Liquid input assembly for microflow measurement, flow measurement device and method

Abstract

The application discloses a liquid input assembly, a flow measurement device and a method for micro flow measurement, comprising: a liquid outlet pipe, the liquid outlet pipe comprising a horizontal liquid outlet section, the end of the horizontal liquid outlet section being provided with a liquid outlet port; a capillary receiving pipe, the capillary receiving pipe comprising a horizontal pipe section and a vertical pipe section which are in communication with each other, the horizontal pipe section being horizontally aligned with the horizontal liquid outlet section, the end of the horizontal pipe section being provided with a liquid receiving port, the end of the vertical pipe section being provided with a liquid discharge port, the first distance being provided between the end surface of the liquid receiving port and the end surface of the liquid outlet port, so that the liquid discharged from the liquid outlet port is intermittently sucked into the liquid receiving port, and the liquid discharge port intermittently drops the liquid into a liquid collecting container. The application solves the problem in the prior art that after a continuous liquid column is formed through a capillary tube, the liquid continuously flows into the container, so that the weighing balance lacks a stable reading time, and after the continuous liquid column flows into the container, the liquid column still causes the force between the capillary tube and the container to exist, if the flow changes slightly, the change in the shape of the liquid column will cause the change of the accessory force, thereby causing errors.

Description

Technical Field

[0001] The present invention relates to the field of flow measurement technology, and in particular to a liquid input component, a flow measurement device and a method for measuring micro flow. Background Art

[0002] Existing micro-flow measurement technologies generally employ mass methods, injecting the liquid to be measured into a container and then periodically weighing and accumulating the flow to obtain the average flow error. Liquid collection methods can be categorized as either submerged or suspended above the liquid surface within the collection container. Liquid collection methods for submerged liquids can also be categorized as whether or not the liquid is covered by an oil film.

[0003] In practical applications, these collection forms each have their own advantages and disadvantages: when the needle is immersed in the liquid surface, although the accumulation of liquid on the needle is eliminated, the surface tension formed between the needle and the liquid surface in the container generates an additional force acting on the balance. In the process of continuous injection of liquid into the container to make the liquid level continue to rise, the liquid outlet pressure and surface tension of the needle will continue to change, causing measurement errors. If the liquid surface is covered with an oil film, this error will be further increased.

[0004] Another improvement is to suspend the needle vertically on the capillary tube of the collection container to form a continuous liquid column with a very small height, and at the same time guide the liquid to flow continuously downward to keep the liquid level constant, thereby avoiding the influence of the liquid level change on the surface tension. However, the liquid column still creates a force between the needle and the container. If the flow rate changes slightly, the change in the shape of the liquid column will cause a change in the force acting on the attachment, thereby causing errors.

[0005] In addition, after forming a continuous liquid column through the capillary, the liquid continuously flows into the container, resulting in a lack of a stable reading time for the weighing balance, affecting the measurement accuracy. Summary of the Invention

[0006] The main purpose of the present invention is to provide a liquid input component for micro flow measurement, so as to solve the problem that micro flow measurement in the related art still has large measurement errors.

[0007] In order to achieve the above object, the present invention provides a liquid input assembly for measuring micro flow, comprising:

[0008] a liquid outlet pipe, the liquid outlet pipe comprising a horizontal liquid outlet section, an end of the horizontal liquid outlet section being provided with a liquid outlet;

[0009] A capillary receiving tube, the capillary receiving tube comprising a horizontal tube section and a vertical tube section that are interconnected, the horizontal tube section being horizontally aligned with the horizontal liquid outlet section, the end of the horizontal tube section being provided with a liquid receiving port, the end of the vertical tube section being provided with a liquid discharge port, the end surface of the liquid receiving port being spaced apart from the end surface of the liquid outlet so that liquid discharged from the liquid outlet is sucked into the liquid receiving port at intervals, and the liquid discharge port drips the liquid into a liquid collection container at intervals;

[0010] The inner diameter of at least some of the vertical pipe sections is greater than the inner diameter of the horizontal pipe section.

[0011] Furthermore, the first distance is smaller than the outer diameter of the liquid outlet and larger than the maximum distance required to form a continuous liquid column between the liquid outlet and the liquid receiving port.

[0012] Furthermore, the first distance is smaller than 1 / 2 of the outer diameter of the liquid outlet.

[0013] Furthermore, the capillary receiving tube includes a first tube segment and a second tube segment that are interconnected, the first tube segment includes the horizontal tube segment, the vertical tube segment includes the second tube segment, and the inner diameter of the second tube segment is greater than the inner diameter of the first tube segment;

[0014] The liquid receiving port is provided at the end of the first pipe section, and the liquid discharge port is provided at the end of the second pipe section.

[0015] Furthermore, the first pipe section also includes a corner section, the inner surface of the corner section is set to be an arc surface, and the corner radius of the corner section is 1D-2D, where D is the outer diameter of the first pipe section.

[0016] Furthermore, the first pipe segment and the second pipe segment are connected via a transition segment, and the transition segment is configured to be conical, wherein the small diameter end of the transition segment is connected to the first pipe segment, and the large diameter end of the transition segment is connected to the second pipe segment.

[0017] Furthermore, the end of the horizontal liquid outlet section close to the capillary receiving tube is configured as a tapered structure, and the diameter of the end of the tapered structure close to the capillary receiving tube is equal to the diameter of the liquid receiving port;

[0018] The first distance is the distance between an end of the tapered structure close to the capillary receiving tube and an end of the liquid receiving port.

[0019] According to another aspect of the present invention, there is provided a flow measurement device, comprising the above-mentioned liquid input assembly, and:

[0020] Internal evaporation shield;

[0021] An outer anti-evaporation component, wherein the outer anti-evaporation component cover is arranged on the inner anti-evaporation cover;

[0022] a weighing balance, arranged in the inner anti-evaporation cover;

[0023] a liquid collection container, disposed in the inner anti-evaporation cover and placed on the weighing balance, the liquid collection container having a receiving cavity for receiving the liquid to be measured;

[0024] The lower end of the vertical tube section of the capillary receiving tube passes through the top of the inner anti-evaporation cover and extends into the accommodating cavity, and the horizontal tube section of the capillary receiving tube is located between the inner anti-evaporation cover and the outer anti-evaporation assembly;

[0025] The horizontal liquid outlet section is horizontally aligned with the horizontal pipe section after passing through the outer anti-evaporation component.

[0026] Furthermore, a first humidity regulating structure is provided in the outer anti-evaporation component, and the first humidity regulating structure is used to increase the humidity in the outer anti-evaporation component.

[0027] Furthermore, the micro flow measurement device further includes an outer anti-evaporation cover, which is arranged on the top of the inner anti-evaporation cover and located on the inner side of the outer windproof cover;

[0028] The inner anti-evaporation cover covers the horizontal pipe section of the capillary receiving tube, and the horizontal liquid outlet section passes through the outer windproof cover and is horizontally aligned with the horizontal pipe section;

[0029] A moist water-absorbing strip is arranged in the inner anti-evaporation cover.

[0030] According to another aspect of the present invention, a flow measurement method is provided, which uses the above-mentioned flow measurement device and the following steps:

[0031] Squeezing the liquid of the measured flow rate from the liquid outlet of the liquid outlet pipe to form a slightly convex liquid surface;

[0032] Utilizing the liquid receiving port of the capillary receiving tube to absorb the liquid squeezed out of the liquid outlet at a time interval of T1;

[0033] After the liquid drips from the liquid outlet of the capillary receiving tube into the liquid collection container for the first time, reading the reading of the weighing balance at each time interval T1;

[0034] The liquid flow rate is determined based on the reading of the weighing balance at each time T1.

[0035] In the embodiments of the present invention, first, the horizontal alignment of the liquid outlet pipe and the capillary receiving tube converts the continuous liquid flow into equal-time interval suction, thereby providing a stable reading time for the weighing balance, improving the repeatability and accuracy of flow measurement, and thus solving the problem in the related art that after forming a continuous liquid column through the capillary tube, the liquid continuously flows into the container, resulting in a lack of a stable reading time for the weighing balance.

[0036] Secondly, the liquid sucked into the capillary receiving tube is stored in the capillary receiving tube. Since the inner diameter of the capillary receiving tube is extremely small, the contact area between its port and the external air is also extremely small, which significantly reduces the evaporation of the liquid.

[0037] In addition, because the liquid receiving port of the capillary receiving tube is horizontally aligned with the liquid outlet of the liquid outlet tube, the direction of movement of the extruded liquid is perpendicular to the direction of gravity, which can reduce the protrusion height of the micro-convex liquid surface, allowing the capillary receiving tube to be as close as possible to the liquid outlet, reducing the volume and mass of the micro-convex liquid surface, and reducing the impact of evaporation and residual droplets from the micro-convex liquid surface on the measurement results. At the same time, if a transient micro-liquid column is generated between the liquid outlet and the liquid receiving port, the capillary force between the liquid receiving end of the capillary receiving tube, the micro-liquid column, and the liquid outlet is horizontal, orthogonal to the measurement direction of the weighing balance, thereby reducing the impact on the weighing balance reading.

[0038] Then, because the liquid outlet of the capillary receiving tube drips the liquid into the liquid collection container at intervals, no continuous liquid column is formed between the liquid outlet and the liquid collection container, so that there is no additional force between the capillary receiving tube and the liquid collection container, and no measurement error is caused when the flow rate changes;

[0039] In addition, the pipe section with an increased inner diameter in the vertical pipe section is used to increase the liquid holding capacity, reduce the dripping frequency of the liquid from the liquid discharge port, and reduce the evaporation of the liquid. At the same time, when the inner diameter of the horizontal pipe section is small, the evaporation of the liquid in the horizontal pipe section can also be reduced, thereby improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention and to make other features, objects, and advantages of the present invention more apparent. The accompanying drawings and descriptions of the exemplary embodiments of the present invention are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 is a schematic cross-sectional view of a micro flow measurement device according to an embodiment of the present invention;

[0042] Figure 2 is a perspective structural diagram of a micro flow measurement device according to an embodiment of the present invention;

[0043] Figure 3 2 is a schematic structural diagram of a liquid outlet tube and a capillary receiving tube according to an embodiment of the present invention;

[0044] Figure 4 is a schematic structural diagram of a capillary receiving tube according to one embodiment of the present invention;

[0045] Figure 5 is a schematic cross-sectional view of a micro flow measurement device according to an embodiment of the present invention;

[0046] Among them, 1 liquid collection container, 101 containing cavity, 2 measured medium, 3 weighing balance, 4 inner anti-evaporation cover, 5 packing assembly, 50 sealing packing, 51 exhaust pipe, 6 outer wind shield, 7 liquid outlet pipe, 70 liquid outlet, 8 capillary receiving tube, 80 first pipe section, 801 corner section, 81 second pipe section, 82 liquid discharge outlet, 83 liquid receiving port, 84 horizontal pipe section, 85 vertical pipe section, 9 water absorption strip, 10 outer anti-evaporation cover, 11 evaporation well, 12 evaporable liquid, 13 receiving tank, 14 installation chamber. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that the terms used in this manner are interchangeable where appropriate to facilitate the description of the embodiments of the present invention.

[0049] In the present invention, the terms "upper," "lower," "inner," and the like indicate positions or locations based on those shown in the accompanying drawings. These terms are primarily intended to better describe the present invention and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0050] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0051] Furthermore, the terms "disposed," "provided with," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediary, or an internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0052] Additionally, the term "plurality" shall mean two or more.

[0053] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0054] To solve related technical problems, such as Figures 1 to 5 As shown, an embodiment of the present invention provides a liquid input component for measuring micro flow, comprising:

[0055] The liquid outlet pipe 7 includes a horizontal liquid outlet section, and a liquid outlet 70 is provided at the end of the horizontal liquid outlet section;

[0056] The capillary receiving tube 8 includes a horizontal tube section 84 and a vertical tube section 85 that are interconnected. The horizontal tube section 84 is horizontally aligned with the horizontal liquid outlet section. A liquid receiving port 83 is provided at the end of the horizontal tube section 84, and a liquid discharge port 82 is provided at the end of the vertical tube section 85.

[0057] There is a first distance between the end surface of the liquid receiving port 83 and the end surface of the liquid outlet 70, so that the liquid discharged from the liquid outlet 70 is sucked into the liquid receiving port 83 at intervals, and the liquid outlet 82 drips the liquid into the liquid collection container 1 at intervals;

[0058] The inner diameter of at least part of the vertical pipe section 85 is greater than the inner diameter of the horizontal pipe section 84 .

[0059] In this embodiment, the capillary receiving tube 8 is configured to be L-shaped, that is, the capillary receiving tube 8 includes a horizontal tube section 84 and a vertical tube section 85, and the liquid receiving port 83 and the liquid discharge port 82 on the capillary receiving tube 8 are respectively located at the ends of the horizontal tube section 84 and the vertical tube section 85.

[0060] The liquid outlet tube 7 also has a section that is horizontally aligned with the horizontal portion of the capillary receiving tube 8, namely, a horizontal liquid outlet section, and the liquid outlet 70 of the liquid outlet tube 7 is located at the end of the horizontal liquid outlet section. In this embodiment, the liquid outlet 70 of the liquid outlet tube 7 is not in direct contact with the liquid receiving port 83 of the capillary receiving tube 8, and a certain distance, namely, a first distance, is maintained between the two. The specific value of the first distance should satisfy the following requirements: the liquid squeezed out through the liquid outlet 70 can contact the liquid receiving port 83 after forming a micro-convex liquid surface of a certain size, and be sucked into the capillary receiving tube 8 through the liquid receiving port 83, and no continuous liquid column will be formed between the liquid outlet 70 and the liquid receiving port 83 after being sucked in. In other words, the capillary receiving tube 8 can absorb the liquid squeezed out from the liquid outlet 70 at intervals and drip the liquid into the liquid collection container 1 at intervals through the liquid discharge port 82.

[0061] In this embodiment, firstly, the horizontal alignment of the liquid outlet tube 7 and the capillary receiving tube 8 converts the continuous liquid flow into equal time interval inhalation, thereby providing a stable reading time for the weighing balance 3 and improving the repeatability and accuracy of the flow measurement;

[0062] Secondly, the liquid sucked into the capillary receiving tube 8 is stored in the capillary receiving tube 8. Since the inner diameter of the capillary receiving tube 8 is extremely small, the contact area between its port and the external air is also extremely small, which significantly reduces the evaporation of the liquid.

[0063] In addition, since the liquid receiving port 83 of the capillary receiving tube 8 is horizontally aligned with the liquid outlet 70 of the liquid outlet tube 7, the movement direction of the extruded liquid is perpendicular to the direction of gravity, which can reduce the protruding height of the micro-convex liquid surface, so that the capillary receiving tube 8 can be as close to the liquid outlet 70 as possible, reducing the volume and mass of the micro-convex liquid surface, and reducing the evaporation amount of the micro-convex liquid surface and the influence of residual droplets on the measurement results; at the same time, if an instantaneous tiny liquid column is generated between the liquid outlet 70 and the liquid receiving port 83, the capillary force between the liquid receiving end of the capillary receiving tube 8, the tiny liquid column, and the liquid outlet 70 is horizontal, which is orthogonal to the measurement direction of the weighing balance 3, thereby reducing the influence on the reading of the weighing balance 3.

[0064] At the same time, since the liquid outlet 82 of the capillary receiving tube 8 drips liquid into the liquid collection container 1 at intervals, no continuous liquid column is formed between the liquid outlet 82 and the liquid collection container 1, so that there is no additional force between the capillary receiving tube 8 and the liquid collection container 1, and no measurement error will be caused when the flow rate changes.

[0065] In addition, the pipe section with an increased inner diameter in the vertical pipe section is used to increase the liquid holding capacity, reduce the dripping frequency of the liquid from the liquid discharge port, and reduce the evaporation of the liquid. At the same time, when the inner diameter of the horizontal pipe section is small, the evaporation of the liquid in the horizontal pipe section can also be reduced, thereby improving the measurement accuracy.

[0066] To allow the capillary tube 8 to absorb the liquid to be measured at intervals, the first spacing must meet certain conditions. If the first spacing is too small, a continuous liquid column will form between the liquid outlet 70 of the liquid outlet tube 7 and the liquid receiving port 83 of the capillary tube 8. At this time, the capillary tube 8 is in a continuous liquid intake process, causing the liquid outlet 82 of the capillary tube 8 to continuously drip, and the weighing balance 3 lacks a suitable reading time. If the first spacing is too large, the micro-convex liquid surface squeezed through the liquid outlet 70 may not contact the liquid receiving port 83 of the capillary tube 8, resulting in the liquid not being properly absorbed into the capillary tube 8.

[0067] To this end, in this embodiment, Figure 3 As shown, the first spacing is smaller than the outer diameter of the liquid outlet 70 and greater than the maximum distance required to form a continuous liquid column between the liquid outlet 70 and the liquid receiving port 83. Furthermore, in a preferred embodiment, the first spacing is less than 1 / 2 of the outer diameter of the liquid outlet 70. In one embodiment, the minimum micro-convex droplet extruded through the liquid outlet 70 has a mass of 0.03 mg. The degree of droplet protrusion can be determined based on liquid tension.

[0068] In addition, it should be noted that in order to facilitate the formation of a certain micro-convex liquid at the end of the liquid outlet pipe 7, the end of the horizontal liquid outlet section of the liquid outlet pipe 7 in this embodiment is set to a conical structure close to the capillary receiving tube 8, and the diameter of the end of the conical structure close to the capillary receiving tube 8 is equal to the diameter of the liquid receiving port 83; the first spacing is the spacing between the end of the conical structure close to the capillary receiving tube 8 and the end of the liquid receiving port 83.

[0069] Based on the L-shaped configuration of the capillary receiving tube 8, this embodiment further improves upon it. Specifically, because the inner diameter of the capillary receiving tube 8 is very small, the liquid storage capacity is extremely limited. If the cumulative volume of the absorbed liquid exceeds the volume of the capillary tube, it will drip into the collection container. Once dripping, the liquid will expand into a flat, thin layer, significantly increasing its surface area and dramatically increasing its evaporation rate. Therefore, to increase the liquid holding capacity of the capillary receiving tube 8 and reduce its evaporation rate without affecting its capillary action, the capillary receiving tube 8 in this embodiment has a variable diameter structure, i.e., the inner diameter of at least some of the vertical tube sections 85 is larger than the inner diameter of the horizontal tube section 84.

[0070] Specifically, such as Figure 1 and Figure 2As shown, in this embodiment, the capillary receiving tube 8 includes a first tube segment 80 and a second tube segment 81 that are interconnected. The first tube segment 80 includes a horizontal tube segment 84, and the vertical tube segment 85 includes a second tube segment 81. The inner diameter of the second tube segment 81 is larger than the inner diameter of the first tube segment 80. The second tube segment 81 extends into the accommodating cavity 101, and the liquid discharge port 82 is located at the lower end of the second tube segment 81; the first tube segment 80 includes a horizontal section, and the liquid receiving port 83 is located at the end of the horizontal section.

[0071] In this embodiment, the first tube segment 80 has a smaller inner diameter, allowing it to absorb liquid and hold a certain mass of liquid through capillary action. The second tube segment 81 has a larger inner diameter, significantly increasing its liquid holding capacity. The interaction between the first and second tube segments 80, 81 allows the capillary receiving tube 8 to smoothly absorb liquid while increasing its liquid holding capacity and reducing liquid evaporation with a smaller cross-sectional area.

[0072] In summary, the present invention achieves the technical effect of reducing the error in tiny flow measurement and improving the accuracy of tiny flow measurement by improving the measuring device in multiple directions, thereby solving the problem that tiny flow measurement in related technologies still has large measurement errors.

[0073] Furthermore, since the capillary receiving tube 8 of the present invention is L-shaped, it has two structural forms after being divided into the first tube section 80 and the second tube section 81. One of them is that the first tube section 80 includes a portion of the horizontal tube section 84, and the second tube section 81 includes a portion of the horizontal tube section 84 and all the vertical tube sections 85. The other is that the first tube section 80 includes all the horizontal tube sections 84 and a portion of the vertical sections, and the second tube section 81 includes the remaining vertical tube sections 85. Since the liquid needs to flow horizontally first and then vertically in the capillary receiving tube 8, in order to make the flow process of the liquid smoother, the capillary receiving tube 8 in this embodiment is preferably a structural form in which the first tube section 80 includes all the horizontal tube sections 84 and a portion of the vertical tube sections 85, and the second tube section 81 only includes the remaining vertical tube sections 85.

[0074] Since the liquid flows vertically instead of horizontally in the capillary receiving tube 8 after being sucked in, the vertical liquid in the tube moves downward under the action of weight, but the horizontal liquid movement direction is perpendicular to the direction of gravity. Therefore, the horizontal liquid in the tube must be continuous with the vertical liquid at the corner of the capillary receiving tube 8 to achieve continuous liquid suction. To this end, it is necessary to ensure that the corner of the capillary receiving tube 8 is smooth as much as possible, without generating local resistance that would cause liquid continuity interruption or gas accumulation. If the radius of the corner is too large, it may cause the capillary receiving tube 8 to extend too long outside the liquid collection container 1, causing the balance to be overloaded. Therefore, the corner is further improved in the present embodiment.

[0075] Specifically, in this embodiment, the first pipe section 80 also includes a corner section 801, which connects the horizontal pipe section 84 and the vertical pipe section 85. The inner surface of the corner section 801 is configured as an arc, and the corner radius of the corner section 801 is 1D-2D, where D is the outer diameter of the first pipe section 80. Furthermore, to ensure smooth liquid suction, the liquid receiving port 83 opposite the liquid outlet pipe 7 is cylindrical so that capillary force is not affected by changes in pipe diameter. Furthermore, both the first pipe section 80 and the second pipe section 81 are cylindrical.

[0076] Since the inner diameter of the second pipe section 81 is larger than that of the first pipe section 80, in order to reduce the impact of the change in the inner diameter of the pipe section on the liquid in the first pipe section 80 after entering the second pipe section 81, Figure 4 As shown, in this embodiment, the first pipe section 80 and the second pipe section 81 are connected by a transition section 84. The transition section 84 is configured in a tapered shape, with the smaller diameter end of the transition section 84 connected to the first pipe section 80 and the larger diameter end of the transition section 84 connected to the second pipe section 81. This allows the liquid to fully infiltrate the inner wall of the pipe after entering the transition section 84 and gradually expel air, allowing the liquid to flow smoothly within the transition section 84 and the second pipe section 81. In one embodiment of the transition section 84, the angle between the generatrix of the transition section 84 and the axis is 10°-15°.

[0077] In addition, on this basis, the connection between the small diameter end of the transition section 84 and the first pipe section 80 can be made into an arc chamfer, and the connection between the large diameter end of the transition section 84 and the second pipe section 81 can also be made into an arc chamfer.

[0078] On the basis of the above-mentioned embodiment, this embodiment Figures 1 to 5 As shown, a micro flow measurement device based on a mass method is provided, the measurement device comprising:

[0079] Internal evaporation protection cover 4;

[0080] The outer anti-evaporation component 15 is provided on the inner anti-evaporation cover 4;

[0081] A weighing balance 3 is provided in an inner evaporation-proof cover 4;

[0082] The liquid collection container 1 is placed in the inner evaporation-proof cover 4 and placed on the weighing balance 3;

[0083] A packing assembly 5 is disposed in the liquid collection container 1. The packing assembly 5 is made of a low water absorption material and is breathable. A cavity 101 for accommodating the liquid to be measured is defined between the lower end of the packing assembly 5 and the bottom of the liquid collection container 1.

[0084] The capillary receiving tube 8 is configured to be L-shaped, with a liquid receiving port 83 and a liquid discharge port 82 at the upper and lower ends of the capillary receiving tube 8, respectively. The lower end of the capillary receiving tube 8 vertically passes through the packing assembly and extends into the accommodating cavity 101, and the upper end of the capillary receiving tube 8 passes through the inner anti-evaporation cover 4 and bends horizontally;

[0085] The liquid outlet pipe 7 includes a horizontal liquid outlet section, and a liquid outlet port 70 is provided at the end of the horizontal liquid outlet section. After passing through the outer anti-evaporation component 15, the liquid outlet port 70 of the liquid outlet pipe 7 is horizontally aligned with the liquid receiving port 83 and maintains a first spacing, so that the liquid discharged from the liquid outlet port 70 is sucked into the liquid receiving port 83 at intervals, and the liquid outlet 82 drips the liquid into the liquid collection container 1 at intervals.

[0086] In this embodiment, the installation process of the micro-flow measurement device can be as follows: place the liquid collection container 1 on the weighing scale 3 and arrange the packing assembly 5 within the liquid collection container 1. Of course, the packing assembly 5 can also be arranged within the liquid collection container 1 first, and then the liquid collection container 1 with the packing assembly 5 is placed on the weighing scale 3. The packing assembly 5 can be arranged in different ways depending on the type of packing. When the packing assembly 5 includes a foamed filler, the packing assembly 5 can be formed into the liquid collection container 1 by foaming. When the packing assembly 5 is a separate component, the packing assembly 5 can be installed within the liquid collection container 1 for use. To improve the liquid weighing capacity of the liquid collection container 1, the weight of the packing assembly 5 should be as low as possible, that is, the packing assembly 5 should be made of lightweight material. In this embodiment, a cavity 101 for accommodating the liquid to be measured is defined between the lower end of the packing assembly 5 and the bottom of the liquid collection container 1. This cavity 101 can accommodate a certain amount of liquid, namely, the measured medium 2. The volume of the cavity 101 should be greater than the volume of liquid required to complete the entire measurement process.

[0087] In addition, after the packing assembly 5 is arranged in the liquid collection container 1, the accommodating cavity 101 forms a relatively closed space, thereby reducing the influence of external airflow on the evaporation amount of the liquid in the accommodating cavity 101, and constraining the accommodating cavity 101 within a suitable range, which is conducive to measurement.

[0088] In order to allow the liquid in the liquid receiving tube to be smoothly injected into the accommodating cavity 101 , it is necessary to discharge the air in the accommodating cavity 101 while injecting the liquid into the accommodating cavity 101 , thereby maintaining the internal and external pressure balance and allowing the liquid to flow smoothly.

[0089] The present invention places the accommodating cavity 101 in the liquid collection container 1 in a relatively closed environment by providing the packing assembly 5. The liquid to be measured entering the accommodating cavity 101 is not easily affected by external airflow, thereby reducing the evaporation of the liquid to be measured. At the same time, the packing assembly 5 constrains the accommodating cavity 101 within a suitable range. Furthermore, since the packing assembly 5 is air permeable, when the liquid to be measured flows into the accommodating cavity 101, the gas in the accommodating cavity 101 can be discharged, allowing the liquid to be measured to flow in smoothly.

[0090] In this embodiment, since an inner anti-evaporation cover 4 and an outer anti-evaporation component 15 are provided, in order to allow the air in the internal space to flow, exhaust holes can be opened on the inner anti-evaporation cover 4 and the outer anti-evaporation component 15, or the lower ends of the inner anti-evaporation cover 4 and the outer anti-evaporation component 15 are in non-sealed contact with the supporting surface (such as a desktop).

[0091] After placing the liquid collection container 1, the inner evaporation shield 4 can be installed over the weighing scale 3 and the liquid collection container 1. This arrangement reduces the impact of external airflow on the liquid within the liquid collection container 1, thereby reducing evaporation and, consequently, measurement errors. The overall dimensions of the inner evaporation shield 4 can be designed based on the dimensions of the weighing scale 3 and the liquid collection container 1, and are not limited in this embodiment. A first mounting hole can be defined at the upper end of the inner evaporation shield 4, corresponding to the center of the liquid collection container 1, for passage of the capillary receiving tube 8.

[0092] The vertical tube section 85 of the capillary receiving tube 8 passes through the first mounting hole in the inner evaporation shield 4 and extends into the packing assembly 5. The vertical tube section 85 then penetrates the packing assembly 5, allowing the liquid in the capillary receiving tube 8 to be injected into the receiving cavity 101 of the liquid collection container 1. The horizontal tube section 84 of the capillary receiving tube 8 is located above the inner evaporation shield 4 and is used to cooperate with the liquid outlet pipe 7 to draw the liquid squeezed out of the liquid outlet pipe 7 into the capillary receiving tube 8.

[0093] After the capillary receiving tube 8 is positioned, the outer evaporation prevention assembly 15 can be installed outside the inner evaporation prevention cover 4 and onto the capillary receiving tube 8. A second mounting hole can be provided on the side of the outer evaporation prevention assembly 15, through which at least a portion of the liquid outlet tube 7 can be horizontally extended to correspond with the liquid receiving port 83 of the capillary receiving tube 8. During the injection process, liquid flows out through the liquid outlet 70 of the liquid outlet tube 7 and is drawn into the capillary receiving tube 8 through the liquid receiving port 83. Therefore, the outer evaporation prevention assembly 15 can reduce the impact of external airflow changes on the liquid between the liquid outlet 70 and the liquid receiving port 83, thereby reducing the evaporation of this portion of liquid and thereby minimizing measurement errors.

[0094] In addition, it should be noted that when the filler assembly 5 is formed in the liquid collection container 1 by foaming, the capillary receiving tube 8 can be first positioned in the middle of the liquid collection container 1 through specific tooling, and then the filler assembly 5 can be formed between the capillary receiving tube 8 and the side wall of the liquid collection container 1.

[0095] Since a packing assembly 5 is arranged in the liquid collection container 1, and the packing assembly 5 has the characteristics of low water absorption and breathability, after the liquid is injected into the containing chamber in the liquid collection container 1, the air in the containing chamber can be discharged through the packing assembly 5, so that the pressure in the containing chamber is consistent with the ambient pressure, ensuring that the speed at which the liquid is absorbed is constant and is not affected by the amount of liquid injected.

[0096] In summary, the present invention achieves the technical effect of reducing the error in tiny flow measurement and improving the accuracy of tiny flow measurement by improving the measuring device in multiple directions, thereby solving the problem that tiny flow measurement in related technologies still has large measurement errors.

[0097] Since the packing component 5 in the present invention needs to have low water absorption and air permeability, in one embodiment of the packing component 5, the packing component 5 is made of a porous material with low water absorption. The tiny pores can be used to discharge air after the liquid is injected into the receiving cavity 101, thereby balancing the internal and external pressures. For example, a polymer material with micropores such as polyamide, polyethylene, and polypropylene can be used.

[0098] In another embodiment of the packing assembly 5, as Figure 1 and Figure 2 As shown, the packing assembly 5 includes a sealing packing 50 and an exhaust pipe 51. The sealing packing 50 is made of a material with low water absorption and is not breathable. The ventilation requirement of the packing assembly 5 is achieved through the exhaust pipe 51, so the exhaust pipe 51 passes through the sealing packing 50. After the liquid is injected into the receiving cavity 101, the air in the receiving cavity 101 can be discharged through the exhaust pipe 51, thereby maintaining the internal and external pressure balance.

[0099] In this embodiment, the sealing filler 50 is made of a lightweight foamed material with low water absorption and good elasticity, and the inner diameter of the exhaust pipe 51 is the same as the inner diameter of the liquid outlet pipe 7. The weight of the sealing filler 50 and the exhaust pipe 51 should be as small as possible to improve the liquid weighing capacity of the liquid collection container 1. After the sealing filler 50 is formed by foaming between the capillary receiving tube 8 and the inner wall of the liquid collection container 1, the inner diameter value of the liquid pipe 7 is obtained based on the minimum flow rate being measured, and the same exhaust pipe 51 is selected as the standard exhaust pipe 51. The exhaust pipe 51 is then made to penetrate the sealing filler 50 to achieve constant speed "liquid in, air out". Finally, for other measured flow rates, an integer multiple of the standard exhaust pipes 51 can be inserted into the sealing filler 50 to achieve pressure balance under different flow rates.

[0100] In another embodiment, the sealing filler 50 may be a prefabricated component. During prefabrication, at least two axially extending through-holes may be formed in the sealing filler 50. Since the sealing filler 50 is made of an elastic material, one through-hole allows the second tube section 81 of the capillary receiving tube 8 to pass through and securely fit therewith, while the other through-hole allows the exhaust pipe 51 to pass through and securely fit therewith. The outer diameter of the sealing filler 50 matches the inner diameter of the liquid collection container 1. Due to the elasticity of the sealing filler 50, the sealing filler 50 can be inserted into the liquid collection container 1 and secured thereto.

[0101] In a preferred embodiment of the exhaust pipe 51, since the exhaust pipe 51 is used to exhaust the gas in the liquid collection container 1 after the liquid enters the liquid collection container 1, when the inner diameter of the exhaust pipe 51 is the same as the inner diameter of the liquid outlet pipe 7, it is inevitable that the internal and external pressures of the liquid collection container 1 can be balanced. However, considering that the viscosity of the gas is lower than that of the liquid, the gas discharge rate will be higher than the liquid entry rate, and the inner diameter of the exhaust pipe 51 will also affect the evaporation rate of the liquid in the liquid collection container 1. Therefore, in this embodiment, the inner diameter of the exhaust pipe 51 is set to be smaller than the inner diameter of the liquid outlet pipe 7. This allows the liquid evaporation rate to be further reduced while achieving "liquid in, gas out" at equal speeds, thereby improving measurement accuracy.

[0102] In the liquid collection container 1, the liquid outlet 82 of the capillary receiving tube 8 should not come into contact with the liquid surface already collected in the liquid collection container 1. The advantages of this are: first, it avoids the influence of surface tension, buoyancy, liquid pressure and other forces caused by the liquid outlet 82 being inserted into the liquid surface on the flow of liquid in the capillary receiving tube 8, thereby ensuring that the liquid discharge flow rate is stable and does not change due to the increase in the liquid level in the liquid collection container 1.

[0103] Secondly, the conventional method of inserting liquid outlet 82 below the liquid surface requires a certain amount of liquid to be pre-stored in liquid collection container 1 to cover liquid outlet 82. This reduces the effective weighing range and requires the use of a balance with a larger capacity, resulting in a corresponding amount of weighing error and limiting overall measurement accuracy. However, by controlling liquid outlet 82 of capillary receiving tube 8 so that it does not contact the surface of the collected liquid in liquid collection container 1, there is no need for pre-stored liquid in liquid collection container 1. The effective weighing range accounts for at least 70% of the balance, allowing the use of a balance with a smaller capacity, further increasing the minimum weighing value and significantly improving overall measurement accuracy.

[0104] To achieve the above objectives, the length of the liquid outlet 82 extending from the lower end of the sealing packing 50 needs to be determined based on the volume of liquid to be collected in the liquid collection container 1. Specifically, the distance between the liquid outlet 82 and the inner bottom surface of the liquid collection container 1 is greater than the height of the liquid in the receiving cavity 101 during the measurement process.

[0105] In order to further reduce the evaporation of the liquid to be measured, Figure 5 As shown, the micro-flow measurement device in this embodiment also includes an evaporation well 11, which is disposed within the inner evaporation shield 4. An axially extending mounting chamber 14 is provided within the evaporation well 11. The mounting chamber 14 is sleeved onto the outside of the liquid collection container 1 and the weighing scale 3, with a gap between the mounting chamber 14 and the liquid collection container 1 and the weighing scale 3. A second humidity adjustment structure 13 is provided above the evaporation well, configured to increase the humidity within the mounting chamber. In one embodiment, the second humidity adjustment structure 13 comprises a receiving tank disposed at the upper end of the evaporation well, which contains an evaporable liquid.

[0106] Specifically, it should be noted that in this embodiment, an additional evaporation well 11 is disposed inside the inner evaporation shield 4. This evaporation well 11 is sleeved onto the weighing scale 3 and the liquid collection container 1 via a mounting chamber 14. A gap is maintained between the evaporation well 11 and the weighing scale 3 and the liquid collection container 1, preventing contact. This prevents the weight of the evaporation well 11 from affecting the weighing scale 3. In this embodiment, the mounting chamber 14 is an axially continuous chamber, with the weighing scale 3 located at its lower portion. The capillary receiving tube 8 can enter the liquid collection container 1 through its upper portion.

[0107] To reduce evaporation of the liquid in liquid collection container 1, the humidity of the gas within inner anti-evaporation cover 4 needs to be increased. To this end, in this embodiment, a receiving groove 131 is provided at the upper end of evaporation well 11. Receiving groove 131 is filled with evaporable liquid 132. The evaporation of the liquid in receiving groove 131 saturates the humidity within inner anti-evaporation cover 4 and maintains it constant, thereby minimizing evaporation of the liquid in liquid collection container 1 and further improving measurement accuracy.

[0108] In one embodiment of the accommodating groove 131 , the accommodating groove 131 may be configured as an annular groove opened along the circumference of the evaporation well 11 , and the annular groove is located outside the installation chamber 14 .

[0109] On the basis of the above embodiment, in order to further reduce the evaporation of liquid, as Figure 5As shown, the outer evaporation prevention assembly in this embodiment includes an outer windshield 6 and an outer evaporation prevention cover 10. The outer evaporation prevention cover 10 is disposed on top of the inner evaporation prevention cover 4, and the outer windshield 6 is disposed outside the outer evaporation prevention cover 10 and the inner evaporation prevention cover 4. The upper end of the capillary receiving tube 8 extends into the outer evaporation prevention cover 10, and the liquid outlet 70 of the liquid outlet tube 7 passes through the outer windshield 6 and the outer evaporation prevention cover 10 in sequence and is horizontally aligned with the liquid receiving port 83. A first humidity regulating structure 9 is disposed within the outer evaporation prevention cover 10, and is used to increase the humidity within the outer evaporation prevention cover 10. In one embodiment, the first humidity regulating structure 9 includes a wetted water-absorbing strip embedded in the outer evaporation prevention cover 10.

[0110] Specifically, in this embodiment, the outer evaporation prevention cover 10 is provided on the top of the inner evaporation prevention cover 4 and is located on the inner side of the outer wind shield 6; the outer evaporation prevention cover 10 covers the portion of the capillary receiving tube 8 extending out of the inner evaporation prevention cover 4, that is, it covers at least the horizontal tube section 84 of the capillary receiving tube 8, and the liquid outlet 70 of the liquid outlet pipe 7 passes through the outer evaporation prevention cover 10, that is, the horizontal liquid outlet section is horizontally aligned with the horizontal tube section 84 after passing through the outer evaporation prevention cover 10; a moist water absorbent strip is provided inside the outer evaporation prevention cover 10.

[0111] Specifically, because the liquid outlet 70 of the liquid outlet tube 7 and the liquid receiving port 83 of the capillary receiving tube 8 are not directly connected, but rather maintain a certain distance between them, the liquid to be measured between the liquid outlet 70 and the liquid receiving port 83 may come into contact with the outside air, resulting in a certain amount of evaporation. To this end, in this embodiment, an outer evaporation shield 10 is arranged on top of the inner evaporation shield 4. The outer evaporation shield 10 covers the liquid outlet 70 and the liquid receiving port 83, and a wet water absorption strip is arranged within the outer evaporation shield 10. The liquid contained in the water absorption strip can bring the air humidity within the outer evaporation shield 10 to a stable saturated state, thereby saturating the air humidity near the liquid outlet 70 and the liquid receiving port 83, reducing the amount of evaporation of the liquid during the process of being drawn into the capillary receiving tube 8 through the liquid receiving port 83, and further improving measurement accuracy.

[0112] Furthermore, the water absorbing strips in this embodiment are provided in two circles, and the two circles of water absorbing strips are respectively embedded in the inner top surface of the outer anti-evaporation cover 10 and the outer top surface of the inner anti-evaporation cover 4 .

[0113] According to another aspect of the present invention, a method for measuring a small flow rate is provided, which uses the above-mentioned small flow rate measuring device and the following steps:

[0114] The liquid to be measured is squeezed out from the liquid outlet 70 of the liquid outlet pipe 7 to form a slightly convex liquid surface;

[0115] The liquid squeezed out from the liquid outlet 70 is sucked in at a time interval of T1 by the liquid receiving port 83 of the capillary receiving tube 8;

[0116] After the liquid is first discharged from the capillary receiving tube 8 and drips into the liquid collecting container 1, the reading of the weighing balance 3 is read at each time interval T1;

[0117] The liquid flow rate is determined based on the reading of the weighing balance 3 at each time T1.

[0118] Specifically, in this embodiment, the liquid to be measured is squeezed out of the liquid outlet 70 of the liquid outlet tube 7, forming a slightly convex liquid surface. Once the liquid surface contacts the liquid receiving port 83 of the capillary receiving tube 8, it is rapidly drawn in and cut off by capillary action, gradually accumulating within the vertical portion of the capillary receiving tube 8. Once a certain mass of liquid has accumulated within the vertical portion, the liquid drips from the liquid outlet 82 at the lower end of the vertical portion into the liquid collection container 1. The mass of the liquid collection container 1 is then determined using a weighing scale 3, thereby obtaining the mass of the dripping liquid. The mass method can be used to calculate the liquid flow rate. When using the mass method, the liquid flow rate can be calculated by accumulating the readings of each T1.

[0119] Because there is a gap between the liquid outlet 70 of the liquid outlet tube 7 and the liquid receiving port 83 of the capillary receiving tube 8 in the present invention, the liquid squeezed out of the liquid outlet 70 must form a certain micro-convex liquid surface before it can be absorbed by the liquid receiving port 83. In this embodiment, time T1 is the sum of the time required to form the micro-convex liquid surface and the time required for the liquid receiving port 83 to absorb the portion of liquid. Therefore, the specific value of T1 needs to be designed based on the properties of the liquid to be measured, the structure of the liquid outlet tube 7, and the structure of the capillary receiving tube 8, and this embodiment does not impose any limitation on its specific value.

[0120] When the micro-flow measurement device includes an evaporation well and an outer evaporation shield, the humidity of the air inside the inner evaporation shield and the air inside the outer evaporation shield are first controlled to reach a set value during flow measurement. Then, the liquid to be measured is injected into the liquid outlet pipe to perform the flow measurement process described above. During the measurement process, the humidity of the air inside the inner evaporation shield and the air inside the outer evaporation shield are monitored in real time and controlled simultaneously, thereby reducing the amount of liquid evaporation during the measurement process.

Claims

1. A liquid input component for measuring micro flow, characterized in that: include: a liquid outlet pipe, the liquid outlet pipe comprising a horizontal liquid outlet section, an end of the horizontal liquid outlet section being provided with a liquid outlet; A capillary receiving tube, the capillary receiving tube comprising a horizontal tube section and a vertical tube section that are interconnected, the horizontal tube section being horizontally aligned with the horizontal liquid outlet section, the end of the horizontal tube section being provided with a liquid receiving port, and the end of the vertical tube section being provided with a liquid discharge port; A first distance is provided between the end surface of the liquid receiving port and the end surface of the liquid outlet, so that the liquid discharged from the liquid outlet is sucked into the liquid receiving port at intervals, and the liquid outlet drips the liquid into the liquid collection container at intervals; The inner diameter of at least part of the vertical pipe sections is larger than the inner diameter of the horizontal pipe sections; The first distance is smaller than the outer diameter of the liquid outlet and larger than the maximum distance required to form a continuous liquid column between the liquid outlet and the liquid receiving port.

2. The liquid input assembly according to claim 1, characterized in that The first distance is smaller than 1 / 2 of the outer diameter of the liquid outlet.

3. The liquid input assembly according to claim 1, characterized in that The capillary receiving tube includes a first tube segment and a second tube segment, the first tube segment includes the horizontal tube segment, the vertical tube segment includes the second tube segment, and the inner diameter of the second tube segment is greater than the inner diameter of the first tube segment; The liquid receiving port is provided at the end of the first pipe section, and the liquid discharge port is provided at the end of the second pipe section.

4. The liquid input assembly according to claim 3, characterized in that The first pipe section further includes a corner section, the inner surface of the corner section is configured as an arc surface, and the corner radius of the corner section is 1D-2D, where D is the outer diameter of the first pipe section.

5. The liquid input assembly according to claim 4, characterized in that The first pipe section and the second pipe section are connected via a transition section. The transition section is configured to be conical. The small diameter end of the transition section is connected to the first pipe section, and the large diameter end of the transition section is connected to the second pipe section.

6. The liquid input assembly according to claim 5, characterized in that An end of the horizontal liquid outlet section close to the capillary receiving tube is configured as a tapered structure, and a diameter of the end of the tapered structure close to the capillary receiving tube is equal to a diameter of the liquid receiving port; The first distance is the distance between an end of the tapered structure close to the capillary receiving tube and an end of the liquid receiving port.

7. A flow measurement device, characterized in that: The liquid input assembly according to any one of claims 1 to 6, and: Internal evaporation shield; An outer anti-evaporation component, wherein the outer anti-evaporation component cover is arranged on the inner anti-evaporation cover; a weighing balance, arranged in the inner anti-evaporation cover; a liquid collection container, disposed in the inner anti-evaporation cover and placed on the weighing balance, the liquid collection container having a receiving cavity for receiving the liquid to be measured; The lower end of the vertical tube section of the capillary receiving tube passes through the top of the inner anti-evaporation cover and extends into the accommodating cavity, and the horizontal tube section of the capillary receiving tube is located between the inner anti-evaporation cover and the outer anti-evaporation assembly; The horizontal liquid outlet section is horizontally aligned with the horizontal pipe section after passing through the outer anti-evaporation component.

8. The flow measurement device according to claim 7, characterized in that: A first humidity regulating structure is provided in the outer anti-evaporation component, and the first humidity regulating structure is used to increase the humidity in the outer anti-evaporation component.

9. A flow measurement method, characterized in that: Using the flow measurement device as claimed in claim 7, and the following steps: Squeezing the liquid of the measured flow rate from the liquid outlet of the liquid outlet pipe to form a slightly convex liquid surface; Utilizing the liquid receiving port of the capillary receiving tube to absorb the liquid squeezed out of the liquid outlet at a time interval of T1; After the liquid drips from the liquid outlet of the capillary receiving tube into the liquid collection container for the first time, reading the reading of the weighing balance at each time interval T1; The liquid flow rate is determined based on the reading of the weighing balance at each time T1.

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