Standard gas dispensing device

Abstract

The utility model provides a kind of standard gas gas distribution device, it is related to standard gas preparation device technical field, including including gas distribution main pipe, raw material gas branch pipe, gas distribution branch pipe, negative pressure pipe, vent pipe, vacuum system, inlet valve V1, vacuum valve V2, vent valve V3, pressure measuring valve V4, outlet valve V5, two-way diaphragm valve one K1, two-way diaphragm valve two K2, pressure gauge one S1, pressure gauge two S2;The raw material gas branch pipe is connected by inlet valve V1 with raw material gas branch pipe one end of gas distribution main pipe, and the other end of gas distribution main pipe is connected by outlet valve V5 with gas distribution branch pipe, and the raw material gas branch pipe and gas distribution branch pipe are connected two-way diaphragm valve one K1 and two-way diaphragm valve two K2 respectively;Vacuum valve V2 is connected with pressure gauge one S1 and negative pressure pipe by gas distribution main pipe, and negative pressure pipe is connected with vacuum system;Vent valve V3 is connected with vent pipe by gas distribution main pipe;Pressure gauge two S2 is connected by pressure measuring valve V4 with gas distribution main pipe, and the present application is easy to operate and can guarantee high-precision standard gas preparation device.

Description

Technical Field

[0001] This utility model relates to the technical field of standard gas preparation devices, specifically to a standard gas mixing device. Background Technology

[0002] Standard gases, as important reference materials, are used in industrial production, environmental monitoring, and scientific research to calibrate measuring instruments, evaluate analytical methods, and transfer measurement values. The main methods for preparing standard gases are gravimetric methods and partial pressure methods, both of which require a stable and airtight gas mixing device.

[0003] An existing standard gas generation device, such as the device disclosed in Chinese Utility Model Patent (Authorization Announcement No. CN203829931U), mainly uses multiple three-in-one-out four-way valves and switching valves for flow path control, and the pipelines are connected by compression fittings.

[0004] The above-mentioned device has the following drawbacks in practical applications:

[0005] The three-inlet, one-outlet diaphragm valve used has a complex structure, making inspection and repair difficult when a malfunction occurs.

[0006] The purity control is limited, the dead volume of the system pipeline is large, and the inner wall treatment is relatively simple, which makes it easy for component adsorption to occur, affecting the accuracy and purity of the final product. In particular, when preparing standard gases at the ppm level or even lower concentrations, it is difficult to guarantee the accuracy. Utility Model Content

[0007] To overcome the problems in the prior art, this utility model provides a standard gas mixing device. This application proposes a standard gas preparation device with optimized structure, high airtightness, simple operation, and high precision.

[0008] A standard gas distribution device includes a main gas distribution pipe, a raw material gas branch pipe, a gas distribution branch pipe, a negative pressure pipe, a vent pipe, a vacuum system, an inlet valve V1, a vacuum valve V2, a vent valve V3, a pressure measuring valve V4, an outlet valve V5, a two-way diaphragm valve K1, a two-way diaphragm valve K2, a pressure gauge S1, and a pressure gauge S2.

[0009] One end of the gas distribution main pipe is connected to the raw material gas branch pipe through the inlet valve V1, and the other end of the gas distribution main pipe is connected to the gas distribution branch pipe through the outlet valve V5. The raw material gas branch pipe and the gas distribution branch pipe are respectively connected to the two-way diaphragm valve K1 and the two-way diaphragm valve K2.

[0010] The main gas distribution pipe is connected to the negative pressure pipe and pressure gauge S1 via vacuum valve V2, and the negative pressure pipe is connected to the vacuum system.

[0011] The main gas distribution pipe is connected to the vent pipe via vent valve V3;

[0012] The main gas distribution pipe is connected to pressure gauge S2 via pressure testing valve V4, and pressure testing valve V4 is connected to an overpressure alarm device.

[0013] Furthermore, the gas distribution device also includes a PLC controller. Pressure gauge S1 and pressure gauge S2 are connected to the PLC controller. The PLC controller is connected to the inlet valve V1, vacuum valve V2, vent valve V3, pressure measuring valve V4, outlet valve V5, two-way diaphragm valve K1, and two-way diaphragm valve K2.

[0014] Furthermore, the gas distribution device also includes a pipeline heating device, which includes a flexible electric heating tape spirally wound around the outside of the main gas distribution pipe, the raw material gas branch pipe, the gas distribution branch pipe, the negative pressure pipe, and the vent pipe.

[0015] Furthermore, the pipelines and valves of the gas distribution device are all sealed together using VCR connections.

[0016] Furthermore, the vacuum system consists of a vacuum unit composed of a rotary vane pump and a molecular pump.

[0017] Furthermore, the main gas distribution pipe, raw material gas branch pipe, gas distribution branch pipe, negative pressure pipe, and vent pipe are EP-grade L stainless steel pipelines, which have undergone passivation treatment.

[0018] Furthermore, the two-way diaphragm valve K2 of the gas distribution branch pipe is connected to the gas cylinder interface with a PTFE gasket press-type sealing structure.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. The VCR connection method is adopted to replace the traditional compression fitting. When used with rotary vane pumps and molecular pump vacuum units, the system vacuum can reach below 1 Pa and the pressure resistance can reach above 20 MPa. This fundamentally eliminates the problem of micro-leakage and provides a prerequisite for high-precision gas distribution.

[0021] 2. EP-grade 316L stainless steel pipelines are used and undergo special chemical treatment. Combined with two-way diaphragm valves, the flow path is simplified, effectively avoiding component adsorption. At the same time, the added pipeline heating device further reduces system residue and ensures the accuracy of the mixed gas composition.

[0022] 3. The optimized valve system and PTFE gasket cylinder connectors not only simplify operation but also improve the reliability and safety of the connection.

[0023] 4. The two-way diaphragm valve has a simple and reliable structure. The VCR connector can be repeatedly disassembled and reassembled and has stable sealing performance, which greatly reduces the difficulty and cost of equipment maintenance. Attached Figure Description

[0024] To clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments are explained.

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the valve structure of this utility model.

[0027] Figure 3 This is a schematic diagram of the heating device structure of this utility model. Detailed Implementation

[0028] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, so as to facilitate the understanding of those skilled in the art.

[0029] See Figure 1 , Figure 2 , Figure 3 This utility model proposes a standard gas distribution device, the core of which is a gas distribution main pipe 1, which serves as a central manifold for gas mixing and distribution.

[0030] The air intake section of the device includes at least one raw gas branch pipe 2. Each branch pipe is equipped with a two-way diaphragm valve K1 at the front end for connecting to the raw gas cylinder. The rear end of the raw gas branch pipe 2 is connected to one end of the gas distribution main pipe 1 through the air intake valve V1. The structure of the air intake valve V1 allows one or more gas lines to be selected from multiple raw gas branch pipes and introduced into the main pipe.

[0031] The gas outlet section of the device includes a gas distribution branch pipe 3, which is connected to the other end of the gas distribution main pipe 1 through a gas outlet valve V5. The outlet end of the gas distribution branch pipe 3 is equipped with a two-way diaphragm valve K2, which is used to connect to the product gas cylinder to be filled. In this embodiment, a gas cylinder interface with a PTFE gasket press-type sealing structure is connected after the K2 valve to ensure the sealing and durability of the connection.

[0032] Several functional interfaces are set on the gas distribution main pipe 1:

[0033] Vacuum and low pressure monitoring port: It is connected to the negative pressure pipe 4 through the air inlet valve V1. Pressure gauge S1 is connected here to accurately measure the vacuum and low pressure in the gas distribution main pipe 1, such as the partial pressure. The negative pressure pipe 4 is connected to the external vacuum system 6. The vacuum system 6 is composed of a two-stage vacuum unit consisting of a rotary vane pump and a molecular pump, which can provide a strong evacuation capacity for the entire pipeline system.

[0034] Vent port: Connected to vent pipe 5 via vent valve V3, used to safely release residual gas in the system or to relieve pressure in an emergency;

[0035] High pressure monitoring port: It is connected to pressure gauge S2 via pressure valve V4, and is used to accurately monitor the high pressure status in the main pipe when filling the product gas cylinder, so as to ensure the accuracy of the filling pressure. The pressure valve V4 is connected to overpressure alarm device 8 to ensure timely feedback of overpressure information.

[0036] To achieve the goals of high precision and high purity, this device employs several optimized designs:

[0037] Connection method: All pipe and valve connections in the system use VCR connection. This metal-face sealing structure has higher reliability and airtightness compared to compression fittings, and can effectively prevent leakage.

[0038] Pipeline material: All pipelines, including the main gas distribution pipe 1, are made of EP (electropolished) grade 316L stainless steel and have undergone passivation treatment. This makes the inner wall of the pipeline extremely smooth and clean, and has excellent corrosion resistance, minimizing gas adsorption.

[0039] Heating and degassing: The entire pipeline system, including the main pipe 1 and each branch pipe 2, 3, 4, 5, is externally wrapped with a pipeline heating device 7 made of flexible electric heating tape, which heats and bakes the pipeline, effectively removing moisture and other impurities adsorbed on the inner wall.

[0040] Automated control: The device is equipped with a PLC controller. Pressure gauges S1 and S2 serve as sensing units, feeding back the measured pressure signals to the PLC in real time. The PLC precisely controls the opening and closing of all valves V1-V5, K1, and K2 according to the preset program, realizing the full automation of the gas distribution process, eliminating human error, and improving efficiency and consistency.

[0041] Work process:

[0042] Before gas mixing begins, the PLC controller is started, K1 and K2 are closed, and the vacuum system (6) and heating device (7) are started to evacuate and heat the entire system. When pressure gauge S1 shows that the vacuum level meets the standard, V2 is closed;

[0043] Subsequently, the PLC precisely controls the opening of K1 and V1 according to the configuration requirements, introduces the component gas, and monitors its partial pressure through S1. After all the component gases are introduced in sequence, the standard gas is filled into the product gas cylinder through valves such as V6 and K2, while S2 monitors the final filling pressure.

[0044] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A standard gas mixing device, characterized in that, Includes main gas distribution pipe (1), raw material gas branch pipe (2), gas distribution branch pipe (3), negative pressure pipe (4), vent pipe (5), vacuum system (6), inlet valve (V1), vacuum valve (V2), vent valve (V3), pressure measuring valve (V4), outlet valve (V5), two-way diaphragm valve one (K1), two-way diaphragm valve two (K2), pressure gauge one (S1), and pressure gauge two (S2); One end of the gas distribution main pipe (1) is connected to the raw material gas branch pipe (2) through the inlet valve (V1), and the other end of the gas distribution main pipe (1) is connected to the gas distribution branch pipe (3) through the outlet valve (V5). The raw material gas branch pipe (2) and the gas distribution branch pipe (3) are respectively connected to the two-way diaphragm valve one (K1) and the two-way diaphragm valve two (K2). The gas distribution main pipe (1) is connected to the negative pressure pipe (4) and the pressure gauge (S1) through the vacuum valve (V2), and the negative pressure pipe (4) is connected to the vacuum system (6); The main gas distribution pipe (1) is connected to the vent pipe (5) via the vent valve (V3); The gas distribution main pipe (1) is connected to pressure gauge 2 (S2) through pressure measuring valve (V4), and the pressure measuring valve (V4) is connected to overpressure alarm device (8).

2. The standard gas mixing device according to claim 1, characterized in that, The gas distribution device also includes a PLC controller. Pressure gauge 1 (S1) and pressure gauge 2 (S2) are connected to the PLC controller. The PLC controller is connected to the inlet valve (V1), vacuum valve (V2), vent valve (V3), pressure measuring valve (V4), outlet valve (V5), two-way diaphragm valve 1 (K1), and two-way diaphragm valve 2 (K2).

3. The standard gas mixing device according to claim 1, characterized in that, The gas distribution device also includes a pipeline heating device (7), which includes a flexible electric heating tape spirally wrapped around the outside of the main gas distribution pipe (1), the raw material gas branch pipe (2), the gas distribution branch pipe (3), the negative pressure pipe (4), and the vent pipe (5).

4. The standard gas mixing device according to claim 1, characterized in that, The pipelines and valves of the gas distribution device are all sealed together using VCR connection.

5. The standard gas mixing device according to claim 1, characterized in that, The vacuum system consists of a vacuum unit composed of a rotary vane pump and a molecular pump.

6. The standard gas mixing device according to claim 1, characterized in that, The main gas distribution pipe (1), the raw material gas branch pipe (2), the gas distribution branch pipe (3), the negative pressure pipe (4), and the vent pipe (5) are all EP-grade 316L stainless steel pipelines, which have been passivated.

7. The standard gas mixing device according to claim 1, characterized in that, The two-way diaphragm valve (K2) of the gas distribution branch pipe (3) is connected to the gas cylinder interface with a PTFE gasket press-type sealing structure.

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