Airflow controller with constant effective value output under low voltage

Abstract

The invention relates to the technical field of airflow controllers, in particular to an airflow controller with constant effective value output under low voltage, which comprises a base, a pipeline, a detection unit, a processing unit and a control valve, and is characterized in that the detection unit comprises a base body and two metal probes, and the two metal probes are both provided with filter assemblies; the filter assembly comprises a fixed plate, a rotating plate and a filter screen, the fixed plate is fixed on the upper side of the metal probe, the rotating plate is coaxially and rotatably mounted at the bottom of the metal probe, the filter screen is cylindrical and annularly surrounds the metal probe between the fixed plate and the rotating plate, and a driving assembly is arranged at the bottom of the rotating plate. By arranging the rotating plate, the annular filter screen and the driving assembly, airflow is dried before entering the filter screen and making contact with the metal probe, the airflow dries the filter screen when coming out of the filter screen, it is prevented that water vapor in the airflow influences the detection precision of the metal probe, and the detection precision of the metal probe is improved. And the reduction of the water vapor filtering effect of the filter screen after long-time use is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of airflow controllers, in particular to an airflow controller with a constant effective value output under low voltage. Background Art

[0002] A gas flow controller, also known as a mass flow controller (MFC), not only functions as a mass flow meter but, more importantly, automatically controls gas flow. The user can set the flow rate as needed, and the MFC automatically maintains the flow rate at the set value. This value persists even with fluctuations in system pressure or ambient temperature. Simply put, a mass flow controller is a flow stabilization device that can be set manually or automatically controlled by a computer.

[0003] Among them, the thermal mass flow controller is also a type of airflow controller, which is powered by 15V~24V DC. When in use, the thermal mass flow controller detects the airflow flowing through the airflow controller through two metal probes, usually platinum wire, tungsten wire or thin film resistor. Among them, the metal probe located in the front is used for heating, while the metal probe located in the rear is used for temperature measurement. A constant temperature difference ΔT is generated between the two metal probes. When the control valve is closed, the measured value is equivalent to the zero flow value, and the current signal is transmitted to the processing unit, which compares the required value with the measured value. The processing unit then adjusts the opening size of the control valve to ensure that the airflow is stably output according to the set value.

[0004] However, because the first metal probe in the aforementioned thermal airflow controller requires heating, when the airflow contains water vapor, the metal probe is rapidly cooled by the water vapor, resulting in a rapid change in ΔT. This, in turn, leads to large errors in the airflow controller's output control of airflow flow, making it impossible to accurately control the airflow output to the set value, significantly impacting production. Furthermore, because the metal probe itself is heated, the rapid cooling caused by the water vapor can easily lead to oxidation and corrosion of the metal probe, thereby shortening its service life.

[0005] Existing solutions typically involve adding a filter to the air inlet of the airflow controller. This filter absorbs moisture and filters dust from the airflow, preventing contact between moisture and dust and the metal probe, thereby ensuring the controller's control accuracy and extending the life of the metal probe. However, after prolonged use, the filter reaches saturation with moisture and requires prompt replacement, otherwise it loses its ability to filter moisture. This replacement requires stopping the airflow, disrupting continuous production.

[0006] To this end, a gas flow controller with constant effective value output under low voltage is provided to solve the problem that the filter screen cannot effectively protect the metal probe after long-time absorption of water vapor in the gas. SUMMARY

[0007] The purpose of the present application is to provide a gas flow controller with constant effective value output under low voltage, which solves the problem that the filter screen cannot effectively protect the metal probe after long-time absorption of water vapor in the gas, to ensure the regulation accuracy of the gas flow controller.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A gas flow controller with constant effective value output under low voltage comprises a base, a pipeline for circulating gas is formed on the base, a detection unit is arranged on the base, the detection unit comprises a base body and two metal probes, the two metal probes are arranged on the base body with a spacing therebetween, and both metal probes are inserted into the pipeline inside the base, the metal probe close to the air inlet of the pipeline is used for heating, and the other metal probe is used for temperature measurement, a processing unit is further arranged on the base, the processing unit is electrically connected with the detection unit, a control valve for regulating the opening and closing size of the pipeline is further arranged on the base, the control valve is electrically connected with the processing unit, a filter assembly is arranged on both metal probes, the filter assembly comprises a fixed plate, a rotating plate and a filter screen, the fixed plate and the rotating plate are both circular, the fixed plate is coaxially fixed on the upper side of the metal probe, the rotating plate is coaxially rotatably installed on the bottom of the metal probe, the filter screen is cylindrical, the filter screen is fixedly connected to the rotating plate at the bottom, and the filter screen encloses the metal probe between the fixed plate and the rotating plate in a ring shape, and a driving assembly is arranged at the bottom of the rotating plate.

[0009] The filter screen encloses the metal probe in a ring shape, the gas flow first contacts the filter screen after entering the pipeline of the gas flow controller, the filter screen filters and adsorbs the water vapor in the gas flow, and the dried gas flow contacts the metal probe after being dried by the filter screen, thereby avoiding the contact between the water vapor and the metal probe and ensuring the detection accuracy of the gas flow controller.

[0010] The driving assembly is used to drive the rotating plate and the filter screen to rotate, so that the filter screen can rotate after adsorbing water vapor in the airflow to allow another dry part to adsorb water vapor in the subsequent airflow, and the part adsorbing water vapor is rotated to the rear of the advancing direction of the airflow, so that the dry airflow can dry the filter screen when the dry airflow is discharged from the inside of the filter screen. The automatic rotation of the filter screen also enables the filter screen to uniformly dry the airflow, avoids the failure of the filtering effect caused by the local overuse of the filter screen, and prolongs the service life of the filter screen. In addition, since the filter screen can automatically rotate, the filter screen can be rotated in time to the rear of the advancing direction of the airflow after adsorbing water vapor in the airflow, so that the dry airflow can dry the filter screen, and the use effect of the filter screen is further improved.

[0011] Both metal probes are protected by the filter screen, that is, the airflow in contact with the two metal probes is dried, effectively ensuring the detection accuracy of the airflow controller, and the water vapor is naturally carried by the airflow, so that the water vapor will not affect the original gas in the airflow after being dried by the filter screen and returning to the airflow.

[0012] Preferably, the driving assembly comprises a fixed shaft fixedly installed at the bottom of the rotating plate, the fixed shaft is coaxially arranged with the rotating plate, and a plurality of blades are arranged on the fixed shaft.

[0013] The blades are arranged to drive the blades to rotate when the airflow flows, instead of the traditional driving assembly. The traditional driving assembly has problems such as complex structure, large space occupation, high energy consumption, and inconvenient maintenance. The method of driving the blades to rotate by using the airflow can simplify the overall structure, reduce unnecessary mechanical parts, and reduce the manufacturing cost and maintenance difficulty of the equipment.

[0014] A plurality of blades are arranged on the fixed shaft, and the plurality of blades are circumferentially and uniformly distributed on the fixed shaft based on the axis of the fixed shaft. Such a design can make full use of the energy of the airflow. The circumferentially and uniformly distributed blades can receive the force of the airflow in all directions, so that the blades can rotate more efficiently. When the airflow blows through the blades, each blade will be pushed by the airflow, thereby driving the fixed shaft and the rotating plate to rotate together. This design can maximize the use of the energy of the airflow and improve the working efficiency of the equipment.

[0015] By arranging the blades, the airflow originally used to transport raw materials is used as the driving assembly, which not only achieves the purpose of driving by the airflow instead of the traditional driving assembly, but also saves energy and reduces the noise during the operation of the equipment compared with the motor, which helps to improve the comfort of the production environment.

[0016] Preferably, the filter screen is made of an alumina ceramic membrane, a plurality of support rods are vertically fixed on the rotating plate, and the plurality of support rods are located on the side of the filter screen close to the metal probe and are fixedly connected with the filter screen.

[0017] The hydroxyl groups on the surface of the alumina ceramic membrane or the material used as the filter screen can quickly adsorb the water vapor in the airflow, filter the water vapor out of the gas, and condense the water vapor into small water droplets on the membrane surface. The micropores of the alumina ceramic membrane can allow the gas to pass through quickly, and the gas has low resistance to permeation, which will not affect the contact between the airflow and the metal probe. Moreover, the alumina ceramic membrane has the characteristics of backblowing regeneration, so when the airflow flows from the inside to the outside of the filter screen, the water droplets on the alumina ceramic membrane can be blown off, and the alumina ceramic membrane can quickly recover its water absorption capacity. However, the alumina ceramic membrane has the disadvantage of brittleness, so a plurality of support rods are arranged on the rotating plate to support and fix the alumina ceramic membrane, preventing it from being damaged by stress when the gas flow is large and ensuring the stability of the equipment during use.

[0018] Preferably, a plurality of installation grooves are formed in the side wall of the fixed shaft, the projection of the installation grooves on the radial cross section of the fixed shaft is a right triangle as a whole, the installation grooves are evenly distributed on the fixed shaft with the axis of the fixed shaft as the reference circle, the vane is vertically installed in the installation groove, and the vane coincides with the diameter of the fixed shaft when the vane is attached to the shorter leg of the right triangle of the installation groove.

[0019] By arranging the installation grooves, when the vane is impacted by the airflow, the vane on one side is stressed against the shorter leg of the right triangle of the installation groove, at this time the vane coincides with the diameter of the fixed shaft, and the stress area between the vane and the airflow is the largest. When the vane rotates to the other half circle with the rotating plate, the flow direction of the airflow does not change, and when the airflow impacts the vane, the vane can rotate towards the longer leg of the right triangle of the installation groove and store part of the vane in the installation groove. In this way, the stress areas of the two half-circle vanes and the airflow are inconsistent, and the airflow can drive the rotating plate and the filter screen to rotate in one direction, thereby ensuring that the filter screen on the rotating plate can uniformly adsorb the water vapor in the airflow and avoiding the situation that only part of the filter screen is working, further ensuring the detection accuracy of the airflow controller and the overall regulation accuracy of the airflow controller.

[0020] Preferably, the diameters of the fixed plates are greater than the diameter of the rotating plate, a scraping strip is vertically fixed and installed on each fixed plate, the scraping strip is located on the outside of the sleeve-shaped filter screen, the scraping strip is attached to the surface of the filter screen, and the scraping strip is located on the back side of the filter screen in the airflow advancing direction.

[0021] By setting the scraping strip, the water droplets on the filter screen are scraped off when the filter screen rotates, preventing the water droplets on the filter screen from gathering too much and being quickly blown dry by the dry airflow flowing out from the inside of the filter screen. It ensures that the filter screen can maintain a dry state when it rotates back to the front, ensuring that the filter screen can stably and effectively adsorb water vapor in the airflow, avoiding contact between the water vapor and the metal probe.

[0022] Preferably, the bottom end of the scraping strip is inclined downward to form a guide portion, the bottommost end of the guide portion extends outside the rotating plate, and the endpoint of the bottommost end of the guide portion is located outside the circumference formed when the blade rotates.

[0023] After the scraping strip removes the water droplets from the filter screen, the water droplets gather on the scraping strip and flow downward under the action of gravity. By setting the guide portion, the water droplets are guided during the downward flow, preventing the water droplets from directly dripping onto the rotating plate after gathering. It prevents the rotating plate from rotating with increased resistance due to the large amount of water droplets dripping onto the rotating plate, preventing the rotating plate from rotating with difficulty, ensuring that the filter screen can rotate stably to evenly filter water vapor in the airflow, and further ensuring the detection accuracy and control accuracy of the airflow controller.

[0024] Preferably, the scraping strip and the guide portion are provided with a plurality of guide grooves, the plurality of guide grooves are uniformly distributed in the vertical direction on the scraping strip and the guide portion, and the guide grooves are all inclined downward away from the axis of the metal probe. The guide grooves use capillary effect to adsorb the water droplets scraped off by the scraping strip on the surface of the scraping strip, and make the water droplets flow along the guide grooves and the scraping strip downward to the outside of the scraping strip, and then make the water droplets finally flow along the outside of the scraping strip to the guide portion and drip from the bottom of the guide portion, thereby further avoiding the water droplets from dripping onto the rotating plate.

[0025] Preferably, the fixed plate and the rotating plate are both made of plastic material, the fixed plate is fixed to the upper side of the metal probe by gluing, the rotating plate is provided with a ring groove in the shape of an inverted "T" at the top, and the metal probe is provided with a ring-shaped protrusion at the bottom, the ring-shaped protrusion at the bottom of the metal probe is inserted into the ring groove and connected with the rotating plate.

[0026] The fixed plate and the rotating plate are made of plastic material, which can effectively reduce the heat transfer from the metal probe to the fixed plate or the rotating plate. Avoiding the situation that the heat of the metal probe is quickly transferred to the fixed plate and the rotating plate, increasing the heat dissipation area, and causing the temperature of the metal probe to decrease quickly. Using plastic material can avoid this situation and ensure the accuracy of detection.

[0027] The plastic rotating plate also exhibits self-lubricating properties. This self-lubricating property reduces friction between the plate and other contacting components during rotation. This reduced friction helps minimize energy loss, ensuring smoother rotation and preventing issues like stalling and jerking caused by excessive friction. Furthermore, plastic rotating plates are lighter than metal, making them more easily rotated.

[0028] The mounting plate is glued to the top of the metal probe. Gluing is a common and reliable connection method, ensuring a tight and stable connection between the mounting plate and the metal probe. Compared to other connection methods, such as welding, which can affect the material properties of the metal probe and mounting plate, gluing provides a secure connection without altering the properties of the materials, and is relatively simple and cost-effective.

[0029] An inverted T-shaped groove is defined at the top of the rotating plate, while an annular protrusion is located at the bottom of the metal probe. This protrusion inserts into the groove and connects to the rotating plate. This inverted T-shaped groove and protrusion provide excellent positioning and guidance. The protrusion's insertion into the groove prevents horizontal displacement of the rotating plate, ensuring a stable relative position between the rotating plate and the metal probe. Furthermore, the inverted T-shaped design allows the rotating plate to rotate smoothly along the protrusion, providing reliable support and guidance for the plate's rotation and further ensuring smooth rotation.

[0030] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention is designed to provide an airflow controller with a constant effective value output at a low voltage. By providing a rotating plate and an annular filter, the filter filters out water vapor in the airflow before the airflow contacts the metal probe. When the dry airflow contacts the metal probe and then flows out of the filter, the dry airflow carries away the water vapor on the filter. This prevents the water vapor in the airflow from affecting the detection accuracy of the metal probe and avoids the reduction of the filter's filtering effect on water vapor after long-term use.

[0031] 2. The present invention designs an airflow controller with a constant effective value output under low voltage. By using an alumina ceramic membrane as a filter and providing a scraper on the outside of the filter, the filter's filtering effect on water vapor in the airflow is further improved, and the drying speed of the filter is increased to ensure that the filter can be quickly recycled, further guaranteeing the detection accuracy of the metal probe.

[0032] 3. The present invention designs an airflow controller with a constant effective value output under low voltage. By setting blades as driving components, the flow of airflow flushes the blades to drive the rotating plate to rotate, thereby saving production costs and maintenance costs. At the same time, by setting a mounting groove and rotating the blades inside the mounting groove, the unidirectional rotation of the rotating plate is realized, ensuring that the filter can evenly adsorb water vapor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a three-dimensional diagram of the internal structure of the present invention; Figure 3 It is a right side view of the present invention; Figure 4 For the present invention Figure 3 Cross-sectional view at AA in the middle; Figure 5 For the present invention Figure 4 Enlarged view of point B in the middle; Figure 6 Schematic diagram of the three-dimensional structure of the detection unit in the present invention; Figure 7 It is a front view of the detection unit in the present invention; Figure 8 For the present invention Figure 7 Cross-sectional view at CC.

[0034] In the figure: 1. Base; 2. Pipeline; 3. Detection unit; 301. Base; 302. Metal probe; 4. Processing unit; 5. Control valve; 501. Electromagnet; 502. Spring; 503. Valve core; 6. Fixed plate; 7. Rotating plate; 8. Filter; 9. Fixed shaft; 10. Blade; 11. Support rod; 12. Mounting groove; 13. Scraper; 14. Guide part; 15. Guide groove; 16. Ring groove; 17. Ring protrusion; 18. Force zone; 19. Avoidance zone; 20. Heating wire; 21. Temperature sensor; D. Airflow direction. DETAILED DESCRIPTION

[0035] See also Figures 1 to 8 The present invention provides an airflow controller with constant effective value output under low voltage, and the technical solution is as follows: As an embodiment of the present invention, refer to Figures 1 to 5The utility model provides a kind of air flow controller with constant effective value output at low voltage, including pedestal 1, pipeline 2 for flowing gas is opened on pedestal 1, detection unit 3 is provided on pedestal 1, detection unit 3 includes base body 301 and two metal probes 302, two metal probes 302 are spaced apart on base body 301, and two metal probes 302 are inserted into pipeline 2 inside pedestal 1, the part of metal probe 302 close to the air inlet of pipeline 2 is wound with heating wire 20 inside base body 301, heating wire 20 is used to heat metal probe 302, the part of two metal probes 302 inside base body 301 is provided with temperature sensor 21 for detecting temperature. Processing unit 4 is further provided on pedestal 1, processing unit 4 is electrically connected with detection unit 3, control valve 5 for regulating and controlling the size of pipeline 2 opening and closing is further provided on pedestal 1, control valve 5 is solenoid valve, control valve 5 includes electromagnet 501, spring 502 and valve core 503, control valve 5 is electrically connected with processing unit 4.

[0036] Reference Figure 4 、 Figure 5 、 Figure 6 And Figure 7 Two metal probes 302 are provided with filter assembly, filter assembly includes fixed plate 6, rotating plate 7 and filter screen 8, fixed plate 6 and rotating plate 7 are made of plastic material. Fixed plate 6 and rotating plate 7 are circular, and the diameter of fixed plate 6 is greater than the diameter of rotating plate 7, fixed plate 6 is coaxially fixed on the upper side of metal probe 302 by gluing, rotating plate 7 is provided with inverted "T" shape ring groove 16 in the top center, the bottom of metal probe 302 is provided with annular protrusion 17, the annular protrusion 17 of the bottom of metal probe 302 is inserted into ring groove 16 and connected coaxially with rotating plate 7, and rotating plate 7 can rotate relative to metal probe 302.

[0037] Reference Figure 5 Filter screen 8 is made of alumina ceramic membrane, filter screen 8 is cylindrical, filter screen 8 is fixedly connected on rotating plate 7 by gluing at the bottom, and metal probe 302 between fixed plate 6 and rotating plate 7 is surrounded by filter screen 8. Four support rods 11 are also vertically fixed on rotating plate 7, support rod 11 is also made of plastic material, four support rods 11 are located on the side of filter screen 8 close to metal probe 302, and four support rods 11 are fixedly connected with filter screen 8 by gluing.

[0038] Reference Figures 5 to 7Each fixed plate 6 is vertically fixedly installed with a scraping strip 13 by gluing, the scraping strip 13 is located between the fixed plate 6 and the rotating plate 7, the scraping strip 13 is also made of plastic material, the scraping strip 13 is located outside the sleeve-shaped filter screen 8, the scraping strip 13 is attached to the surface of the filter screen 8, the scraping strip 13 is located at the back side of the filter screen 8 in the airflow advancing direction D, the bottom end of the scraping strip 13 at the back side is inclined downward to form a guide portion 14, the bottom end of the guide portion 14 extends outside the rotating plate 7, and the end point of the bottom end of the guide portion 14 is located outside the circumference formed when the blade 10 rotates, preventing water droplets from falling on the blade 10. In addition, the scraping strip 13 and the guide portion are provided with a plurality of guide grooves 15 on the two sides, the plurality of guide grooves 15 are vertically spaced and uniformly distributed on the scraping strip 13 and the guide portion 14, and the guide grooves 15 are inclined downward away from the axis of the metal probe 302.

[0039] In addition, referring to Figures 5 to 7 , the bottom of the rotating plate 7 is provided with a driving assembly for driving the rotating plate 7 and the filter screen 8 to rotate. The driving assembly includes a fixed shaft 9 fixedly installed at the bottom of the rotating plate 7, the fixed shaft 9 is coaxially arranged with the rotating plate 7, six installation grooves 12 are formed in the side wall of the fixed shaft 9, the projection of the installation groove 12 on the radial cross section of the fixed shaft 9 is a right triangle as a whole, and the six installation grooves 12 are uniformly distributed on the fixed shaft 9 with the axis of the fixed shaft 9 as the reference circle. The driving assembly further includes six blades 10, the six blades 10 correspond to the six installation grooves 12, each blade 10 is vertically rotatably installed in the corresponding installation groove 12, and when the blade 10 is attached to the shorter right angle side of the installation groove 12, the diameter of the blade 10 coincides with the fixed shaft 9. Among them, the fixed shaft 9 and the blade 10 are made of plastic material, the fixed shaft 9 can be integrally formed with the rotating plate 7, or can be fixedly connected to the bottom of the rotating plate 7 by gluing.

[0040] Before use, referring to Figure 4The two ends of the pipeline 2 on the base 1 of the airflow controller are connected to the conveying airflow system that needs to be controlled, and when connected, the airflow needs to enter the airflow controller from the end close to the metal probe 302 for heating. Then the power cord of the airflow controller is connected, and the use can begin. When in use, the required airflow is set by the processing unit 4, and the processing unit 4 adjusts the temperature of the metal probe 302 for heating according to the set value, and detects the temperature of the metal probe 302 for heating, while the other metal probe 302 only detects the temperature of the metal probe 302. The temperature difference ΔT between the two is fed back to the electromagnet 501 of the control valve 5 by the processing unit 4, and the magnetic force of the electromagnet 501 is adjusted to control the valve core 503 of the control valve 5, so as to control the opening and closing of the pipeline 2 and keep the airflow constant. When the airflow increases, the temperature of the metal probe 302 for heating is cooled by the airflow, and the temperature difference ΔT decreases. After the processing unit 4 detects it, in order to adjust the temperature difference back to ΔT, the processing unit 4 feeds back the signal to the control valve 5, so that the control valve 5 controls the opening and closing of the pipeline 2 to ensure that the airflow is stable according to the set value. When the temperature difference ΔT increases, it means that the airflow decreases. In order to ensure the stability of the airflow output, the processing unit 4 feeds back to the control valve 5, and the control valve 5 adjusts the opening and closing of the pipeline 2 to be larger.

[0041] When the airflow flows through the two metal probes 302, referring to Figure 4 、 Figure 5 , the airflow first contacts the surface of the filter screen 8. The surface of the filter screen 8 made of alumina ceramic film has affinity for water vapor in the airflow, and the water vapor is adsorbed by the surface of the filter screen 8, and the airflow smoothly passes through the filter screen 8 into the inside of the filter screen 8. At this time, the airflow is dried, and the water vapor does not contact the metal probe 302, so that the metal probe 302 is not suddenly and rapidly cooled, ensuring the detection accuracy of the airflow controller, and the processing unit 4 does not incorrectly adjust the opening and closing of the control valve 5 due to the interference of the water vapor, ensuring the stable control of the airflow controller on the output of the airflow.

[0042] When the airflow flows from the pipeline 2, referring to Figures 4 to 6 , part of the airflow also washes the blades 10 below the rotating plate 7. After being impacted by the airflow, the blades 10 drive the rotating plate 7 and the filter screen 8 to rotate, and after the filter screen 8 rotates, it can uniformly contact the airflow and effectively dry the airflow, avoiding the situation that only the front part of the filter screen 8 can contact the airflow and dry the airflow.

[0043] During the rotation of the filter screen 8, referring to Figure 4 and Figure 5When the dry airflow contacts the metal probe 302 and flows from the interior of the filter 8 through the filter 8 and out of the filter 8 again, the dry airflow dries the filter 8, freeing moisture from it. The rotation of the filter 8 also allows the side that has absorbed moisture to rotate to the rear, allowing the filter 8 to simultaneously filter moisture from the airflow while simultaneously drying it. This prevents the filter 8 from losing its moisture absorption capacity or even becoming ineffective after prolonged use. Furthermore, because the metal probe 302 heats the airflow, the airflow exiting the filter 8 can better dry it. The metal probe 302, located at the rear and not used for heating, is less affected by moisture and, with the filter 8 filtering the airflow, can still dry the filter 8 using the airflow, effectively protecting its service life.

[0044] At the same time, during the rotation of the filter 8, refer to Figures 5 to 7 The scraper bar 13 is located behind the filter 8 in the direction of airflow D and abuts against the outer surface of the filter 8. As the filter 8 rotates, the scraper bar 13 scrapes off water droplets that have been filtered and adsorbed on its surface, preventing the airflow from being too humid to quickly dry the filter 8. The scraped water droplets are guided by the capillary effect of the scraper bar 13 and the guide grooves 15 thereon, flowing along the scraper bar 13 to the outer side of the scraper bar 13 away from the metal probe 302, and eventually dripping down the scraper bar 13 and the guide portion 14. The provision of the scraper bar 13 effectively ensures the drying speed of the filter 8.

[0045] refer to Figure 8 Because the blade 10 is rotatably mounted within the mounting groove 12, when the blade 10 is impacted by the airflow, within a semicircular region of the force-bearing area 18, the blade 10 is impacted by the airflow and abuts against a shorter right-angled side of the mounting groove 12. At this point, the diameters of the blade 10 and the fixed shaft 9 coincide, and the force-bearing area between the blade 10 and the airflow is maximized. When the blade 10 rotates with the rotating plate 7 to a semicircular region of the avoidance area 19, the direction of the airflow remains unchanged. When the airflow impacts the blade 10, the blade 10 can rotate toward the longer right-angled side of the mounting groove 12, and a portion of the blade 10 is retracted within the mounting groove 12. This creates two semicircular regions where the blade 10 and the airflow have different force-bearing areas. The airflow can drive the rotating plate 7 and the filter 8 to rotate consistently in one direction, thereby ensuring that the filter 8 on the rotating plate 7 can uniformly absorb moisture in the airflow, preventing the filter 8 from being partially operational. This further ensures the detection accuracy of the airflow controller, and thus the overall airflow control accuracy of the airflow controller.

[0046] The above describes one specific embodiment of the present application in detail in combination with the drawings, but the present application is not limited to the above described embodiment. For those skilled in the art, various changes, modifications, replacements and variations of the embodiment can be made without departing from the principles and ideas of the present application, and should still fall within the protection scope of the present application.

Claims

1. An airflow controller with a constant effective value output at low voltage, comprising a base (1), a pipeline (2) for circulating gas being provided on the base (1), a detection unit (3) being provided on the base (1), the detection unit (3) comprising a base (301) and two metal probes (302), the two metal probes (302) being spaced apart and arranged on the base (301), and both metal probes (302) being inserted into the pipeline (2) inside the base (1), a processing unit (4) being further provided on the base (1), the processing unit (4) being electrically connected to the detection unit (3), a control valve (5) being further provided on the base (1) for regulating the opening and closing size of the pipeline (2), the control valve (5) being electrically connected to the processing unit (4), and characterized in that: A filter assembly is provided on each of the two metal probes (302), and the filter assembly includes a fixed plate (6), a rotating plate (7) and a filter screen (8). The fixed plate (6) and the rotating plate (7) are both circular, and the fixed plate (6) is coaxially fixed to the upper side of the metal probe (302). The rotating plate (7) is coaxially rotatably installed on the bottom of the metal probe (302). The filter screen (8) is cylindrical, and the bottom of the filter screen (8) is fixedly connected to the rotating plate (7), and the filter screen (8) annularly surrounds the metal probe (302) between the fixed plate (6) and the rotating plate (7). A driving assembly for driving the rotating plate (7) and the filter screen (8) to rotate is provided at the bottom of the rotating plate (7).

2. The airflow controller with constant effective value output at low voltage according to claim 1, characterized in that: The driving assembly comprises a fixed shaft (9) fixedly mounted on the bottom of the rotating plate (7), the fixed shaft (9) being coaxially arranged with the rotating plate (7), a plurality of blades (10) being arranged on the fixed shaft (9), and the plurality of blades (10) being uniformly distributed on the fixed shaft (9) with the axis of the fixed shaft (9) as a reference circumference.

3. The airflow controller with constant effective value output at low voltage according to claim 1, characterized in that: The filter screen (8) is made of an alumina ceramic membrane. A plurality of support rods (11) are vertically fixed on the rotating plate (7). The plurality of support rods (11) are all located on a side of the filter screen (8) close to the metal probe (302). The plurality of support rods (11) are all fixedly connected to the filter screen (8).

4. The airflow controller with constant effective value output at low voltage according to claim 2, characterized in that: A plurality of mounting grooves (12) are provided on the side wall of the fixed shaft (9), and the projection of the mounting grooves (12) on the radial cross section of the fixed shaft (9) is a right triangle as a whole. The plurality of mounting grooves (12) are evenly distributed on the fixed shaft (9) with the axis of the fixed shaft (9) as the reference circumference. The blades (10) are vertically rotatably mounted inside the mounting grooves (12). When the blades (10) are in contact with the shorter right-angled sides of the mounting grooves (12), the diameters of the blades (10) and the fixed shaft (9) coincide.

5. The airflow controller with constant effective value output at low voltage according to claim 4, characterized in that: The diameter of the fixed plate (6) is larger than the diameter of the rotating plate (7). A scraper (13) is vertically fixedly installed on the fixed plate (6). The scraper (13) is located outside the sleeve-shaped filter (8). The scraper (13) is in contact with the surface of the filter (8). The scraper (13) is located on the rear side of the filter (8) in the forward direction (D) of the airflow.

6. The airflow controller with constant effective value output at low voltage according to claim 5, characterized in that: The bottom end of the scraper (13) is tilted downward to form a guide portion (14), the bottom end of the guide portion (14) extends outside the rotating plate (7), and the bottom end point of the guide portion (14) is located outside the circumference formed when the blade (10) rotates.

7. An airflow controller with constant effective value output at low voltage according to claim 6, characterized in that: A plurality of guide grooves (15) are provided on the scraper strip (13) and the guide portion. The plurality of guide grooves (15) are evenly distributed vertically on the scraper strip (13) and the guide portion (14). The guide grooves (15) are all inclined downward in a direction away from the axis of the metal probe (302).

8. The airflow controller with constant effective value output at low voltage according to claim 4, characterized in that: The fixed plate (6) and the rotating plate (7) are both made of plastic material. The fixed plate (6) is fixed to the upper side of the metal probe (302) by gluing. The top of the rotating plate (7) is provided with an inverted "T"-shaped annular groove (16). The bottom of the metal probe (302) is provided with an annular protrusion (17). The annular protrusion (17) at the bottom of the metal probe (302) is inserted into the annular groove (16) and connected to the rotating plate (7).

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