Automatic gas-liquid distribution system with adjustable output pressure

Abstract

The utility model discloses an automatic gas-liquid distribution system with adjustable output pressure, which relates to the technical field of dilution gas distribution and comprises a to-be-diluted gas inlet, a diluted gas inlet and a liquid feeding inlet, the to-be-diluted gas inlet is connected with a first one-way valve, and the diluted gas inlet is respectively connected with a second one-way valve and a third one-way valve. The outlet end of the first one-way valve is sequentially connected with a first mass flow meter and the inlet end of a first mixing chamber, the outlet end of the second one-way valve is connected with a second mass flow meter, and the outlet end of the second mass flow meter is connected with a first switch valve and a second switch valve respectively; the gas distribution device is not only suitable for dilution gas distribution of a gas source, but also has wide applicability in occasions where liquid is diluted and configured into standard gas. Through gas-liquid mixing, dilution and gas distribution, uniform and stable high-concentration and low-concentration standard gas can be provided. The pressure difference between the two ends of the gas resistor is controlled through the mass flow meter and the two pressure regulators, and continuous dilution of the first-stage dilution gas is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of dilution and gas distribution, and specifically relates to an automatic gas-liquid distribution system with adjustable output pressure. Background Art

[0002] As a reference material, standard gas can be widely used in the calibration of instruments, atmospheric environment monitoring, medical and health, evaluation of analytical methods and other fields. However, it is difficult to purchase some standard gases with appropriate concentrations. For example, substances such as methanol, acetone, acetaldehyde, and acrolein are in a liquid state under normal temperature and pressure. It faces some challenges to configure these liquid organic solvents into gas reference materials stored in high-pressure steel cylinders. Low-concentration calibration gases are easily adsorbed by the cylinder body and valves and are not easy to store, resulting in the actual released concentration not matching the expected value. High-concentration calibration gases are not easy to vaporize completely, resulting in unstable concentration output.

[0003] There are online dilution and mixing devices on the market that use the principles of dynamic gas distribution such as the permeation method and the diffusion method to prepare calibration gases from organic liquids. However, the consumable costs of these devices are relatively high. The generated calibration gases often need to be stored in gas bags before entering the analytical instrument, and then introduced into the analytical device by manually squeezing the gas bag or using a pump as the power. Large errors are often introduced during the sample transfer process, and the working efficiency is low, making it difficult to ensure the stability and accuracy of the gas reference material. Therefore, an automatic gas-liquid distribution system with adjustable output pressure is proposed. Content of the Utility Model

[0004] To solve the above problems, that is, to solve the problems proposed in the above background art, the utility model proposes an automatic gas-liquid distribution system with adjustable output pressure, which includes an inlet for the gas to be diluted, an inlet for the diluting gas, and an inlet for liquid feeding. The inlet for the gas to be diluted is connected with a first one-way valve. The inlet for the diluting gas is respectively connected with a second one-way valve and a third one-way valve. The outlet end of the first one-way valve is successively connected with a first mass flowmeter and the inlet end of a first mixing chamber. The outlet end of the second one-way valve is connected with a second mass flowmeter. The outlet end of the second mass flowmeter is respectively connected with a first switching valve and a second switching valve. The first switching valve is connected with the inlet end of the first mixing chamber. The outlet end of the first mixing chamber is successively connected with a first gas resistance and an outlet for the gas-diluted sample gas.

[0005] The third one-way valve is successively connected with a third mass flowmeter and the inlet end of an evaporation chamber. The inlet for liquid feeding is successively connected with an injection pump and the inlet end of the evaporation chamber. The outlet end of the evaporation chamber is respectively connected with a second gas resistance and a third gas resistance. The second gas resistance is connected with an outlet for the liquid primary-diluted sample gas. The third gas resistance is successively connected with a second mixing chamber, a fourth gas resistance, and an outlet for the liquid secondary-diluted sample gas. The second switching valve is connected to the inlet end of the second mixing chamber.

[0006] A further setting of the present utility model is that: the outlet end of the evaporation chamber is connected to a first pressure controller, the outlet end of the second mixing chamber is connected to a second pressure controller, the outlet end of the first mixing chamber is connected to a third pressure controller, and the outlet ends of the first pressure controller, the second pressure controller and the third pressure controller are all connected to a drain port.

[0007] A further setting of the present utility model is that: the pressure of the first pressure controller is greater than that of the second pressure controller.

[0008] A further setting of the present utility model is that: the first pressure controller, the second pressure controller and the third pressure controller all adopt back pressure control mode.

[0009] A further setting of the present utility model is that: the connection part between the injection pump and the evaporation chamber adopts a sealed design, the injection pump is a liquid automatic propulsion device for adjusting the liquid flow rate, the inner wall of the evaporation chamber is treated with silanized inertness and is placed in a temperature-adjustable constant temperature area.

[0010] A further setting of the present utility model is that: the first mixing chamber and the first gas resistance are jointly placed in a temperature-adjustable constant temperature area, and the second gas resistance, the third gas resistance, the second mixing chamber and the fourth gas resistance are jointly placed in a temperature-adjustable constant temperature area.

[0011] The beneficial technical effects of the present utility model are as follows: This device is not only applicable to the dilution and gas mixing of gas sources, but also has wide applicability in the occasion of diluting liquids into standard gases. Through gas-liquid mixing and dilution for gas mixing, it can provide uniform and stable high-concentration and low-concentration standard gases. By controlling the pressure difference at both ends of the gas resistance through a mass flow meter and two pressure regulators, the device can continuously dilute the primary dilution gas without transferring the diluted standard gas to another device or container for dilution, thus greatly simplifying the operation process and reducing the possibility of operation errors and contamination. Whether it is a gas or a liquid to be diluted source, the pressure of the output standard gas can be precisely controlled and adjusted, and it can be directly connected to the sampling device of the analytical instrument to achieve stable pressure and continuous automatic sampling. This can not only be used for the calibration of analytical instruments, but also greatly improve the work efficiency and meet the requirements of modern laboratories and industrial production for high efficiency and high precision. Description of the Drawings

[0012] Figure 1 is the process schematic diagram of the present utility model.

[0013] Figure 2 is the reproducibility spectrum diagram of the primary dilution sample of methanol liquid provided by the present utility model.

[0014] Figure 3 is the reproducibility diagram of the secondary dilution sample of the 7 kinds of benzene series mixed standard solution in the embodiment of the present utility model.

[0015] Reference numerals: 1, inlet for gas to be diluted; 2, inlet for dilution gas; 3, first one-way valve; 4, second one-way valve; 5, third one-way valve; 6, liquid feeding inlet; 7, first mass flowmeter; 8, second mass flowmeter; 9, third mass flowmeter; 10, syringe pump; 11, evaporation chamber; 12, first switching valve; 13, second switching valve; 14, second gas resistance; 15, third gas resistance; 16, first pressure controller; 17, second mixing chamber; 18, second pressure controller; 19, first mixing chamber; 20, fourth gas resistance; 21, first gas resistance; 22, third pressure controller; 23, gas-diluted sample gas outlet; 24, liquid primary-diluted sample gas outlet; 25, liquid secondary-diluted sample gas outlet; 26, exhaust port. Specific embodiments

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] Please refer to Figures 1-3 , the present invention provides a technical solution: an automatic gas-liquid gas distribution system with adjustable output pressure, including an inlet 1 for gas to be diluted, an inlet 2 for dilution gas, and a liquid feeding inlet 6. The inlet 1 for gas to be diluted is connected to a first one-way valve 3. The inlet 2 for dilution gas is respectively connected to a second one-way valve 4 and a third one-way valve 5. The outlet end of the first one-way valve 3 is sequentially connected to a first mass flowmeter 7 and the inlet end of a first mixing chamber 19. The outlet end of the second one-way valve 4 is connected to a second mass flowmeter 8. The outlet end of the second mass flowmeter 8 is respectively connected to a first switching valve 12 and a second switching valve 13. The first switching valve 12 is connected to the inlet end of the first mixing chamber 19. The outlet end of the first mixing chamber 19 is sequentially connected to a first gas resistance 21 and a gas-diluted sample gas outlet 23;

[0018] The third one-way valve 5 is sequentially connected to a third mass flowmeter 9 and the inlet end of an evaporation chamber 11. The liquid feeding inlet 6 is sequentially connected to a syringe pump 10 and the inlet end of the evaporation chamber 11. The outlet end of the evaporation chamber 11 is respectively connected to a second gas resistance 14 and a third gas resistance 15. The second gas resistance 14 is connected to a liquid primary-diluted sample gas outlet 24. The third gas resistance 15 is sequentially connected to a second mixing chamber 17, a fourth gas resistance 20, and a liquid secondary-diluted sample gas outlet 25. The second switching valve 13 is connected to the inlet end of the second mixing chamber 17;

[0019] The outlet end of the evaporation chamber 11 is connected to a first pressure controller 16, the outlet end of the second mixing chamber 17 is connected to a second pressure controller 18, and the outlet end of the first mixing chamber 19 is connected to a third pressure controller 22. The outlet ends of the first pressure controller 16, the second pressure controller 18, and the third pressure controller 22 are all connected to the exhaust port 26.

[0020] The pressure of the first pressure controller 16 is greater than that of the second pressure controller 18. By changing the pressure difference between the first pressure controller and the second pressure controller and the flow rate of the second mass flowmeter 8, different proportions of liquid secondary dilution gas can be obtained.

[0021] The first pressure controller 16, the second pressure controller 18, and the third pressure controller 22 all adopt backpressure control mode, and the output sample gas does not pass through the valve, avoiding the adsorption and pollution of the sample gas by the valve. The gas and liquid dilution sample gas outlets can be directly connected to the sampling device of the analytical instrument, and the sampling pressure and flow rate can be adjusted according to requirements to ensure continuous and stable standard gas output.

[0022] The connection between the injection pump 10 and the evaporation chamber 11 is designed to be sealed. The inner wall of the evaporation chamber 11 is treated with silanized inertness and placed in a temperature-adjustable constant temperature area. The injection pump 10 is an automatic liquid propulsion device that can precisely adjust the liquid flow rate.

[0023] The first mixing chamber 19 and the first gas resistance 21 are jointly placed in a temperature-adjustable constant temperature area, and the second gas resistance 14, the third gas resistance 15, the second mixing chamber 17, and the fourth gas resistance 20 are jointly placed in a temperature-adjustable constant temperature area.

[0024] The detailed connection means are well-known technologies in the art. The following mainly introduces the working principle and process, and the specific work is as follows. Gas dilution process: When the source to be diluted is a gas, the first switching valve 12 is opened, and the gas to be diluted and the dilution gas enter the first mixing chamber 19 respectively through the first mass flowmeter 7 and the second mass flowmeter 8 to control the required flow rates for mixing. A third pressure controller 22 is provided at the exhaust port. Liquid dilution process: When the source to be diluted is a liquid, the liquid sample is quantitatively added to the evaporation chamber 11 at a constant temperature through the injection pump 10. The liquid is vaporized in the evaporation chamber 11 and diluted and mixed with the dilution gas controlled by the third mass flowmeter 9 to output the sample gas. The pressure at the primary dilution sample gas output port is adjusted by the first pressure controller 16 and the second gas resistance 14. When a secondary dilution gas with a lower concentration is required, a part of the primary dilution gas enters the second mixing chamber 17 through the first pressure controller 16, the second pressure controller 18 and the third gas resistance 15 to control a constant flow rate. The first switching valve 12 is closed, and the second switching valve 13 is opened. The dilution gas controlled by the second mass flowmeter 8 enters the second mixing chamber 17. The output pressure of the secondary dilution sample gas is jointly adjusted by the second pressure controller 18 and the fourth gas resistance 20. Among them, the pressure of the first pressure controller 16 is greater than the pressure of the second pressure controller 18. Different proportions of liquid secondary dilution gas can be obtained by changing the pressure difference between the first pressure controller 16 and the second pressure controller 18 and the flow rate of the second mass flowmeter 8. The first one-way valve 3, the first mixing chamber 19, and the second mixing chamber 17 are made of metal materials treated with silanization inert. The first, second, third, and fourth gas resistances and the flow path pipeline through which the gas to be diluted passes are inert metal pipelines treated with silanization.

[0025] Example 1

[0026] An experiment on preparing a standard gas from methanol liquid and chromatographic instrument analysis was carried out. The data results are shown in Table 1, and the reproducibility chromatogram results are shown in Figure 2 .

[0027] The methanol liquid was added to the liquid feeding device 6, the high-purity nitrogen gas inlet 2 was connected, the liquid primary dilution sample gas outlet 24 was connected to the sampling device of a gas chromatograph equipped with a hydrogen flame ionization detector, and the waste gas exhaust port 26 was connected to a fume hood. Parameters were set on the display and operation software. The injection flow rate of the injection pump 10, the temperature of the evaporation chamber 11, and the pressure of the first pressure controller 16 were set.

[0028] After the gas preparation was started, the injection pump was started, the third mass flowmeter 9 controlled the corresponding flow rate, the first switching valve 12 and the second switching valve 13 were both in the closed state, and the prepared standard gas entered the valve sampling system of the gas chromatograph, and the system was analyzed continuously for 7 times.

[0029] Example 2

[0030] An experiment was conducted to prepare a standard gas from a mixed standard substance of 7 kinds of benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene, and styrene in methanol and perform chromatographic instrument analysis. The data results are shown in Table 1, and the reproducibility chromatogram results are shown in Figure 3 .

[0031] Add the benzene series standard solution to the liquid feeding device 6, connect high-purity nitrogen to the dilution gas inlet 2, connect the liquid secondary dilution sample gas outlet 25 to the injection device of a gas chromatograph equipped with a photoionization detector, and connect the waste gas evacuation port 26 to a fume hood. Set the parameters on the display and operation software. Set the injection flow rate of the injection pump 10, the temperature of the evaporation chamber 11, the pressures of the first pressure controller 16 and the second pressure controller 18, and the temperatures of the second mixing chamber 17, the third gas resistance 15, and the fourth gas resistance 20. The pressure of the second pressure controller 18 is the gas injection pressure, and the pressure of the first pressure controller 16 is greater than that of the second pressure controller 18, with a default pressure difference of 20 KPa.

[0032] After the gas preparation is started, the injection pump is started, the first switching valve 12 is closed, the second switching valve 13 is opened, the second flowmeter 8 and the third mass flowmeter 9 control the corresponding flow rates, and the prepared standard gas enters the valve injection system of the gas chromatograph, and the system is continuously analyzed 7 times.

[0033]

[0034] Table 1

[0035] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic gas-liquid gas distribution system with adjustable output pressure, comprising an inlet (1) for the gas to be diluted, an inlet (2) for the diluting gas, and an inlet (6) for liquid feeding. The inlet (1) for the gas to be diluted is connected to a first one-way valve (3), and the inlet (2) for the diluting gas is respectively connected to a second one-way valve (4) and a third one-way valve (5), characterized in that: The outlet end of the first one-way valve (3) is successively connected to the inlet end of a first mass flowmeter (7) and a first mixing chamber (19). The outlet end of the second one-way valve (4) is connected to a second mass flowmeter (8). The outlet end of the second mass flowmeter (8) is respectively connected to a first switching valve (12) and a second switching valve (13). The first switching valve (12) is connected to the inlet end of the first mixing chamber (19). The outlet end of the first mixing chamber (19) is successively connected to a first gas resistance (21) and a gas dilution sample gas outlet (23). The third one-way valve (5) is successively connected to a third mass flowmeter (9) and the inlet end of an evaporation chamber (11). The liquid feeding inlet (6) is successively connected to an injection pump (10) and the inlet end of the evaporation chamber (11). The outlet end of the evaporation chamber (11) is respectively connected to a second gas resistance (14) and a third gas resistance (15). The second gas resistance (14) is connected to a liquid primary dilution sample gas outlet (24). The third gas resistance (15) is successively connected to a second mixing chamber (17), a fourth gas resistance (20) and a liquid secondary dilution sample gas outlet (25). The second switching valve (13) is connected to the inlet end of the second mixing chamber (17).

2. The automatic gas-liquid gas distribution system with adjustable output pressure according to claim 1, wherein: The outlet end of the evaporation chamber (11) is connected to a first pressure controller (16). The outlet end of the second mixing chamber (17) is connected to a second pressure controller (18). The outlet end of the first mixing chamber (19) is connected to a third pressure controller (22). The outlet ends of the first pressure controller (16), the second pressure controller (18) and the third pressure controller (22) are all connected to a vent port (26).

3. An automatic gas-liquid gas distribution system with adjustable output pressure according to claim 2, characterized in that: The pressure of the first pressure controller (16) is greater than that of the second pressure controller (18).

4. An automatic gas-liquid gas distribution system with adjustable output pressure according to claim 2, characterized in that: The first pressure controller (16), the second pressure controller (18) and the third pressure controller (22) all adopt a back pressure control mode and are used for adjusting the sample injection pressure and flow rate.

5. An automatic gas-liquid gas distribution system with adjustable output pressure according to claim 1, characterized in that: The connection between the injection pump (10) and the evaporation chamber (11) adopts a sealed design. The injection pump is a liquid automatic propulsion device for adjusting the liquid flow rate. The inner wall of the evaporation chamber (11) is subjected to silanization inert treatment and is placed in a temperature-adjustable constant temperature area.

6. The automatic gas-liquid gas distribution system with adjustable output pressure according to claim 1, characterized in that: The first mixing chamber (19) and the first gas resistance (21) are jointly placed in a temperature-adjustable constant temperature area. The second gas resistance (14), the third gas resistance (15), the second mixing chamber (17) and the fourth gas resistance (20) are jointly placed in a temperature-adjustable constant temperature area.

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