Portable gas chromatograph for measuring indoor air pollutants

Abstract

The utility model relates to the technical field of detection instruments, and particularly discloses a portable gas chromatograph for measuring indoor air pollutants, which comprises a main shell, a gas sample inlet and a carrier gas interface are arranged on one side of the main shell, and the carrier gas interface is arranged on the other side of the main shell. A sample introduction system, a formaldehyde measurement chamber, an enrichment and concentration device, a chromatographic separation device and a PID detector are respectively arranged in the main shell, the carrier gas interface is connected with a carrier gas pressure control device through a pipeline, and the carrier gas pressure control device is connected with the enrichment and concentration device through a control pipeline; according to the utility model, the frame-type design framework is small in size and easy to carry; according to the utility model, the formaldehyde sensor, the gas chromatography and the PI D detector are combined, so that the measurement of related indexes of VOCs can be completed by using one instrument according to the requirements of indoor air quality standards; according to the utility model, the enrichment and concentration device is adopted, so that pollutants can be enriched and concentrated, the concentration of good response effect of the PID detector is achieved, and the use effect of the instrument is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of detection instrument, concretely relates to a portable gas chromatograph for indoor air pollutant measurement. BACKGROUND

[0002] Volatile organic compounds (VOCs) are a class of common atmospheric pollutants, most of which are toxic, and some even have certain carcinogenicity; both formaldehyde and benzene series belong to VOCs and are important characteristic compounds of indoor air pollution; formaldehyde, as an important component in glue, is widely used in various types of furniture using artificial boards, and curtains, carpets, etc. also use formaldehyde to improve wrinkle resistance, color fastness, and water shrinkage resistance. Benzene series is an important component in paint, and a certain amount of benzene series is also contained in various synthetic fibers and glue; during house decoration, these materials containing formaldehyde and benzene series will inevitably be used, and these materials will gradually release formaldehyde and benzene series. In an indoor environment with poor ventilation, long-term exposure of people to low-concentration formaldehyde can cause respiratory tract irritation, skin chapping, etc., while benzene series can cause nerve damage and induce leukemia, and both have carcinogenicity, which poses potential harm to human health.

[0003] Due to the great harm of formaldehyde and benzene series to the human body, it is very important to measure VOCs containing the two in the indoor environment; TVOC and benzene series are usually measured using a photoionization detector (PID detector). However, the traditional PID can only measure TVOC and cannot measure the concentration of each compound such as benzene, toluene, and xylene; according to the provisions of the "GB / T18883-2022 Indoor Air Quality Standard", benzene, toluene, and xylene can be measured by solid adsorption-thermal desorption-gas chromatography, activated carbon adsorption-carbon disulfide desorption-gas chromatography, and portable gas chromatography. The first two methods require on-site sampling and then transportation to the laboratory for processing before measurement using a laboratory-specific gas chromatograph; the whole process is complex, time-consuming, and costly, and if the sample cannot be processed in time, there may be problems of sample timeliness; the portable gas chromatography method can quickly and accurately measure benzene series on site, which is more efficient than the first two methods.

[0004] Portable gas chromatography usually uses a PID detector to measure VOCs, but since the ionization potential of formaldehyde is 10.88eV, which is higher than the detection range of 10.6eV of a common PID detector, it cannot measure formaldehyde simultaneously by a PID detector; the commonly used method for measuring formaldehyde is spectrophotometry, which is complex and not suitable for on-site measurement. UTILITY MODEL CONTENTS

[0005] The utility model discloses a portable gas chromatograph for indoor air pollutant measurement to solve the problem in the foregoing background art.

[0006] To achieve the above object, the utility model provides the following technical scheme:

[0007] A portable gas chromatograph for indoor air pollutant measurement, comprising:

[0008] The main casing is provided with a gas sampling inlet and a carrier gas interface on one side, which are used for introducing sample gas and carrier gas; the other side of the main casing is provided with a tail gas outlet for discharging tail gas; the inside of the main casing is respectively provided with a sampling system, a formaldehyde measuring chamber, an enrichment and concentration device, a chromatographic separation device and a PID detector; the gas sampling inlet is connected with the sampling system through a pipeline; the sampling system is connected with the formaldehyde measuring chamber through a pipeline; the formaldehyde measuring chamber is connected with the enrichment and concentration device through a pipeline; the enrichment and concentration device is connected with the chromatographic separation device through a pipeline; the chromatographic separation device is connected with the PID detector through a pipeline; the carrier gas interface is connected with a carrier gas pressure control device through a pipeline; the carrier gas pressure control device is connected with the enrichment and concentration device through a control pipeline; and the control pipeline is connected with a gas path control device, which is used for switching the gas circulation between the pipelines.

[0009] Preferably, the main casing is a frame type casing.

[0010] Preferably, the formaldehyde measuring chamber comprises a gas chamber and a formaldehyde sensor; after the sample gas is balanced in the gas chamber, the formaldehyde concentration in the sample gas is measured by the formaldehyde sensor.

[0011] Preferably, the enrichment and concentration device is a gas enrichment and concentration instrument, which is a gas enrichment and concentration device in the prior art and will not be described in detail; the gas enrichment and concentration instrument is used for concentrating the gas so that the pollutants in the gas are captured by the enrichment and concentration device.

[0012] Preferably, the chromatographic separation device comprises a gas chromatographic column, a heating system, a cooling system and a temperature measuring system; after the sample enters the gas chromatographic column, the chromatographic column is heated according to a set program instrument, and the separation of the pollutants is completed; then the separated pollutants enter the PID detector.

[0013] Preferably, the gas path control device comprises a switching valve and a motor; after the sampling state is finished, the switching valve is driven by the motor to switch the whole instrument gas path to an analysis state.

[0014] Preferably, the main housing is further provided with a motherboard, which is electrically connected to the sample injection system, formaldehyde measurement chamber, enrichment and concentration device, chromatographic separation device, PID detector, carrier gas pressure control device, gas path control device and display screen. The motherboard completes the control of each component of the instrument, collects the operating status, real-time parameters and signal values ​​of each component, calculates and processes the signals, and sends them to the display screen for display to the user.

[0015] Preferably, a display screen is provided at the upper end of the main housing. The display screen is electrically connected to the motherboard and is embedded in the instrument for easy operation by the user. The display screen has a user-friendly human-computer interaction interface, allowing the user to freely perform operations such as sample measurement and data query.

[0016] Preferably, a power supply device is also installed inside the main housing. The power supply device includes several components such as a lithium battery, a power switch, and a power display. The power switch controls the switching of the instrument's total power supply. The power display shows the battery level, helping the user determine whether charging is needed. A charging interface is installed on one side of the main housing, which is electrically connected to the power supply device for charging the power supply device.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1) This utility model features a frame-type design, which is compact, easy to carry, and suitable for measuring indoor air pollution;

[0019] 2) This utility model combines a formaldehyde sensor, gas chromatography, and PID detector, and can measure VOCs-related indicators using a single instrument to meet the requirements of indoor air quality standards.

[0020] 3) This utility model adopts an enrichment and concentration device, which can enrich and concentrate pollutants in scenarios with low concentration of VOCs such as indoor air pollution, to achieve a concentration that provides good response to the PID detector and improve the performance of the instrument.

[0021] 4) This utility model uses an ultra-small volume gas chromatography column capable of programmed temperature rise, which is the key component of the small size of this utility model. It can effectively separate common VOCs in indoor air pollution while shortening the analysis time and facilitating rapid measurement by users. At the same time, the instrument has the characteristics of low power consumption, which can improve the instrument's battery life.

[0022] 5) This utility model uses a top-embedded screen for user interaction, and the human-computer interaction interface is designed to be user-friendly and easy for users to operate.

[0023] 6)The utility model discloses a lithium battery power supply, long endurance time makes the instrument no longer be limited to external power supply, convenient for user uses in various scenes. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is whole structure schematic diagram of the utility model;

[0025] Figure 2 It is side view of the utility model;

[0026] Figure 3 It is sectional view of the utility model;

[0027] Figure 4 It is local internal structure schematic diagram of the utility model;

[0028] In the drawing: 1, gas inlet; 2, carrier gas interface; 3, formaldehyde measuring chamber; 4, sampling system; 5, enrichment concentration device; 6, carrier gas pressure control device; 7, chromatographic separation device; 8, gas path control device; 9, PID detector; 10, tail gas outlet; 11, display screen; 12, mainboard; 13, power supply device; 14, charging interface. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0030] Embodiment:

[0031] Please refer to Figures 1-4 As shown in the figure, a kind of portable gas chromatograph for indoor air pollutant measurement, comprising:

[0032] The main shell is provided with a gas inlet 1 and a carrier gas interface 2 on one side for introducing sample gas and carrier gas, and is provided with a tail gas outlet 10 on the other side for discharging tail gas. The inner part of the main shell is provided with a sample inlet system 4, a formaldehyde measuring chamber 3, an enrichment and concentration device 5, a chromatographic separation device 7 and a PID detector 9. The gas inlet 1 is connected to the sample inlet system 4 through a pipeline, the sample inlet system 4 is connected to the formaldehyde measuring chamber 3 through a pipeline, the formaldehyde measuring chamber 3 is connected to the enrichment and concentration device 5 through a pipeline, the enrichment and concentration device 5 is connected to the chromatographic separation device 7 through a pipeline, the chromatographic separation device 7 is connected to the PID detector 9 through a pipeline, and the carrier gas interface 2 is connected to a carrier gas pressure control device 6 through a pipeline. The carrier gas pressure control device 6 is connected to the enrichment and concentration device 5 through a control pipeline, and the control pipeline is connected to a gas path control device 8 for switching the gas flow between the pipelines.

[0033] It should be noted that the sample inlet system 4 includes a sample inlet, a sample pipeline and a sample pump. The sample inlet and the sample pipeline are inertized to ensure that no pollutants in the sample are adsorbed. The sample pump is used to extract sample gas so that the gas passes through the formaldehyde measuring chamber and the enrichment and concentration device to complete the measurement.

[0034] Referring to Figures 1-4 As shown in the figure, the main shell is provided as a frame type shell.

[0035] Referring to Figures 1-4 As shown in the figure, the formaldehyde measuring chamber 3 includes a gas chamber and a formaldehyde sensor. After the concentration of the sample gas is balanced in the gas chamber, the formaldehyde concentration in the sample gas is measured by the formaldehyde sensor.

[0036] Referring to Figures 1-4 As shown in the figure, the enrichment and concentration device 5 is provided as a gas enrichment and concentration instrument, which is a gas enrichment and concentration device in the prior art and will not be described in detail. The device is used to concentrate the gas so that the pollutants in the gas are captured by the enrichment and concentration device 5.

[0037] Referring to Figures 1-4 As shown in the figure, the chromatographic separation device 7 includes a gas chromatographic column, a heating system, a cooling system and a temperature measuring system. After the sample enters the gas chromatographic column, the column is heated according to a set program to separate the pollutants, and then the separated pollutants enter the PID detector 9.

[0038] Referring to Figures 1-4 As shown in the figure, the gas path control device 8 includes a switching valve and a motor, which is a pipeline switching device in the prior art. After the sample inlet state is completed, the switching valve is driven by the motor to switch the entire instrument gas path to the analysis state.

[0039] Referring to Figures 1-4As shown, the inside of the main shell is also provided with a main board 12, which is electrically connected with the sample injection system 4, the formaldehyde measuring chamber 3, the enrichment and concentration device 5, the chromatographic separation device 7, the PID detector 9, the carrier gas pressure control device 6, the gas path control device 8 and the display screen 11. The main board 12 controls each component of the instrument, collects the running conditions, real-time parameters and signal values of each component, calculates and processes the signals, and sends them to the display screen 11 to show the user.

[0040] Referring to Figures 1-4 As shown, the upper end of the main shell is provided with a display screen 11, which is electrically connected with the main board 12. The display screen 11 is embedded on the instrument to facilitate user operation. The display screen 11 has a user-friendly man-machine interface built-in, and the user can freely perform sample measurement and data query operations.

[0041] Referring to Figures 1-4 As shown, the inside of the main shell is also provided with a power supply device 13, which includes a lithium battery, a power switch, an electric quantity display and several other components. The power switch realizes the on-off control of the total power supply of the instrument. The electric quantity display shows the electric quantity level in the battery, which helps the user to determine whether the battery needs to be charged. A charging interface 14 is installed on one side of the main shell and is electrically connected with the power supply device 13 for charging the power supply device 13.

[0042] The instrument has two states, one is a sample injection state and the other is an analysis state.

[0043] A. In the sample injection state, the sample injection system 4 works, and the sample gas enters the gas injection port 1, passes through the sample injection system 4, enters the formaldehyde measuring chamber 3, and then enters the enrichment and concentration device 5. The formaldehyde measuring chamber 3 includes a formaldehyde sensor and a gas chamber. After the sample gas is balanced in the gas chamber, the formaldehyde concentration in the sample gas is measured by the formaldehyde sensor. The sample gas then flows through the enrichment and concentration device 5, and the pollutants in the sample gas are captured by the enrichment and concentration device 5.

[0044] B, the gas path control device 8 includes a switching valve and a motor and the like, after the sample introduction state ends, the switching valve is driven by the motor, the whole instrument gas path is switched to the analysis state, the whole gas flow is switched to: the carrier gas enters from the carrier gas interface 2, after the flow is controlled by the carrier gas pressure control device 6, the output is entered into the enrichment and concentration device 5, the instrument is switched to the analysis state, the enrichment and concentration device 5 works, the pollutants captured on the device are released quickly in a short time, carried by the carrier gas into the chromatographic separation device 7, the chromatographic separation device 7 includes a gas chromatographic column, a heating system, a cooling system and a temperature measuring system, after the sample enters the gas chromatographic column, the instrument heats the chromatographic column according to the set program, and the separation of the pollutants is completed, the separated pollutants enter the PID detector 9, and the response signal is generated on the PID detector 9, and finally discharged through the tail gas outlet 10.

[0045] 1) The frame type design architecture of the utility model is small in size, easy to carry, and suitable for measuring indoor air pollution;

[0046] 2) The utility model combines formaldehyde sensors, gas chromatographs and PID detectors, and can measure VOCs related indexes by using one instrument according to the requirements of indoor air quality standards;

[0047] 3) The utility model adopts an enrichment and concentration device, which can enrich and concentrate pollutants in the scene of indoor air pollution with low-concentration VOCs, so as to reach a good concentration of the response effect of the PID detector and improve the use effect of the instrument;

[0048] 4) The utility model adopts an ultra-small volume gas chromatographic column capable of programmed temperature rising, which is a key component of the utility model and is small in size, can effectively separate common VOCs of indoor air pollution, shortens the analysis time, facilitates rapid measurement of users, and has the characteristics of low power consumption, so that the endurance time of the instrument is improved;

[0049] 5) The utility model is provided with an inner-embedded screen at the top for user function interaction, the man-machine interaction interface is friendly and easy to operate and use;

[0050] 6) The utility model is powered by a lithium battery, has a long endurance time, and is no longer limited by an external power supply, so that users can use the instrument in various scenes.

[0051] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the utility model, the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A portable gas chromatograph for indoor air pollutant measurement, characterized by, The application relates to a gas chromatograph, which comprises a main shell, a gas inlet (1) and a carrier gas interface (2) arranged on one side of the main shell, a tail gas outlet (10) arranged on the other side of the main shell, an inlet system (4), a formaldehyde measuring chamber (3), an enrichment and concentration device (5), a chromatographic separation device (7) and a PID detector (9) arranged in the main shell, the gas inlet (1) being connected with the inlet system (4) through a pipeline, the inlet system (4) being connected with the formaldehyde measuring chamber (3) through a pipeline, the formaldehyde measuring chamber (3) being connected with the enrichment and concentration device (5) through a pipeline, the enrichment and concentration device (5) being connected with the chromatographic separation device (7) through a pipeline, the chromatographic separation device (7) being connected with the PID detector (9) through a pipeline, the carrier gas interface (2) being connected with a carrier gas pressure control device (6) through a pipeline, the carrier gas pressure control device (6) being connected with the enrichment and concentration device (5) through a control pipeline, and a gas path control device (8) being connected with the control pipeline. The main shell is arranged as a frame type shell.

2. The portable gas chromatograph for measuring indoor air pollutants according to claim 1, wherein: The formaldehyde measuring chamber (3) comprises a gas chamber and a formaldehyde sensor.

3. The portable gas chromatograph for measuring indoor air pollutants according to claim 2, wherein: The enrichment and concentration device (5) is arranged as a gas enrichment and concentration instrument.

4. The portable gas chromatograph for measuring indoor air pollutants according to claim 3, wherein: The chromatographic separation device (7) comprises a gas chromatographic column, a heating system, a cooling system and a temperature measuring system.

5. The portable gas chromatograph for measuring indoor air pollutants according to claim 4, wherein: The gas path control device (8) comprises a switching valve and a motor.

6. The portable gas chromatograph for measuring indoor air pollutants according to claim 5, wherein: The main shell is internally provided with a main board (12).

7. The portable gas chromatograph for measuring indoor air pollutants according to claim 6, wherein: An upper end of the main shell is provided with a display screen (11), and the display screen (11) is electrically connected with the main board (12).

8. The portable gas chromatograph for measuring indoor air pollutants according to claim 7, wherein: The main shell is internally provided with a power supply device (13), and one side of the main shell is provided with a charging interface (14), and the charging interface (14) is electrically connected with the power supply device (13).

9. The portable gas chromatograph for measuring indoor air pollutants according to claim 8, wherein: ​

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