JP4183090B2 - Coriolis flowmeter upstream and downstream piping structure - Google Patents

Description

  The present invention relates to an upstream pipe extending from a flow meter body of a Coriolis flow meter that obtains a mass flow rate and / or density of a fluid to be measured by detecting a phase difference and / or vibration frequency proportional to the Coriolis force acting on the flow tube. And the downstream piping structure, that is, the upstream and downstream piping structure of the Coriolis flowmeter.

  A Coriolis flowmeter supports one or both ends of a flow tube through which a fluid to be measured flows, and when vibration is applied in a direction perpendicular to the flow direction of the flow tube around the support point, This is a mass flow meter utilizing the fact that the Coriolis force acting on the flow tube to be added is called a flow tube) is proportional to the mass flow rate. Coriolis flowmeters are well known, and the shape of the flow tube in the Coriolis flowmeter is roughly divided into a straight tube type and a curved tube type.

  The straight pipe type Coriolis flowmeter is a straight pipe that is supported by the Coriolis force between the straight pipe support section and the center section when vibration is applied in the direction perpendicular to the straight pipe axis of the straight pipe center supported at both ends. A displacement difference of the tube, that is, a phase difference signal is obtained, and the mass flow rate is detected based on the phase difference signal. Such a straight tube type Coriolis flowmeter has a simple, compact and robust structure. However, it also has a problem that high detection sensitivity cannot be obtained.

On the other hand, the curved tube type Coriolis flow meter is superior to the straight tube type Coriolis flow meter in that it can select the shape to effectively extract the Coriolis force. Can be detected. In addition, as a curved tube type Coriolis flowmeter, one provided with one flow tube (see, for example, Patent Document 1), one provided with two flow tubes in parallel (see, for example, Patent Document 2), or one There are known ones provided in a state in which a flow tube is looped (see, for example, Patent Document 3).
Japanese Examined Patent Publication No. 4-55250 Japanese Patent No. 2939242 Japanese Patent Publication No. 5-69453

  The small-diameter Coriolis flow meter has a narrow upstream pipe and downstream pipe extending from the flow meter body, and the strength of the pipe-only support is weak, so it may be difficult to support the flow meter body. Usually, in such a case, the flowmeter body is fixed as shown in FIG. 30, but two loop structures are formed between the support of the upstream pipe and the downstream pipe and the fixed portion of the flowmeter body. It will end up. When the rigidity of the loop structure is low, it becomes a vibration element, and if this changes in the upstream and downstream directions due to piping stress, gantry distortion, etc., it becomes a factor of zero point shift or instrumental span shift. This principle is that the zero point is likely to shift when elements other than piping, such as the case of the main body of the flow meter, are in contact with the gantry (or the ground), as generally stated in handling Coriolis flow meters. Because it is based on. In order to minimize the change of the vibration element in the upstream and downstream directions, it is advantageous to increase the rigidity between the two supports. However, there is a limit to increasing the rigidity of the gantry.

  On the other hand, when the pipe stress reaches the fixed part of the flow meter body through the gantry, when the residual stress of the gantry welding structure is released, when the flatness of the flow meter body mounting part of the gantry is poor, Even when the stress propagates directly from the upstream / downstream piping toward the flow meter body, it causes a zero point shift or a span shift due to instrumental error.

  In the Coriolis flow meter, when the flow meter body has to be fixed to a gantry, it has been difficult to design a vibration system by adding a spring element.

  In addition, in the case of measuring the flow rate of a gas body, it is known that the fluid temperature changes when the flow is throttled. For example, if there is a pressure regulating valve upstream of the Coriolis flow meter, the downstream of it may be cooled, and temperature changes may propagate from upstream to downstream.In this case, the pipe stress at the time of zero adjustment and the measurement in progress The piping stress will be different. In addition, the Coriolis flowmeter itself becomes a throttle, and the pipe stress may change even when the temperature of the upstream pipe and the downstream pipe of the Coriolis flowmeter are different. Further, pipe stress is not always constant, such as switching of the flow path from the necessity of purging (replacement), reverse flow, change in flow rate and pressure, change in outside air temperature, and impact due to sudden valve opening and closing. In the conventional Coriolis flowmeter piping support, in a sensor with a small phase difference (low sensitivity), a change in the piping state caused a zero point shift or an instrumental span shift.

  This invention is made | formed in view of the situation mentioned above, and makes it a subject to provide the upstream / downstream piping structure of the Coriolis flowmeter which can minimize the influence by piping stress. It is another object of the present invention to provide an upstream / downstream piping structure for a Coriolis flow meter that is unlikely to cause a zero point shift or a span shift due to instrumental error even when an external force is applied to the upstream / downstream piping or flow meter body.

The upstream / downstream piping structure of the Coriolis flowmeter according to the present invention according to claim 1, which has been made to solve the above-mentioned problems, has a structure that is strong against bending and twisting, accommodates a flow tube, and the flowmeter of the flow tube A casing that can protect the main part and is filled with an inert gas inside,
A pedestal mounting plate that attaches the housing to a pedestal, a pair of joints, and a joint support portion that supports the pair of joints;
A flow meter body having a flow tube to be housed in the housing,
Coriolis obtains the mass flow rate and / or density of the fluid to be measured flowing in the flow tube by detecting a phase difference and / or vibration frequency proportional to the Coriolis force acting on the flow tube accommodated in the housing. In the flow meter,
A pipe that connects the flow meter body and the upstream line pipe into which the fluid to be measured flows, and extends from the flow meter body toward the upstream line pipe, and is linear on the line pipe side. A line pipe connection portion formed on the flow meter body, a flow meter main body connection portion formed in a U-shape (or U-shape) on the flow meter main body side, the line pipe connection portion on the upstream side, and the flow meter An intermediate portion that is bent in an arc shape so as to connect the main body connecting portion and turn the direction of the line pipe connecting portion 90 ° with respect to the flow meter main body connecting portion;
The tube axis of the line piping connection portion is set to be orthogonal to the tube axis of the flow meter main body connection portion by the intermediate portion, and a flow control valve and cheese (T ) Through which the upstream line piping is connected, and the upstream pipe in which the joint of the flow meter body is connected to the flow meter body connection portion;
A pipe connecting the flow meter body and the downstream line pipe through which the fluid to be measured flows out and the flow meter body, extending from the flow meter body toward the downstream line pipe, Line piping connection portion formed in a straight line on the side of the line piping, flow meter main body connection portion formed in a U-shape (or U-shape) on the flow meter main body side, and the line piping connection portion And an intermediate portion that is bent and formed in an arc shape so as to connect the flow meter main body connecting portion and turn the line pipe connecting portion 90 ° with respect to the flow meter main body connecting portion,
The tube axis of the line pipe connection part is set to be orthogonal to the tube axis of the flow meter main body connection part by the intermediate part, and the line pipe connection part side end is connected to the pipe axis via the flow control valve. A downstream pipe to which a downstream line pipe is connected, and the joint of the flow meter main body is connected to the flow meter main body connecting portion;
It is composed of a pair of pipe support plates formed in a substantially disk shape, a fixing through hole is formed in the center for fixing to the gantry, a plurality of pipe support grooves, and intermediate portions of the upstream pipe and the downstream pipe And a plurality of through-holes are formed, the intermediate portions of the upstream pipe and the downstream pipe are sandwiched from above and below by the pair of pipe support plates, and the intermediate portions are bent. A pipe support member that is close to and opposed on both sides sandwiching the through hole, and that the upstream pipe and the downstream pipe are supported by the pipe support groove;
Provided
The pipe support member is disposed so that the position of the pipe support member is located above the flowmeter body, and the intermediate portions of the upstream pipe and the downstream pipe are combined into one.

The upstream / downstream piping structure of the Coriolis flow meter according to the present invention described in claim 2 is the upstream / downstream piping structure of the Coriolis flow meter according to claim 1, wherein the upstream piping combined with the piping support member is combined with the upstream piping. The pipe axis of the downstream pipe is matched with the pipe axes of the pair of pipes on the line pipe side of the upstream pipe and the downstream pipe, and the pair of pipes on the flow meter body side of the upstream pipe and the downstream pipe It is characterized in that the pipe axes of the pipes are also matched .

The upstream / downstream piping structure of the Coriolis flow meter of the present invention described in claim 3 is the upstream / downstream piping structure of the Coriolis flow meter according to claim 1 or 2,
The natural frequency of the pair of pipes on the flow meter body side of the upstream pipe and the downstream pipe combined into one using the pipe support member is inconsistent with an integral multiple of the drive frequency of the Coriolis flow meter. with adjusted to, it is characterized in that to adjust the natural frequency of another of the pair of pipes to be a mismatch.

The upstream / downstream piping structure of the Coriolis flow meter of the present invention described in claim 4 is the upstream / downstream piping structure of the Coriolis flow meter according to claim 1 , claim 2 or claim 3 , wherein It is characterized in that it is fixed by means of bundling means with three bolts and nuts .

  The operation relating to the upstream / downstream piping structure of the Coriolis flowmeter of the present invention will be described in detail in the section of the best mode for carrying out the invention.

According to the present invention described in claim 1, Ki out to minimize the effects of pipeline stresses, the pipe stress can be concentrated on one point of the pipe support member which was secured to the frame. Also, as possible it is possible to improve the workability of the fixing of the pipe support member.

According to the second aspect of the present invention, the pipe stress from the upstream line pipe to which the upstream pipe is connected and the pipe stress from the downstream line pipe to which the downstream pipe is connected can be offset. Further, the vibration leaking from the flow meter body to the upstream pipe and the vibration leaking from the flow meter body to the downstream pipe can be offset.

According to the third aspect of the present invention, the upstream pipe and the downstream pipe can be prevented from resonating with the drive frequency of the Coriolis flowmeter. In addition, it is possible to prevent amplification (tuning fork shape) from resonance caused by disturbance vibrations of the upstream and downstream pipes in a pair.

Hereinafter, description will be given with reference to the drawings.
FIG. 1 is a plan view showing an embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of the present invention, FIG. 2 is a front view, and FIG. 3 is a side view. 4 is a plan view of the upstream pipe and the downstream pipe, FIG. 5 is a front view, and FIG. 6 is a side view. FIG. 7 is a plan view of a pipe support plate constituting the pipe support member, and FIG. 8 is a front view including a partial cross section of the pipe support plate.

  1 to 3, reference numeral 1 indicates a Coriolis flow meter attached between an upstream line pipe 2 and a downstream line pipe 3 through which a fluid to be measured (not shown) flows. The Coriolis flow meter 1 includes a flow meter main body 4, an upstream pipe 5 and a downstream pipe 6 extending from the flow meter main body 4, and a pipe support member 7. The upstream pipe 5 extends from the flow meter body 4 toward the upstream line pipe 2, and is connected to the upstream line pipe 2 via a flow control valve 8 and a cheese (T) 9. . The downstream pipe 6 extends from the flow meter body 4 toward the downstream line pipe 3, and is connected to the downstream line pipe 3 via a flow control valve 10. The upstream pipe 5 and the downstream pipe 6 are close to each other, and a pipe support member 7 is provided in the close part.

  The present invention is characterized by the upstream / downstream piping structure of the Coriolis flow meter 1 in which the middle of the upstream piping 5 and the downstream piping 6 is once combined using the piping support member 7. Moreover, this invention has the characteristics also regarding fixation of the flowmeter main body 4 of the Coriolis flowmeter 1 which has this piping structure. Hereinafter, the characteristics of each component of the Coriolis flow meter 1 and the piping structure will be described with reference to FIGS.

  The flow meter main body 4 includes a housing 11, a pedestal reinforcing plate 13 for attaching the flow meter main body 4 to the gantry 12, a flow tube (not shown) housed in the housing 11, and a drive device (not shown). A sensor unit (not shown) having a pair of vibration detection sensors (not shown) and a temperature sensor (not shown), and a signal calculation processing unit (not shown) that performs a calculation process such as mass flow rate based on a signal from the sensor unit (Not shown), an excitation circuit section (not shown) for exciting the drive device, and a terminal box 15 having the signal calculation processing section and the excitation circuit section and having a power supply connection section 14. ing. The flow meter main body 4 having such a configuration obtains the mass flow rate and / or density of the fluid to be measured by detecting a phase difference and / or vibration frequency proportional to the Coriolis force acting on the flow tube. It has become.

  The housing 11 has a structure that is strong against bending and twisting. Moreover, the housing | casing 11 is formed in the magnitude | size which can accommodate the said flow tube. Furthermore, the housing | casing 11 is formed so that main parts of flowmeters, such as the said flow tube, can be protected. The inside of the housing 11 is filled with an inert gas such as argon gas. By filling with the inert gas, condensation on the flow tube or the like is prevented.

  The base reinforcing plate 13 has a base mounting plate 16, a pair of joints 17, and a joint support portion 18 that supports the pair of joints 17. The pedestal mounting plate 16 and the pair of joint support portions 18 are formed of a single metal. The housing 11 is fixed to the substantially upper center of the pedestal mounting plate 16. The pedestal mounting plate 16 is fixed in a state in which this lower surface is in surface contact with the flow meter main body mounting portion 19 of the gantry 12. For fixing the pedestal mounting plate 16 to the flow meter main body mounting portion 19, tightening of three bolts 20 and nuts 21 is employed. By adopting the tightening of the bolts 20 and the nuts 21 at the three points, the surface is determined in spatial coordinates. Therefore, the flow meter body 4 is held at a fixed position with respect to the gantry 12. Reference numeral 22 indicates a spherical washer.

  A pair of inlet / outlet portions 23 of the flow tube are connected to the pair of joints 17, respectively. The pair of inlet / outlet portions 23 are arranged and formed so as to protrude outward from the housing 11.

  The upstream pipe 5 is a pipe connecting the upstream line pipe 2 and the flow meter body 4, and one end of the upstream pipe 5 is connected to the upstream line pipe 2 and the other end is connected to the flow meter body 4 as shown in the figure. Connected to the joint 17. The upstream pipe 5 has an intermediate portion 24 where the pipe support member 7 is provided, a line pipe connecting portion 25 on the upstream line piping 2 side, and a flow meter main body connecting portion 26 on the flow meter main body 4 side. Yes. The intermediate portion 24 is bent in an arc shape so as to turn the direction of the line pipe connection portion 25 by 90 °. The line piping connection part 25 is formed in a linear shape. The tube axis of the line piping connection portion 25 is set to be orthogonal to the tube axis of the flow meter main body connection portion 26 by the intermediate portion 24. The flow meter main body connection portion 26 is formed in a U-shape (or U-shape). The arrangement of the flowmeter main body connecting portion 26 having such a shape is arranged so that the position of the intermediate portion 24, in other words, the position of the pipe support member 7 is positioned above the flowmeter main body 4.

  The downstream pipe 6 is a pipe that connects the downstream line pipe 3 and the flow meter main body 4. One end of the downstream pipe 6 is connected to the downstream line pipe 3 as shown in the figure, and the other end is the flow meter main body 4. Connected to the joint 17. The downstream pipe 6 includes an intermediate portion 27 where the pipe support member 7 is provided, a line pipe connecting portion 28 on the downstream line piping 3 side, and a flow meter main body connecting portion 29 on the flow meter main body 4 side. Yes. The intermediate portion 27 is bent and formed in an arc shape so as to turn the direction of the line pipe connection portion 28 by 90 °. The line piping connection part 28 is formed in a linear shape. The tube axis of the line piping connection portion 28 is set to be orthogonal to the tube axis of the flow meter main body connection portion 29 by the intermediate portion 27. The flow meter main body connection portion 29 is formed in a U-shape (or U-shape). The arrangement of the flowmeter main body connecting portion 29 having such a shape is arranged so that the position of the intermediate portion 27, in other words, the position of the pipe support member 7 is positioned above the flowmeter main body 4.

  The upstream pipe 5 and the downstream pipe 6 will be described in more detail. The flow meter main body connection portion 26 in the upstream pipe 5 and the flow meter main body connection portion 29 in the downstream pipe 6 are different in the following points. That is, although the height H of the two pipes is common at, for example, 206.5 mm, the lengths W1 and W2 in the width direction are different at one (W1) of 263 mm and the other (W2) of 268 mm. Yes. Further, when the driving frequency in the flow meter body 4 is 82 Hz, for example, the former is 287 Hz, which is 3.5 times the driving frequency 82 Hz, and the latter is 270 Hz, which is 3.3 times the driving frequency. This frequency difference is 6% and 20% with respect to the tube frequency, and is generally a frequency difference in which the tuning fork phenomenon hardly occurs.

  In addition, it is known that the bending radius of curvature is advantageously 4D or more in terms of pressure resistance according to the standards of the High Pressure Gas Safety Association. In this embodiment, the curvature radius of bending of all the pipes is 5D (D: tube diameter). The connection of the upstream pipe 5 and the downstream pipe 6 to the joint 17 can be easily performed by slightly bending the flowmeter main body connection portions 26 and 29 because the flowmeter main body connection portions 26 and 29 are U-shaped. It can be connected.

  The pipe support member 7 is provided to once combine the intermediate portions 24 and 27 of the upstream pipe 5 and the downstream pipe 6. In this embodiment, the pipe support member 7 is composed of a pair of pipe support plates 30 that sandwich the intermediate portions 24 and 27 from above and below. The pipe support plate 30 is not particularly limited, but is formed in a substantially disk shape as shown in the drawing. In such a pipe support plate 30, a through hole 31 for fixing to the gantry 12 is formed in the center. Further, the pipe support plate 30 is formed with four pipe support grooves 32, a circular housing recess 33 for housing the intermediate portions 24 and 27, and four through holes 34.

  When the intermediate parts 24 and 27 of the upstream pipe 5 and the downstream pipe 6 are sandwiched from above and below by the pair of pipe support plates 30, the bent parts of the intermediate parts 24 and 27 come close to each other on both sides of the through hole 31 and face each other. It is like that. Further, the upstream pipe 5 and the downstream pipe 6 are supported by a pipe support groove 32. The pipe support member 7 is fixed to the pair of pipe support member mounting portions 37 of the gantry 12 when a bolt 35 is inserted into the central through hole 31 and a nut 36 is screwed. Note that four through holes 34 may be used to fix the pipe support plates 30 to each other.

  When the pipe support member 7 is fixed to the pair of pipe support member mounting portions 37 of the gantry 12, the fixed shaft crosses the line connecting the pipe axes of the line pipe connection portions 25 and 28 of the upstream pipe 5 and the downstream pipe 6. In addition, a line connecting the pipe axes of the flow meter main body connecting portions 26 and 29 is crossed.

  The gantry 12 has a sufficiently rigid structure, and includes a flow meter main body mounting portion 19, a pair of pipe support member mounting portions 37, and a column portion 38. The flow meter main body attaching portion 19 and the pair of pipe support member attaching portions 37 are firmly attached to the column portion 38 with a predetermined interval.

  As described above with reference to FIGS. 1 to 8, according to the present invention, the upstream pipe 5 and the downstream pipe 6 of the Coriolis flow meter 1 are once combined together using the pipe support member 7, The piping support member 7 is fixed to the gantry 12 at one location, and the flowmeter body 4 is fixed to the gantry 12 at three points. Therefore, according to the present invention, even if an external force is applied to the upstream pipe 5, the downstream pipe 6, and the flow meter body 4, the Coriolis flow meter 1 having high stability that does not cause zero point shift or instrumental span shift can be obtained. can do.

  Further, according to the present invention, not only gas measurement but also liquid measurement, not only DC component-like piping stress (effect due to pressure or temperature, impact due to impact pressure that leaves a history) but also AC component continuous. The piping state of the Coriolis flow meter 1 can be kept stable over a long period even against piping vibration.

  In addition, according to the present invention, since the pipe support member 7 is used, it is possible to provide a vibration system that includes only two upstream pipes 5 and 6 that are substantially simple.

  Further, according to the present invention, the fixing of the pipe support member 7 and the gantry 12 is one point, and the upstream pipe 5 and the downstream pipe 6 are opposed to each other with respect to the upstream line pipe 2 and the downstream line pipe 3. By turning 90 degrees horizontally, the stress of the piping can be concentrated on one fixed portion (the fixed shaft of the piping support member 7). As a result, the piping stress can be offset. In addition, by making the force point and the fixed point as close as possible as in the present embodiment, the piping stress of the upstream line piping 2 and the downstream line piping 3 is applied to the gantry 12 without generating a bending moment in the piping. I can tell you.

  Further, according to the present invention, even if vibration leaks from the Coriolis flow meter 1 itself, the vibration element transmitted in the axial direction of the upstream pipe 5 and the downstream pipe 6 is opposed to the leaked vibration. Therefore, the vibration can be canceled in the pipe support member 7 as a mirror image vector. Accordingly, vibration leakage to the upstream line piping 2 and the downstream line piping 3 can be minimized (this is a Coriolis flow meter of the type that supports the conventional main body only by piping without being fixed to the frame) On the other hand, it is a more ideal piping and it is an effective method for fixing the flow meter as a reference device).

  Further, according to the present invention, since the flow meter body 4 is fixed to the gantry 12 by tightening three bolts 20 and nuts 21, piping stress is applied to the fixed portion of the flow meter body 4 through the gantry 12. If the residual stress such as the welded structure of the gantry 12 is released, or if the stress directly propagates from the upstream pipe 5 and the downstream pipe 6 to the flow meter body 4, the gantry It is possible to prevent stress from being generated between the main body 12 and the flow meter body 4. Therefore, the fixed condition can always be kept constant.

  Next, a supplementary explanation of the present invention will be given with reference to FIGS. Here, how effective the present invention is will be described with reference to schematic diagrams. In the figure, member names and the like are included instead of reference numerals.

  FIG. 9 is a three-dimensional view showing a method of fixing the Coriolis flow meter to the gantry. As shown in FIG. 9, the Coriolis flow meter is fixed at four points (fixed by bolts and nuts). In this case, if the gantry is distorted (the fixing points of the gantry and the flow meter main body do not match), distortion or stress may occur in the case (main body) of the Coriolis flow meter during fixation. For this reason, if the characteristics such as instrumental error performance of the Coriolis flow meter deteriorate or the stress is released over a long period of time, the zero point may be shifted or the instrumental error may be shifted due to changes in the fixed conditions. There is sex.

  On the other hand, in FIG. 10, the Coriolis flowmeter is fixed at three points (fixed with a bolt and a nut), and in this case, the Coriolis flowmeter is fixed when it is fixed even if the pedestal is distorted. There is no distortion or stress in the housing (main body). For this reason, characteristics such as instrument differential performance of the Coriolis flowmeter are stable over a long period of time. This requires a great amount of labor to include the four points strictly in the plane, and as can be seen from the fact that this is impossible in practice, fixing the three points is effective.

  11 (a) to 11 (e) and 12 (a) to 12 (e) relate to the fixing method of the flow meter body, and the spring element of the gantry and the spring element of the piping system upstream and downstream of the Coriolis flow meter. Is schematically represented.

  FIG. 11A shows an example in which the main body of the flowmeter is not fixed to the gantry, and shows a state where the upstream and downstream pipes are once collected at one point of the pipe support part (member). The upstream and downstream piping can be a spring element, but even if an external force is applied to the position of the piping support member, the upstream and downstream piping is not affected by the external force because it is one point here.

  FIG.11 (b) has shown the example at the time of fixing a flowmeter main body to a mount with only one point in the state of Fig.11 (a). Here, the space between the pipe support member and the mount can also be a spring element. When an external force is applied to the pipe support member, the flow meter body may move with a degree of freedom other than the displacement in the z-axis direction. However, since the external force acts equally on the spring elements of the upstream / downstream piping, the influence on the sensor is small.

  FIG. 11C shows an example in which the flow meter body is fixed to the gantry at two points. In this case, the fixing of the flow meter body is insufficient.

  FIG. 11D shows an example in which the flow meter body is fixed at three points. In this case, since the surface is determined in spatial coordinates at three points, the flowmeter body is held at a fixed position with respect to the gantry.

  FIG. 11E shows an example in which the flow meter body is fixed to the gantry at four points. In this case, the condition of the fixed surface cannot be constant at four points, and if the external force acting on the pipe support member is propagated to the gantry, the gantry is distorted and stress is generated in the flowmeter body. In some cases, fixing the entire flow meter (flow meter body + upstream / downstream piping) cannot be a fixed condition.

  FIG. 12A shows an example in which the main body of the flowmeter is not fixed to the gantry. FIG. 12A shows a state where the upstream and downstream pipes are supported at two separated positions. This method is mostly used for ordinary Coriolis flowmeters having a large diameter. The upstream and downstream pipes are spring elements. The difference from FIG. 11A is that when the relative relationship (displacement, angular displacement) between the two fixed ends changes due to an external force, the spring elements of the upstream and downstream pipes change.

  FIG.12 (b) has shown the example at the time of fixing the flowmeter main body to the mount at one point in the state of Fig.12 (a). There are two spring elements between the two piping support members and the gantry. When displacements (angular displacements) are given in different directions relative to the two fixed ends, the worst result is obtained in the example shown here (zero shift and instrumental difference shift are large). FIG. 12B corresponds to a state where the case (housing) is lightly in contact with the gantry (ground) in a conventional Coriolis flowmeter fixed only by piping.

  FIG. 12C shows an example in which the flow meter body is fixed to the gantry at two points. In this case, the fixing of the flow meter body is insufficient.

  FIG. 12D shows an example in which the flow meter body is fixed to the gantry at three points. In this case, since the surface is determined in spatial coordinates at three points, the flowmeter main body is held at a fixed position with respect to the gantry.

  FIG. 12E shows an example in which the flow meter body is fixed to the gantry at four points. In this case, the condition of the fixed surface cannot be constant at four points, and if the external force acting on the pipe support member is propagated to the gantry, the gantry is distorted and stress is generated in the flowmeter body. In some cases, fixing the entire flow meter (flow meter body + upstream / downstream piping) cannot be a fixed condition.

  In addition, what can be said in common in FIGS. 12A to 12E is that even if the relative relationship (displacement, angular displacement) between the two fixed ends does not change due to an external force, absolute displacement or angular The relative relationship between the spring elements of the upstream and downstream pipes is greatly changed only by the displacement. An ideal pipe is the example of FIG. 11A, but when the flowmeter main body has to be fixed to the gantry, the example of FIG. 11D is used.

  13 (a) to 13 (d) and 14 (a) to 14 (d) are diagrams in which a fixed point of the flowmeter body and a point of the piping support member are connected. Here, elements that determine relative positional relationships (not vibration elements) are shown.

  FIG. 13A shows an example in which the fixed point is one point and the position of the piping support member is one point, and corresponds to FIG. The number of elements is 1. In FIG. 13A, it can be seen that the space is free to rotate around the axis of the element.

  FIG. 13B shows an example in which there are two fixed points and the position of the pipe support member is one point, which corresponds to FIG. The number of elements is 3. In FIG. 13B, the surface is determined in spatial coordinates. It can be seen that when an external force acts on the pipe support member in a direction perpendicular to the axis connecting the two fixed points, the pipe support member rotates around the axis connecting the two fixed points.

  FIG. 13C shows an example in which the number of fixing points is three and the position of the piping support member is one point, and corresponds to FIG. The number of elements is six. Since FIG. 13C is the smallest unit that forms a cube, the structure does not move even if an external force is applied to the pipe support member.

  FIG. 13D shows an example in which the number of fixing points is 4 and the position of the piping support member is 1, and corresponds to FIG. The number of elements is 10. In FIG. 13D, the number of fixed points is increased by one compared to FIG. 13C. However, it can be seen that the structure becomes complicated and analysis and design become difficult.

  FIG. 14A shows an example in which the fixed point is one point and the position of the pipe support member is two points, and corresponds to FIG. The number of elements is 2. In FIG. 14 (a), it can be seen that the structure is freely rotated with reference to the fixed point due to the displacement of the two pipe support members.

  FIG. 14B is an example in the case where there are two fixed points and the position of the pipe support member is two points, and corresponds to FIG. The number of elements is 5. In FIG. 14B, the degree of freedom of rotation is given to the axis where the displacement of the two pipe support members connects the two fixed points. However, since the two pipe support members are not restrained from each other, the two pipe support members each perform separate rotational movements.

  FIG. 14C shows an example in which the number of fixing points is 3 and the position of the piping support member is 2, and corresponds to FIG. The number of elements is 8. In FIG. 14 (c), the positions of the two pipe support members are determined in the space by three fixed points. However, as compared with FIG. 13C, the number of elements increases, and analysis and design become difficult. In addition, it is difficult to equalize the fixing conditions in the upstream and downstream piping support members.

  FIG. 14D shows an example in which the number of fixing points is 4 and the position of the piping support member is 2, and corresponds to FIG. The number of elements is 14. In FIG. 14 (d), it is easy to make the fixing conditions equal in the upstream and downstream piping support members, but it is understood that the structure becomes complicated and the analysis and design become difficult.

  An ideal pipe is an example of FIG. 13C (FIG. 11D).

  15 (a) to 15 (d), 16 (a) to 16 (d), and 17 (a) to 17 (d) show the number of fixed positions of the flowmeter body and the action of external force. It is explanatory drawing which showed the relationship of the position of a point. There are six degrees of freedom (displacement in the x-axis, y-axis, and z-axis directions and angular displacement around the x-axis, y-axis, and z-axis) in the behavior of the object in spatial coordinates. (Displacement only) shows what angular displacement occurs in the centroid (the center of the fixed portion or the plurality of fixed portions). The reason for focusing on the angular displacement is that the zero displacement of the Coriolis flowmeter and the span shift of the instrumental error are easily caused by the angular displacement.

  As the external force acting on the point of action, if the positive direction in the y direction is the flow direction, the displacement in the left / right, front / rear, up / down direction (external force is represented as displacement here), The rotational motion is represented by the following symbols. Taking the x-axis, y-axis, and z-axis in the left-right, front-back, and upper-lower directions from the upstream to the downstream of the flow meter main body, respectively, the following results.

  (1) Displacement (external force) in the left-right direction (x-axis direction) acting on the action point: X, (2) Displacement (external force) in the front-rear direction (y-axis direction) acting on the action point: Y, (3) Working vertical displacement (z-axis direction) displacement (external force): Z, (4) Angular displacement around the left-right axis (x-axis) of the centroid: Xp (pitching), (5) Front-rear axis of the centroid (y-axis) Angular displacement around: Yr (rolling), (6) Angular displacement around the vertical axis (z-axis) of the centroid: Zy (yawing)

  FIG. 15A is an example in the case where the fixed position is one and the action point coincides with the fixed position. No moment is generated even when the external forces X, Y, and Z are applied to the point of application, so that no angular displacement occurs at the centroid (fixed point).

  FIG. 15B is an example in the case where there are two fixed positions and the action point is at an intermediate point on a line connecting the two fixed positions. No moment is generated even when the external forces X, Y, and Z are applied to the point of application, so that no angular displacement occurs at the centroid (fixed point).

  FIG. 15C shows an example in which there are three fixed positions and the action point is on a plane including the three fixed positions and at the centroid of a triangle. No moment is generated even when the external forces X, Y, and Z are applied to the point of application, so that no angular displacement occurs at the centroid (fixed point).

  FIG. 15D is an example in the case where there are four fixed positions and the action point is on a plane including the four fixed positions and at a quadrangular centroid. No moment is generated even when the external forces X, Y, and Z are applied to the point of application, so that no angular displacement occurs at the centroid (fixed point).

  FIG. 16A shows an example in which there is one fixed position, the action point is on the y-axis, and the distance δ is away from the fixed position. When the external forces X, Y, and Z act on the point of action, an angular displacement Xp about the x axis is generated around the centroid (fixed point) by the moment due to the external force Z. Further, an angular displacement Zy about the z axis is generated by the moment due to the external force X.

  FIG. 16B shows an example in which there are two fixed positions and the action point is separated by a distance δ in the y-axis direction from an intermediate point (centroid) on the line connecting the two fixed positions. When the external forces X, Y, and Z act on the point of action, an angular displacement Xp about the x axis is generated around the centroid due to the moment due to the external force Z. Further, when the structure connecting the two fixed positions has low rigidity, the external force X causes an angular displacement Zy around the z axis.

  FIG. 16C shows an example in which there are three fixed positions and the action point is on a plane including the three fixed positions and is separated from the centroid of the triangle by a distance δ in the y-axis direction. When the external forces X, Y, and Z act on the point of action, the angular displacement Xp around the x-axis occurs due to the moment due to the external force Z when the structure connecting the three fixed positions is low around the centroid. Become. Further, when the structure connecting the three fixed positions has low rigidity, the external force X causes an angular displacement Zy around the z axis.

  FIG. 16D shows an example in which there are four fixed positions and the action point is on a plane including the four fixed positions and is separated from the square centroid by a distance δ in the y-axis direction. When the external forces X, Y, and Z act on the point of action, the angular displacement Xp about the x-axis is generated by the moment due to the external force Z when the structure connecting the four fixed positions is low around the centroid. Become. Further, when the structure connecting the four fixed positions has low rigidity, the external force X causes an angular displacement Zy around the z axis.

  FIG. 17A shows an example in which there is one fixed position, the action point is on the z axis, and is separated from the fixed position by a distance δ. When the external forces X, Y, and Z act on the point of action, an angular displacement Xp about the x axis is generated around the centroid (fixed point) by the moment due to the external force Y. Further, an angular displacement Yr around the y axis is generated by the moment due to the external force X.

  FIG. 17B shows an example in which there are two fixed positions and the action point is separated by a distance δ in the z-axis direction from an intermediate point (centroid) on a line connecting the two fixed positions. When the external forces X, Y, and Z act on the point of action, an angular displacement Xp about the x axis is generated around the centroid due to the moment due to the external force Y. Further, when the structure connecting the two fixed positions has low rigidity, the external force X causes an angular displacement Yr around the y axis.

  FIG. 17C shows an example in which there are three fixed positions and the action point is on a plane including the three fixed positions and is separated from the centroid of the triangle by a distance δ in the z-axis direction. When the external forces X, Y, and Z act on the point of action, the angular displacement Xp around the x axis is generated around the centroid by the moment due to the external force Y when the rigidity of the structure connecting the three fixed positions is low. Become. Further, when the structure connecting the three fixed positions has low rigidity, an angular displacement Yr around the y-axis is generated by the moment due to the external force X.

  FIG. 17D shows an example in which there are four fixed positions and the action point is on a plane including the four fixed positions and is separated from the square centroid by a distance δ in the z-axis direction. When the external forces X, Y, and Z act on the point of action, the angular displacement Xp around the x axis is generated around the centroid by the moment due to the external force Y when the rigidity of the structure connecting the four fixed positions is low. Become. Further, when the structure connecting the four fixed positions has low rigidity, an angular displacement Yr around the y-axis is generated by the moment due to the external force X.

  18 (a) to 18 (d) are examples in which the flowmeter body in FIGS. 15, 16, and 17 is supported at three points, and the distance from the centroid to the point of application of external force is constant, It is a detailed explanatory view when the angle between the connected straight line and a plane including three fixed portions is inclined from the vertical to the horizontal direction.

  FIG. 18A corresponds to FIG. In the present invention, since the upstream and downstream piping of the Coriolis flow meter is once bundled into one, the piping support member bundled with the piping in the plane including the three fixed portions of the flow meter main body and the figure It is very difficult to provide a heart (center of gravity). Actually, as shown in FIG. 18B, the pipe support member is provided at a position away from the centroid of the triangle by the distance δ.

  FIG.18 (c) is a figure of the example which inclined the position of the piping support member by 45 degrees. FIG. 18D is a view corresponding to FIG. 16C and is a view in which the position of the pipe support member is tilted up to 90 ° and is horizontal. 18 (b), 18 (c), and 18 (d), it is FIG. 18 (b) that it is easy to ensure rigidity for all of the external forces X, Y, and Z that act on the action point. Is clear from the fact that the distances a, b, c from the fixed point to the action point are uniform and the force can be distributed. Therefore, it can be said that the position of the piping support member is best present on the axis perpendicular to the triangular plane and including the centroid.

  FIG. 19A is an overall view showing the positional relationship of the pipe support members that once bundle the upstream and downstream pipes of the Coriolis flowmeter. The upstream / downstream line piping and the upstream / downstream piping line piping connection portion face the flow meter main body connection portion of the upstream / downstream piping in the xy plane and are held so as to be turned by 90 °. Here, the line pipe moves in the pipe axis direction when pressure, temperature, and pipe stress change. At this time, since the pipe support member is fixed at one point, the pipe support member may be rotated by an external force, and stress may be applied to the upstream and downstream pipes of the Coriolis flowmeter. Therefore, the connection of the line piping to the piping support member is made by aligning the tube axis of the upstream and downstream line piping with the fixing point (fixing portion of the piping support member), and the upstream piping tube shaft and the downstream piping tube. It should be desirable to match the axis. This will be specifically described below.

  FIG. 19B shows an example in which both the upstream and downstream line piping and the upstream and downstream line piping connection portions are offset to the positive side in the x-axis direction. Here, the pipe axes of the line piping connection portions of the upstream / downstream line piping and the upstream / downstream piping match. In such a state, even if the external force A acts in the opposite direction, no moment is generated at the fixed point unless the amount is different. However, when the external forces B act in the same direction, an angular displacement Zy around the z axis occurs at the fixed point in any case.

  FIG. 19C shows an example in which the tube axes of the upstream and downstream line piping and the upstream and downstream piping are the same and pass through a fixed point. Here, even if the external force A acts in the opposite direction, the fixed point does not move unless the amount is different. However, when the external forces B act in the same direction, the fixing point may be displaced in the y-axis direction (no problem if the fixing is sufficiently strong).

  In FIG. 19 (d), the upstream line piping and the upstream piping line piping connection portion are offset to the x axis direction plus side, and the downstream piping and downstream piping line piping connection portions are offset to the x axis direction minus side. This is an example. That is, the pipe axis of the line piping connection portion of the upstream / downstream line piping and the upstream / downstream piping does not match. Here, when the external force A acts in opposite directions, an angular displacement Zy around the z axis is generated at the fixed point in any case. Further, when the external forces B act in the same direction, the fixing point may be displaced in the y-axis direction (no problem if the fixing is sufficiently strong).

  FIG. 19E shows an example in which the upstream and downstream line piping and the upstream and downstream piping are connected to the positive side in the z-axis direction. Here, the pipe axes of the line piping connection portions of the upstream / downstream line piping and the upstream / downstream piping match. In such a state, even if the external force A acts in the opposite direction, no moment is generated at the fixed point unless the amount is different. However, when the external forces B act in the same direction, an angular displacement Xp around the x axis occurs at the fixed point in any case.

  Since FIG. 19F is the same as FIG. 19C, description thereof is omitted.

  In FIG. 19 (g), the upstream line piping and the upstream line piping connection portion are offset to the positive z-axis direction, and the downstream piping and downstream line piping connection portions are offset to the negative z-axis direction. This is an example. That is, the pipe axis of the line piping connection portion of the upstream / downstream line piping and the upstream / downstream piping does not match. Here, when the external force A acts in the opposite direction, an angular displacement Xp about the x axis is generated at the fixed point in any case. Further, when the external forces B act in the same direction, the fixing point may be displaced in the y-axis direction (no problem if the fixing is sufficiently strong).

  Therefore, the fixing of the line piping connection portion of the upstream / downstream piping by the piping support member is the same as the tube axis of the line piping connection portion of the upstream / downstream piping as shown in FIG. 19 (c) (FIG. 19 (f)). It can also be seen that it is desirable to pass through a fixed point. In addition, this principle is applicable similarly to the flowmeter main body connection part of the upstream / downstream piping connected to a piping support member.

  Next, another embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of the present invention will be described with reference to FIGS. In the figure, a member name or the like is put in place of the reference numeral.

  FIG. 20 shows an example in which the upper surface of the flow meter body of the Coriolis flow meter is directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned 90 ° horizontally, and connected to the pipe line. The pipe support member is fixed to the frame at the center of the lower surface.

  FIG. 21 shows an example in which the flowmeter main body of the Coriolis flowmeter is not directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned 90 ° horizontally, and connected to the pipe line. The pipe support member is fixed to the frame at the center of the lower surface.

  FIG. 22 shows an example in which the upper surface of the flow meter main body of the Coriolis flow meter is directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned in the vertical direction of 180 °, and connected to the pipe line. The pipe support member is fixed to the frame at the center of the lower surface.

  FIG. 23 shows an example in which the flow meter body of the Coriolis flow meter is not directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned in the vertical direction of 180 °, and connected to the pipe line. The pipe support member is fixed to the frame at the center of the lower surface.

  FIG. 24 shows an example in which the upper surface of the flow meter body of the Coriolis flow meter is directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member and turned 90 ° vertically, and further turned 90 ° in the opposite direction on the same plane (crank-like bending), and Connected to the piping line. The pipe support member is fixed to the frame at the center of the lower surface.

  FIG. 25 shows an example in which the flowmeter main body of the Coriolis flowmeter is not directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member and turned 90 ° vertically, and further turned 90 ° in the opposite direction on the same plane (crank-like bending), and Connected to the piping line. The pipe support member is fixed to the frame at the center of the lower surface.

  FIG. 26 shows an example in which the lower surface of the flow meter main body of the Coriolis flow meter is directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned 90 ° horizontally, and connected to the pipe line. The pipe support member is fixed to the gantry at the center of the upper surface.

  FIG. 27 shows an example in which the lower surface of the flow meter main body of the Coriolis flow meter is directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned 90 ° horizontally, and connected to the pipe line. The pipe support member is fixed to the frame at the center of the lower surface.

  FIG. 28 shows an example in which the upper surface of the flow meter main body of the Coriolis flow meter is directly fixed to the gantry. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned 90 ° horizontally, and connected to the pipe line. The pipe support member is fixed to the gantry at the center of the upper surface.

  FIG. 29 shows an example in which the lower surface of the flow meter main body of the Coriolis flow meter is directly fixed to the frame. The upstream and downstream pipes of the Coriolis flowmeter are once collected by the pipe support member, turned 90 ° horizontally, and connected to the pipe line. The pipe support member is fixed to the frame at the center of the upper surface and the center of the lower surface. FIG. 29 corresponds to the example of FIGS.

  In addition, it goes without saying that the present invention can be variously modified without departing from the spirit of the present invention.

It is a top view which shows one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention. It is a front view of the upstream and downstream piping structure of a Coriolis flow meter. It is a side view of the upstream and downstream piping structure of a Coriolis flow meter. It is a top view of upstream piping and downstream piping. It is a front view of upstream piping and downstream piping. It is a side view of upstream piping and downstream piping. It is a top view of the piping support board which comprises a piping support member. It is a front view containing the partial cross section of a piping support board. It is a three-dimensional view showing a method of fixing the Coriolis flowmeter to the gantry (fixed at four points). It is a three-dimensional view showing a method of fixing the Coriolis flowmeter to the gantry (fixed at three points). It is explanatory drawing (pipe support member is one point) which represented typically the spring element of a mount frame, and the spring element of the upstream and downstream piping system of a Coriolis flowmeter. It is explanatory drawing (two piping support members) which represented typically the spring element of the mount frame, and the spring element of the upstream and downstream piping system of a Coriolis flowmeter. It is the figure (the piping support member is one point) which connected the fixed point of the flowmeter main body, and the point of the piping support member. It is the figure which connected the fixed point of the flowmeter main body, and the point of a piping support member (two piping support members). It is explanatory drawing which showed the number of the fixed positions of a flowmeter main body, and the relationship of the position of the action point of external force. It is explanatory drawing (the action point leaves | separates in a y-axis direction) which showed the number of the fixed positions of a flowmeter main body, and the relationship of the position of the action point of an external force. It is explanatory drawing (the action point leaves | separates to az-axis direction) which showed the number of the fixed positions of a flowmeter main body, and the relationship of the position of the action point of external force. This is an example of the case where the flow meter body is supported at three points. The distance from the centroid to the point of action of the external force is constant, and the angle between the connected straight line and the plane including the three fixed portions is perpendicular. It is explanatory drawing at the time of inclining in a horizontal direction. It is explanatory drawing which shows the positional relationship and effect | action of the line piping connection part of upstream / downstream line piping and upstream / downstream piping. It is a schematic diagram which shows other embodiment of the upstream and downstream piping structure of the Coriolis flowmeter of this invention, (a) is a top view (only piping), (b) is a front view, (c) is a side view. is there. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention. It is a schematic diagram which shows other one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention. It is a schematic diagram (equivalent to FIGS. 1-3) which shows one Embodiment of the upstream / downstream piping structure of the Coriolis flowmeter of this invention. It is a schematic diagram which shows the attachment state of the Coriolis flowmeter of a prior art example, (a) is a front view, (b) is a side view. It is a schematic diagram which shows the attachment state of the Coriolis flowmeter of a prior art example, (a) is a front view, (b) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coriolis flow meter 2 Upstream line piping 3 Downstream line piping 4 Flowmeter main body 5 Upstream piping 6 Downstream piping 7 Piping support member 11 Housing | casing 12 Mount 13 Base reinforcement plate 16 Base mounting plate 17 Joint 18 Joint support 20 Bolt 21 Nut 30 Piping support plate

Claims (4)

A housing that has a structure that is strong in bending and twisting, accommodates a flow tube, can protect the flow meter main part of the flow tube, and is filled with an inert gas inside;
A pedestal mounting plate that attaches the housing to a pedestal, a pair of joints, and a joint support portion that supports the pair of joints;
A flow meter body having a flow tube to be housed in the housing,
Coriolis obtains the mass flow rate and / or density of the fluid to be measured flowing in the flow tube by detecting a phase difference and / or vibration frequency proportional to the Coriolis force acting on the flow tube accommodated in the housing. In the flow meter,
A pipe that connects the flow meter body and the upstream line pipe into which the fluid to be measured flows, and extends from the flow meter body toward the upstream line pipe, and is linear on the line pipe side. A line pipe connection portion formed on the flow meter body, a flow meter main body connection portion formed in a U-shape (or U-shape) on the flow meter main body side, the line pipe connection portion on the upstream side, and the flow meter An intermediate portion that is bent in an arc shape so as to connect the main body connecting portion and turn the direction of the line pipe connecting portion 90 ° with respect to the flow meter main body connecting portion;
The tube axis of the line piping connection portion is set to be orthogonal to the tube axis of the flow meter main body connection portion by the intermediate portion, and a flow control valve and cheese (T ) Through which the upstream line piping is connected, and the upstream pipe in which the joint of the flow meter body is connected to the flow meter body connection portion;
A pipe connecting the flow meter body and the downstream line pipe through which the fluid to be measured flows out and the flow meter body, extending from the flow meter body toward the downstream line pipe, Line piping connection portion formed in a straight line on the side of the line piping, flow meter main body connection portion formed in a U-shape (or U-shape) on the flow meter main body side, and the line piping connection portion And an intermediate portion that is bent and formed in an arc shape so as to connect the flow meter main body connecting portion and turn the line pipe connecting portion 90 ° with respect to the flow meter main body connecting portion,
The tube axis of the line pipe connection part is set to be orthogonal to the tube axis of the flow meter main body connection part by the intermediate part, and the line pipe connection part side end is connected to the pipe axis via the flow control valve. A downstream pipe to which a downstream line pipe is connected, and the joint of the flow meter main body is connected to the flow meter main body connecting portion;
It is composed of a pair of pipe support plates formed in a substantially disk shape, a fixing through hole is formed in the center for fixing to the gantry, a plurality of pipe support grooves, and intermediate portions of the upstream pipe and the downstream pipe And a plurality of through-holes are formed, the intermediate portions of the upstream pipe and the downstream pipe are sandwiched from above and below by the pair of pipe support plates, and the intermediate portions are bent. A pipe support member that is close to and opposed on both sides sandwiching the through hole, and that the upstream pipe and the downstream pipe are supported by the pipe support groove;
Provided
An upstream / downstream piping structure of a Coriolis flow meter, wherein the piping support member is disposed so that the position of the piping support member is located above the flow meter main body, and the intermediate portions of the upstream piping and the downstream piping are combined into one. The pipe axes of the upstream pipe and the downstream pipe combined into one using the pipe support member are as follows:
Together to match the tube axis of the pair of pipes each line pipe side of the upstream pipe and the downstream pipe, tube axes of the pair of piping of the flowmeter body side of the upstream pipe and the downstream pipe also match
The upstream / downstream piping structure of the Coriolis flow meter according to claim 1, which is configured as described above. The upstream pipe and the downstream pipe combined into one using the pipe support member are:
The natural frequency of the pair of pipes on the flow meter body side is adjusted to be inconsistent with an integral multiple of the driving frequency of the Coriolis flowmeter, and the natural frequencies of the pair of pipes are not matched with each other. Adjust to
The upstream / downstream piping structure of the Coriolis flow meter according to claim 1 or 2, wherein the upstream and downstream piping structures are as described above. Fixed to the base of the flow meter body,
The upstream / downstream piping structure of a Coriolis flow meter according to claim 1, 2 or 3, wherein the upstream and downstream piping structure is performed by means of bundling means for tightening three bolts and nuts .

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