Industrial standard gas automatic proportioning device

Abstract

The utility model relates to industrial automation technical field discloses an industrial standard gas automatic proportioning device, including the cabinet body, the cabinet body inside is physically divided into the gas confluence area of upper part and the electrical control area of lower part, be provided with a plurality of parallel gas treatment branch in the gas confluence area, operation and display panel, set up in the front side of electrical control area, mixer, including outer mixing cylinder and inner mixing cylinder, the lateral wall of outer mixing cylinder is set up with a plurality of communicating holes, a plurality of communicating holes with the export of a plurality of gas treatment branch are linked, back pressure regulating valve, its installation in the export of outer mixing cylinder, in the utility model, through setting back pressure regulating valve, the working environment of core flowmeter is stabilized, and the proportioning precision is promoted, simultaneously, the safety interlock design of its normally closed valve, cooperate electrolytic polishing pipeline and metal face seal joint, on the basis that realizes active safety protection, guarantees the high purity of mixed gas again.

Description

Technical Field

[0001] This utility model relates to the field of industrial automation technology, and in particular to an automatic proportioning device for industrial standard gases. Background Technology

[0002] Currently, in cutting-edge fields such as semiconductor manufacturing, environmental monitoring, biomedicine, and scientific research, precisely controlling the concentration of multiple gas components and forming a stable and homogeneous mixed standard gas is a crucial fundamental technology. The processes in these high-tech industries place extremely stringent requirements on the accuracy, stability, and purity of the gas atmosphere. Therefore, high-performance automated industrial standard gas mixing devices have become key equipment for ensuring the success of their production and experiments.

[0003] Regarding the aforementioned issues, a typical existing gas proportioning device operates as follows: multiple gas sources are connected to the device, with a mass flow controller (MFC) connected in series in each pipeline. After the operator sets the target flow rate for each gas, the MFC measures the gas. Subsequently, all the measured gases are introduced into a static mixing chamber, where they diffuse and mix through a fixed flow guide structure. After mixing, the gas is directly delivered from the device's outlet to downstream gas consumption points to supply process equipment or analytical instruments.

[0004] However, in practical applications, existing gas proportioning devices have significant drawbacks. First, their proportioning accuracy is highly susceptible to external environmental interference. The stability of mass flow controllers is heavily dependent on the constant pressure difference across them. When the mixed gas outlet is directly connected to the user's process equipment, pressure fluctuations caused by the start-up, shutdown, or changes in operating conditions of downstream equipment are transmitted back to the mixing chamber without buffering, directly impacting the outlet of each mass flow controller, causing its instantaneous flow rate to deviate from the set value, and ultimately resulting in drastic fluctuations in the output gas concentration. Second, the safety mechanisms of existing devices are relatively passive. They lack real-time monitoring and active interlocking of the pressure of each gas source. Once a gas path experiences abnormal pressure due to a depleted gas cylinder or pipe blockage, the device cannot automatically cut off that gas path and issue an alarm. This not only leads to serious discrepancies in the proportioning ratio but may even cause safety risks due to gas backflow. Finally, these devices are not well-suited for high-purity or special gases. Their internal pipelines are typically made of ordinary industrial-grade materials with rough inner walls, easily adsorbing gas molecules. When it is necessary to switch to a different formulation ratio, the gas that was previously left on the pipe wall will be slowly released, forming a "memory effect". This seriously contaminates the gas with the new formulation ratio and greatly prolongs the time required for concentration stabilization, which cannot meet the requirements of modern processes for rapid and precise response.

[0005] To address the above problems, an automatic industrial standard gas proportioning device is proposed. Utility Model Content

[0006] To overcome the above shortcomings, this utility model provides an automatic industrial standard gas proportioning device, which aims to solve the problem that the proportioning accuracy of an existing automatic industrial standard gas proportioning device is easily affected by downstream pressure fluctuations.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an industrial standard gas automatic proportioning device, comprising: a cabinet, the interior of which is physically divided into an upper gas convergence area and a lower electrical control area, wherein the gas convergence area is provided with multiple parallel gas processing branches, and each of the gas processing branches is used to process a type of raw material gas.

[0008] An operation and display panel is located on the front side of the electrical control area;

[0009] Normally closed pneumatic valves are used to automatically isolate or connect the gas source of this branch;

[0010] A mass flow controller is used to accurately measure the gas flow rate through this branch.

[0011] A check valve is used to prevent gas backflow.

[0012] The mixer includes an outer mixing cylinder and an inner mixing cylinder. The side wall of the outer mixing cylinder has multiple connecting holes, which are connected to the outlets of the multiple gas processing branches for fully mixing the gases from each branch.

[0013] A back pressure regulating valve, installed at the outlet of the outer mixing cylinder, is used to provide a stable downstream pressure environment for the plurality of mass flow controllers.

[0014] As a further description of the above technical solution:

[0015] The cabinet has multiple air intake pipes installed on its air intake side, and each of the multiple air intake pipes is fixedly connected to a filter.

[0016] As a further description of the above technical solution:

[0017] The pipes in the gas treatment branch that come into contact with the gas are electrolytically polished stainless steel pipes, and the connections between the pipes are made with metal-faced sealing joints.

[0018] As a further description of the above technical solution:

[0019] The normally closed pneumatic valve is a pneumatic diaphragm valve.

[0020] As a further description of the above technical solution:

[0021] A pressure sensor is installed on the rear side of the normally closed pneumatic valve, and the input end of the normally closed pneumatic valve is fixedly connected to the output end of the filter.

[0022] As a further description of the above technical solution:

[0023] Multiple baffles are vertically arranged between the gas convergence zones.

[0024] As a further description of the above technical solution:

[0025] The inner mixing cylinder is rotatably connected inside the cabinet, and both ends of the inner mixing cylinder are closed. A rotating shaft is fixedly connected to the front end of the inner mixing cylinder.

[0026] As a further description of the above technical solution:

[0027] A drive motor is installed on the front side of the cabinet, and the output end of the drive motor is fixedly connected to the inside of the rotating shaft.

[0028] This utility model has the following beneficial effects:

[0029] 1. In this invention, by explicitly setting a back pressure regulating valve downstream of the mass flow controller and a pressure sensor upstream, an extremely stable upstream and downstream pressure environment is created, effectively isolating interference caused by pressure fluctuations from downstream user processes and pressure decay from upstream gas sources. This ensures that the device's proportioning accuracy no longer depends solely on the performance of the MFC itself, but is elevated to a system-wide guarantee, ensuring highly accurate and stable final output gas concentration.

[0030] 2. In this invention, the linkage design of the normally closed pneumatic valve and the pressure sensor constitutes an active preventive safety interlock, enabling automatic and rapid fault-safe shut-off when the intake pressure is abnormal. Simultaneously, the electrolytically polished stainless steel piping and metal-faced sealing joints used in the design fundamentally reduce the risk of gas adsorption and particulate matter shedding, minimizing leakage and cross-contamination, and ensuring the high purity of the mixed gas. Attached Figure Description

[0031] Figure 1 This is a three-dimensional schematic diagram of an automatic industrial standard gas proportioning device proposed in this utility model;

[0032] Figure 2 This is a schematic diagram of the mass flow controller of an industrial standard gas automatic proportioning device proposed in this utility model;

[0033] Figure 3 This is a schematic diagram of the inner mixing cylinder of an industrial standard gas automatic proportioning device proposed in this utility model.

[0034] Legend:

[0035] 1. Cabinet; 2. Operation and display panel; 3. Air inlet pipe; 4. Drive motor; 5. Filter; 6. Normally closed pneumatic valve; 7. Mass flow controller; 8. Check valve; 9. Outer mixing cylinder; 10. Back pressure regulating valve; 11. Inner mixing cylinder; 12. Rotary shaft; 13. Connecting hole. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] Reference Figure 1 - Figure 3 This utility model provides an embodiment of an automatic industrial standard gas mixing device, which is integrated into a cabinet 1. The cabinet 1 is strictly divided into an upper gas mixing area and a lower electrical control area. When gas mixing is required, the operator sets parameters through the operation and display panel 2 located on the front of the electrical control area. Multiple raw gas streams enter the device from their respective inlet pipes 3, first passing through a filter 5 to remove impurities. Then, under the control of the PLC, the normally closed pneumatic valves 6 on each branch open to allow gas to pass through. The gas flows through a high-precision mass flow controller 7, and its flow rate is accurately measured. To prevent backflow of gas from different branches during mixing and affect the measurement accuracy, each gas stream passes through a one-way valve 8 after leaving the mass flow controller 7.

[0038] Subsequently, the gas from all branches enters tangentially into the annular space between the outer mixing cylinder 9 and the inner mixing cylinder 11 of the mixer through different connecting holes 13. At the same time, the drive motor 4 drives the inner mixing cylinder 11 to rotate at high speed through the rotating shaft 12. This active mechanical stirring method can mix the gas more quickly and evenly than static mixing.

[0039] After mixing, all gases must flow through the back pressure regulating valve 10 installed at the outlet of the outer mixing cylinder 9. This valve establishes a constant and stable back pressure for all upstream mass flow controllers 7, thereby ensuring that they operate under optimal conditions and greatly improving the accuracy of the overall mixing ratio and the stability of long-term operation.

[0040] In the gas handling branch, the normally closed pneumatic valve 6, specifically a pneumatic diaphragm valve, is selected. It possesses a fail-safe characteristic, automatically closing in case of power failure or pressure loss. Combined with a pressure sensor installed downstream of the valve, it forms a sensitive and reliable safety interlock. Regarding reliability and purity, all gas-contacting pipelines are made of electrolytically polished stainless steel and connected using metal-faced sealing joints. This ensures extremely high airtightness of the system, effectively preventing the infiltration of external impurities and internal gas micro-leakage. The filter 5 at the branch source not only ensures gas purity but also protects the expensive downstream mass flow controller 7 from particulate matter damage, extending equipment lifespan. Furthermore, within the gas manifold area, multiple vertical baffles organize and separate the parallel gas handling branches, avoiding pipeline cross-interference and vibration, further enhancing the system's structural stability and long-term operational reliability.

[0041] Working Principle: After the operator inputs the mixing ratio command through the operation and display panel 2 located at the front of the electrical control area, multiple raw material gases enter the cabinet 1 through their respective air inlet pipes 3. Each gas flows sequentially through the connected filter 5, then through the normally closed pneumatic valve 6 opened by the controller. The pressure sensor behind the valve measures the gas pressure. The gas then enters the mass flow controller 7 for precise metering. The metered gas then passes through the one-way valve 8 and finally enters the mixer through the connecting hole 13 on the side wall of the outer mixing cylinder 9. Simultaneously with the gas entering, the drive motor 4 drives the inner mixing cylinder 11 to rotate inside the outer mixing cylinder 9 via the rotating shaft 12, actively stirring and mixing the incoming gas. The fully mixed gas flows out from the outlet of the outer mixing cylinder 9 and passes through the back pressure regulating valve 10 before finally being output from the device.

[0042] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An automatic proportioning device for industrial standard gases, characterized in that, include: Cabinet (1), the interior of which is physically divided into an upper gas convergence area and a lower electrical control area. The gas convergence area is provided with multiple parallel gas processing branches, and each of the gas processing branches is used to process a type of raw material gas. An operation and display panel (2) is located on the front side of the electrical control area; A normally closed pneumatic valve (6) is used to automatically isolate or connect the gas source of this branch; A mass flow controller (7) is used to accurately measure the gas flow rate through this branch; One-way valve (8) is used to prevent gas backflow; The mixer includes an outer mixing cylinder (9) and an inner mixing cylinder (11). The side wall of the outer mixing cylinder (9) is provided with a plurality of connecting holes (13). The plurality of connecting holes (13) are connected to the outlets of the plurality of gas processing branches and are used to fully mix the gases from each branch. A back pressure regulating valve (10), which is installed at the outlet of the outer mixing cylinder (9), is used to provide a stable downstream pressure environment for the plurality of mass flow controllers (7).

2. The automatic industrial standard gas proportioning device according to claim 1, characterized in that: The cabinet (1) has multiple air inlet pipes (3) installed on the air inlet side, and each of the multiple air inlet pipes (3) is fixedly connected to a filter (5).

3. The automatic industrial standard gas proportioning device according to claim 1, characterized in that: The pipes in the gas treatment branch that come into contact with the gas are electrolytically polished stainless steel pipes, and the connections between the pipes are made with metal-faced sealing joints.

4. The automatic industrial standard gas proportioning device according to claim 1, characterized in that: The normally closed pneumatic valve (6) is a pneumatic diaphragm valve.

5. The automatic proportioning device for industrial standard gases according to claim 2, characterized in that: A pressure sensor is installed on the rear side of the normally closed pneumatic valve (6), and the input end of the normally closed pneumatic valve (6) is fixedly connected to the output end of the filter (5).

6. The automatic proportioning device for industrial standard gases according to claim 1, characterized in that: Multiple baffles are vertically arranged between the gas convergence zones.

7. The automatic proportioning device for industrial standard gases according to claim 1, characterized in that: The inner mixing cylinder (11) is rotatably connected inside the cabinet (1), and both ends of the inner mixing cylinder (11) are closed. The front end of the inner mixing cylinder (11) is fixedly connected to a rotating shaft (12).

8. The automatic proportioning device for industrial standard gases according to claim 7, characterized in that: A drive motor (4) is provided on the front side of the cabinet (1), and the output end of the drive motor (4) is fixedly connected to the inside of the rotating shaft (12).

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