Sample introduction device for a gas chromatograph

Abstract

The application discloses a sample injection device for a gas chromatograph, characterized in that the device comprises a cabinet, a gas inlet main line passing through a side wall of the cabinet and used for connecting a driving gas, a sample injection channel arranged in the cabinet and connected to the gas inlet main line, wherein the sample injection channel comprises an upper quick connector and a lower quick connector and is configured to selectively detachably connect a sample cylinder or a purge straight pipe between the upper quick connector and the lower quick connector, a sample outlet channel arranged in the cabinet and connected between the sample injection channel and a sample injection interface of the gas chromatograph, a loop pipeline, a part of which is arranged in the cabinet and connected to a discharge interface of the gas chromatograph, and a gas-liquid separation device arranged in the cabinet and connected to the loop pipeline.

Description

Technical Field

[0001] This utility model relates to the field of gas chromatography analysis equipment technology, specifically to an injection device for a gas chromatograph. Background Technology

[0002] In gas chromatography analysis, the stability and ease of operation of the injection system significantly impact testing efficiency and results. However, existing gas chromatograph injection devices have significant shortcomings in practical applications. Traditional injection systems often require separate and complex piping systems for the driving gas (e.g., nitrogen) and sample gas. Changing sample cylinders is cumbersome, time-consuming, and labor-intensive, and the disassembly and assembly process easily introduces external air or residual impurities, affecting subsequent detection accuracy; cleaning the tubing also lacks convenient pathways. When detecting toxic or flammable gases, existing chromatographs often directly emit exhaust gases, or the exhaust gas treatment device is located outside the main equipment. Furthermore, the exhaust gas frequently carries liquid impurities; if backflowed or directly enters subsequent tubing, it can easily damage the chromatograph or cause environmental pollution. Traditional injection devices mostly employ a single-channel structure, requiring the instrument to be stopped and the test interrupted during continuous detection, standard gas vs. sample gas comparison, or tubing purging, hindering flexible switching between multiple operating conditions and greatly limiting instrument utilization.

[0003] Therefore, in order to address the above problems, there is an urgent need for a new type of sample introduction device that can simplify pipelines, improve the safety of exhaust gas treatment, and significantly improve testing efficiency. Utility Model Content

[0004] To address the technical problems of complex and cumbersome pipeline replacement, safety hazards in exhaust emissions, and low efficiency of single-channel testing in existing technologies, this utility model provides a sample introduction device for a gas chromatograph.

[0005] This utility model proposes a sample introduction device for a gas chromatograph, characterized in that it comprises: a cabinet; a main gas inlet, which passes through the side wall of the cabinet and is used to connect to the driving gas; a sample introduction channel, which is disposed in the cabinet and connected to the main gas inlet, wherein the sample introduction channel includes an upper quick connector and a lower quick connector, and is configured to selectively and detachably connect a sample cylinder or a purge tube between the upper quick connector and the lower quick connector; a sample outlet channel, which is disposed in the cabinet and connected between the sample introduction channel and the sample introduction interface of the gas chromatograph; a loop pipeline, a portion of which is disposed in the cabinet and connected to the exhaust interface of the gas chromatograph; and a gas-liquid separation device, which is disposed in the cabinet and connected to the loop pipeline.

[0006] According to an optional implementation, the sample inlet channel includes an upper valve and a lower valve; the upper valve is connected in series between the main air inlet and the upper quick connector; the lower valve is connected in series between the lower quick connector and the sample outlet channel.

[0007] According to an optional implementation, the upper valve and the lower valve are manual valves or solenoid valves.

[0008] According to an optional implementation, the cabinet includes an exhaust vent and an exhaust fan installed in the exhaust vent.

[0009] According to an optional implementation, the cabinet includes a gas leak alarm; and the exhaust fan is electrically connected to the gas leak alarm.

[0010] According to an optional implementation, the main air intake path includes a check valve, an intake valve, and a pressure gauge connected in series outside the cabinet.

[0011] According to an optional implementation, the cabinet includes a front door and a transparent window and handle disposed on the front door.

[0012] According to an optional implementation, the cabinet includes a grounding terminal disposed on the outer wall.

[0013] According to an optional embodiment, the cabinet includes an upper bracket disposed on the inner side of the top wall for supporting the main air intake, and a lower bracket disposed at the bottom for supporting the sample inlet channel, the sample outlet channel, and the sample cylinder or the purge tube that is engaged between the two.

[0014] According to an optional implementation, the injection device includes at least two independent injection channels.

[0015] This invention employs a pipeline reuse structure combining quick-connect couplings and straight pipe replacement. The upper and lower quick-connect couplings allow the driving gas (such as nitrogen) in the same inlet channel to perform both driving sample injection and cleaning / purging functions. When changing cylinders, the purging straight pipe can be connected in a short time, eliminating the need for complex independent cleaning pipeline arrangements and enabling direct purging of the downstream sample outlet channel.

[0016] This invention integrates a gas-liquid separation device directly into the bottom of the cabinet, which can effectively trap liquid impurities in the exhaust gas to protect the chromatograph and confine harmful exhaust gases inside the cabinet.

[0017] The cabinet of this utility model has a grounded outer shell, and the exhaust fan can be connected to a gas leak alarm, making the cabinet suitable for detecting toxic and flammable gases.

[0018] This invention employs a dual-channel independent control architecture. Equipped with at least two independent sample inlet channels, it enables uninterrupted continuous detection. Users can simultaneously connect standard gas and sample gas for real-time comparison, or perform sample injection testing in one channel while using the other channel to connect a straight tube for purging and cleaning, maximizing the instrument's testing efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the external structure of the sample introduction device according to this utility model; Figure 2 This is a schematic diagram of the internal structure of the sample injection device according to the present invention, in which a sample cylinder is installed; Figure 3 This is a schematic diagram of the internal structure of the sample injection device according to the present invention, in which a purge tube is installed.

[0020] Figure label: 1-Rack; 11-Exhaust vent; 12-Exhaust fan; 13-Transparent window; 14-Handle; 15-Grounding terminal; 16-Base; 2-Intake main line; 21-Intake valve; 22-Check valve; 23-Pressure gauge; 3-Sample inlet channel; 31-Upper valve; 32-Upper quick connector; 33-Sample cylinder; 34-Purge tube; 35-Lower quick connector; 36-Lower valve; 4-Sample outlet channel; 5-Circuit piping; 6-Gas-liquid separation device; 71 - Upper support; 72 - Lower support.

[0021] It should be understood that the accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0023] Figure 1 This is a schematic diagram of the external structure of the sample introduction device according to this utility model. Figure 2 and Figure 3 This is a schematic diagram of the internal structure of the sample introduction device according to this utility model. (See attached diagram.) Figure 1 , Figure 2 and Figure 3The sample introduction device for the gas chromatograph includes a cabinet 1 as the main structure. In this embodiment, the external dimensions of the cabinet 1 can be 770mm × 400mm × 350mm (this size is only a preferred embodiment and can be flexibly adjusted according to the site). The cabinet 1 includes a front door, and a transparent window 13 for observing the internal operating status and a handle 14 are provided on the front door. To meet the detection requirements of flammable and explosive gases and prevent static electricity accumulation, a grounding terminal 15 is connected to the side or bottom of the cabinet 1. The cabinet 1 can be mounted on a base 16 with a larger footprint to increase its stability.

[0024] The sample introduction device also includes a main air inlet 2 passing through the side wall of the cabinet 1, for connecting to an external driving gas (nitrogen is used in this embodiment). The main air inlet 2 is equipped with a check valve 22, an inlet valve 21, and a pressure gauge 23 installed in series outside the cabinet 1 to prevent gas backflow and monitor the input gas pressure in real time. The sample introduction device also includes an upper support 71 located inside the cabinet 1. The upper support 71 is fixed to the top plate of the cabinet 1 to support the main air inlet 2.

[0025] The sample introduction device also includes one or more sample introduction channels 3 and corresponding sample exit channels 4. Each sample introduction channel 3 is independently located inside the cabinet 1. Each sample introduction channel 3 includes an upper valve 31, an upper quick connector 32, a lower quick connector 35, and a lower valve 36. A quick-release station is formed between the upper quick connector 32 and the lower quick connector 35. The quick-release station can be used to vertically clamp a sample cylinder 33 or clamp a purge tube 34 of the same length as the sample cylinder 33. The output end of the lower quick connector 35 is connected to the sample exit channel 4 via the lower valve 36. The sample exit channel 4 extends to the outside of the cabinet 1 and connects to the corresponding sample introduction interface of an external gas chromatograph (not shown). The upper valve 31 and the lower valve 36 can be manual valves or solenoid valves connected to an automated control system for remote opening and closing. The sample introduction device also includes a lower support 72 located inside the cabinet 1. The lower bracket 72 is fixed to the base plate of the cabinet 1 to support the sample inlet channel 3, the sample outlet channel 4, and the sample cylinder 33 or the purge tube 34 that is clamped between the two.

[0026] The sample introduction device also includes a loop line 5 and a gas-liquid separator 6. The loop line 5 is connected to the corresponding exhaust port of the gas chromatograph to receive the exhaust gas emitted after the gas chromatograph completes its test and reintroduce it into the cabinet 1. The gas-liquid separator 6 is located inside the cabinet 1 and can be a collection bottle with a certain volume. The loop line 5 extends into the gas-liquid separator 6. After the exhaust gas enters the gas-liquid separator 6, the entrained liquid is trapped within the separator 6, preventing damage to the external environment and subsequent pipelines. The gas separated from the exhaust gas leaves the gas-liquid separator 6 and dissipates into the internal microenvironment of the cabinet 1.

[0027] The sample introduction device also includes an exhaust port 11 located on the back or side of the cabinet 1, and an exhaust fan 12 installed in the exhaust port 11. The exhaust fan 12 can be set to a normally open state.

[0028] The sample introduction device of this utility model includes a normal sample introduction mode, a purge cleaning mode, and a dual-channel collaborative mode.

[0029] In normal sample injection mode, the sample cylinder 33 containing the sample is snapped between the upper quick connector 32 and the lower quick connector 35 of the sample injection channel 3. The upper valve 31 and the lower valve 36 are opened, allowing nitrogen gas input through the main inlet 2 to act as back pressure, forcing the sample gas in the sample cylinder 33 into the outlet channel 4, which is then sent to the gas chromatograph for detection. The exhaust gas after testing enters the gas-liquid separator 6 via the loop pipeline 5 for gas-liquid separation. The separated gas is discharged into the cabinet and exhausted through the exhaust fan 12.

[0030] In the purging and cleaning mode, the sample cylinder 33 between the upper valve 31 and the lower valve 36 is replaced by the purging straight pipe 34. At this time, nitrogen is used as the purging gas, flowing sequentially through the upper quick connector 32, the purging straight pipe 34, the lower quick connector 35, and the downstream sample outlet channel 4 to achieve purging and cleaning of the pipeline.

[0031] In the dual-channel collaborative mode, each injection channel 3 can be used for the same or different tasks. For example, one injection channel 3 can be used for sample injection, while the other injection channel 3 can be kept on standby to achieve uninterrupted continuous detection. For example, one injection channel 3 can be connected to a standard gas cylinder, while the other injection channel 3 can be connected to the sample cylinder to be tested, enabling simultaneous detection and comparison of the standard and the sample. For example, one injection channel 3 can be connected to the sample cylinder 33 for sample injection testing, while the other injection channel 3 can be connected to the purge tube 34 for pipeline cleaning, thereby improving detection efficiency.

[0032] The preferred embodiments disclosed above are merely illustrative of this application. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. The selection and detailed description of these embodiments in this specification are intended to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize it. This application is limited only by the claims and their full scope and equivalents.

Claims

1. An injection device for a gas chromatograph, characterized by, include: Server rack (1); The main air intake (2) passes through the side wall of the cabinet (1) and is used to access the driving gas; The sample inlet channel (3) is located in the cabinet (1) and connected to the main air inlet (2), wherein the sample inlet channel (3) includes an upper quick connector (32) and a lower quick connector (35), and is configured to selectively and detachably connect a sample cylinder (33) or a purge tube (34) between the upper quick connector (32) and the lower quick connector (35). The sample outlet channel (4) is located inside the cabinet (1) and is connected between the sample inlet channel (3) and the sample inlet interface of the gas chromatograph. The loop pipeline (5) is partially located inside the cabinet (1) and connected to the exhaust port of the gas chromatograph; as well as A gas-liquid separation device (6) is installed inside the cabinet (1) and connected to the loop pipeline (5).

2. The sample introduction device for a gas chromatograph according to claim 1, characterized in that, The sample inlet channel (3) includes an upper valve (31) and a lower valve (36); The upper valve (31) is connected in series between the main intake (2) and the upper quick connector (32); The lower valve (36) is connected in series between the lower quick connector (35) and the sample outlet channel (4).

3. The sample introduction device for a gas chromatograph according to claim 2, characterized in that, The upper valve (31) and the lower valve (36) are manual valves or solenoid valves.

4. The sample introduction device for a gas chromatograph according to claim 1, characterized in that, The cabinet (1) includes an exhaust port (11) and an exhaust fan (12) installed in the exhaust port (11).

5. The sample introduction device for a gas chromatograph according to claim 4, characterized in that, The cabinet (1) includes a gas leak alarm; and The exhaust fan (12) is electrically connected to the gas leak alarm.

6. The sample introduction device for a gas chromatograph according to claim 1, characterized in that, The main air intake (2) includes a check valve (22), an air intake valve (21), and a pressure gauge (23) connected in series outside the cabinet (1).

7. The sample introduction device for a gas chromatograph according to claim 1, characterized in that, The cabinet (1) includes a front door and a transparent window (13) and a handle (14) disposed on the front door.

8. The sample introduction device for a gas chromatograph according to claim 1, characterized in that, The cabinet (1) includes a grounding terminal (15) disposed on the outer wall.

9. The sample introduction device for a gas chromatograph according to claim 1, characterized in that, The cabinet (1) includes an upper bracket (71) located on the inner side of the top wall for supporting the main air intake (2), and a lower bracket (72) located at the bottom for supporting the sample inlet channel (3), the sample outlet channel (4), and the sample cylinder (33) or the purge tube (34) that is engaged between the two.

10. The sample injection device for a gas chromatograph according to claim 1, characterized in that, The injection device includes at least two independent injection channels (3).

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