Air path structure of a particle counter

Abstract

The utility model provides a kind of particle counter air path structure, it is mainly constituted by sensor shell, air path pipeline, flow regulating pipe and micro pressure difference detection component, air path pipeline contains air inlet pipe and air outlet pipe, air inlet pipe outlet is less than air outlet pipe air inlet, flow regulating pipe is composed of at least two sections of communicating pipeline, micro pressure difference detection component is communicated with air path pipeline by first, second micro pressure difference sampling pipe, and is connected micro pressure difference sensor, flow regulating pipe and air path pipeline have multiple connection modes, under different connection mode, air path pipeline has pipe diameter narrow section, limit ring and the like structure.The utility model discards complex algorithm and control process, realizes air flow effective regulation, simplifies regulation and control process, optimizes pipeline connection and flow regulating pipe design, reduces dependence on expensive components, reduces cost, flow regulating pipe specific setting can also be used to obtain micro pressure difference data, with remarkable practical value and market prospect.

Description

Technical Field

[0001] This utility model relates to the field of particle counter technology, specifically to a gas path structure for a particle counter. Background Technology

[0002] In practical applications of particle counters, whether it is the detection of suspended particulate matter in the air in the field of environmental monitoring or the monitoring of fine particulate pollutants in industrial production such as semiconductor manufacturing, accurate detection and precise adjustment of the air flow rate in fluid pipelines are key factors to ensure the measurement accuracy and reliability of particle counters.

[0003] Currently, flow detection primarily relies on traditional flow meter methods. However, with the increasing market demand for miniaturized and portable particle counters, technology for obtaining flow rate through micro-pressure differential has emerged and is gradually being applied in the fluid piping of particle counters. Simultaneously, to adapt to the unique fluid piping characteristics of particle counters, the throttling orifice has also undergone corresponding adaptive improvements.

[0004] In existing technologies, to accurately control the flow rate of a particle counter within the target range, dynamic closed-loop adjustment of the flow rate is required. A common approach is to use a control module with a microcontroller to acquire flow data, and then adjust the speed of the pump or fan based on this data to regulate the flow rate. However, this process has several problems: firstly, the entire regulation process involves multiple stages, including flow detection, pump or fan drive feedback, and complex control algorithms, making the system design extremely complex and significantly increasing the difficulty of later maintenance; secondly, the control module with the microcontroller itself is expensive, and the complex flow detection components and the high-precision drive requirements for the pump or fan further contribute to the high overall cost, which to some extent limits the widespread application and market promotion of particle counters.

[0005] Therefore, how to overcome the shortcomings of the existing technology mentioned above has become the subject of this utility model. Utility Model Content

[0006] In view of this, the purpose of this utility model is to provide a gas path structure for a particle counter.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0008] A gas path structure for a particle counter includes a sensor housing, a gas path pipe communicating with the cavity inside the sensor housing, and a flow regulating pipe and a micro-differential pressure detection component communicating with the gas path pipe.

[0009] The air passage includes an air inlet pipe and an air outlet pipe that are respectively connected to the sensor housing, and the air outlet of the air inlet pipe is smaller than the air inlet of the air outlet pipe.

[0010] The flow regulating pipe consists of at least two pipe sections connected in the direction of airflow, and the smallest inner diameter of each pipe section is smaller than the smallest inner diameter of the gas pipeline.

[0011] The micro differential pressure detection component includes a first micro differential pressure sampling tube, a second micro differential pressure sampling tube, and a micro differential pressure sensor. The first micro differential pressure sampling tube and the second micro differential pressure sampling tube are connected in communication with the walls of the air inlet pipe and / or the air outlet pipe, and the first micro differential pressure sampling tube and the second micro differential pressure sampling tube are respectively connected to the micro differential pressure sensor.

[0012] Optionally, the inner diameter of each pipe section increases gradually from the airflow inlet to the outlet.

[0013] Optionally, the gas pipeline has a narrowing section between the connection point of the first differential pressure sampling tube and the gas pipeline, and between the connection point of the second differential pressure sampling tube and the gas pipeline;

[0014] The flow control tube is connected to the gas pipeline outside the connection point between the first differential pressure sampling tube and the gas pipeline and the connection point between the second differential pressure sampling tube and the gas pipeline.

[0015] Optionally, the flow control tube is located inside the gas pipeline and between the connection point of the first differential pressure sampling tube and the gas pipeline, and the connection point of the second differential pressure sampling tube and the gas pipeline.

[0016] Optionally, the flow control pipe is connected to the air inlet of the air inlet pipe or the air outlet of the air outlet pipe.

[0017] Optionally, the inner wall of the gas pipeline is provided with a limiting ring, which is located before the air inlet or after the air outlet of the flow regulating pipe.

[0018] Optionally, the diameter of the limiting ring is larger than the maximum inner diameter of the flow regulating pipe.

[0019] Optionally, the diameter of the limiting ring is larger than the inner diameter of the flow regulating pipe near the limiting ring.

[0020] Optionally, the flow control pipe includes a first flow control pipe, a second flow control pipe, and a third flow control pipe arranged along the airflow direction with increasing diameter, wherein the first flow control pipe, the second flow control pipe, and the third flow control pipe are connected in sequence.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] 1. The air outlet of the inlet pipe in this application is smaller than the air inlet of the outlet pipe. It is combined with the flow regulating pipe, which consists of at least two gradually increasing pipe sections connected along the airflow direction. The flow regulating pipe uses the minimum diameter section to control the fluid flow rate under a given pressure, limiting the flow rate in the airflow pipe. It also uses the relationship between the fluid velocity and pressure in pipes of different diameters to stabilize the fluid in the pipe, allowing the airflow to be naturally regulated in the air path. It can achieve the initial stable regulation of the airflow without complex control algorithms and additional control equipment, greatly simplifying the flow regulation process.

[0023] 2. By using multi-section flow control tubes with gradually changing diameters (such as three sections with diameters from small to large), the airflow can be more precisely regulated. The flow control tubes of different diameters adjust the airflow rate in sequence, so that the airflow reaches a more ideal state when entering the subsequent air path. Combined with a micro differential pressure sensor, the air path system's ability to regulate flow and the accuracy of detection are further improved.

[0024] 3. Setting a limiting ring before the air inlet of the flow regulating pipe reduces airflow impact, and setting a limiting ring after the air outlet can resist airflow impact. Both can further mitigate the sudden changes in airflow caused by the change in the inner diameter before and after the limiting ring, optimize the airflow state, enable the particle counter to work stably in a variety of complex environments, and improve the applicability and versatility of the equipment. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Appendix Figure 1 This is a schematic diagram of the structure of the flow regulating pipe connected to the outlet of the outlet pipe in Embodiment 1 of this application;

[0027] Appendix Figure 2 This is a schematic diagram of the structure of the flow control pipe connected to the air inlet of the air inlet pipe in Embodiment 1 of this application;

[0028] Appendix Figure 3 This is a schematic diagram of the structure of Embodiment 2 of this application.

[0029] Explanation of reference numerals and components in the accompanying drawings:

[0030] 1. Sensor housing; 2. Gas path pipe; 21. Inlet pipe; 211. Pipe diameter narrowing section; 22. Outlet pipe; 221. Limiting ring; 3. Micro-differential pressure detection component; 31. First micro-differential pressure sampling tube; 32. Second micro-differential pressure sampling tube; 33. Micro-differential pressure sensor; 4. Flow regulating pipe; 41. First flow regulating pipe; 42. Second flow regulating pipe; 43. Third flow regulating pipe. Detailed Implementation

[0031] The technical solution of this utility model will now be clearly and completely described through specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0032] See appendix Figures 1-3As shown, the air path structure of a particle counter according to this application includes a sensor housing 1, an air path pipe 2 communicating with the inner cavity of the sensor housing 1, and a flow regulating pipe 4 and a micro-pressure difference detection component 3 communicating with the air path pipe 2. The air path pipe 2 includes an inlet pipe 21 and an outlet pipe 22, which are respectively connected to the sensor housing 1. The outlet of the inlet pipe 21 is smaller than the inlet of the outlet pipe 22. According to the prior art, the particle counter inputs airflow into the inner cavity of the sensor housing 1 through the inlet pipe 21, and then the airflow is discharged from the inner cavity of the sensor housing 1 through the outlet pipe 22. The cross-sectional area of ​​the inner cavity along the airflow direction is much larger than the outlet of the inlet pipe 21 and the inlet of the outlet pipe 22. This will not be described further here. The difference in the inner diameter of the outlet of the inlet pipe 21 and the inlet of the outlet pipe 22 helps the airflow to be discharged smoothly from the sensor housing 1. The airflow direction is defined as the air entering through the inlet pipe 21 and exiting through the outlet pipe 22. The flow regulating pipe 4 is arranged along the airflow direction in the airflow pipe 2. Specifically, it can be sleeved inside the airflow pipe 2 or connected to the airflow pipe 2. The flow regulating pipe 4 consists of at least two pipe sections connected along the airflow direction, and the smallest inner diameter of each pipe section is smaller than the smallest inner diameter of the airflow pipe 2. That is, the flow regulating pipe 4 includes at least two pipe sections with different inner diameters that are connected (e.g., three sections), and the smallest inner diameter of each pipe section is the smallest inner diameter in the airflow structure of this application. This unique flow regulating pipe design can be flexibly used with a flow meter and can also work in conjunction with a micro-differential pressure detection method. The micro-differential pressure detection component 3 includes a first micro-differential pressure sampling tube 31, a second micro-differential pressure sampling tube 32, and a micro-differential pressure sensor 33. The first micro-differential pressure sampling tube 31 and the second micro-differential pressure sampling tube 32 are connected to the walls of the inlet pipe 21 and / or the outlet pipe 32, and are respectively connected to the micro-differential pressure sensor 33. These components are used to collect micro-differential pressure data in the gas path, providing a basis for flow detection for the control module in the particle counter, which is connected to the micro-differential pressure sensor 33, to obtain flow data after acquiring the micro-differential pressure data. It should be understood that the particle counter also includes a fan or pump connected to the gas path pipeline for drawing fluid, and, under otherwise unchanged conditions, a pipeline section through the flow regulating pipe 4 to transport fluid. The size of the cross section and the control of pressure can achieve flow control. Under the condition that the working conditions of the fan or pump remain unchanged, the minimum pipe diameter in the flow regulating pipe 4 in this application can control the output airflow. The micro differential pressure sensor 33 sends the detected differential pressure data to the control module with a microcontroller to obtain the airflow detection data of the air passage pipe 2. The control module can control the working intensity of the fan or pump according to the airflow detection data, and further adjust the airflow based on the airflow regulated by the flow regulating pipe 4. Based on the above, the flow regulating pipe 4 has already limited the airflow through the pipe diameter. This adjustment greatly reduces the range and difficulty of the airflow adjustment, and is more about fine-tuning, that is, reducing the difficulty and complexity of adjusting the airflow of a single fan or pump.

[0033] Ideally, the inner diameter of each pipe section increases gradually from the airflow inlet to the outlet.

[0034] Preferably, the gas pipeline 2 has a narrowing section 211 between the connection point of the first micro-differential pressure sampling tube 31 and the connection point of the second micro-differential pressure sampling tube 32 and the gas pipeline 2. The flow regulating pipe 4 is connected to the gas pipeline 2 outside the connection point between the first micro-differential pressure sampling tube 31 and the gas pipeline 2 and the connection point of the second micro-differential pressure sampling tube 32 and the gas pipeline 2. Optionally, the flow regulating pipe 4 is connected to the inlet of the inlet pipe 21 or the outlet of the outlet pipe 22. For example, a detachable sleeve connection can be used. This connection method uses a sleeve structure and is usually equipped with a sealing ring to ensure airtightness. It has the advantages of easy installation and disassembly, and facilitates pipeline maintenance and modification. A screw connection can also be used, or a seamless connection can be selected. Seamless connection technology such as welding can make the connection parts of the pipeline smoother, reduce gas flow resistance and leakage risk, and is suitable for application scenarios with high requirements for airtightness and flow stability.

[0035] Here, the flow rate output from the gas path duct 2 can be limited by the flow regulating pipe 4. Flow regulating pipes 4 with different diameters adjust the airflow sequentially, ensuring the airflow reaches a more ideal state when entering subsequent gas paths. Combined with the micro-differential pressure detection component 3 for flow rate detection, this further enhances the gas path system's ability to regulate flow and the accuracy of detection. The gas path duct 2 has a narrowing section 211 between the connection point of the first micro-differential pressure sampling pipe 31 and the connection point of the second micro-differential pressure sampling pipe 32. When the airflow passes through the narrowing section 211, the flow velocity increases, generating a significant pressure difference at both ends of the narrowing section. In terms of performance, this pressure difference is used by the micro-differential pressure detection component 3 to output a pressure difference, enabling the particle counter's control module to more accurately measure the gas flow rate in the gas path duct based on the pressure difference.

[0036] In practical applications, the narrowing section 211 is suitable for fields with high requirements for flow gas detection accuracy, such as trace pollutant detection in environmental monitoring and respiratory gas analysis in biomedicine, and can meet the high-precision detection needs of these fields.

[0037] Preferably, the flow regulating pipe 4 is located within the gas path pipe 2 and between the connection points of the first micro-differential pressure sampling pipe 31 and the gas path pipe 2, and the second micro-differential pressure sampling pipe 32 and the gas path pipe 2. Here, the flow regulating pipe 4 is used both for more precise adjustment of the airflow rate and to create a pressure difference in the gas path pipe 2 at the connection points of the first micro-differential pressure sampling pipe 31 and the second micro-differential pressure sampling pipe 32, so that the micro-differential pressure sensor 33 can acquire the pressure difference data and the particle counter control module can calculate the flow rate data based on the pressure difference data.

[0038] Preferably, a limiting ring 221 is provided on the inner wall of the gas pipeline 2. The limiting ring 221 is located before the air inlet or after the air outlet of the flow regulating pipe 4. Setting the limiting ring 221 before the air inlet of the flow regulating pipe 4 can reduce the direct impact of airflow on the flow regulating pipe 4. Setting the limiting ring 221 after the air outlet can resist the impact of airflow. Both can further mitigate the sudden change in airflow caused by the change in the inner diameter before and after the limiting ring 221. Preferably, the flow regulating pipe 4 abuts against the limiting ring 221, and the limiting ring 221 is fixedly set on the inner wall of the gas pipeline 2.

[0039] Optionally, the diameter of the limiting ring 221 is larger than the maximum inner diameter of the regulating pipe 4, or the diameter of the limiting ring 221 is larger than the inner diameter of the regulating pipe 4 near the limiting ring 221. When the particle counter is working, airflow exists within the gas path pipe 2, and this airflow exerts a certain force on the regulating pipe 4. The limiting ring 221 can effectively prevent the regulating pipe 4 from shifting under the influence of the airflow. Because the diameter of the limiting ring 221 is larger than the maximum inner diameter of the regulating pipe 4 or larger than the inner diameter of the regulating pipe 4 near the limiting ring 221, it ensures that the diameter of the limiting ring 221 is larger than the inner diameter of the regulating pipe 4 near the limiting ring 221, thus ensuring that the regulating pipe 4 is always in the optimal position for effectively regulating the airflow.

[0040] For a better option, see the appendix. Figures 1-3 As shown, the flow control pipe 4 includes a first flow control pipe 41, a second flow control pipe 42, and a third flow control pipe 43, arranged along the airflow direction with increasing diameters. These three pipes are sequentially connected, and this multi-segment design further refines the control of the airflow. Different pipe segments allow for gradual adjustment of the airflow, achieving more precise flow velocity and pressure control. The multi-segment flow control pipe can adapt to more complex airflow conditions and is more adaptable to different flow ranges and gas properties. Furthermore, by rationally designing the diameter and length of each flow control segment, optimal airflow control can be achieved, improving the efficiency and performance of the gas path system.

[0041] Example 1:

[0042] See appendix Figure 1 and attached Figure 2As shown, an inlet pipe 21 and an outlet pipe 22 are connected to the sensor housing 1, ensuring a good seal at the connection to prevent external gas from interfering with the airflow inside the gas path. The outlet of the inlet pipe 21 is accurately aligned with the inlet of the outlet pipe 22, and the outlet of the inlet pipe 21 is smaller than the inlet of the outlet pipe 22. Next, a first micro-differential pressure sampling tube 31 is connected to the inlet pipe 21, and a second micro-differential pressure sampling tube 32 is connected to the outlet pipe 22, with their other ends connected to the micro-differential pressure sensor 33. At this time, a flow regulating tube 4 is connected to the outlet of the outlet pipe 22 or the inlet of the inlet pipe. The inner diameter of the flow regulating tube 4 gradually increases from the airflow inlet to the outlet. Simultaneously, it is checked whether the narrowing section 211 of the gas path 2 between the connection point of the first micro-differential pressure sampling tube 31 and the connection point of the second micro-differential pressure sampling tube 32 and the gas path 2 meets the design requirements. In addition, a limiting ring 221 is installed inside the gas pipeline 2 to ensure that it can effectively mitigate the impact of airflow.

[0043] In actual operation, the airflow enters through the inlet pipe 21. As it passes through the narrowing section 211, the airflow velocity and pressure change, and the resulting micro-pressure difference is collected by the first micro-pressure difference sampling pipe 31 and the second micro-pressure difference sampling pipe 32. This data is then transmitted to the micro-pressure difference sensor 33 and the particle counter control module for flow detection. The flow regulating pipe 4 further adjusts the outflow of airflow to maintain it within the target range. The entire process requires no complex control algorithms or expensive control modules, achieving effective flow regulation.

[0044] Example 2:

[0045] See appendix Figure 3 As shown, the sensor housing 1 and the gas path pipe 2 are installed first. This time, the first micro-differential pressure sampling tube 31 and the second micro-differential pressure sampling tube 32 are connected to the outlet pipe 22 simultaneously. Then, the flow regulating tube 4 is fitted inside the gas path pipe 2, positioned between the connection point of the first micro-differential pressure sampling tube 31 and the gas path pipe 2, and the connection point of the second micro-differential pressure sampling tube 32 and the gas path pipe 2. Here, the flow regulating tube 4 serves both as a narrowing section for the first and second micro-differential pressure sampling tubes 31 and 32 to collect micro-differential pressure data in the gas path, and as a flow regulating tube, it also regulates the flow rate, thereby achieving precise control of the particle counter's gas path flow rate while reducing system cost and complexity.

[0046] As can be seen from the above embodiments, the particle counter gas path structure of this application can effectively simplify, reduce costs, and increase precision in flow control in practical applications, and has significant practical value and market prospects.

[0047] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gas path structure for a particle counter, comprising a sensor housing, a gas path pipe communicating with an inner cavity of the sensor housing, and a flow regulating pipe and a micro-differential pressure detection component communicating with the gas path pipe, characterized in that: The air passage includes an air inlet pipe and an air outlet pipe that are respectively connected to the sensor housing, and the air outlet of the air inlet pipe is smaller than the air inlet of the air outlet pipe. The flow regulating pipe consists of at least two pipe sections connected in the direction of airflow, and the smallest inner diameter of each pipe section is smaller than the smallest inner diameter of the gas pipeline. The micro differential pressure detection component includes a first micro differential pressure sampling tube, a second micro differential pressure sampling tube, and a micro differential pressure sensor. The first micro differential pressure sampling tube and the second micro differential pressure sampling tube are connected in communication with the walls of the air inlet pipe and / or the air outlet pipe, and the first micro differential pressure sampling tube and the second micro differential pressure sampling tube are respectively connected to the micro differential pressure sensor.

2. The gas path structure of a particle counter according to claim 1, characterized in that, The inner diameter of each pipe section increases progressively from the airflow inlet to the outlet.

3. The gas path structure of a particle counter according to claim 1, characterized in that, The gas pipeline has a narrowing section between the connection point of the first differential pressure sampling tube and the gas pipeline, and between the connection point of the second differential pressure sampling tube and the gas pipeline; The flow control tube is connected to the gas pipeline outside the connection point between the first differential pressure sampling tube and the gas pipeline and the connection point between the second differential pressure sampling tube and the gas pipeline.

4. The gas path structure of a particle counter according to claim 1, characterized in that, The flow control tube is located inside the gas pipeline and between the connection point of the first differential pressure sampling tube and the gas pipeline, and the connection point of the second differential pressure sampling tube and the gas pipeline.

5. The gas path structure of a particle counter according to claim 3, characterized in that, The flow control pipe is connected to the air inlet of the air inlet pipe or the air outlet of the air outlet pipe.

6. The gas path structure of a particle counter according to any one of claims 1-5, characterized in that, The inner wall of the gas pipeline is provided with a limiting ring, which is located before the air inlet or after the air outlet of the flow regulating pipe.

7. The gas path structure of a particle counter according to claim 6, characterized in that, The diameter of the limiting ring is larger than the maximum inner diameter of the flow regulating pipe.

8. The gas path structure of a particle counter according to claim 6, characterized in that, The diameter of the limiting ring is larger than the inner diameter of the flow regulating pipe near the limiting ring.

9. The gas path structure of a particle counter according to claim 2, characterized in that, The flow regulating pipe includes a first flow regulating pipe, a second flow regulating pipe, and a third flow regulating pipe arranged along the airflow direction with increasing diameters, and the first flow regulating pipe, the second flow regulating pipe, and the third flow regulating pipe are connected in sequence.

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