A soap film flowmeter for measuring large flow rates

Abstract

The present invention belongs to the technical field of measuring the flow of fluids continuously passing through an instrument, and discloses a soap film flowmeter for measuring large flow, including an upper cavity, a soap film tube, a soap liquid pool, a film-forming ring, and a film-forming ring lifting device. The upper cavity is sealed and connected to the upper part of the outer wall of the soap film tube, and the film-forming ring is connected to the film-forming ring lifting device. There are at least two soap film tubes, and the upper and lower parts of the outer wall of each soap film tube are respectively provided with infrared counter tubes. This technical solution disperses the capacity of large flow for each soap film tube by setting a plurality of soap film tubes, so that the accuracy of large flow measurement is the same as the measurement accuracy of each soap film tube; and the soap film formed by the outer wall of the soap film tube and the inner wall of the film-forming ring is torn or vibrated through the cracks of the film-forming ring under the action of the film-breaking column, thereby successfully breaking the film and avoiding the generation of double films. At the same time, the problem of accurate measurement of large flow and avoidance of double films is solved, so that the measurement condition is idealized and the detection data is accurate.

Description

Technical Field

[0001] The invention belongs to the technical field of measuring the flow of a fluid continuously passing through an instrument, and in particular relates to a soap film flowmeter for measuring a large flow. Background Art

[0002] The working principle and structural type of the soap film flowmeter are described in detail in the Metrology Verification Regulations of the People's Republic of China JJG586-2006 "Soap Film Flowmeter". In the prior art, the structural type of the soap film flowmeter is a soap film tube with a scale, an upper infrared pair tube is provided on the upper part of the outer wall of the soap film tube, a lower infrared pair tube is provided on the lower part of the outer wall of the soap film tube, the lower opening of the soap film tube is an air inlet, a film-forming ring is provided at the lower part of the soap film tube, and a soap film liquid is provided under the film-forming ring. Its working principle is: the measured gas enters the soap film tube through the lower opening of the soap film tube, i.e., the air inlet, and the film-forming ring produces a soap film from the soap film liquid, and then moves upward, and the soap film rises along the soap film tube. When the soap film rises to the lower infrared pair tube on the outer wall of the soap film tube, the timer starts timing, and when the soap film rises to the upper infrared pair tube on the outer wall of the soap film tube, the timer stops timing. The instantaneous flow rate flowing through the soap film flowmeter can be calculated by the measured time and the volume between the upper infrared pair tube and the lower infrared pair tube of the soap film tube. The electronic soap film flowmeter directly displays the instantaneous flow rate when the soap film passes through the lower and upper limits of a pair of sensors installed on the outer wall during its rising process, making the measurement data more accurate.

[0003] However, in actual work, we often encounter problems that are not suitable for solving by theory. According to the above theory, if a large flow rate needs to be measured, the larger the flow rate, the larger the volume of the soap film tube. The diameter of the soap film tube can be kept unchanged and the height of the soap film tube can be increased. However, the soap film is easy to break if the flow rate is very fast. Even if it is not broken, the time for the soap film to go from the lower photoelectric tube to the upper photoelectric tube is very short. The soap film may go from the bottom photoelectric tube to the top photoelectric tube in an instant. The smaller the time difference, the greater the timing error, and the error of the final measured flow rate will also be large. Another way is to make the soap film tube thicker and increase the diameter of the soap film tube. The larger the diameter of the soap film tube, the greater the influence of airflow pressure and gravity. The soap film will present a concave surface facing the airflow direction. The concave surface will bulge a certain height in the airflow direction, so the concave surface will affect the measurement of the photoelectric tube, and at the same time make the soap film unstable and easy to break. It brings errors to the flow measurement and cannot be measured accurately. People realize that soap film flowmeters cannot measure large flow rates, so they have to abandon soap film flowmeters, which is the most accurate measurement method, and use other indirect methods to measure flow rates. Therefore, in the prior art, there is a blank in the field of soap film flowmeters for large flow measurement.

[0004] In addition, assuming that the above problem is solved, during the measurement process, after the film-lifting button is pressed for the first time, an annular soap film will be formed on the outer wall of the soap film tube and the inner wall of the film-lifting ring. When the film-lifting button is pressed for the second time, the film-lifting ring will fall to the lower end of the soap film tube to form a new film that will cover the soap film tube. When the film-lifting ring is immersed in the soap liquid and the film-lifting button is released, the film-lifting ring moves upward under the elastic force of the spring. When the film-lifting ring is separated from the soap film liquid surface, a film will be formed again. In this way, two films will be formed in the process of pressing the film-lifting button once. In this way, it is necessary to record the time points when the two films pass through the two sets of sensors respectively, and calculate the time difference between each film passing through the two sets of sensors, and find the average value, which is the time difference × the volume of the soap film tube between the known sensor cross section = the flow rate per unit time through the soap film tube (unit L / min). Such a solution is not only cumbersome to calculate and interferes with the calculation of the flow rate, but also once any film breaks during the movement, resulting in data loss, it will cause measurement failure.

[0005] Therefore, it is necessary to provide a soap film flowmeter that can measure large flow rates, ensure accuracy and avoid double film. Summary of the invention

[0006] The soap film tube has an upper scale mark and a lower scale mark. An upper infrared counter tube is provided at the upper scale mark on the outer wall of the soap film tube, and a lower infrared counter tube is provided at the lower scale mark on the outer wall of the soap film tube.

[0007] There is no soap film flowmeter for large flow measurement in the prior art, and it is impossible to avoid double film formation in the soap film flowmeter. Other methods cannot ensure measurement accuracy. In view of the above defects of the prior art, this scheme is proposed, with the aim of providing a soap film flowmeter with a large range and avoiding double film formation in a large flow soap film flowmeter, which is specifically achieved through the following scheme.

[0008] A soap film flowmeter for measuring large flow rates comprises an upper cavity, a soap film tube, a soap liquid pool, a film-forming ring and a film-forming ring lifting device. The upper cavity is sealed and connected to the upper portion of the outer wall of the soap film tube, the film-forming ring is connected to the film-forming ring lifting device, there are at least two soap film tubes, and infrared counter tubes are respectively provided on the upper and lower portions of the outer wall of each soap film tube.

[0009] Furthermore, the soap film tubes share a film-forming ring, which is convenient to operate and easy to check whether the film has formed without checking one by one.

[0010] Furthermore, the film-forming ring is a non-perfect circle. If multiple soap film tubes are lined up in a row, a large soap film will be formed using a perfect circle film-forming ring. As mentioned above, large soap films are unstable and are greatly affected by gravity. They may also cause a concave-convex surface on the soap film, making the time when the soap film is received by the lower tube mouth of the soap film tube asynchronous. The volume of gas flowing through the soap film tube will change, causing errors in the measurement results. The soap film tubes lined up in a row can be applied to long elliptical soap film tubes, the short axis of the ellipse is slightly larger than the outer wall of the soap film tube, and the long axis of the ellipse is slightly larger than the total length of all the soap film tubes lined up in a row. In this way, since the short axis of the ellipse is shorter, it is not easy to form a concave-convex surface due to the influence of gravity, so that the measurement accuracy is higher.

[0011] Furthermore, the soap film tubes are evenly distributed, which can also stabilize the soap film at the bottom of each soap film tube, making each soap film more stable, which is conducive to accurate measurement of large flow rates.

[0012] Furthermore, the film-lifting ring is connected to two film-lifting ring lifting devices. The film-lifting pull rod passes through the film-lifting spring, one end of which is connected to the film-lifting button, and the other end is connected to the film-lifting ring. The film-lifting ring is connected to a film-lifting ring lifting device. If there are too many soap film tubes, the film-lifting ring is very large, and the side connected to the film-lifting ring lifting device may be higher than the other side, causing the soap films of each soap film tube to be out of sync, affecting the measurement accuracy.

[0013] Furthermore, the film-forming ring is provided with a crack. To prevent double film, the film-forming ring crack is used to tear the soap film between the outer wall of the soap film tube and the film-forming ring.

[0014] Furthermore, a film-breaking column is provided in the moving direction of the film-lifting ring, and the film-breaking column applies pressure to the vicinity of the crack on the film-lifting ring, causing the crack to become larger, and finally tearing the soap film between the outer wall of the soap film tube and the film-lifting ring.

[0015] Furthermore, a soap film tube support is provided on the outer wall of the soap film tube, and a film breaking column is provided on the soap film tube support. The outer wall of the soap film tube and the soap film tube support are sealed and connected.

[0016] Furthermore, the film-lifting ring is subjected to the force of the film-breaking column in the moving direction of the film-lifting ring, so that the film-lifting ring is broken along the crack.

[0017] Furthermore, the film-lifting ring is subjected to a force from the film-breaking column in a direction perpendicular to the film-lifting ring and the movement direction, so that the film-lifting ring is broken along the crack.

[0018] This technical solution disperses the capacity of each soap film tube for large flow by setting up multiple soap film tubes, so that the accuracy of large flow measurement is the same as the measurement accuracy of each soap film tube; and through the cracks in the film ring, the soap film formed by the outer wall of the soap film tube and the inner wall of the film ring is torn or vibrated under the action of the film breaking column, thereby successfully breaking the film and avoiding the formation of double films. At the same time, it solves the problems of accurate measurement of large flow and avoidance of double films, idealizes the measurement conditions, and makes the detection data accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 : Structural diagram of a prior art soap film flowmeter.

[0020] Figure 2 : Structural diagram of Example 1 of the soap film flowmeter for measuring large flow rates of the present invention.

[0021] Figure 3 : Structural diagram of soap film flowmeter embodiment 2 for measuring large flow rates of the present invention.

[0022] Figure 4 : Structural diagram of soap film flowmeter embodiment 3 for measuring large flow rates of the present invention.

[0023] Figure 5 : Schematic diagram of the positional relationship between the soap film tube and the film-forming ring of Example 3 of the present invention.

[0024] Figure 6 : Structural diagram of soap film flowmeter embodiment 4 for measuring large flow rates of the present invention.

[0025] Figure 7 : Schematic diagram of the positional relationship between the soap film tube and the film-forming ring of Example 4 of the present invention.

[0026] Figure 8 : Structural diagram of soap film flowmeter embodiment 5 for measuring large flow rates of the present invention.

[0027] Fig. 9 : Structural diagram of soap film flowmeter embodiment 6 for measuring large flow rates of the present invention.

[0028] Fig.10 : Structural diagram of soap film flowmeter embodiment 7 for measuring large flow rates of the present invention.

[0029] Fig.11 : Structural diagram of soap film flowmeter embodiment 8 for measuring large flow rates of the present invention.

[0030] Wherein: 1. upper cavity; 2. first upper sealing ring; 3. first upper infrared tube; 4. first soap film tube; 5. first lower infrared tube; 6. film lifting button; 7. film lifting spring; 8. film lifting ring and film lifting ring pull rod; 9. soap liquid pool; 10. second soap film tube; 11. second upper infrared tube; 12. third soap film tube; 13. third upper infrared tube; 14. second lower infrared tube; 15. third lower infrared tube; 16. third lower sealing ring; 17. film lifting ring; 18. soap film liquid; 19. exhaust port; 20. soap film tube bracket; 21. second lower sealing ring; 22. first lower sealing ring; 23. second upper sealing ring; 24. third upper sealing ring; 25. crack; 26. film breaking column. DETAILED DESCRIPTION

[0031] The technical solution is described in detail according to the accompanying drawings.

[0032] like Figure 1 The figure shows the principle of the soap film flowmeter of the prior art. The soap film tube is connected to the upper cavity 1. The upper cavity 1 is provided with an exhaust port 19. A sealing ring is provided between the upper cavity 1 and the soap film tube. An upper infrared transmitting tube and an upper infrared receiving tube are provided on the upper part of the soap film tube. A lower infrared transmitting tube and a lower infrared receiving tube are provided on the lower part of the soap film tube. A soap liquid pool 9 is provided under the soap film tube. The soap liquid pool 9 contains soap film liquid 18. A film-lifting ring 17 is immersed in the soap film liquid 18. The film-lifting ring 17 pulls up the soap film to cover the lower end of the soap film tube. The exhaust port 19 starts to exhaust air. The soap film rises in the soap film tube and passes through the lower infrared transmitting tube and the lower infrared receiving tube of scale B and continues to rise. After a period of time, the soap film passes through the upper infrared generating tube and the upper infrared receiving tube of scale A. The time when the soap film goes from scale B to scale A and the volume of the gas are recorded, and the flow rate of the gas can be known. The existing soap film flowmeter can only measure flow rates below 10L. The diameter of the soap film tube is 30mm. The accuracy of each soap film flowmeter is 0.5, that is, the error is 0.5%. If you need to measure a large flow rate, you need to replace it with a large diameter soap film tube. However, the larger the flow rate, the larger the volume of the soap film tube needs to pass through. The diameter of the soap film tube can be kept unchanged and the height of the soap film tube can be increased. However, the soap film is easy to break due to the high flow rate. Even if it is not broken, the time for the soap film to pass from the lower photoelectric tube to the upper photoelectric tube is very short. The soap film may pass from the bottom photoelectric tube to the top photoelectric tube in an instant. The smaller the time difference, the greater the timing error, and the error of the final measured flow rate will also be large. Another way is to make the soap film tube thicker and make the diameter of the soap film tube larger. The larger the diameter of the soap film tube, the greater the influence of airflow pressure and gravity. The soap film will present a concave surface facing the airflow direction. The concave surface will bulge a certain height in the airflow direction, so the concave surface will affect the measurement of the photoelectric tube. At the same time, the larger the diameter of the soap film, the more unstable the soap film will be, and the soap film page will be easily broken. These will bring errors to the flow measurement and cannot be accurately measured. For example, if you measure 30L and use a 60mm soap film tube, the error will reach 1%. If a larger flow rate is measured, the above-mentioned problems will occur. Even if the above-mentioned problems do not occur, the measured error will be very large and the measurement will lose its meaning.

[0033] The large flow soap film flowmeter of the present invention comprises a soap film tube 10, a soap liquid pool 9, a film ring 17 and a lifting device for the film ring 17. The film ring 17 is connected to the lifting device for the film ring 17, and is provided with at least one soap film tube 10. The upper and lower parts of each soap film tube 10 are respectively provided with infrared pairs of tubes. This technical solution solves the technical problem that the prior art cannot use a soap film flowmeter to measure a large flow by using at least two small soap film flow tubes, and avoids various problems caused by large-diameter soap film measurement. At the same time, the error of each soap film flowmeter single tube is 0.5%, and the error of a soap film tube measuring a flow of 10L is 0.05. To measure a flow of 100L, 10 soap film tubes measuring 10L are used, and the total error is 10*0.05=0.5, and the total flow is 100L, then the measured total error is 0.5 divided by 100, which is still 0.5%. It can be seen from this that no matter how large the flow is measured, the error is constant, and it is still the error of each soap film tube, that is, 0.5%.

[0034] Example 1

[0035] like Figure 2As shown, the soap film flowmeter for measuring large flow in this embodiment is provided with an upper cavity 1, three soap film tubes, a soap liquid pool 9, a film-forming ring 17 and a lifting device for the film-forming ring 17, wherein the three soap film tubes are respectively a first soap film tube 4, a second soap film tube 10 and a third soap film tube 12, which are arranged according to the positions of the three vertices of an equilateral triangle, each soap film tube has a diameter of 30 mm, the upper cavity 1 is sealedly connected to the outer walls of the three soap film tubes, the upper cavity 1 is sealedly connected to the outer walls of the three soap film tubes, the upper openings of the three soap film tubes are in the upper cavity 1, the upper cavity 1 is sealed with the first soap film tube 4 using a first upper sealing ring 2, the upper cavity 1 is sealed with the first soap film tube 4, and the upper cavity 1 is sealed with the first upper sealing ring 2. The second soap film tube 10 is sealed with a second upper sealing ring 23, the upper cavity 1 and the third soap film tube 12 are sealed with a third upper sealing ring 24, the upper cavity 1 is provided with an air extraction port 19, the upper part of the outer wall of the first soap film tube 4 is provided with a first upper infrared tube 3, the lower part of the outer wall of the first soap film tube 4 is provided with a first lower infrared tube 5, the upper part of the outer wall of the second soap film tube 10 is provided with a second upper infrared tube 11, the lower part of the outer wall of the second soap film tube 10 is provided with a second lower infrared tube 14, the upper part of the outer wall of the third soap film tube 12 is provided with a third upper infrared tube 13, and the lower part of the outer wall of the third soap film tube 12 is provided with a third lower infrared tube 15. A soap film tube bracket 20 is provided to fix the lower ends of the three soap film tubes, a first lower sealing ring 22 is provided between the soap film tube bracket 20 and the first soap film tube 4, a second lower sealing ring 21 is provided between the soap film tube bracket 20 and the second soap film tube 10, and a third lower sealing ring 16 is provided between the soap film tube and the third soap film tube 12. The film-lifting ring 17 lifting device is arranged on the soap film tube support 20. The film-lifting ring 17 lifting device comprises a film-lifting spring 7, a film-lifting ring pulling rod 8 and a film-lifting button 6. The film-lifting ring pulling rod 8 passes through the film-lifting spring 7, one end of which is connected to the film-lifting button 6, and the other end is connected to the film-lifting ring 17. The film-lifting ring 17 is a region separately divided for each soap film tube, and the plane where the film-lifting ring 17 is located is parallel to the plane where the lower tube mouth of the soap film tube is located. The film-lifting ring pulling rod 8 is perpendicular to the plane where the film-lifting ring 17 is located and connected to it.

[0036] During measurement, the button of the film-forming ring 17 is pressed and then released. The film-forming ring 17, which is set for each soap film tube, is stained with soap film liquid 18 to form a soap film. The film-forming ring 17 rises under the action of the film-forming spring 7. When it reaches the lower tube openings of the three soap film tubes, the soap film is covered under the tube openings. Under the action of the air suction port 19 of the upper cavity 1, the gas flows, causing the soap film in the soap film tube to move upward. When the soap film in the soap film tube reaches the infrared pair tube at the lower part of the soap film tube, the infrared pair tube records the moment. When the soap film in the soap film tube continues to rise to the infrared pair tube at the upper part of the soap film tube, the infrared pair tube records the moment. The difference between the above two moments is the time when the fluid passes through the soap film tube. Combined with the volume of the soap film tube between the upper and lower sets of infrared pair tubes, the maximum flow to be measured can be obtained.

[0037] Example 2

[0038] like Figure 3As shown, in this embodiment, on the basis of embodiment 1, the film-forming ring 17 is adjusted, and a separate soap film area is not set for each soap film tube, but the same soap film is used as a whole. The other structures are the same as those in embodiment 1 and are not described here. Sharing a film-forming ring 17 is convenient for operation, and it is easy to check whether the film has formed without checking one by one. Avoid accidental rupture of the soap film in a single area causing measurement failure.

[0039] During measurement, the button of the film ring 17 is pressed and then released. The film ring 17, which is stained with soap film liquid 18 to form a soap film, rises under the action of the film spring 7. When it reaches the lower tube mouth of the soap film tube, the soap film is covered below the tube mouth. Under the action of the air suction port 19 of the upper cavity 1, the gas flows, causing the soap film in the soap film tube to move upward. When the soap film in the soap film tube reaches the infrared pair tube at the lower part of the soap film tube, the infrared pair tube records this moment. When the soap film in the soap film tube continues to rise to the infrared pair tube at the upper part of the soap film tube, this moment is recorded. The difference between the above two moments is the time when the fluid passes through the soap film tube. Combined with the volume of the soap film tube between the upper and lower infrared pair tubes, the maximum flow rate to be measured can be obtained.

[0040] Example 3

[0041] like Figure 4 and Figure 5 As shown, the difference between this embodiment and embodiment 2 is that the three soap film tubes are arranged in a straight line, and the soap film tube is an elongated elliptical shape. The other structures are the same as those in embodiment 2 and will not be described here. The soap film tubes are arranged in a straight line, and a circular film-forming ring 17 will form a large soap film. As mentioned above, the large soap film is unstable and is greatly affected by gravity. It is also possible to bring about a concave-convex surface of the soap film, so that the time when the soap film is received by the lower tube mouth of the soap film tube is not synchronized, and the volume of gas flowing through the soap film tube will change, resulting in errors in the measurement results. The soap film tubes arranged in a straight line can be used for elongated elliptical soap film tubes, the short axis of the ellipse is slightly larger than the outer wall of the soap film tube, and the long axis of the ellipse is slightly larger than the total length of all soap film tubes arranged in a straight line. In this way, since the short axis of the ellipse is short, it is not easy to form a concave-convex surface under the influence of gravity, so that the measurement accuracy is higher.

[0042] During measurement, the button of the film-forming ring 17 is pressed and then released. The long elliptical film-forming ring 17, which is stained with soap film liquid 18 and forms a soap film, rises under the action of the film-forming spring 7. When it reaches the lower tube mouth of the soap film tube, the soap film is covered below the tube mouth. Under the action of the air suction port 19 of the upper cavity 1, the gas flows, causing the soap film in the soap film tube to move upward. When the soap film in the soap film tube reaches the infrared pair tube at the lower part of the soap film tube, the infrared pair tube records this moment. When the soap film in the soap film tube continues to rise to the infrared pair tube at the upper part of the soap film tube, this moment is recorded. The difference between the above two moments is the time when the fluid passes through the soap film tube. Combined with the volume of the soap film tube between the upper and lower infrared pair tubes, the maximum flow to be measured can be obtained.

[0043] Example 4

[0044] like Figure 6 and Figure 7 As shown, compared with Example 2, this embodiment adds two soap film tubes, a total of five soap film tubes, which are placed according to the positions of the five vertices of the regular pentagon. The other structures are the same as those in Example 2 and are not described here. The uniform distribution can stabilize the soap film at the bottom of the five soap film tubes, making each soap film more stable, which is conducive to the accurate measurement of large flow rates.

[0045] During measurement, the button of the film ring 17 is pressed and then released. The soap film ring, which is stained with soap film liquid 18 and forms a soap film, rises under the action of the film spring 7. When it reaches the lower tube openings of the five soap film tubes, the soap film is covered below the tube openings. Under the action of the air suction port 19 of the upper cavity 1, the gas flows, causing the soap film in the five soap film tubes to move upward. When the soap film in the five soap film tubes reaches the infrared pair tube at the lower part of the soap film tube, the infrared pair tube records the moment. When the soap film in the five soap film tubes continues to rise to the infrared pair tube at the upper part of the soap film tube, the moment is recorded. The difference between the above two moments is the time when the fluid passes through the soap film tube. Combined with the volume of the soap film tube between the upper and lower infrared pair tubes, the maximum flow to be measured can be obtained.

[0046] Example 5

[0047] like Figure 8 As shown, the difference between this embodiment and embodiment 4 is that a set of film-lifting ring 17 lifting device is added on the opposite side of the original film-lifting ring 17 lifting device. It ensures that the heights of both sides of the film-lifting ring 17 are the same, and the film-lifting ring 17 moves smoothly. The other structures are the same as those of embodiment 4, and will not be repeated here.

[0048] Example 6

[0049] like Fig. 9 As shown, the difference between this embodiment and embodiment 2 is that the film-lifting ring 17 has a crack 25 that runs through the film-lifting ring 17 obliquely downward, so that the film-lifting ring 17 can overlap each other at both sides of the crack 25, or can be separated from each other. The other structures are the same as those of embodiment 2, and will not be described here.

[0050] During measurement, the lifting device of the film-lifting ring 17 is pressed once, the film-lifting ring 17 is immersed in the soap liquid pool 9, the force applied to the lifting device of the film-lifting ring 17 is removed, the film-lifting ring 17 is connected to the film-lifting ring pull rod 8 and bounces up under the action of the film-lifting spring 7, the soap film contacts the lower surface of the soap film tube, the lower surface of the soap film tube is covered with soap film, and there is also an annular soap film in the annular space between the outer wall of the soap film tube and the film-lifting ring 17. Before the second measurement, the film-lifting pull rod is pressed quickly and forcefully, and the end of the film-lifting ring near the edge of the crack 25 connected to the film-lifting ring pull rod 8 rapidly drops under the action of force, while the other end of the crack 25 remains in its original position under the action of inertia, so that the film-lifting ring 17 has a relative movement at both ends of the crack 25, and the soap film in the annular space between the outer wall of the soap film tube and the film-lifting ring 17 is torn by the relative movement brought about by the inertia.

[0051] When the film-lifting ring 17 is immersed in the soap liquid pool 9 for the second time, the force on the film-lifting ring film-lifting ring pull rod 8 is removed, and the film-lifting ring 17 is connected to the film-lifting ring pull rod 8 and the film-lifting spring 7 and bounces up. Since the film-lifting ring 17 is provided with a crack 25 at the connection between the film-lifting ring pull rod 8 and the film-lifting ring 17 and the crack 25 is in the direction of the slash " / ", the end of the crack 25 near the edge of the film-lifting ring and the film-lifting ring pull rod 8 is at the right end of the slash " / ", and the other end of the crack 25 is at the right end of the slash " / ". At the left end of the slash “ / ”, when the film-lifting ring film-lifting ring pull rod 8 moves upward under the action of the film-lifting spring 7, the part of the film-lifting ring 17 at the right end of the slash “ / ” will move upward with the part of the film-lifting ring 17 at the left end of the slash “ / ”, so there is no relative motion problem caused by inertia, and the film-lifting ring 17 is connected as a whole by the film-lifting ring film-lifting ring pull rod 8 and bounces up under the action of the film-lifting spring 7, the soap film contacts the lower surface of the soap film tube, and the lower surface of the soap film tube is covered with soap film, completing the second measurement.

[0052] Each time a measurement is completed, the time it takes for the soap film to pass through the upper and lower pairs of infrared tubes is recorded respectively to obtain the time difference. The time difference × the volume of the soap film tube between the cross sections of the soap film tube = the flow rate passing through the soap film tube per unit time (unit L / min). If it is not under standard conditions, use the known compensation formula for conversion.

[0053] Example 7

[0054] like Fig.10 As shown, the difference between this embodiment and embodiment 6 is that a film breaking column 26 is provided on the movement track of the film removing ring 17 and on the soap film tube support 20. The other structures are the same as those of embodiment 6 and will not be described in detail here.

[0055] The film-lifting ring 17 has a crack 25, and the direction of the crack 25 is obliquely downward. The crack 25 cuts off the film-lifting ring 17. The outer wall of the soap film tube is provided with a soap film tube support 20, and a film-breaking column 26 is provided on the soap film tube support 20 above the crack 25 of the film-lifting ring 17. The film-breaking column 26 is a cylindrical structure. When the film-lifting ring 17 moves below the film-breaking column 26, the film-breaking column 26 presses the film-lifting ring 17 to give it a downward force. Due to the existence of the crack 25 on the film-lifting ring 17, the crack 25 of the film-lifting ring 17 gradually increases, thereby tearing the soap film downward. The film-lifting spring 7, the film-lifting pull rod and the film-lifting button 6 serve as the lifting device of the film-lifting ring 17. The film-lifting pull rod passes through the film-lifting spring 7, one end of which is connected to the film-lifting button 6, and the other end is connected to the film-lifting ring 17. The plane where the film-lifting ring 17 is located is parallel to the plane where the lower pipe mouth of the soap film tube is located. The film-lifting ring film-lifting ring pull rod 8 is perpendicular to the plane where the film-lifting ring 17 is located and connected to it.

[0056] Example 8

[0057] like Fig.11 As shown, the difference between this embodiment and embodiment 7 is that the shape of the membrane breaking column 26 is not cylindrical, but a columnar structure with thinner ends and thicker middle. The other structures are the same as those of embodiment 7 and will not be described here.

[0058] The film-lifting ring 17 has a crack 25, and the direction of the crack 25 is vertically downward. The crack 25 cuts off the film-lifting ring 17. The outer wall of the soap film tube is provided with a soap film tube support 20, and a film-breaking column 26 is provided on the soap film tube support 20 above the crack 25 of the film-lifting ring 17. The film-breaking column 26 is a thick upper and narrow lower structure. When the film-lifting ring 17 moves below the film-breaking column 26, the narrow mouth of the film-breaking column 26 enters the film-lifting ring 17. As the film-lifting ring 17 continues to move upward, the film-breaking column 26 gradually becomes thicker. The film-breaking column 26 gives the film-lifting ring 17 an outward supporting force. Because of the existence of the crack 25 on the film-lifting ring 17, the crack 25 of the film-lifting ring 17 gradually increases, thereby tearing the soap film outward. The film-lifting spring 7, the film-lifting pull rod and the film-lifting button 6 serve as the lifting device of the film-lifting ring 17. The film-lifting pull rod passes through the film-lifting spring 7, one end of which is connected to the film-lifting button 6, and the other end is connected to the film-lifting ring 17. The plane where the film lifting ring 17 is located is parallel to the plane where the lower pipe opening of the soap film tube is located. The film lifting ring film lifting ring pull rod 8 is perpendicular to the plane where the film lifting ring 17 is located and is connected thereto.

[0059] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and the present invention is not limited to the above-mentioned optimal embodiments. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the scope of protection of the present invention.

Claims

1. A soap film flowmeter for measuring large flow, comprising an upper cavity, a soap film tube, a soap liquid pool, a film ring and a film ring lifting device, wherein the upper cavity is sealed and connected to the upper part of the outer wall of the soap film tube, and the film ring is connected to the film ring lifting device, characterized in that: There are at least two soap film tubes, and the upper and lower parts of the outer wall of each soap film tube are respectively provided with infrared counter tubes; a film-breaking column is provided in the moving direction of the film-lifting ring, specifically, a soap film tube support is provided on the outer wall of the soap film tube, and a film-breaking column is provided on the soap film tube support; the film-lifting ring is subjected to the force of the film-breaking column in the moving direction of the film-lifting ring, so that the film-lifting ring is broken along the crack.

2. A soap film flowmeter for measuring large flow according to claim 1, characterized in that: The soap film tubes share a film-forming ring.

3. A soap film flowmeter for measuring large flow according to claim 2, characterized in that: The film-forming ring is a non-perfect circle.

4. A soap film flowmeter for measuring large flow according to any one of claims 1 to 3, characterized in that: Soap film tubes are evenly distributed.

5. A soap film flowmeter for measuring large flow according to claim 4, characterized in that: The film-lifting ring is connected to two film-lifting ring lifting devices.

6. The soap film flowmeter for measuring large flow according to any one of claims 1 to 3, characterized in that: The film-forming ring is provided with a crack.

7. A soap film flowmeter for measuring large flow according to claim 6, characterized in that: The film-lifting ring is subjected to a force from the film-breaking column in a direction perpendicular to the film-lifting ring and the moving direction, so that the film-lifting ring is broken along the crack.

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