Air flow controller with constant effective value output at low voltage

Abstract

The application relates to the technical field of air flow controllers, in particular to an air flow 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, the detection unit comprises a base body and two metal probes, filtering assemblies are arranged on the two metal probes, the filtering assemblies comprise fixing plates, rotating plates and filter screens, the fixing plates are fixed to the upper sides of the metal probes, the rotating plates are coaxially and rotatably arranged at the bottoms of the metal probes, the filter screens are cylindrical, the metal probes between the fixing plates and the rotating plates are surrounded by the filter screens, and the bottoms of the rotating plates are provided with driving assemblies. The air flow is dried before contacting the metal probes in the filter screens, and the filter screens are dried when the air flow comes out of the filter screens, so that the detection precision of the metal probes is prevented from being affected by the water vapor in the air flow, and the filtering effect of the filter screens on the water vapor is prevented from being reduced after long-time use.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of airflow controllers, in particular to an airflow controller with constant effective value output at low voltage. BACKGROUND

[0002] An airflow controller, also known as a mass flow controller, is not only a mass flow meter, but more importantly, it can automatically control the flow of gas. That is, the user can set the flow rate as needed, and the MFC will automatically maintain the flow rate at the set value, even if the system pressure fluctuates or the ambient temperature changes. In short, a mass flow controller is a flow stabilizing device that can be manually set or automatically controlled by a computer.

[0003] Among them, the thermal mass flow controller is also a kind of airflow controller, which uses 15V-24V DC power supply. When the thermal mass flow controller is in use, two metal probes are used to detect the airflow passing through the internal airflow controller, usually platinum wire, tungsten wire or thin film resistance. Among them, the metal probe in front is used for heating, and the metal probe at the back is used for temperature measurement, and a constant temperature difference ΔT is generated between the two metal probes. When the control valve is closed, the measurement value is equal to the zero flow value, and the current signal is transmitted to the processing unit, and the processing unit compares the required value with the measured value, and then adjusts the opening size of the control valve to ensure that the airflow is stable. Output according to the set value.

[0004] However, the above-mentioned thermal airflow controller, because the first metal probe needs to be heated, when the airflow contains water vapor, the metal probe will be quickly cooled by the water vapor in the airflow, causing ΔT to change rapidly, thereby causing the output control of the airflow controller to have a large error. The output of the airflow cannot be accurately controlled at the set value, which has a great impact on production. In addition, since the metal probe itself is in a heated state, after being quickly cooled by water vapor, the metal probe is easily oxidized and corroded, thereby reducing the service life of the metal probe.

[0005] The existing solution is usually to add a filter screen at the air inlet of the airflow controller, which absorbs water vapor in the airflow and filters dust in the airflow, so as to avoid the contact between water vapor and dust in the airflow and the metal probe, and to ensure the regulation and control accuracy of the airflow controller and the service life of the metal probe. However, when the filter screen is used for a long time, the filter screen reaches a saturated state of absorbing water vapor, and the filter screen needs to be replaced in time, otherwise the filter screen will lose the filtering effect of water vapor. When the filter screen is replaced, the supply of airflow needs to be stopped, which affects continuous production activities.

[0006] To this end, a gas flow controller with constant effective value output under low voltage is provided to solve the problem that the metal probe cannot be effectively protected after the filter screen is saturated with water vapor in the gas for a long time. 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 metal probe cannot be effectively protected after the filter screen is saturated with water vapor in the gas for a long time, to ensure the regulation accuracy of the gas flow controller.

[0008] To achieve the above purpose, the present application provides the following technical solutions:

[0009] 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 surrounds 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.

[0010] The filter screen surrounds 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.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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 using the airflow to drive the blades to rotate can simplify the overall structure, reduce unnecessary mechanical parts, and reduce the manufacturing cost and maintenance difficulty of the equipment.

[0015] 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.

[0016] 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 using the airflow to drive instead of the traditional driving assembly, but also saves energy and reduces the noise of the equipment during operation compared with the motor, which helps to improve the comfort of the production environment.

[0017] Preferably, the filter screen is made of an alumina ceramic membrane, a plurality of support rods are vertically fixed on the rotating plate, the plurality of support rods are located on the side of the filter screen close to the metal probe, and the plurality of support rods are fixedly connected with the filter screen.

[0018] The hydroxyl groups on the surface of the alumina ceramic membrane or the material used as the filter screen can quickly adsorb water vapor in the airflow, filter out the water vapor from the gas, and condense the water vapor into small water droplets on the membrane surface. The micropores can allow the gas to pass quickly, and the gas has the characteristics of low air permeation resistance and will not affect the contact between the airflow and the metal probe. Moreover, the alumina ceramic membrane has the characteristics of being able to be blown and regenerated, 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 the alumina ceramic membrane from being damaged under stress when the gas flow is large, and ensuring the stability of the equipment during use.

[0019] 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 plurality of installation grooves are uniformly distributed on the fixed shaft with the axis of the fixed shaft as the reference circle, the vane is vertically rotatably 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.

[0020] By arranging the installation grooves, when the vane is impacted by the airflow, the vane on one side is stressed and abuts 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 maximum. When the vane is rotated to the other half circle along with the rotating plate, the flow direction of the airflow does not change, the vane can be rotated towards the longer leg of the right triangle of the installation groove and part of the vane can be accommodated in the installation groove when the vane is impacted by the airflow. In this way, the stress areas of the two half-circle vanes and the airflow are inconsistent, the airflow can drive the rotating plate and the filter screen to rotate in one direction, and the filter screen on the rotating plate can uniformly adsorb the water vapor in the airflow, avoiding the situation that only part of the filter screen is working, further ensuring the detection accuracy of the airflow controller, and further ensuring the overall regulation and control accuracy of the airflow controller.

[0021] Preferably, the diameters of the fixed plates are greater than the diameter of the rotating plate, a scraping strip is vertically and fixedly 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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, and the rotating plate is provided with a "T" shaped ring groove at the top, and the metal probe is provided with a ring-shaped protrusion at the bottom, and the ring-shaped protrusion at the bottom of the metal probe is inserted into the ring groove to connect with the rotating plate.

[0027] The fixed plate and the rotating plate are made of plastic material. Since the thermal conductivity of plastic is poorer than that of metal, the heat transfer from the metal probe to the fixed plate or the rotating plate can be effectively reduced. 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.

[0028] Meanwhile, the rotating plate made of plastic material has a self-lubricating effect. During the rotation of the rotating plate, the self-lubricating property can reduce the friction between the rotating plate and other contacting components. The reduction of friction helps to reduce energy loss, make the rotation smoother, avoid problems such as rotation jamming and instability caused by excessive friction, and thus ensure the smoothness of the rotation of the rotating plate. Meanwhile, the rotating plate made of plastic material is lighter than that made of metal material, which is more conducive to the rotation of the rotating plate.

[0029] The fixed plate is fixed to the upper side of the metal probe by means of gluing. Gluing is a common and reliable connection method, which can tightly combine the fixed plate and the metal probe and provide stable connection. Compared with other connection methods such as welding, which may affect the material properties of the metal probe and the fixed plate, gluing can achieve firm connection without changing the material properties, and the operation is relatively simple and the cost is relatively low.

[0030] A ring groove in the shape of an inverted "T" is formed at the top of the rotating plate, and a ring-shaped protrusion is arranged at the bottom of the metal probe, which is inserted into the ring groove to connect with the rotating plate. The cooperation of the inverted "T" shaped ring groove and the ring-shaped protrusion has good limiting and guiding effects. On the one hand, the insertion of the ring-shaped protrusion into the ring groove can prevent the displacement of the rotating plate in the horizontal direction, ensuring the stability of the relative position between the rotating plate and the metal probe; on the other hand, the design of the inverted "T" shape enables the rotating plate to rotate smoothly along the ring-shaped protrusion during rotation, providing reliable support and guidance for the rotation of the rotating plate, and further ensuring the smoothness of the rotation.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] 1. The air flow controller with constant effective value output at low voltage designed by the present application can only contact the metal probe after the water vapor in the air flow is filtered by the filter screen, and the dry air flow can carry away the water vapor on the filter screen when it flows out from the filter screen after contacting the metal probe, thereby preventing the water vapor in the air flow from affecting the detection accuracy of the metal probe and avoiding the reduction of the filtering effect of the filter screen on water vapor after long-term use.

[0033] 2. The air flow controller with constant effective value output at low voltage designed by the present application further improves the filtering effect of the filter screen on water vapor in the air flow and the drying speed of the filter screen by using an aluminum oxide ceramic membrane as the filter screen and arranging a scraping strip outside the filter screen, so as to ensure that the filter screen can be quickly recycled and further protect the detection accuracy of the metal probe.

[0034] 3. The air flow controller with constant effective value output at low voltage, which is characterized in that the blade is arranged as the driving component, the rotating plate is rotated by the flow of air washing the blade, the production cost and the maintenance cost are saved, the one-way rotation of the rotating plate is realized by arranging the installation groove and rotatingly installing the blade in the installation groove, and the filter screen can uniformly adsorb water vapor. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a perspective view of the internal structure of the present application;

[0036] Figure 2 is a perspective view of the internal structure of the present application;

[0037] Figure 3 is a right view of the present application;

[0038] Figure 4 is a sectional view of A-A in the present application; Figure 3

[0039] Figure 5 is an enlarged view of B in the present application; Figure 4

[0040] Figure 6 is a perspective view of the detection unit in the present application;

[0041] Figure 7 is a front view of the detection unit in the present application;

[0042] Figure 8 is a sectional view of C-C in the present application. Figure 7

[0043] In the figure: 1, base; 2, pipeline; 3, detection unit; 301, base body; 302, metal probe; 4, processing unit; 5, control valve; 501, electromagnet; 502, spring; 503, valve core; 6, fixed plate; 7, rotating plate; 8, filter screen; 9, fixed shaft; 10, blade; 11, support rod; 12, installation groove; 13, scraping strip; 14, guide part; 15, flow guide groove; 16, ring groove; 17, annular protrusion; 18, stress area; 19, avoidance area; 20, heating wire; 21, temperature sensor; D, air flow advancing direction. DETAILED DESCRIPTION

[0044] Referring to Figures 1 to 8 , the present application provides an air flow controller with constant effective value output at low voltage, and the technical scheme is as follows:

[0045] As an embodiment of the present application, referring to Figures 1 to 5 ​​​The 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.

[0046] 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 top center is provided with inverted "T" shape ring groove 16, 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 is coaxially connected with rotating plate 7, and rotating plate 7 can rotate relative to metal probe 302.

[0047] Reference Figure 5 Filter screen 8 is made of alumina ceramic membrane, filter screen 8 is cylindrical, filter screen 8 bottom is fixedly connected on rotating plate 7 by gluing, and metal probe 302 between fixed plate 6, 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, four support rods 11 are fixedly connected with filter screen 8 by gluing.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] During the rotation of the filter screen 8, referring to Figure 4 and Figure 5When the dry airflow finishes contacting the metal probe 302 and flows out of the filter 8 again from inside the filter 8, the dry airflow dries the filter 8, allowing moisture to escape from it. The rotation of the filter 8 also moves the side that absorbed moisture to the rear, achieving a simultaneous filtration of moisture from the airflow and drying of the filter 8 by the airflow itself. This prevents the filter 8 from becoming less effective at adsorbing moisture after prolonged use. Simultaneously, because the metal probe 302 heats the airflow, the airflow exiting the filter 8 dries it more effectively. The metal probe 302, located at the rear and not used for heating, is less affected by moisture and is further dried by the filter 8. Therefore, even without heating the airflow itself, the metal probe 302 can still dry the filter 8 using the airflow, effectively extending its service life.

[0054] Meanwhile, as filter 8 rotates, reference Figures 5 to 7 The scraper 13 is located behind the filter screen 8 in the airflow direction D and abuts against the outer surface of the filter screen 8. When the filter screen 8 rotates, the scraper 13 scrapes off the water droplets filtered and adsorbed on its surface, preventing the airflow from being too humid and unable to dry the filter screen 8 quickly. Guided by the capillary effect of the scraper 13 and the guide groove 15 on it, the scraped water droplets flow along the scraper 13 to the outside of the scraper 13 away from the metal probe 302, and finally drip down along the scraper 13 and the guide part 14. The design of the scraper 13 effectively ensures the drying speed of the filter screen 8.

[0055] refer to Figure 8 Because the blade 10 is rotatably mounted inside the mounting groove 12, when the blade 10 is impacted by the airflow, within a semi-circular area of ​​the force-bearing zone 18, the blade 10 is impacted by the airflow and comes into contact with the shorter right-angled side of the mounting groove 12. At this time, the diameter of the blade 10 coincides with that of the fixed shaft 9, and the force-bearing area between the blade 10 and the airflow is at its maximum. When the blade 10 follows the rotating plate 7 to a semi-circular area of ​​the avoidance zone 19, because the airflow direction remains unchanged, when the airflow impacts the blade 10, the blade 10 can rotate towards the longer right-angled side of the mounting groove 12 and a part of the blade 10 is housed inside the mounting groove 12. In this way, the force-bearing areas of the two semi-circles of the blade 10 and the airflow are not consistent. The airflow can drive the rotating plate 7 and the filter screen 8 to rotate in one direction, thereby ensuring that the filter screen 8 on the rotating plate 7 can evenly adsorb the water vapor in the airflow, avoiding the situation where only a part of the filter screen 8 is working, further ensuring the detection accuracy of the airflow controller, and thus ensuring the overall control accuracy of the airflow controller.

[0056] 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. A low-voltage airflow controller with constant effective value output, comprising a base (1), a pipeline (2) for flowing gas is arranged on the base (1), a detection unit (3) is arranged on the base (1), the detection unit (3) comprises a base body (301) and two metal probes (302), the two metal probes (302) are arranged on the base body (301) with a spacing, and the two metal probes (302) are inserted into the pipeline (2) inside the base (1), a processing unit (4) is further arranged on the base (1), the processing unit (4) is electrically connected with the detection unit (3), a control valve (5) for regulating the opening and closing size of the pipeline (2) is further arranged on the base (1), and the control valve (5) is electrically connected with the processing unit (4), characterized in that, Two said metal probe (302) are provided with filter assembly, the filter assembly includes fixed plate (6), rotating plate (7) and filter screen (8), the fixed plate (6) and rotating plate (7) are circular, the fixed plate (6) is coaxially fixed on the upper side of metal probe (302), the rotating plate (7) is coaxially rotatably installed at the bottom of metal probe (302), the filter screen (8) is cylindrical, the filter screen (8) is fixedly connected to the rotating plate (7) at the bottom, and the filter screen (8) surrounds the metal probe (302) between the fixed plate (6) and the rotating plate (7) in a ring shape, 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), a plurality of blades (10) are arranged on the fixed shaft (9), and the plurality of blades (10) are circumferentially distributed on the fixed shaft (9) based on the axis of the fixed shaft (9); a plurality of mounting grooves (12) are formed in the sidewall of the fixed shaft (9), the projection of the mounting groove (12) on the radial cross section of the fixed shaft (9) is in the shape of a right triangle as a whole, and the plurality of mounting grooves (12) are circumferentially distributed on the fixed shaft (9) based on the axis of the fixed shaft (9); the blade (10) is vertically rotatably installed in the mounting groove (12), and when the blade (10) is attached to the shorter leg of the mounting groove (12), the diameter of the blade (10) coincides with the diameter of the fixed shaft (9).

2. 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 alumina ceramic membrane, a plurality of support rods (11) are vertically fixed on the rotating plate (7), the plurality of support rods (11) are located on the side of the filter screen (8) close to the metal probe (302), and the plurality of support rods (11) are fixedly connected with the filter screen (8).

3. The airflow controller with constant effective value output at low voltage according to claim 1, characterized in that, The diameter of the fixed plate (6) is greater than the diameter of the rotating plate (7), a scraping strip (13) is vertically fixed and installed on the fixed plate (6), 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), and the scraping strip (13) is located on the back side of the filter screen (8) in the airflow advancing direction (D).

4. The airflow controller with constant effective value output at low voltage according to claim 3, characterized in that, The bottom end of the scraping strip (13) 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.

5. The airflow controller with constant effective value output at low voltage according to claim 4, characterized in that, A plurality of guide grooves (15) are arranged on the scraping strip (13) and the guide portion (14), the plurality of guide grooves (15) are vertically 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).

6. The airflow controller with constant effective value output at low voltage according to claim 1, characterized in that, The fixed plate (6) and the rotating plate (7) are made of plastic material, the fixed plate (6) is fixed on the upper side of the metal probe (302) by gluing, the rotating plate (7) is provided with a reverse "T" shaped ring groove (16) on the top, the metal probe (302) is provided with a ring-shaped convex (17) on the bottom, and the ring-shaped convex (17) on the bottom of the metal probe (302) is inserted into the ring groove (16) and connected with the rotating plate (7).

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