CN216646367U

CN216646367U - VOCs gas chromatography-detector detecting system

Info

Publication number: CN216646367U
Application number: CN202123183378.4U
Authority: CN
Inventors: 王丽玮; 张洁; 凌静怡; 蔡安娟; 李雪妍; 张妍
Original assignee: Jiangsu Environmental Engineering Technology Co Ltd
Current assignee: Jiangsu Environmental Engineering Technology Co Ltd
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2022-05-31
Anticipated expiration: 2031-12-17

Abstract

The utility model discloses a VOCs gas chromatography-detector detection system, which comprises two sets of sample introduction and separation modules and two sets of detectors, wherein the two sets of sample introduction and separation modules and the two sets of detectors are connected by a four-way valve; each sample injection and separation module comprises a sample injector and a chromatographic column which are sequentially connected, wherein the sample injector is used for sampling gas, and the collected sample enters two different sets of detectors through a four-way valve for detection and analysis after being separated by the chromatographic column. This system adopts two sets of chromatographic columns and detectors, through reasonable regulation and control collocation, realizes the better separation to characteristic VOCs component, and the more suitable detector of quick collocation to the accuracy that the VOCs of multiple different grade type was detected to this complete set of detecting system is realized, has improved the accuracy that the VOCs detected greatly.

Description

VOCs gas chromatography-detector detecting system

Technical Field

The utility model belongs to the field of VOCs detection, and particularly relates to a VOCs gas chromatography-detector detection system.

Background

Volatile Organic Compounds (VOCs) in the atmosphere are important precursors for causing atmospheric environmental problems such as dust haze and photochemical pollution, and with the development of environmental air quality guarantee work in China, VOCs gradually become factors for restricting the benign development of economy and society. Due to the wide variety and complex sources of VOCs, the detection of VOCs components is often limited. The gas chromatography-detector technology is a common VOCs component detection technology at present. However, the separation degree of the chromatographic column for substances with different polarities is limited to be different, and the detector is often sensitive to the VOCs of specific species, so that in field tests of atmospheric pollution prevention and control, the identification sensitivity and accuracy of characteristic VOCs are often insufficient. The problem of inaccurate measurement of VOCs has become an important factor for restricting the work of pollution prevention and control of VOCs.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem of providing a novel VOCs detection system aiming at the defects of the prior art so as to improve the sensitivity and accuracy of the detection of characteristic VOCs components.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

a VOCs gas chromatography-detector detection system comprises two sets of sample introduction separation modules and two sets of detectors, wherein the two sets of sample introduction separation modules and the two sets of detectors are connected by a four-way valve;

each sample injection and separation module comprises a sample injector and a chromatographic column which are sequentially connected, wherein the sample injector is used for sampling gas, and the collected sample enters two different sets of detectors through a four-way valve for detection and analysis after being separated by the chromatographic column.

Specifically, the first set of sample separation modules comprises a first sample injector and a first chromatographic column; the first chromatographic column air inlet is connected with the first sample injector air outlet, and the first chromatographic column air outlet is connected with the first interface of the four-way valve.

Specifically, the second set of sample separation modules comprises a second sample injector and a second chromatographic column; and the air inlet of the second chromatographic column is connected with the air outlet of the second sample injector, and the air outlet of the second chromatographic column is connected with a second interface of the four-way valve.

Specifically, the two sets of detectors comprise a first detector and a second detector, the first detector is connected with a third interface of the four-way valve, and the second detector is connected with a fourth interface of the four-way valve.

Further, a first flow controller is arranged in the first sample injector, and the sample injection flow of the first sample injector is controlled by the first flow controller; the first chromatographic column is provided with a first temperature control module, and the gas separation temperature of the first chromatographic column is controlled through the first temperature control module.

Furthermore, a second flow controller is arranged in the second sample injector, and the sample injection flow of the second sample injector is controlled by the second flow controller; and a second temperature control module is arranged on the second chromatographic column, and the gas separation temperature of the second chromatographic column is controlled by the second temperature control module.

Has the advantages that:

the detection system provided by the utility model adopts two sets of chromatographic columns and detectors, and realizes better separation of characteristic VOCs components through reasonable regulation and control collocation, and fast collocation of more suitable detectors, so that accurate monitoring of various types of VOCs by using the whole detection system is realized, and the accuracy of VOCs detection is greatly improved.

Drawings

The foregoing and/or other advantages of the utility model will become further apparent from the following detailed description of the utility model when taken in conjunction with the accompanying drawings.

Fig. 1 is a functional block diagram of the detection system.

Fig. 2 is a sampling state diagram of the detection system.

Fig. 3 is a first inspection state diagram of the inspection system.

Fig. 4 is a second inspection state diagram of the inspection system.

Wherein each reference numeral represents:

101 a first injector; 102 a first flow controller; 103 a first chromatographic column; 104 a first temperature control module; 105 a first detector; 201 a second injector; 202 a second flow controller; 203 a second chromatographic column; 204 a second temperature control module; 205 a second detector; 301 a second interface; 302 a fourth interface; 303 a first interface; 304 third interface.

Detailed Description

The utility model will be better understood from the following examples.

The structures, proportions, and dimensions shown in the drawings and described in the specification are for understanding and reading the present disclosure, and are not intended to limit the scope of the present disclosure, which is defined in the claims, and are not essential to the skilled in the art. In addition, the terms "upper", "lower", "front", "rear" and "middle" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the relative positions may be changed or adjusted without substantial technical changes.

As shown in fig. 1, the detection system of the VOCs gas chromatography-detector comprises two sets of sample introduction separation modules and two sets of detectors, wherein the two sets of sample introduction separation modules and the two sets of detectors are connected by a four-way valve; each sample injection and separation module comprises a sample injector and a chromatographic column which are sequentially connected, wherein the sample injector is used for sampling gas, and the collected sample enters two different sets of detectors through a four-way valve for detection and analysis after being separated by the chromatographic column.

As shown in fig. 2, the first set of sample separation modules comprises a first sample injector 101 and a first chromatography column 103; the air inlet of the first chromatographic column 103 is connected with the air outlet of the first sample injector 101, and the air outlet of the first chromatographic column 103 is connected with the first interface 303 of the four-way valve.

The second set of sample separation modules comprises a second sample injector 201 and a second chromatographic column 203; the air inlet of the second chromatographic column 203 is connected with the air outlet of the second sample injector 201, and the air outlet of the second chromatographic column 203 is connected with a second interface 301 of the four-way valve.

The two sets of detectors comprise a first detector 105 and a second detector 205, the first detector 105 is connected to a third interface 304 of the four-way valve, and the second detector 205 is connected to a fourth interface 302 of the four-way valve.

A first flow controller 102 is arranged in the first sample injector 101, and the sample injection flow of the first sample injector 101 is controlled by the first flow controller 102; the first chromatographic column 103 is provided with a first temperature control module 104, and the gas separation temperature of the first chromatographic column 103 is controlled by the first temperature control module 104.

A second flow controller 202 is arranged in the second sample injector 201, and the sample injection flow of the second sample injector 201 is controlled by the second flow controller 202; the second chromatographic column 203 is provided with a second temperature control module 204, and the gas separation temperature of the second chromatographic column 203 is controlled by the second temperature control module 204.

In this embodiment, both the first flow controller 102 and the second flow controller 202 employ ACU20FD-M high precision mass flow controllers (span); the first temperature control module 104 and the second temperature control module 204 both employ E5CD digital thermostats.

The whole system adjusts the sampling frequency through flow control, adjusts the temperatures of different chromatographic columns through temperature control, and can be applied to the two chromatographic columns and the two detectors in a series-parallel way through the combination of the chromatographic columns and the detectors which are different and the combination of the chromatographic columns and the detectors which are controlled by the communicating valve, thereby realizing the separation and detection of VOCs components with different properties.

The detection system is used for detecting the mixed sample gas containing hydrocarbons, benzene series, chlorohydrocarbons and OVOCs multi-component species VOCs, and comprises the following specific steps:

first, the first flow controller 102 regulates the gas flow to start the sample injection, the sample enters the first chromatographic column 103 (packed column GDX-104) from the first sample injector 101 for separation, and at this time, the first temperature control module 104 controls the temperature of the first chromatographic column 103 to 400 ℃, so as to separate the benzene series and the macromolecular hydrocarbon. Meanwhile, the first interface 303 and the fourth interface 302 of the four-way valve are opened, the second detector 205(FID detector) is connected, the separated gas enters the second detector 205, and the content of the benzene series and the macromolecular hydrocarbon is measured.

Then, the sample is injected by adjusting the gas flow through the second flow controller 202, and the sample enters the second chromatographic column 203(CD-5, 30m 0.25mm 0.25um capillary chromatographic column) from the second sample injector 201 to be separated, at which time the temperature of the second chromatographic column 203 is controlled to 70 ℃ by the second temperature control module 204, and the chlorinated hydrocarbons and the OVOCs are separated. At the same time, the second port 301 and the third port 304 of the four-way valve are opened, the first detector 105 (photo ion detector PID) is connected, the separated gas enters the first detector 105, and the contents of chlorinated hydrocarbons and OVOCs are measured.

The whole detection system is matched with two sets of different or same chromatographic columns, and similarly, different or same detectors can be matched, and the quick series connection of different chromatographic columns and different detectors can be realized through valve regulation. For example, the column 103 may be in communication with the first detector 105, and the column 103 may be in communication with the second detector 205. During field detection, the chromatographic column and the detector can be matched in a targeted manner according to the actual condition of a sample, so that the optimal separation and detection of various VOCs components are realized.

While the present invention provides a method and system for detecting VOCs using a gas chromatograph-detector, and a number of methods and approaches are possible for implementing the method and system, it should be noted that those skilled in the art can make various modifications and enhancements without departing from the principles of the present invention, and such modifications and enhancements are also considered to be within the scope of the present invention. All the components not specified in the present embodiment can be realized by the prior art.

Claims

1. A VOCs gas chromatography-detector detection system is characterized by comprising two sets of sample introduction separation modules and two sets of detectors, wherein the two sets of sample introduction separation modules and the two sets of detectors are connected by a four-way valve;

2. The VOCs gas chromatography-detector detection system of claim 1, wherein the first set of sample separation modules comprises a first sample injector (101) and a first chromatographic column (103); the air inlet of the first chromatographic column (103) is connected with the air outlet of the first sample injector (101), and the air outlet of the first chromatographic column (103) is connected with a first interface (303) of the four-way valve.

3. The VOCs gas chromatography-detector detection system of claim 1, wherein the second set of sample separation modules comprises a second sample injector (201) and a second chromatographic column (203); the air inlet of the second chromatographic column (203) is connected with the air outlet of the second sample injector (201), and the air outlet of the second chromatographic column (203) is connected with a second interface (301) of the four-way valve.

4. A VOCs gas chromatography-detector detection system as claimed in claim 1 wherein the two sets of detectors comprise a first detector (105) and a second detector (205), the first detector (105) being connected to a third port (304) of the four-way valve and the second detector (205) being connected to a fourth port (302) of the four-way valve.

5. The detection system for VOCs according to claim 2, wherein the first flow controller (102) is disposed in the first sample injector (101), and the sample injection flow of the first sample injector (101) is controlled by the first flow controller (102); the first chromatographic column (103) is provided with a first temperature control module (104), and the gas separation temperature of the first chromatographic column (103) is controlled by the first temperature control module (104).

6. The VOCs gas chromatography-detector detection system of claim 3, wherein a second flow controller (202) is disposed in the second sample injector (201), and the sample injection flow of the second sample injector (201) is controlled by the second flow controller (202); and a second temperature control module (204) is arranged on the second chromatographic column (203), and the gas separation temperature of the second chromatographic column (203) is controlled through the second temperature control module (204).