JP4612346B2 - Flowmeter - Google Patents

Description

  The present invention relates to a flow meter, and more particularly to a through-bolt inserted between a flange of an upstream pipe and a flange of a downstream pipe with both ends of the flow meter body abutting with flanges of the upstream pipe and the downstream pipe. The present invention relates to a flow meter configured to clamp both ends of a flow meter body by tightening.

  Hereinafter, the prior art will be described using an ultrasonic vortex flow meter as an example of a flow meter.

  A conventional ultrasonic vortex flowmeter has a flowmeter body having a flow path through which a fluid to be measured flows, and a vortex generator formed in the flow path so as to extend in a direction perpendicular to the flow direction. One or two ultrasonic sensors are provided downstream of the body so as to detect Karman vortices generated downstream of the vortex generator. One set of ultrasonic sensors is provided in the flow path so as to face each other, one is a transmitting side that transmits ultrasonic waves, and the other is a receiving side that receives ultrasonic waves propagated in the fluid to be measured It becomes.

  In this type of ultrasonic vortex flowmeter, an ultrasonic reception signal propagated through a Karman vortex generated alternately in proportion to the flow velocity in the flow path, and an ultrasonic signal supplied to the transmission side. By comparing the phase with the transmission signal of the sound wave, the Doppler effect that the ultrasonic wave receives from the Karman vortex is detected as a sinusoidal phase modulation amount.

  In addition, in an ultrasonic vortex flowmeter using two sets of ultrasonic sensors, by comparing the phases of two ultrasonic signals that propagate the fluid from the opposite directions relative to the Karman vortex flow, Only the phase change received from the Karman vortex is extracted by canceling the influence of the sound velocity change of the fluid to be measured.

  The conventional ultrasonic vortex flowmeter configured as described above is theoretically configured to extract the Doppler effect received by the ultrasonic wave from the Karman vortex as a phase change, so that it is independent of the type of fluid being measured. Vortices can be detected.

  Here, in the case where the fluid to be measured is a corrosive fluid, in order to prevent the flow meter body from corroding and eluting into the fluid to be measured, the flow passage wall of the flow meter body should be resistant to corrosion. A lining layer is formed by coating with a high resin material. (For example, refer to Patent Document 1).

  In this flow meter, in order to maintain the strength of the flow meter itself, the lining layer is reinforced by embedding a reinforcing plate in the lining layer formed in the flow path of the flow meter body.

Furthermore, the structure of the flow meter body to the piping is as follows: the both ends of the flow meter body are in contact with the flange of the upstream pipe and the flange of the downstream pipe, and the flange of the upstream pipe and the flange of the downstream pipe A structure is employed in which the bolts are clamped by tightening through-bolts that are inserted through the bolts.
Japanese Patent No. 3027170 (Japanese Patent Laid-Open No. 4-99916)

  However, as described above, with the both ends of the flow meter body in contact with the flange of the upstream pipe and the flange of the downstream pipe, the through bolts inserted through the flange of the upstream pipe and the flange of the downstream pipe In the flowmeter having a mounting structure that is clamped by tightening, if the through-bolt tightening force is large, the flowmeter body itself is distorted, and this distortion may reduce the flow measurement accuracy of the fluid under test.

  In particular, when the flow meter body is made of resin, the flow meter body itself may be insufficient in strength. In this case, even if the through bolt tightening force is appropriate, the tightening force causes the above-mentioned tightening force. There is a risk that the same problem as the above problem may occur.

  As described in the above prior art, even if the reinforcing plate is provided on the lining layer of the resin flowmeter body, the tightening force of the through bolts does not affect the flowmeter body. There was a problem that distortion of the flow meter body could not be prevented.

Furthermore, when the flowmeter is a vortex flowmeter, if the flowmeter body is distorted, the mounting position of the vortex generator and the angle with respect to the flow path, etc. change slightly, and the conditions for the generation of Karman vortices change, There arises a problem that the flow measurement accuracy may be lowered.
Then, an object of this invention is to provide the flowmeter which solved the said subject.

The invention according to claim 1 has a flow path through which the fluid to be measured passes inside the main body of the flow meter and a measurement unit for measuring the flow rate of the fluid to be measured flowing through the flow path, In the flowmeter that is brought into contact with the flange of the side pipe and the downstream pipe, and the flowmeter body is clamped by tightening a through bolt inserted between the flange of the upstream pipe and the flange of the downstream pipe,
A reinforcing member having an insertion hole through which the through bolt is inserted is interposed between the flange of the upstream pipe and the flange of the downstream pipe ;
Provide flanges at both ends of the flow meter body,
The reinforcing member includes an abutting portion extending in a radial direction so as to abut on the back surface of the flange provided at both ends of the flowmeter main body .

The invention according to claim 2 is characterized in that the flowmeter main body and the reinforcing member are made of the same resin material.

According to the present invention, contact the reinforcing member upstream Rutotomoni is interposed between the flange and the downstream pipe flange of the pipe, the back surface of both ends flanges of the flowmeter body having an insertion hole through bolt is inserted As described above, since the abutting portion extending in the radial direction is provided on the reinforcing member, the compressive load acting on the flow meter body can be dispersed to the reinforcing member and the flow meter body can be prevented from being distorted. Therefore, even when the flow meter main body is formed of a resin material, it is possible to prevent the flow meter main body from being deformed due to a compressive load at the time of attachment and to prevent a reduction in measurement accuracy.
Further, according to the present invention, since the flowmeter main body and the reinforcing member are made of the same resin material, the thermal expansion amount of the flowmeter main body and the reinforcing member becomes uniform when measuring high temperature fluid, and the sealing performance is improved. Maintained.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing an ultrasonic vortex flow meter to which an embodiment of a flow meter according to the present invention is applied. FIG. 2 is a longitudinal sectional view taken along line A1-A1 in FIG. FIG. 3 is a cross-sectional view showing the configuration of the ultrasonic vortex flowmeter. 4 is a longitudinal sectional view taken along line A2-A2 in FIG.
As shown in FIGS. 1 to 4, the ultrasonic vortex flow meter 10 includes a resin flow meter main body 12, a flow rate instruction unit 14 provided on the upper part of the flow meter main body 12, and a flow meter main body 12. A connecting mechanism 20 that connects the upstream pipe 16 and the downstream pipe 18 to each other so as to sandwich both ends is provided.

  The flow meter body 12 is integrally formed of, for example, a resin material such as polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), or polypropylene (PP) having excellent chemical resistance. It has a flow path 22 through which fluid flows, and a vortex generator 24 that stands upright in the flow path 22. In addition, the flow meter body 12 has an inlet 26 through which the fluid to be measured flows in at both ends and an outlet 28 through which the fluid to be measured flows out, and an inflow side flange 30 projecting radially from the outer periphery. And an outflow side flange 32. The vortex generator 24 is provided in the flow path 22 of the inflow port 26.

  Between the inflow side flange 30 and the outflow side flange 32, ribs 34 (34a to 34d) protruding radially from the outer periphery of the flow meter main body 12 are provided at intervals of 90 degrees. The ribs (protrusions) 34 are deformation-preventing reinforcing ribs that increase the pressure resistance of the flow meter body 12 against the compressive load between the inflow side flange 30 and the outflow side flange 32.

  In addition, cylindrical sensor attachment portions 36 and 37 are formed on the side surface of the central portion of the flow meter main body 12 so as to be continuous with the ribs 34 (34a to 34d). The sensor attachment portions 36 and 37 are formed so as to protrude on both sides of the flow meter main body 12, and a transmission side ultrasonic sensor 60 and a reception side ultrasonic sensor 62 are attached inside. In addition, lid members 64 and 66 that protect the transmission-side ultrasonic sensor 60 and the reception-side ultrasonic sensor 62 and seal the sensor attachment portions 36 and 37 are mounted at the entrances of the sensor attachment portions 36 and 37. .

  Here, the flow measurement of the ultrasonic vortex flowmeter 10 will be described.

  As shown in FIG. 3, in the ultrasonic vortex flowmeter 10, the ultrasonic wave transmitted from the transmission-side ultrasonic sensor 60 propagates in the fluid to be measured flowing in the flow path 22 and receives the reception-side ultrasonic wave. It is received by the sensor 62. Karman vortices generated downstream of the vortex generator 24 are generated at a period proportional to the flow velocity of the fluid to be measured, and Karman vortices having different spiral directions are alternately generated. The ultrasonic wave is accelerated or decelerated in the traveling direction when passing through the Karman vortex depending on the spiral direction of the Karman vortex. Therefore, the frequency (period) of the ultrasonic wave received by the reception-side ultrasonic sensor 62 varies due to the Karman vortex.

  As shown in FIG. 4, the flow rate instructing unit 14 obtains the flow velocity of the fluid to be measured flowing through the flow path 22 from the Karman vortex generation cycle (frequency) and calculates the flow rate of the fluid to be measured, as will be described later. A portion 68 is provided. The calculation unit 68 includes a transmission circuit 70 that outputs a drive signal having a fixed period to the transmission-side ultrasonic sensor 60, a reception circuit 72 that receives a detection signal from the reception-side ultrasonic sensor 62, and a drive signal and a reception signal. It has a phase comparison circuit 74 that compares phases, and a flow rate calculation circuit 76 that calculates the flow rate by integrating the Karman vortex detection signals output from the phase comparison circuit 74.

  The signal line 78 of the transmission side ultrasonic sensor 60 is inserted into a through hole 80 that penetrates the flow meter main body 12 upward and is connected to the transmission circuit 70. The signal line 82 of the reception-side ultrasonic sensor 62 is inserted into a through-hole 84 that passes through the flow meter main body 12 upward and is connected to the reception circuit 72.

  In the flow rate calculation circuit 76, the measured flow that flows through the flow path 22 based on the frequency of the Karman vortex obtained from the phase difference between the drive signal output from the transmission circuit 70 and the reception signal output from the reception-side ultrasonic sensor 62. Calculate the fluid flow rate. Then, the flow rate instruction unit 14 displays the numerical value of the instantaneous flow rate measured on the digital display unit 86.

Here, the connection mechanism 20 will be described.
The coupling mechanism 20 includes a through bolt 38 (38a to 38d) inserted between the flange 16a of the upstream pipe 16 and the flange 18a of the downstream pipe 18 and a reinforcement through which the through bolt 38 (38a to 38d) is inserted. A member 40 (40a to 40d), a packing 42 interposed between the flanges 16a and 18a, the inflow side flange 30 and the outflow side flange 32, and nuts 44 screwed into both ends of the bolts 38 (38a to 38d). It consists of.

  Since the compression force is applied between the flanges 16 a and 18 a by the tightening force of each nut 44, the packing 42 provides a liquid-tight seal between the flanges 16 a and 18 a and the inflow side flange 30 and the outflow side flange 32. The packing 42 is also interposed between the flanges 16 a and 18 a and both ends of the reinforcing member 40 (40 a to 40 d), and has a function of absorbing the compressive force when the nut 44 is tightened.

  The reinforcing member 40 (40a to 40d) is formed in a cylindrical shape having an insertion hole 46 through which the through bolt 38 (38a to 38d) is inserted. Further, the reinforcing member 40 (40a to 40d) is formed so that the entire length (length in the longitudinal direction) is the same as the length of the flow meter body 12 in the flow direction. Therefore, the compressive force applied between the flanges 16a and 18a by the tightening force of each nut 44 is distributed to both end surfaces of the flow meter main body 12 and both end surfaces of the reinforcing member 40 (40a to 40d). Therefore, the flow meter main body 12 is fixed between the flange 16a of the upstream pipe 16 and the flange 18a of the downstream pipe 18 so that the compressive force due to tightening of each nut 44 is relaxed and distortion does not occur.

  The reinforcing member 40 (40a to 40d) is formed of the same resin material as that of the flow meter main body 12, and has the same thermal expansion coefficient as that of the flow meter main body 12 even when measuring a high-temperature fluid or when installed in a high-temperature environment. Therefore, the thermal expansion amounts of both end faces of the flow meter main body 12 and both end faces of the reinforcing member 40 (40a to 40d) become uniform, and the sealing performance by the packing 42 is maintained.

  In addition, the reinforcing member 40 (40a to 40d) is attached so that the outer periphery thereof is in contact with the outer periphery of the inflow side flange 30 and the outflow side flange 32, and thus restricts the mounting position in the radial direction of the flow meter body 12. That is, the flow meter main body 12 is aligned (aligned) so that the axial centers thereof coincide with the axial centers of the upstream pipe 16 and the downstream pipe 18.

  FIG. 5 is a front view of the ultrasonic vortex flowmeter of the second embodiment. 6 is a longitudinal sectional view taken along line BB in FIG. FIG. 7 is a front view of the reinforcing member 140 of the second embodiment. 5 and 6, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 5 and 6, the coupling mechanism 120 according to the second embodiment is a through bolt 38 (38 a to 38 d) inserted between the flange 16 a of the upstream pipe 16 and the flange 18 a of the downstream pipe 18. A reinforcing member 140 (140a to 140d) through which the through bolt 38 (38a to 38d) is inserted, a packing 42 interposed between the flanges 16a and 18a, the inflow side flange 30 and the outflow side flange 32, and the bolt 38. And nuts 44 screwed into both end portions of (38a to 38d).

  As shown in FIG. 7, the reinforcing member 140 (140a to 140d) includes a cylindrical portion 148 having an insertion hole 146 through which the through bolt 38 (38a to 38d) is inserted, and radial directions from both ends of the cylindrical portion 148. And projecting contact portions 150 and 152. The end portion separation distance L of the contact portions 150 and 152 is the same as the separation distance between the inflow side flange 30 and the outflow side flange 32.

  The cylindrical portion 148 is formed so that the total length is shorter than the length of both end faces of the flow meter main body 12. Therefore, the cylindrical portion 148 is attached in a state where both end surfaces are separated from the packing 42.

  The abutment portions 150 and 152 are formed so as to abut against the back surfaces of the inflow side flange 30 and the outflow side flange 32, and inflow when a compressive load is applied to the inflow side flange 30 and the outflow side flange 32. It functions as a support portion that supports the side flange 30 and the outflow side flange 32 from the back side.

  Further, the contact portions 150 and 152 are attached in a direction extending toward the axial center of the flow meter main body 12, and the end portions are in contact with the outer periphery of the flow meter main body 12 and the ribs 34 (34 a to 34 d). ) Is inserted between. Therefore, when the rotational force that rotates the cylindrical portion 148 is applied to the reinforcing member 140 (140a to 140d), the contact portions 150 and 152 contact the side surfaces of the ribs 34 (34a to 34d) and rotate. Regulated movement is restricted.

  Thereby, the reinforcing member 140 (140a to 140d) is prevented from transmitting the rotational force due to the tightening of the nuts 44, and the packing 42 is prevented from being deformed in the rotational direction.

  Therefore, the compressive force applied between the flanges 16a and 18a by the tightening force of each nut 44 is distributed to both end surfaces of the flow meter main body 12 and the contact portions 150 and 152 of the reinforcing members 140 (140a to 140d). Therefore, the flow meter main body 12 is fixed between the flange 16a of the upstream pipe 16 and the flange 18a of the downstream pipe 18 so that the compressive force due to tightening of each nut 44 is relaxed and distortion does not occur.

  The reinforcing member 140 (140a to 140d) has an outer periphery of the cylindrical portion 148 in contact with the outer periphery of the inflow side flange 30 and the outflow side flange 32, and end portions of the contact portions 150 and 152 on the outer periphery of the flow meter main body 12. In order to make contact, the mounting position in the radial direction of the flow meter main body 12 is regulated. That is, the axial center of the flowmeter main body 12 is aligned (aligned) by the contact portions 150 and 152 so as to coincide with the axial centers of the upstream pipe 16 and the downstream pipe 18.

  FIG. 8 is a longitudinal sectional view showing a reinforcing member of the third embodiment. In FIG. 8, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 8, the reinforcing members 160 and 162 of the third embodiment are formed in an arc shape in cross section, and have insertion holes 164 and 166 through which the through bolts 38 are inserted, respectively. Since the reinforcing members 160 and 162 have an end surface area larger than that of the above-described cylindrical shape, sufficient strength against a compressive load at the time of attachment can be ensured.

  Further, since the two through bolts 38 are inserted through the reinforcing members 160 and 162, the reinforcing members 160 and 162 are prevented from rotating when the nut 44 screwed into the through bolt 38 is tightened. The curved inner peripheral surfaces 160a and 162a of the reinforcing members 160 and 162 are in contact with the outer peripheries of the inflow side flange 30 and the outflow side flange 32 so that the shaft center of the flowmeter body 12 is the upstream side pipe 16 and the downstream side pipe 18. Positioning (alignment) is performed so as to match the axis.

  Thus, the pair of reinforcing members 160 and 162 can increase the reinforcing strength at the time of attachment as compared with those of the first and second embodiments, and the number of parts can be reduced, so that the attachment work can be easily performed. Further, the reinforcing members 160 and 162 have a large area of the outer peripheral surfaces 160b and 162b, and function as a protector for protecting the flow meter main body 12 by covering the left and right side surfaces of the flow meter main body 12.

  In the above embodiment, the ultrasonic vortex flowmeter is described as an example. However, the present invention is not limited to this, and can be applied to other types of flowmeters.

  Moreover, in the said Example, although the reinforcement member shall be shape | molded with the same resin material as a flowmeter main body, the material of a reinforcement member is not restricted to a resin material, Of course, you may form with a metal.

It is a front view showing an ultrasonic vortex flow meter to which an embodiment of a flow meter according to the present invention is applied. It is a longitudinal cross-sectional view which follows the A1-A1 line | wire in FIG. It is a cross-sectional view showing a configuration of an ultrasonic vortex flowmeter. It is a longitudinal cross-sectional view which follows the A2-A2 line in FIG. 6 is a front view of an ultrasonic vortex flow meter of Example 2. FIG. It is a longitudinal cross-sectional view which follows the BB line in FIG. It is a front view of the reinforcing member 140 of Example 2. FIG. 10 is a longitudinal sectional view showing a reinforcing member of Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ultrasonic vortex flowmeter 12 Flowmeter main body 14 Flow instruction | indication part 16 Upstream side piping 18 Downstream side piping 20 Connection mechanism 22 Flow path 24 Eddy generator 30 Inflow side flange 32 Outflow side flange 34 (34a-34d) Rib 38 ( 38a to 38d) Through bolts 40 (40a to 40d), 140 (140a to 140d), 160, 162 Reinforcing member 42 Packing 44 Nut 46, 146, 164, 166 Insertion hole 60 Transmission side ultrasonic sensor 62 Reception side ultrasonic sensor 68 Calculation part 148 Cylindrical part 150,152 Contact part

Claims (2)

The flowmeter body has a flow path through which the measured fluid passes and a measuring section for measuring the flow rate of the measured fluid flowing through the flow path, and both ends of the flowmeter body are connected to the flanges of the upstream pipe and the downstream pipe. In the flow meter that holds the flow meter body by tightening a through bolt inserted between the flange of the upstream pipe and the flange of the downstream pipe,
A reinforcing member having an insertion hole through which the through bolt is inserted is interposed between the flange of the upstream pipe and the flange of the downstream pipe ;
Provide flanges at both ends of the flow meter body,
The flowmeter according to claim 1, wherein the reinforcing member has a contact portion extending in a radial direction so as to contact a back surface of the flange provided at both ends of the flowmeter body . The flowmeter according to claim 1, wherein the flowmeter main body and the reinforcing member are made of the same resin material .

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