A dust particle counter

Abstract

The utility model discloses a dust particle counter belongs to dust -free room environmental monitoring equipment technical field, including the shell, the inside of shell is installed with dust particle collection mechanism, piezoelectric type heat abstractor, particle counting mechanism and air pump respectively, piezoelectric type heat abstractor installs at the other side of shell, dust particle collection mechanism is through the connecting pipe with particle counting mechanism and piezoelectric type heat abstractor intercommunication, piezoelectric type heat abstractor includes the exhaust valve with dust particle collection mechanism intercommunication and installs the control panel at the one side of exhaust valve, install piezoelectric radiator that makes the vibration flake of wind source of making vibration flake produce the dither of electromotive force on the control panel, the utility model discloses through electromotive force makes the vibration flake produce the dither and utilizes the vibration flake of dither and produces the wind source, utilizes piezoelectric type heat abstractor and does not have mechanical friction, fundamentally avoided the generation of the self micro -contamination source of this counter when dust particle detection.

Description

Technical Field

[0001] This utility model relates to the technical field of cleanroom environmental monitoring equipment, specifically a dust particle counter. Background Technology

[0002] According to ISO 14644-1, cleanrooms are classified into cleanliness levels based on the number of particles of different sizes per unit volume. For example, ISO Class 5 requires a maximum particle concentration of 3520 particles / m³ for particles ≥0.5μm. 3 For particles ≥0.3μm, the maximum particle concentration is 10200 particles / m³. 3 For particles ≥0.2μm, the maximum particle concentration is 23,700 particles / m³. 3 The dust particle counter provides data support for cleanliness classification by monitoring particle concentration in real time and verifies whether the environment meets the requirements. Currently, dust particle counters in cleanrooms typically use cooling fans and heat sinks to dissipate heat from the chip circuit board. When the fan is working, it relies on a motor to drive the fan blades to rotate. During long-term operation, the carbon brushes, lubricating oil, and other components inside the motor will generate particles such as carbon powder and metal shavings due to friction. These particles may enter the sampling area of ​​the dust particle counter with the airflow, interfering with the measurement results. Therefore, the cooling fan itself can become a source of pollution, thus affecting the production environment of the cleanroom. Utility Model Content

[0003] The purpose of this invention is to provide a dust particle counter that utilizes a piezoelectric heat dissipation mechanism to avoid generating pollution sources during the heat dissipation process, thereby reducing the impact on the cleanroom production environment and solving the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a dust particle counter, comprising a housing, wherein a dust microparticle collecting mechanism, a piezoelectric heat dissipation mechanism, a particle counting mechanism, and an air pump are respectively installed inside the housing. The dust microparticle collecting mechanism is installed on one side of the housing, and the air pump is connected to the dust microparticle collecting mechanism. The piezoelectric heat dissipation mechanism is installed on the other side of the housing. The dust microparticle collecting mechanism is connected to the particle counting mechanism and the piezoelectric heat dissipation mechanism through a connecting pipe. The side wall of the housing is provided with heat dissipation holes. The piezoelectric heat dissipation mechanism includes an exhaust valve connected to a dust microparticle collection mechanism and a control board installed on one side of the exhaust valve. The control board is equipped with a piezoelectric heat sink that generates airflow by causing a vibrating plate to vibrate through electromotive force. One end of the exhaust valve is connected to an exhaust pipe.

[0005] Preferably, the outer shell includes a bottom shell and a cover shell, the dust microparticle collection mechanism and the piezoelectric heat dissipation mechanism are respectively fixed on the inner walls of both sides of the bottom shell, and the cover shell is detachably installed on the upper end of the bottom shell.

[0006] Preferably, the dust microparticle collection mechanism includes a collection cylinder fixed to one side of the bottom shell, one end of the collection cylinder is connected to the outside of the bottom shell, and the other end of the collection cylinder is connected to an air pump through a connecting pipe.

[0007] Preferably, the air inlet of the particle counting mechanism is connected to the air outlet of the air pump via a connecting pipe, and the air outlet of the particle counting mechanism is connected to the exhaust valve.

[0008] Preferably, the heat dissipation holes are arranged in a rectangular array on adjacent sides of the bottom shell, and a cooling plate is provided at the heat dissipation hole on one side of the bottom shell.

[0009] Preferably, the exhaust valve is fitted with a protective cover with one open side, the cooling chip is fixed to the outer wall of one side of the protective cover, and the control board is fixed to one side of the exhaust valve by bolts, with the control board located at the open part of the protective cover.

[0010] Preferably, the piezoelectric heat sink includes a piezoelectric structure made of a bridge-shaped vibrating sheet and heat dissipation fins. The piezoelectric structure is integrated inside the heat dissipation fins or closely attached to the surface of the heat dissipation fins. By adjusting the electromotive force at both ends of the piezoelectric structure, the middle part of the vibrating sheet is deformed, causing the vibrating sheet to vibrate. The vibrating sheet generates an air source to dissipate heat from the heat dissipation fins.

[0011] Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model, through the cooperation of a piezoelectric heat dissipation mechanism, a dust microparticle collection mechanism and a particle counting mechanism, uses electromotive force to cause the vibrating plate to shake and uses the shaking vibrating plate to generate an air source. The piezoelectric heat dissipation eliminates mechanical friction, fundamentally avoiding the generation of micro-contamination sources by the counter itself when detecting dust particles, and avoiding the problem of external pollutants being drawn in that may be caused by the open design of traditional fans, thus ensuring the stability of the cleanroom environment.

[0012] 2. This utility model, through the cooperation of a dust microparticle collection mechanism and an air pump, can introduce air from inside the cleanroom into the particle counting mechanism, enabling accurate detection of the cleanroom environment and ensuring the quality of cleanroom product production. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the heat dissipation hole side structure of this utility model; Figure 3This is a schematic diagram of the internal structure of the outer shell of this utility model; Figure 4 This is a side view of the outer shell structure of this utility model; Figure 5 This is a schematic diagram of the piezoelectric heat dissipation mechanism of this utility model; Figure 6 This is an exploded structural diagram of the piezoelectric heat dissipation mechanism of this utility model.

[0014] In the diagram: 1. Outer shell; 11. Bottom shell; 12. Cover; 2. Collection cylinder; 3. Exhaust pipe; 4. Heat dissipation hole; 5. Piezoelectric heat dissipation mechanism; 51. Cooling chip; 52. Protective cover; 53. Control board; 54. Piezoelectric radiator; 55. Exhaust valve; 6. Air pump; 7. Particle counting mechanism; 8. Connecting pipe. Detailed Implementation

[0015] 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.

[0016] Please see Figure 1-6 This utility model provides a technical solution: a dust particle counter, including a housing 1. Inside the housing 1, a dust microparticle collection mechanism, a piezoelectric heat dissipation mechanism 5, a particle counting mechanism 7, and an air pump 6 are respectively installed. The dust microparticle collection mechanism is installed on one side of the housing 1, and the air pump 6 is connected to the dust microparticle collection mechanism. The piezoelectric heat dissipation mechanism 5 is installed on the other side of the housing 1. The dust microparticle collection mechanism is connected to the particle counting mechanism 7 and the piezoelectric heat dissipation mechanism 5 through a connecting pipe 8. The side wall of the housing 1 is provided with heat dissipation holes 4. Through the cooperation of the dust microparticle collection mechanism and the air pump 6, air inside the cleanroom can be introduced into the particle counting mechanism 7, which can accurately detect the cleanroom environment and ensure the quality of cleanroom product production. The piezoelectric heat dissipation mechanism 5 includes an exhaust valve 55 connected to a dust particle collection mechanism and a control board 53 installed on one side of the exhaust valve 55. The control board 53 is equipped with a piezoelectric heat sink 54 that generates airflow by causing a vibrating plate to vibrate through electromotive force. One end of the exhaust valve 55 is connected to an exhaust pipe 3. The vibrating plate is generated by causing a vibrating plate to vibrate through electromotive force, and the vibrating plate generates airflow. The piezoelectric heat dissipation eliminates mechanical friction, fundamentally avoiding the generation of particulate pollution sources and avoiding the problem of external pollutant intake that may be caused by the open design of traditional fans, thus ensuring the stability of the cleanroom environment.

[0017] The piezoelectric radiator 54 includes a piezoelectric structure made of a bridge-shaped vibrating sheet and heat dissipation fins. The piezoelectric structure is integrated inside the heat dissipation fins or closely attached to the surface of the heat dissipation fins. By adjusting the electromotive force at both ends of the piezoelectric structure, the middle part of the vibrating sheet is deformed, causing the vibrating sheet to vibrate. The vibrating sheet generates a wind source to dissipate heat from the heat dissipation fins.

[0018] The piezoelectric heat sink 54 also includes a MEMS microelectromechanical system that works in conjunction with the vibrating sheet. It utilizes the inverse piezoelectric effect of the piezoelectric material and the precision drive of the MEMS to realize the conversion between mechanical vibration and electrical signal. Specifically, when an AC voltage is applied to the piezoelectric sheet, the internal lattice structure of the piezoelectric material, such as piezoelectric ceramic or aluminum nitride, is deformed, causing the vibrating sheet to generate mechanical vibration. Conversely, if mechanical stress is applied to the vibrating sheet, an electric charge will be generated. The vibration state is fed back in real time, and the frequency and amplitude of the driving voltage are adjusted to achieve closed-loop control. MEMS (Micro-Electro-Mechanical Systems) integrates mechanics and electrical systems through micron-level structures. Its driving mechanism directly utilizes the inverse piezoelectric effect of a vibrating sheet without the need for additional structural conversion. It has the advantages of high energy density, low power consumption, and fast response. The displacement, frequency, and other parameters of the vibrating sheet are monitored in real time through MEMS accelerometers or pressure sensors, and the signals are then fed back to the driving components to achieve dynamic adjustment. The outer casing 1 includes a bottom shell 11 and a cover 12. The dust microparticle collection mechanism and the piezoelectric heat dissipation mechanism 5 are respectively fixed on the inner walls of both sides of the bottom shell 11. The cover 12 is detachably installed on the upper end of the bottom shell 11. The cover 12 and the bottom shell 11 are connected by bolts, which facilitates the disassembly of the cover 12 for maintenance of the electrical components inside the outer casing 1.

[0019] The dust microparticle collection mechanism includes a collection cylinder 2 fixed to one side of the bottom shell 11. One end of the collection cylinder 2 is connected to the outside of the bottom shell 11, and the other end of the collection cylinder 2 is connected to the air pump 6 through the connecting pipe 8. The air pump 6 draws airflow from the external environment and introduces the airflow into the particle counting mechanism 7 through the collection cylinder 2 so that the particle counting mechanism 7 can accurately measure the concentration of particles in the airflow.

[0020] The air inlet of the particle counting mechanism 7 is connected to the air outlet of the air pump 6 through the connecting pipe 8. The air outlet of the particle counting mechanism 7 is connected to the exhaust valve 55. The airflow passing through the particle counting mechanism 7 can be discharged through the exhaust valve 55, so that the airflow can pass smoothly through the particle counting mechanism 7.

[0021] The heat dissipation holes 4 are arranged in a rectangular array on the adjacent sides of the bottom shell 11. The cooling chip 51 is located at the heat dissipation hole 4 on one side of the bottom shell 11. The heat dissipation holes 4 facilitate the dissipation of heat generated inside the outer shell 1. The cooling chip 51 is used to dissipate heat generated inside the protective cover 52.

[0022] The exhaust valve 55 is fitted with a protective cover 52 with one side open. The cooling chip 51 is fixed to the outer wall of one side of the protective cover 52. The control plate 53 is fixed to one side of the exhaust valve 55 by bolts, and the control plate 53 is located at the opening of the protective cover 52, providing support for the exhaust valve 55 through the protective cover 52. The particle counting mechanism includes a housing and a dust particle counting sensor located inside the housing. The dust particle counter sensor uses laser scattering (the blocking and scattering effect of particles on laser light) and photoelectric signal conversion (converting light signals into countable electrical signals) to identify and count particles in the airflow. Dust particle counting sensors, such as the LM-2.83LPM series dust particle counter sensor, are examples. This invention applies a piezoelectric heat dissipation mechanism to a dust particle counter for detecting dust particle concentration in cleanrooms. To verify its effectiveness in detecting dust particles in cleanrooms, the following verification is provided: Test 1: Standard Cleanroom Self-Cleaning Test Measurement environment: Standard cleanroom Test Method: The standard instrument used was a METONE-3411 (calibrated by the National Institute of Metrology). Each sampling time was 1 minute, and the air flow rate was 28.3L. The number of particles measured by the METONE-3411 was compared. Since particles can have different sizes, the number of particles with 6 different sizes was compared. The test results are shown in Table 1 below (the unit of particle count is particles / 28.3L): Table 1

[0023] The data in Table 1 shows that a standard cleanroom can reach Class 1 of the ISO 14644-1 international standard after the 15th sampling (15 minutes after normal purification).

[0024] Test 2: Dust Particle Generation Test Measurement environment: Standard cleanroom Test Method: The standard instrument used was a METONE-3411 (calibrated by the National Institute of Metrology). Each sampling time was 1 minute, and the air flow rate was 28.3L. Dust generation was detected in a cleanroom under the same conditions using a dust particle counter (comparative example in Table 2) with a cooling fan and heat sink fins to dissipate heat from the control board, and a dust particle counter (example in Table 2) with a piezoelectric cooling mechanism to dissipate heat from the control board. Since particles can have different sizes, the number of particles with six different sizes was compared. The test results are shown in Table 2 below (the unit for particle count is particles / 28.3L): Note: All data in Table 2 were obtained after normal laboratory sealing and purification for 20 minutes before the start of the metrological tests.

[0025] Table 2

[0026] The data in Table 2 shows that the dust particle counter that uses a cooling fan and heat sink fins to cool the control board will produce dust particles with a diameter of 0.1μm-0.3μm, while the dust particle counter that uses a piezoelectric cooling mechanism to cool the control board will produce virtually no dust. Test 3: Heat dissipation performance test Test environment: Standard temperature-controlled cleanroom, room temperature 25 degrees Celsius Test method: The machine operates normally without any downtime for 10 hours, and the operating temperature is measured at the 30th, 60th, 120th, 300th, and 600th minutes. Measurement locations: temperature of the instrument's internal cavity, temperature of the laser particle sensor's heat sink; Test Groups: Comparative Example: Dust particle counter using a cooling fan and heat sink fins to dissipate heat from the control board; Example: Dust particle counter using a piezoelectric cooling mechanism to dissipate heat from the control board; The test results are shown in Table 3 below: Table 3:

[0027] The data in Table 3 shows that using a piezoelectric heat sink to dissipate heat from the control board containing dust particles will not generate pollution sources and can basically achieve the same effect as using a cooling fan in conjunction with heat sink fins to dissipate heat from the chip circuit board.

[0028] Note: Although the operating temperature of the prototype is higher than that of the normal fan prototype, it still meets the requirements for normal operation. In the future, the operating temperature of the instrument can be reduced by increasing the number of piezoelectric fans or increasing the air volume of the piezoelectric fans.

[0029] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dust particle counter, characterized in that: The device includes an outer shell (1), inside which a dust microparticle collection mechanism, a piezoelectric heat dissipation mechanism (5), a particle counting mechanism (7), and an air pump (6) are respectively installed. The dust microparticle collection mechanism is installed on one side of the outer shell (1), and the air pump (6) is connected to the dust microparticle collection mechanism. The piezoelectric heat dissipation mechanism (5) is installed on the other side of the outer shell (1). The dust microparticle collection mechanism is connected to the particle counting mechanism (7) and the piezoelectric heat dissipation mechanism (5) through a connecting pipe (8). The side wall of the outer shell (1) is provided with heat dissipation holes (4). The piezoelectric heat dissipation mechanism (5) includes an exhaust valve (55) connected to a dust microparticle collection mechanism, and a control plate (53) installed on one side of the exhaust valve (55). The control plate (53) is equipped with a piezoelectric heat sink (54) that generates a vibrating plate by electromotive force and generates an air source by the vibrating plate. One end of the exhaust valve (55) is connected to an exhaust pipe (3).

2. A dust particle counter according to claim 1, characterized in that: The outer shell (1) includes a bottom shell (11) and a cover (12). The dust microparticle collection mechanism and the piezoelectric heat dissipation mechanism (5) are respectively fixed on the inner walls of both sides of the bottom shell (11). The cover (12) is detachably installed on the upper end of the bottom shell (11).

3. A dust particle counter according to claim 2, characterized in that: The dust particle collection mechanism includes a collection cylinder (2) fixed on one side of the bottom shell (11). One end of the collection cylinder (2) is connected to the outside of the bottom shell (11), and the other end of the collection cylinder (2) is connected to the air pump (6) through the connecting pipe (8).

4. A dust particle counter according to claim 3, characterized in that: The air inlet of the particle counting mechanism (7) is connected to the air outlet of the air pump (6) through the connecting pipe (8), and the air outlet of the particle counting mechanism (7) is connected to the exhaust valve (55).

5. A dust particle counter according to claim 4, characterized in that: The heat dissipation holes (4) are arranged in a rectangular array on the adjacent sides of the bottom shell (11), and a cooling plate (51) is provided at the heat dissipation hole (4) on one side of the bottom shell (11).

6. A dust particle counter according to claim 5, characterized in that: The exhaust valve (55) is fitted with a protective cover (52) with one side open. The cooling chip (51) is fixed to the outer wall of one side of the protective cover (52). The control plate (53) is fixed to one side of the exhaust valve (55) by bolts, and the control plate (53) is located at the opening of the protective cover (52).

7. A dust particle counter according to claim 6, characterized in that: The piezoelectric radiator (54) includes a piezoelectric structure made of a bridge-shaped vibrating sheet and heat dissipation fins. The piezoelectric structure is integrated inside the heat dissipation fins or closely attached to the surface of the heat dissipation fins. By adjusting the electromotive force at both ends of the piezoelectric structure, the middle part of the vibrating sheet is deformed, causing the vibrating sheet to vibrate. The vibrating sheet generates a wind source to dissipate heat from the heat dissipation fins.

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