressure observation is arranged on the electric air pump.