JP2007121168A - Ultrasonic flowmeter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in conventional ultrasonic flowmeters wherein a pipe body requires a certain length to enlarge the shape. <P>SOLUTION: A measurement pipe 7 through which measurement fluid flows comprises a first circulation passage 7a, a second circulation passage 7b, and an inclined plane 7c formed in the connection part between the first circulation passage 7a and the second circulation passage 7b. An inlet 7d orthogonal to a side surface of the first circulation passage 7a is formed near the end of the first circulation passage 7a, an outlet 7e orthogonal to a side surface of the second circulation passage 7b is formed near the end of the second circulation passage 7b. A first piezoelectric vibrator 8 is mounted to the end of the first circulation passage 7a, and a second piezoelectric vibrator 9 is mounted to the end of the second circulation passage 7b. A reflector 10 is mounted to the inclined plane 7c formed in the connection part between the first circulation passage 7a and the second circulation passage 7b, and a flow measuring circuit 11 is connected to the first piezoelectric vibrator 8 and the second piezoelectric vibrator 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic flowmeter configured to bend a measurement tube through which a measurement liquid flows at a right angle.

  As a conventional ultrasonic flowmeter of this type, as shown in FIG. 2, piezoelectric vibrators 2 and 3 are attached to both ends of the tube 1 which are sealed, and a piezoelectric body is attached to the end of the tube 1. The vibrators 2 and 3 are connected, and the measurement liquid inlet 5 and the measurement liquid outlet 6 are provided on the side of the tube 1, and the measurement liquid introduced from the measurement liquid inlet 5 passes through the tube 1 and flows into the measurement liquid. An apparatus configured to measure the flow rate of the measurement liquid flowing out of the outlet 6 and flowing through the tubular body 1 with the flow rate measurement circuit 4 by transmitting and receiving ultrasonic waves with the piezoelectric vibrators 2 and 3 has been proposed. .

In the ultrasonic flow meter of FIG. 2 configured as described above, the tube body 1 needs a certain length in order to transmit and receive ultrasonic waves with the piezoelectric vibrators 2 and 3, and therefore the shape becomes large. There's a problem.
Japanese Patent Application No. 2003-16972

  The problem to be solved is that in the conventional ultrasonic flowmeter, the tube body needs a certain length, so that the shape becomes large.

  In the present invention, the measurement pipe for flowing the measurement fluid forms the first flow path and the second flow path substantially at right angles, and the inlet is perpendicular to the side surface at the side near the end of the first flow path. The outlet is formed on the side of the inlet that is perpendicular to the side surface at the side near the end of the second flow passage, and at the connection portion of the first flow passage and the second flow passage. An inclined surface is provided, the reflector is attached to the inclined surface of the measurement tube, the first piezoelectric vibrator is attached to the end of the first flow path, and the second piezoelectric vibrator is the second flow path. The first piezoelectric vibrator and the second piezoelectric vibrator transmit and receive ultrasonic waves to measure the flow rate of the measurement fluid flowing through the measurement tube.

  In the ultrasonic flowmeter of the present invention, a pipe having a straight flow portion that flows in one direction between the acoustic lenses to which the ultrasonic transducer is attached is attached, and the measurement fluid that flows through the straight flow portion is inclined. In such a configuration, the measurement fluid is configured so as not to cause a flow loss in the straight flow portion, and the flow velocity and the flow rate can be accurately measured.

  In the present invention, a straight flow part of a pipe for flowing measurement fluid is attached between acoustic lenses equipped with ultrasonic transducers, and an inclined part is attached obliquely from the end of the straight flow part, so that the measurement fluid flows linearly. It is configured so that no distribution loss occurs at the head, and an acoustic propagation medium is attached to the acoustic lens so that ultrasonic waves emitted from the ultrasonic transducer can be transmitted and received effectively. Can be measured accurately.

  FIG. 1 is a side sectional view of an ultrasonic flowmeter according to an embodiment of the present invention. A measurement pipe 7 for flowing a measurement fluid includes a first flow path 7a, a second flow path 7b, a first flow path 7a, and a first flow path. An inclined surface 7c formed at the connection portion of the two flow passages 7b, and an inflow port 7d is formed in the vicinity of the end of the first flow passage 7a so as to be orthogonal to the side surface of the first flow passage 7a. An outlet 7e is formed in the vicinity of the end of the second flow passage 7b so as to be orthogonal to the side surface of the second flow passage 7b, and the first piezoelectric vibrator 8 is formed at the end of the first flow passage 7a. Is attached, the second piezoelectric vibrator 9 is attached to the end of the second flow passage 7b, and an inclined surface is formed at the connection portion between the first flow passage 7a and the second flow passage 7b. A reflector 10 is attached to 7 c, and a flow rate measuring circuit 11 is connected to the first piezoelectric vibrator 8 and the second piezoelectric vibrator 9.

  In the ultrasonic flowmeter of this embodiment configured as described above, when the measurement liquid is flowing from the inlet 7d to the pipe 7, the oscillation output from the flow measurement circuit 11 is output from the first piezoelectric vibrator 8. When inputted, the ultrasonic wave irradiated from the piezoelectric vibrator 8 is reflected by the reflector 10 and received by the second piezoelectric vibrator 9, and a flow measurement circuit is connected to the second piezoelectric vibrator 9. When an oscillation signal is input from 11, ultrasonic waves are emitted from the second piezoelectric vibrator 9, and the ultrasonic waves are reflected by the reflector 10 and input to the first piezoelectric vibrator 8. By alternately repeating, the time for the ultrasonic wave generated from the first piezoelectric vibrator 8 to reach the second piezoelectric vibrator 9 and the ultrasonic wave generated from the second piezoelectric vibrator 9 are Due to the time difference from the time to reach the piezoelectric vibrator 8, the first flow of the measuring tube 7 Flow rate and flow velocity of the measured fluid flowing through the road 7a and a second flow passage 7b can be measured by the flow rate measuring circuit 11.

  In the above embodiment, the inlet 7d and the outlet 7 of the measuring tube 7 are formed in the vicinity of each other, but either the inlet 7d or the outlet 7e is formed on the opposite side. Alternatively, both may be formed on the opposite outer side.

It is side surface sectional drawing of the ultrasonic flowmeter of the Example of this invention. It is side surface sectional drawing of the conventional ultrasonic flowmeter.

Explanation of symbols

7 Measuring Tube 8 First Piezoelectric Vibrator 9 Second Piezoelectric Vibrator 10 Reflector 11 Flow Measurement Circuit

Claims (3)

  The first flow path and the second flow path are formed substantially at right angles, and the inlet is formed in a side portion near the end of the first flow path perpendicular to the side surface. An outflow port is formed on the side of the inflow port at a side portion in the vicinity of the end portion so as to be orthogonal to the side surface, and a measuring fluid is provided with an inclined surface provided at a connection portion between the first flow path and the second flow path. A measuring tube, a reflector mounted on an inclined surface of the measuring tube, a first piezoelectric vibrator mounted on an end of the first flow path, and an end of the second flow path The flow rate of the measurement fluid flowing through the measurement tube is measured by transmitting and receiving ultrasonic waves between the first piezoelectric vibrator and the second piezoelectric vibrator. An ultrasonic flowmeter characterized by that.   The ultrasonic flowmeter according to claim 1, wherein an inlet of the first inflow passage is formed on an opposite side surface of the inflow inlet.   The ultrasonic flowmeter according to claim 1, wherein an outlet of the second flow passage is formed on an opposite side surface of the outlet.

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