Utrasonic flow meter with u-type measurement tube

Abstract

Provided is an ultrasonic flow meter with a U-type measurement tube. The ultrasonic flow meter of the present invention is of an ultrasonic sensor straight pipe type, in which the ultrasonic flow meter with high reliability and excellent measurement performance is provided by minimizing a path difference in the horizontal flow of a fluid in a measurement conduit of the U-type flow meter, the influence of an air layer generated in a pipe can be minimized because the axial line of a connection conduit and the axial line of a measurement conduit form a step therebetween, and manufacturing and production can be facilitated due to a simple structure.

Description

Ultrasonic flow meter with U-shaped measuring tube

[0001] The present invention relates to a flow meter having a U-shaped measuring tube in which a horizontal pipe connecting pipe and an ultrasonic measuring pipe are stepped, in which the flow rate is measured by utilizing the difference in the propagation times of the forward and reverse directions of ultrasonic waves propagating in a fluid, by utilizing the characteristic that the propagation speed of ultrasonic waves propagating in a fluid flowing through a pipe becomes faster when in the same direction as the flow direction of the fluid, that is, in the forward direction, and becomes slower when in the direction opposite to the fluid flow.

[0002] An ultrasonic flow meter is a means of measuring the amount of fluid flowing in a pipe. It measures the speed of ultrasonic waves propagating in the fluid by forming a measuring pipe that can secure a transmission and reception path of ultrasonic waves within a certain portion of the fluid flowing in the pipe when ultrasonic waves propagate in the fluid. The shape of the measuring pipe that secures the propagation path of the ultrasonic waves varies depending on the diameter. In large-diameter ultrasonic flow meters, an inclined straight pipe type measuring pipe is mainly used, in which the propagation path of the ultrasonic waves forms a certain angle with the direction of the fluid flow. In small-diameter flow meters, such as ultrasonic water meters, a reflector-type ultrasonic flow meter is mainly applied and used, which secures the propagation path of the ultrasonic waves along the movement path of the fluid in the pipe using a reflector. In extremely small-diameter flow meters for industrial or medical purposes, such as semiconductor equipment, a flow meter with a U-shaped measuring pipe is used.

[0003] A flow meter having a small-diameter ultrasonic sensor and a straight U-shaped measuring tube is configured with a straight measuring tube in which ultrasonic sensors are installed facing each other, and the measuring tube is formed to have a step with respect to a connecting tube consisting of an inlet tube and an outlet tube, so that the fluid flowing downward from the inlet tube on the upstream side of the measuring tube flows into a horizontal measuring tube through a downward flow tube, and the fluid flowing horizontally from the measuring tube and flowing out flows into the outlet tube through an upward flow tube, which is an outlet space.

[0004] In the reference drawing of the conventional U-shaped ultrasonic flow meter of FIG. 2 referred to here, the ultrasonic propagation path of the measuring pipe (30) is the distance (d1) formed by the space between the ultrasonic sensor (40), the measuring pipe (31), and the downward flow pipe (11), the length (L1) of the measuring pipe (31), and the distance (d2) formed by the space of the upward flow pipe (12) between the measuring pipe (31) and the ultrasonic sensor (41), that is, d1 + L1 + d2, and it can be seen that the fluid flow in the d1, d2 section is vertical flow, and in the L1 section is horizontal flow.

[0005] The velocity v of the fluid flowing at a velocity V at a constant angle Θ to the propagation path of the ultrasonic waves is expressed as VcosΘ, and when Θ=90 degrees, v=0, so the horizontal movement path of the fluid in the upper part of the measuring pipe is L1, and in the lower part is d1+L1+d2, so the maximum difference in the horizontal flow path of the fluid in the measuring pipe is d1+d2, and this soon causes a measurement error, so that it is difficult to use a U-shaped measuring pipe. In the present invention, a technology that can apply a measuring pipe to an ultrasonic flow meter that uses a U-shaped measuring pipe that is not restricted by the diameter of the measuring pipe is provided, so as to increase the measurement reliability, and an ultrasonic flow meter having a U-shaped measuring pipe that can also have a backflow prevention function simply added by using a pipe structure according to the needs of the field is proposed.

[0006]

[0007] As a means of solving the above problem, a method of minimizing the path difference of the horizontal flow of fluid within a measuring pipe is provided by applying an oblong pipe structure formed with a cross-sectional area greater than that of a cylinder, as shown in Fig. 3, instead of the generally used cylindrical pipe structure, for the downward flow pipe connecting the inlet pipe to the measuring pipe and the upward flow pipe connecting the measuring pipe to the outlet pipe, thereby reducing the distance (d1) between the ultrasonic sensor and the measuring pipe and changing the flow of fluid between the ultrasonic sensor and the measuring pipe from the upward or downward vertical flow to the up, down, left, and right omnidirectional flow as shown in Fig. 3-b, thereby providing a means of minimizing the path difference in the horizontal direction of the fluid flow, thereby providing an ultrasonic flowmeter having a U-shaped measuring pipe, regardless of the diameter of the measuring pipe.

[0008] The ultrasonic flow meter of the present invention is a straight-through type ultrasonic sensor, and provides an ultrasonic flow meter having high reliability and high measurement precision by minimizing the horizontal path difference of the fluid flow inside the measuring pipe in the measuring pipe of the U-shaped flow meter, and also has a step between the connecting pipe and the measuring pipe, so that the influence of the air layer generated in the pipe can be minimized, thereby increasing field adaptability and reducing production costs with a simple structure, and by utilizing the structural features, it is possible to provide an ultrasonic flow meter having a U-shaped measuring pipe that includes an efficient backflow prevention means on the discharge pipe.

[0009] Figure 1 is a measurement tube of a U-type ultrasonic flow meter to which the present invention is applied.

[0010] 2-a of Fig. 2 is a measuring tube of a conventional U-type ultrasonic flow meter.

[0011] 2-b of Fig. 2 is a longitudinal cross-sectional view of the measuring tube of Fig. 2 in the a direction.

[0012] 3-a of Figure 3 is a cross-sectional view of a U-shaped measuring tube of the ultrasonic flowmeter of the present invention.

[0013] 3-b of Figure 3 is a longitudinal cross-sectional view of a U-shaped measuring tube in the b direction of 3-a.

[0014] 3-c of Figure 3 is a cross-sectional view of a U-shaped measuring tube in the c direction of 3-a.

[0015] 4-a of Fig. 4 is a cross-sectional view of an ultrasonic flow meter measuring tube having a backflow prevention means.

[0016] 4-b of Fig. 4 is a plug of a backflow prevention valve space.

[0017] 4-c of Fig. 4 is a check valve

[0018] Figure 5 is a measuring tube of the ultrasonic flow meter of the present invention having a backflow prevention means.

[0019] Hereinafter, specific details for carrying out the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 3, the measuring pipe of the ultrasonic flow meter of the present invention includes an inlet pipe (10) and an outlet pipe (20) connected to the pipe as horizontal pipes, and a measuring pipe (30) provided at the bottom with a step (100). The measuring pipe is formed as a horizontal pipe of a certain diameter, in which an upstream ultrasonic sensor (40) and a downstream ultrasonic sensor (41) are inserted and connected facing each other at both ends, and which provides a propagation path of ultrasonic waves and a horizontal flow path of fluid flow, and is composed of a measuring pipe (31), a downward flow pipe (11) connected to the inlet pipe (10) at the upper end of the upstream end, and an upward flow pipe (12) connected to the outlet pipe (20) at the upper end of the downstream end of the measuring pipe (31). In the following description, in the pipe structure formed by the cross-section of the flow pipe, the distance in the short-axis direction is referred to as the width, and the distance in the long-axis direction is referred to as the length. Referring to FIG. 3, the downward flow pipe (11) and the upward flow pipe (12) are formed as oblong pipes with a width (14) smaller than the diameter (15) of the measuring pipe and a length (13) larger than the diameter (15) of the measuring pipe, and the cross-sectional area is equal to or larger than the cross-sectional area of ​​the measuring pipe (31) to prevent pressure loss. That is, if the diameter of the measuring pipe (31) is 15 mm, the cross-sectional area is 177㎟. In a measuring pipe having a diameter of 15 mm, if the width (14) of the rectangular pipe structure of the downward flow pipe (11) and the upward flow pipe (12) is 5 mm, the length (13) is preferably 35.4 mm or more, and if the width (14) of the rectangular pipe structure is 7.5 mm, the length (13) is preferably 23.6 mm or more. The width and length of the rectangular pipe can be determined differently depending on the measurement performance and shape of the intended flow meter, and it is preferable that the width be less than half the diameter of the measuring pipe (31), but there is no restriction thereto.As described above, not only is the distance d1, d2 between the ultrasonic sensor and the measuring tube greatly reduced, but also the space (11) flowing into the measuring tube (31) is larger than the diameter (15) of the measuring tube, so that the fluid flows not vertically downward or vertically upward as in FIG. 2-b, but in all directions (16) up, down, left, and right as in FIG. 3-b, toward the measuring tube (31), and has a flow path that flows out in all directions from the measuring tube to the downward flow pipe (12) on the downstream side, so that the path difference of the horizontal flow of the fluid within the measuring tube (30) can be greatly reduced, and the measurement error of the propagation time of the ultrasonic wave measured at a certain period can also be greatly reduced. The shape of the upper flow pipe and the lower flow pipe is described as oblong, but it can be replaced with various shapes such as an elliptical pipe, a combination of a rectangular pipe and a circular pipe, etc., as long as the flow path for inflow and outflow into the measuring pipe can be secured as described above.

[0020] In addition, the measuring tube of the U-shaped ultrasonic water meter of the present invention can provide a backflow prevention means on the outlet pipe (20). Looking at the backflow prevention means formed with reference to FIG. 4, a flow space (115) of a backflow prevention valve is formed on the outlet pipe (20), an inclined surface is formed within the flow space to form a step (110) and a valve hole (111) toward the downstream side, and a backflow prevention valve (112) having a valve hole opening / closing part (119) for opening and closing the valve hole and a flow axis (113), a flow guide (118) having a flow hole for guiding the flow of the backflow prevention valve, and a stopper (114) having a fastening means (117) for sealing the valve flow space (115) are provided. The above-mentioned check valve (112) may be provided with a valve flow axis (113) that can open and close the valve hole (111) by being guided by the flow guide (118) of the plug (114) by the pressure of the flowing fluid, and a soft packing such as silicone may be provided on the contact surface opening / closing part (119) of the valve hole to maintain airtightness when the valve hole is sealed by the backflow flow. The valve flow axis acts to allow the check valve to flow in the direction toward the valve hole by being guided by the flow guide (112), and is formed to have a depth that guarantees the flow distance, so that when the fluid flows in the forward direction, the valve hole is opened by hydraulic pressure, and when it flows in the reverse direction, the valve hole is closed, thereby preventing the backflow.

[0021] Although the present invention has been described with reference to an embodiment illustrated in the attached drawings, this is merely exemplary, and it will be understood that various modifications and equivalent other embodiments are possible from this by those skilled in the art, but this is within the technical spirit of the present invention.

[0022] When the U-shaped measuring tube of the ultrasonic flow meter is manufactured as described above, the signal line of the ultrasonic sensor is connected to the electronic circuit, and the speed of the fluid flow in the measuring tube is detected by the operation of the electronic circuit unit with a built-in processor and the built-in ultrasonic flow meter operating software, and the ultrasonic flow meter is provided by collecting the information on the flow rate passing through the tube and the status information of the flow meter and displaying it on the display unit (LCD) and providing it to a remote system through wired or wireless communication means.

[0023] The ultrasonic flow meter of the present invention can be used as a small-diameter water meter for measuring the amount of tap water used, a gas meter for measuring the amount of gas used, or a flow meter for measuring industrial facilities.

[0024] 10: Inlet pipe 20: Outlet pipe

[0025] 11: Downstream flow pipe: A flow pipe connecting the inlet pipe and the inlet section of the measuring pipe.

[0026] 12: Upstream flow pipe: A flow pipe connecting the outlet of the measuring pipe and the outlet pipe.

[0027] 13: The distance (length) in the longitudinal direction of the cross-section of the downward flow pipe and the upward flow pipe

[0028] 14: Distance (width) in the short-axis direction of the cross-section of the downward flow pipe and the upward flow pipe

[0029] 15: Diameter of the measuring tube

[0030] 16: Flow direction of fluid entering the measuring tube

[0031] 30: Measuring pipe: A pipe that includes an ultrasonic sensor and forms a propagation path for ultrasonic waves.

[0032] 31: Measuring pipe: A pipe that allows horizontal flow of fluid with a constant diameter within the measuring pipe.

[0033] 40: Upstream ultrasonic sensor 41: Downstream ultrasonic sensor

[0034] d1, d2: Distance between ultrasonic sensor and measuring tube L1: Length of measuring tube

[0035] 100; step, height difference between the axis connecting the inlet and outlet pipes and the axis of the measuring pipe

[0036] 112: Check valve 113: Flow shaft of check valve

Claims

1. In an ultrasonic flow meter that is connected to a pipe through which a fluid flows and measures the flow rate An inlet pipe that is connected to the pipe and connects the flow of incoming fluid to the downward flow pipe; A downward flow pipe that forms a downward flow path for fluid from the inlet pipe to the inlet portion of the measuring pipe, and is provided such that the longitudinal distance (13) of the fluid flow space connected to the measuring pipe is larger than the diameter (15) of the measuring pipe, and the separation distance (d1,14) between the ultrasonic sensor and the measuring pipe is smaller than the diameter (15) of the measuring pipe; A measuring pipe that forms a horizontal flow of fluid and a propagation path of ultrasonic waves and has a step downwards along the axis of the inlet and outlet pipes; A pair of ultrasonic sensors installed facing each other along the central axis of the measuring pipe; A measuring pipe that forms a horizontal flow of fluid within the measuring pipe; An upward flow pipe in which the longitudinal distance (13) of the fluid flow space connected to the measuring pipe and which forms an upward flow passage of the fluid from the outlet of the measuring pipe to the outlet pipe is larger than the diameter (15) of the measuring pipe, and the separation distance (d2,14) between the ultrasonic sensor and the measuring pipe is smaller than the diameter (15) of the measuring pipe; An outlet pipe that connects the flow of fluid flowing out of the upper flow pipe to the pipe; An ultrasonic flow meter having a U-shaped measuring tube that measures the flow rate by utilizing the time difference between the propagation time of ultrasonic waves in the forward direction of the fluid flow and the propagation time of ultrasonic waves in the reverse direction within the measuring tube.

2. In claim 1 An ultrasonic flow meter having a U-shaped measuring tube characterized in that the outlet pipe (20) is formed as a horizontal pipe that forms a step with the measuring pipe (30) and is connected to the upper flow pipe (12) and is connected to an external horizontal pipe, and further includes a step (110) formed as an inclined surface on the outlet pipe (20), a valve hole (111), a backflow prevention valve (112), and a stopper, and a backflow prevention means provided.

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