Dust particle counter with compact structure

Abstract

The dust particle counter with the compact structure comprises a shell, a sampling head and an exhaust port are installed on the shell, the sampling head is connected to a particle counting module through a three-way lossless switching valve, and the downstream of the particle counting module is sequentially connected with an exhaust filter, an orifice flowmeter and a fan through pipelines. An air outlet of the fan is connected to the exhaust port, and a third connector of the three-way lossless switching valve is connected with a self-cleaning high-efficiency filter; and the main control board is electrically connected with the three-way lossless switching valve, the particle counting module and the fan. The device is compact in structure, can realize automatic switching between a sampling mode and a self-cleaning mode, and is convenient to operate.

Description

Technical Field

[0001] The utility model belongs to the field of air quality monitoring equipment, and in particular relates to a dust particle counter with a compact structure. Background Art

[0002] The dust particle counter is an instrument for measuring the particle size and distribution of particles in the ambient air. Its measurement principle is based on the Mie scattering theory. When a single particle enters the photosensitive area with the airflow and is irradiated by the light beam, it generates scattered light. The intensity of the scattered light is related to the particle size. By collecting the scattered light and converting it into an electrical signal through a photodetector, the particle size can be measured and counted. It is widely used in clean room grade determination, pharmaceuticals, microelectronics, precision machinery and other fields.

[0003] The working states of the dust particle counter are divided into self-cleaning and sampling. The self-cleaning requirement of "JJF 1190 Dust Particle Counter Calibration Specification" is to connect the sampling port of the particle counter to an ultra-high efficiency filter (or the self-cleaning port provided by the instrument) to put the particle counter in a self-cleaning state.

[0004] At present, the dust particle counters on the market generally use air pumps as the power source, and the high-efficiency filter needs to be manually connected during self-cleaning. On the one hand, the pulsating characteristics of the air pump will cause the sampling flow to fluctuate, and it needs to be used with an air container to obtain a stable sampling flow, which makes the volume of the whole machine not compact enough, affecting the portability of the product; on the other hand, it will produce obvious vibrations during operation, affecting the measurement accuracy of the particle counting sensor. At the same time, manually connecting the high-efficiency filter for self-cleaning is cumbersome, and a high-efficiency filter needs to be prepared with the host, and manual operation is prone to increase the uncertainty of the results. Summary of the invention

[0005] In view of the technical problems that the existing dust particle counters are not compact in size and the manual connection with a high-efficiency filter for self-cleaning operation is cumbersome, the utility model proposes a dust particle counter which uses a fan as a power source and realizes lossless switching between a sampling state and a self-cleaning state through a three-way lossless switching valve.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A dust particle counter with a compact structure comprises a shell, a sampling head and an exhaust port are installed on the shell, the sampling head is connected to a particle counting module via a three-way lossless switching valve, the downstream of the particle counting module is connected to an exhaust filter, an orifice flow meter and a fan in sequence via a pipeline, the air outlet of the fan is connected to the exhaust port, and the third joint of the three-way lossless switching valve is connected to a self-cleaning high-efficiency filter;

[0008] It also includes a main control board, which is electrically connected to the three-way lossless switching valve, the particle counting module, and the fan.

[0009] Preferably, a touch screen is installed on the housing.

[0010] Preferably, a printer is installed on the housing.

[0011] Preferably, the shell is provided with heat dissipation holes, and a heat dissipation fan for internal cooling is installed in the shell.

[0012] Preferably, a handle is installed on the shell.

[0013] Preferably, the three-way lossless switching valve includes a valve body, a connecting assembly and a driving assembly, a ball core is installed in the valve body, the connecting assembly includes a mounting plate, a connecting bracket is connected to the mounting plate, the driving assembly includes a driving motor and a communication control board, the valve body is installed on the fixing plate, the driving motor and the communication control board are installed on the connecting bracket, the output shaft of the driving motor is connected to the driving shaft, the driving shaft is connected to the ball core and drives the ball core to rotate; a shading sheet is installed on the driving shaft, and a photoelectric sensor cooperating with the shading sheet is provided on the connecting bracket.

[0014] Preferably, the length direction of the drive motor is parallel to the length direction of the valve body.

[0015] Preferably, the drive shaft is connected to the ball core from the T-shaped intersection of the valve body.

[0016] Compared with the prior art, the advantages and positive effects of the utility model are:

[0017] The dust particle counter of the utility model adopts a fan as a power source to replace an air pump, does not require an air container, improves the stability of the flow rate and the compactness of the device structure, and increases the portability of the device.

[0018] By setting up a three-way lossless switching valve, the sampling nozzle and the self-cleaning high-efficiency filter can be connected in parallel, and the sampling mode and the self-cleaning mode can be automatically switched according to the operation needs through the control system to improve the sampling efficiency. The three-way lossless switching valve can ensure that the aerosol passing through the pipeline does not produce interception loss, improve the accuracy of the photometer concentration detection value, and keep the internal gas path clean, eliminate mutual interference between upstream and downstream, and improve the accuracy of detection.

[0019] The self-cleaning high-efficiency filter is built into the main unit, so there is no need to carry an additional self-cleaning high-efficiency filter, which increases the overall portability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an isometric view of the dust particle counter of the utility model;

[0021] Figure 2 Another isometric view of the dust particle counter of the utility model;

[0022] Figure 3 This is a schematic diagram of the internal structure of the dust particle counter of the utility model;

[0023] Figure 4 This is a gas path connection principle diagram of the dust particle counter of the utility model;

[0024] Figure 5 This is a schematic diagram of the structure of the three-way lossless switching valve of the dust particle counter of the utility model;

[0025] Figure 6 It is a cross-sectional view of the three-way lossless switching valve of the dust particle counter of the utility model;

[0026] In the above figures: 1. Shell; 2. Back panel; 3. Exhaust port; 4. Handle; 5. Sampling head; 6. Cooling fan; 7. Printer; 8. Touch screen; 9. Three-way lossless switching valve; 91. Valve body; 92. Ball core; 93. Mounting plate; 94. Connecting bracket; 95. Drive motor; 96. Communication control board; 97. Shading sheet; 98. Photoelectric sensor; 99. Drive shaft; 10. Particle counting module; 11. Fan; 12. Orifice flowmeter; 13. Main control board; 14. Self-cleaning high-efficiency filter; 15. Exhaust high-efficiency filter. DETAILED DESCRIPTION

[0027] In order to better understand the present invention, a detailed description is given below in conjunction with the accompanying drawings and embodiments.

[0028] Example: Figure 1-Figure 4 As shown, a dust particle counter with a compact structure includes a housing 1. A handle 4 and a sampling head 5 connecting the inside and outside of the housing 1 are installed on the top wall of the housing 1, and an exhaust port 3 is arranged on the back plate 2 of the housing 1. A three-way lossless switching valve 9, a particle counting module 10, an exhaust high-efficiency filter 15, an orifice flowmeter 12, a fan 11, and a self-cleaning high-efficiency filter 14 are installed in the housing 1. The sampling head 5 is connected to the particle counting module 10 via the three-way lossless switching valve 9, and the downstream of the particle counting module 10 is connected to the exhaust high-efficiency filter 15, the orifice flowmeter 12 and the fan 11 in sequence through the pipeline, and the air outlet of the fan 11 is connected to the exhaust port 3; the third joint of the three-way lossless switching valve 9 is connected to the self-cleaning high-efficiency filter 14.

[0029] like Figure 5 , Figure 6As shown, the three-way lossless switching valve includes a valve body 91, a connecting assembly and a driving assembly. A ball core 92 is installed in the valve body 91, and the connecting assembly includes a mounting plate 93 located on the side of the valve body 91, and a connecting bracket 94 is connected to the mounting plate 93. The driving assembly includes a driving motor 95 and a communication control board 96, and the driving motor 95 and the communication control board 96 are installed on the connecting bracket 94, and the length direction of the driving motor 95 is parallel to the length direction of the valve body 91. The output shaft of the driving motor 95 is connected to the driving shaft 99. The driving shaft is connected to the ball core 92 at the T-shaped intersection of the valve body 91 and drives the ball core 92 to rotate. A light shielding sheet 97 is installed on the driving shaft 99, and a photoelectric sensor 98 cooperating with the light shielding sheet 97 is provided on the connecting bracket 94, and the photoelectric sensor 98 is electrically connected to the communication control board 96.

[0030] A main control board 13 is also installed in the housing 1, and the main control board 13 is electrically connected to the three-way lossless switching valve 9, the particle counting module 10 and the fan 11. A pressure sensor is integrated on the main control board 13, and the pressure sensor is connected to the pressure measuring hole of the orifice flowmeter 12 through an air path.

[0031] In order to facilitate input of control parameters and display of test conditions and test results, a touch screen 8 and a printer 7 are also installed on the housing 1. The touch screen 8 and the printer 7 are both electrically connected to the main control board 13, and the test results can be directly printed out through the printer 7.

[0032] To facilitate heat dissipation, heat dissipation holes are provided on the housing 1, and a heat dissipation fan 6 is installed inside the housing 1 to prevent internal overheating.

[0033] Working principle:

[0034] When the dust particle counter works in sampling mode, the fan 11 sucks the gas to be detected from the sampling port through the three-way lossless switching valve 9 into the particle counting module 10, and the particle counting module 10 detects the size and number of dust particles in the gas, and then transmits the signal to the main control board 13. At this time, the third connector of the three-way lossless switching valve 9 is not connected. After that, the gas to be detected enters the orifice flowmeter 12, and the main control board 13 obtains the gas flow rate according to the pressure value detected by the pressure sensor, and finally obtains the concentration of dust particles in the gas, which is displayed on the touch screen 8 and can be printed out by the printer 7. The gas finally passes through the exhaust high-efficiency filter 15, and the exhaust high-efficiency filter 15 filters the harmful substances that may exist in the gas and discharges it through the exhaust port 3.

[0035] When the dust particle counter needs to work in the self-cleaning mode, the three-way lossless switching valve 9 cuts off the sampling nozzle channel and opens the self-cleaning high-efficiency filter 14 channel. The gas enters the particle counting module 10 and the downstream exhaust high-efficiency filter 15, orifice flowmeter 12 and fan 11 through the self-cleaning high-efficiency filter 14, and is finally discharged from the exhaust port 3.

[0036] The dust particle counter described in this embodiment uses a fan 11 as a power source to replace an air pump, and does not require an air volume, which improves the stability of the flow rate and the compactness of the device structure, and increases the portability of the device. By setting a three-way lossless switching valve 9, the sampling nozzle and the self-cleaning high-efficiency filter 14 are connected in parallel, and the sampling mode and the self-cleaning mode can be automatically switched according to the operation needs through the control system, thereby improving the sampling efficiency. The three-way lossless switching valve 9 can ensure that the aerosol passing through the pipeline does not produce interception losses, improve the numerical accuracy of the photometer concentration detection, and at the same time keep the internal air path clean, eliminate mutual interference between upstream and downstream, and improve the accuracy of detection. The three-way lossless switching valve 9 has a compact structure and occupies a small space. The self-cleaning high-efficiency filter 14 is built into the main unit, and there is no need to carry the self-cleaning high-efficiency filter 14 separately, which increases the overall portability of the device.

[0037] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A compact dust particle counter, characterized by: It comprises a shell, a sampling head and an exhaust port are installed on the shell, the sampling head is connected to a particle counting module via a three-way lossless switching valve, the downstream of the particle counting module is connected to an exhaust filter, an orifice flow meter and a fan in sequence via a pipeline, the air outlet of the fan is connected to the exhaust port, and the third joint of the three-way lossless switching valve is connected to a self-cleaning high-efficiency filter; It also includes a main control board, which is electrically connected to the three-way lossless switching valve, the particle counting module, and the fan.

2. The compact dust particle counter according to claim 1 is characterized in that: A touch screen is installed on the shell.

3. The compact dust particle counter according to claim 1 is characterized in that: A printer is installed on the shell.

4. The compact dust particle counter according to claim 1 is characterized in that: The shell is provided with heat dissipation holes, and a heat dissipation fan for cooling the interior is installed in the shell.

5. The compact dust particle counter according to claim 1 is characterized in that: A handle is installed on the shell.

6. The compact dust particle counter according to claim 1 is characterized in that: The three-way lossless switching valve includes a valve body, a connecting assembly and a driving assembly, a ball core is installed in the valve body, the connecting assembly includes a mounting plate, a connecting bracket is connected to the mounting plate, the driving assembly includes a driving motor and a communication control board, the valve body is installed on the fixing plate, the driving motor and the communication control board are installed on the connecting bracket, the output shaft of the driving motor is connected to the driving shaft, the driving shaft is connected to the ball core and drives the ball core to rotate; a shading sheet is installed on the driving shaft, and a photoelectric sensor cooperating with the shading sheet is provided on the connecting bracket.

7. The compact dust particle counter according to claim 6 is characterized in that: The length direction of the driving motor is parallel to the length direction of the valve body.

8. The compact dust particle counter according to claim 6, characterized in that: The drive shaft is connected to the ball core from the T-shaped intersection of the valve body.

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