JP3383576B2 - Pulsation absorption structure of flow meter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow meter used as an electronic gas meter or the like, and more particularly, to a pulsation in a speculative flow meter for intermittently measuring a flow velocity in a flow path to estimate an integrated flow rate. The present invention relates to a pulsation absorbing structure of a flow meter that reduces the influence of (pressure fluctuation, flow speed fluctuation).

[0002]

2. Description of the Related Art In recent years, as a flow meter used in an electronic gas meter or the like, an electronic sensor provided in a flow path is used to intermittently utilize an appropriate physical quantity that changes according to the flow velocity of a fluid flowing in the flow path. Predictive flowmeters are widely used that detect the current flow rate and intermittently measure the flow velocity in the flow path based on the detection signal of the electronic sensor to estimate the integrated flow rate. In addition, such a stochastic flowmeter, when evaluated by the electronic sensor used, is an ultrasonic type that uses an acoustic transducer, which is an element that transmits and receives ultrasonic waves in the fluid, and The fluidic type that uses a fluidic element for detecting the pressure fluctuation of the fluid is widely used.

FIG. 6 shows the basic structure of an ultrasonic flow meter 20 used as an electronic gas meter. The flow meter 20 is provided with an inlet 26 and an outlet 27 of a fluid to be measured (gas in this case) on the outer surface of the case 24, and is supplied to the measuring unit 28 and the inlet 26 on the outer surface of the case in the case 24. The fluid at the inlet end 2 of the measuring unit 28
8a, an in-case introduction path 29a, an in-case discharge path 29b for guiding the fluid passing through the measuring section 28 from the outlet end 28b of the measuring section 28 to the outlet 27 on the outer surface of the case, and a sensor provided in the measuring section 28. And an arithmetic processing circuit (not shown) for performing a predetermined arithmetic processing based on the detection signal of the sensor. The in-case introduction path 29a and the in-case discharge path 29b both utilize the inner wall surface of the case 24.

The measuring unit 28 includes a measuring conduit 22 which also serves as a gas flow path and an ultrasonic wave propagating conduit, and a pair of acoustic transducers 21 for transmitting and receiving ultrasonic waves between both ends of the measuring conduit 22. , 23. An arithmetic processing device (not shown) installed in the case 24 is, for example,
Acoustic transducer 2 on the inlet end 28a side of the measuring unit 28
The ultrasonic signal is generated from 1 and is received by the acoustic transducer 23 on the outlet end 28b side, and the propagation time t ₁ of the ultrasonic signal in the gas flow direction between the transducers is measured. Next, the operations of both transducers are switched so that an ultrasonic signal is generated from the transducer 23 on the outlet end 28b side, and the transducer 2 on the inlet end 28a side is generated.
The signal is received at 1 and the propagation time t _{2 in the} direction opposite to the gas flow direction is measured. The flow velocity V of the gas flowing in the measurement conduit 22 is intermittently calculated based on the difference in propagation time between the two measured propagation times t ₁ and t ₂ , and the cross-sectional area of the measurement conduit 22 is determined by this flow velocity V. Calculate the instantaneous flow rate by multiplying by. Further, the instantaneous flow rate is multiplied by a sampling time which is a constant measurement interval to obtain a passing flow rate, and the passing flow rate is integrated to obtain an integrated flow rate. The integrated flow rate obtained by the arithmetic processing unit (not shown) is displayed on a display unit (not shown) mounted on the outer surface of the case 24.

In such an electronic flow meter 20, compared with a conventional membrane (mechanical) meter which detects a pressure fluctuation of a fluid by displacement of a flexible membrane and measures a flow rate based on the detected value. Generally, the measuring unit 28 that detects a physical quantity necessary for measuring the flow rate can be made compact, and as a result, the entire flow meter can be made compact. Further, if the case 24 has the same size, it is possible to secure a larger empty space in the case as compared with the conventional membrane type meter, and the empty space can be utilized to further add value to the circuit. It will be possible to add equipment such as or.
Further, in such an electronic flow meter 20, since the sensor sensitivity is high, it is possible to measure a small amount of flow rate and to improve the measurement accuracy.

[0006]

By the way, a combustor such as a gas heat pump (GHP) which consumes fluid such as gas supplied through a flow meter of this kind, has a pressure fluctuation and a flow velocity fluctuation in the supplied gas during use. There are things that cause the pulsation of. Then, as shown in FIG. 7A, when the pulsation 25 generated by the combustor 30 propagates in the flow meter through the gas flow from the flow meter 20, the gas flow in the measurement conduit 22 is changed. There is a risk of pulsating flow. Further, when a plurality of flowmeters 20A, 20B, ... Are branched and connected to the main supply pipe 31, as shown in FIG. 7B, generation of the combustor 30A connected to the upstream flowmeter 20A. Pulsation 25A caused by flowmeter 2
0A and the gas flow in the branch supply pipe 31a may be transmitted to the downstream flowmeters 20B, ... That is, for example, in the downstream flow meter 20B, both the pulsation 25B from the combustor 30B connected to itself and the pulsation 25B from the combustor 30A connected to the upstream flow meter 20A are propagated. However, there is a possibility that the pulsating flow in the measurement conduit 22 will become more violent under the influence of both pulsations 25A and 25B.

In the flow meter 20 described above, when a pulsating flow is generated in the gas flow in the measuring pipe 22 due to the influence of the pulsation generated by the combustor, as shown in FIG.
When the flow velocity V of the gas flow is detected at t and the passing flow rate is obtained by multiplying the detected flow velocity V by the sampling time Δt, the shaded portion in the figure is an error, and the passing flow rate is integrated to obtain the integration. The flow rate is an integrated value that is significantly different from the actual gas usage, which causes a serious problem of increased measurement error.

Therefore, in the flow meter 20 described above, it is desirable to take measures to prevent the propagation of pulsation to the measuring conduit 22, but if the mechanism for reducing the propagation of pulsation becomes complicated,
A new problem that it becomes difficult to incorporate it into the flowmeter 20 of a limited size, or it becomes necessary to devise the structure and arrangement of the measuring unit 28, which leads to a major remodeling and a significant cost increase. Occurs.

An object of the present invention is to solve the above problems, and in a flow meter used for an electronic gas meter or the like, it is possible to efficiently reduce the propagation of pulsation into the measuring section, and also to reduce the case and It is to provide a pulsation absorbing structure for a flow meter that can realize accurate flow rate measurement easily and inexpensively without requiring a major modification to the measuring unit in the case.

[0010]

The above object of the present invention is to provide an inlet and an outlet for the fluid to be measured on the outer surface of the case, and to appropriately change the inside of the case according to the flow velocity of the fluid flowing in the flow path. A measuring unit that intermittently detects a physical quantity by an electronic sensor provided in the flow path, an in-case introduction path that connects the inlet and the inlet end of the measuring unit, an outlet end of the measuring unit, and the outlet. A pulsation absorbing structure for a flowmeter equipped with an in-case discharge passage, which reduces pulsation acting on the flow of fluid in the measuring section, wherein at least one of the in-case introduction passage and the in-case discharge passage Of the fluid
A partition wall for partitioning the flow into a main flow path and the bypass flow path, the deflection of adjusting the flow direction of the fluid such that a portion of the fluid is equipped in the vicinity of the end portion of the partition wall flows smoothly the bypass channel a structure in which a unit, and the pressure wave that has flowed through the bypass passage and the pressure wave that has flowed through the main flow path
And the bypass flow path length is set so that the phase shifts when they merge, and the deflection means is installed in the case.
Use the curved outer surface of the threaded boss that projects into the case.
Are solved by the pulsation absorber for a flowmeter, characterized in that the use.

According to the pulsation absorbing structure of the flowmeter having the above-mentioned structure, for example, a partition wall for dividing the flow passage into a main flow passage and a bypass flow passage, and a deflecting means for sending a part of the fluid to the bypass flow passage are provided. When equipped in the case discharge path, the pulsation propagated into the case from the combustor connected to the outlet of the flowmeter, when propagating through the case discharge path, is at a predetermined rate by the deflection means. Is divided into a main flow path and a bypass flow path. Along with this, the pulsations that have propagated separately in the respective flow paths are out of phase with each other, so there is a pressure wave that has propagated in the main flow path and a pressure wave that has propagated in the bypass flow path. When they are combined, they cancel each other out, the pressure wave of the pulsation is attenuated / absorbed, and the influence of the pulsation propagated from the downstream of the flowmeter on the measurement unit can be reduced.

Similarly, when the partition wall forming the bypass flow passage and the deflecting means for adjusting the flow direction of the fluid so that a part of the fluid stably flows into the bypass flow passage are provided in the case introduction path. Is the pulsation that has propagated into the case from another flow meter that is branched and connected upstream of the fluid supply channel that is connected to the inlet of the flow meter, when it propagates through the introduction channel in the case. Propagation is divided into a channel and a bypass channel. Along with this, the pulsations that have propagated separately in the respective flow paths are out of phase with each other, so there is a pressure wave that has propagated in the main flow path and a pressure wave that has propagated in the bypass flow path. When they are combined, they cancel each other out, the pressure waves of the pulsation are attenuated / absorbed, and the influence of the pulsation propagated from the upstream of the flowmeter on the measurement unit can be reduced.

Therefore, a partition wall forming a bypass flow path and a deflecting means for stably flowing a part of the fluid into the bypass flow path are provided in both the case introduction path and the case discharge path. Then, the influence of pulsation from both the upstream side and the downstream side of the measurement unit can be reduced.

Further, since the partition wall and the deflecting means as a mechanism for reducing the propagation of pulsation do not require a movable part or the like and have an extremely simple structure, the structure and arrangement of the measuring part are not elaborated. Both can be easily incorporated in the case of the flowmeter.

[0015] In particular, since a configuration in which the curved outer surface which projects into the case of the threaded portion boss portion to be mounted on to case is used as a deflection means to the bypass flow path, the structure of the case itself is effectively utilized It is, use specially the deflection means of separate parts
It is no longer necessary to agree.

Further, it is desirable that a partition wall that divides the in-case introduction path or the in-case discharge path into a main flow path and a bypass flow path is formed integrally with the case. By doing so, it is not necessary to manufacture the partition wall as a separate component.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a pulsation absorbing structure for a flow meter according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a schematic configuration of a first embodiment of a pulsation absorbing structure for a flow meter according to the present invention. This first
The pulsation absorbing structure of the embodiment is applied to the flow meter 1 used as an electronic gas meter. This flow meter 1
On the outer surface of the case 2, an inlet 3 and an outlet 4 for gas as a fluid to be measured and display means (not shown) for displaying a flow rate value calculated by an arithmetic processing circuit described later are provided.

Further, the flowmeter 1 has, in the case 2, provided at both ends of the measuring pipe line 5a with an appropriate physical quantity that changes according to the flow velocity of the fluid flowing in the measuring pipe line 5a provided in a straight tube shape. A measuring unit 5 that intermittently detects with a pair of electronic sensors 5b and 5c, an arithmetic processing circuit (not shown) that calculates the flow rate based on the detection values of the electronic sensors 5b and 5c, and an inlet 3 on the outer surface of the case 2. The in-case introducing passage 6 for guiding the fluid (gas) supplied from the connected main gas supply pipe 31 to the inlet end 5d of the measuring unit 5, and the fluid passing through the measuring unit 5 for the outlet end 5e of the measuring unit 5 From the case 2 to the outlet 4 on the outer surface of the case 2.

The measuring unit 5 is a flow meter 20 shown in FIG.
It corresponds to the measuring unit 28 in. That is, the pair of electronic sensors 5 provided at both ends of the measuring conduit 5a.
Reference numerals b and 5c are acoustic transducers that transmit and receive ultrasonic waves. The length L of the section shaded by a two-dot chain line in FIG. 1 is the length of the measuring unit 5.

Then, the arithmetic processing circuit (not shown) firstly generates an ultrasonic signal from the acoustic transducer 5b on the inlet end 5d side of the measuring section 5 and causes the acoustic transducer 5c on the outlet end 5e side to receive the ultrasonic signal, and then the transducer. The propagation time t ₁ of the ultrasonic signal in the gas flow direction between the two is measured. Next, the operation of both transducers is switched so that an ultrasonic signal is generated from the transducer 5c on the outlet end 5e side and is received by the transducer 5b on the inlet end 5d side, and the propagation time t _{2 in the} direction opposite to the gas flow direction. To measure. The flow velocity V of the gas flowing in the measuring pipe 5a is intermittently obtained based on the difference in propagation time between the two measured propagation times t ₁ and t ₂ , and the cross-sectional area of the measuring pipe 5a is determined by the flow velocity V. Calculate the instantaneous flow rate by multiplying by. Further, the instantaneous flow rate is multiplied by a sampling time which is a constant measurement interval to obtain a passing flow rate, and the passing flow rate is integrated to obtain an integrated flow rate. The integrated flow rate obtained by the arithmetic processing unit (not shown) is displayed on a display unit (not shown) mounted on the outer surface of the case 2.

In the case of this embodiment, the in-case introducing path 6 and the in-case discharging path 7 utilize the inner wall of the case 2 as flow path walls. In addition, the discharge path 7 in the case is
A partition wall 8 for partitioning the inside of the flow passage into a main flow passage 7a and a bypass flow passage 7b, and a partition wall 8 provided near both ends of the partition wall 8 so that a part of the fluid smoothly flows into the bypass flow passage 7b. Deflection means 10a, 10 for adjusting the flow direction of fluid
b.

The deflecting means 10a is for distributing a part of the fluid flowing from the outlet 4 into the in-case discharge passage 7 to the bypass passage 7b. The deflecting means 10b is for allocating a part of the fluid flowing through the measuring pipe line 5a and flowing into the in-case discharge passage 7 to the bypass flow passage 7b. These deflection means 10a and 10b are both
It is a curved outer surface of the boss portion 2a for a screw portion integrally provided in the case 2 and protruding into the case.

Further, the partition wall 8 has a wing shape (crescent shape) in which the bypass passage 7b side is largely curved, and is integrally formed with the case 2. The length of the bypass flow passage 7b is set so that the phase of the pressure wave flowing through the main flow passage 7a and the phase of the pressure wave flowing through the bypass flow passage 7b deviate at the time of merging.

A gas heat pump (GHP) for burning and consuming gas is provided at the outlet 4 of the flow meter 1 as shown in the figure.
Etc. combustors 14A and 14B are connected.

In the flow meter 1 described above, the pulsation 15 propagated from the combustor 14 to the outlet 4 of the case 2 is propagated through the in-case discharge passage 7 by the deflecting means 10a so that the fluid has a predetermined flow ratio. As the channels are distributed to the flow channel 7a and the bypass flow channel 7b, the flow is divided into the respective flow channels and propagates, and when the flows merge, the phases of the main flow channels 7a are deviated from each other, so When the propagating pressure wave and the propagating pressure wave in the bypass passage 7b are combined, they cancel each other out. More specifically, Exit 4
The pressure wave propagating from the inside of the case into the discharge path 7 is
As shown in (a), the amplitude (pressure difference) is ΔP and the period is t.
_In the case of the waveform N of _x , the pressure wave propagating in the main flow path 7a and the pressure wave propagating in the bypass flow path 7b are combined at the confluence of the flows near the deflecting means 10b. In that case, the waveform N _{1 of the} pressure wave propagating in the main flow path 7a and the waveform N _{2 of the} pressure wave propagating in the bypass flow path 7b are as shown in FIG.
As shown in (b), because the phases are out of phase with each other,
When they are combined, they cancel each other out to reduce the amplitude and the period, so that the pulsating pressure wave is attenuated / absorbed. Therefore, the influence of the pulsation propagated from the downstream of the flowmeter 1 on the measurement unit 5 can be reduced, and more accurate flow rate measurement can be realized.

Further, the partition wall 8 and the deflecting means 10a and 10b as a mechanism for reducing the propagation of pulsation do not require a movable part or the like, and the structure is extremely simple. Therefore, the structure and arrangement of the measuring part are special. It can be easily installed in the case of the flowmeter without elaborating. In other words, the case 2 of the flowmeter, the measurement unit 5 in the case 2 and the like do not need to be remodeled, can be easily incorporated into the case 2, and accurate flow rate measurement can be realized easily and at low cost.

The in-case introduction passage 6 and the in-case discharge passage 7 are formed by utilizing the inner wall of the case as flow passage walls, and the screw portion boss portions 2a and 2b mounted on the case 2 are formed.
Since the curved outer surface protruding into the case is used as the deflecting means 10a and 10b to the bypass flow path 7b, the structure of the case itself is effectively utilized, and it is not necessary to specially facilitate the deflecting means as a separate component. It is possible to reduce the number of constituent parts and the number of assembly steps.

Further, the case discharge path 7 is connected to the main flow path 7
Since the partition wall 8 that is divided into a and the bypass flow path 7b is also integrally formed with the case, it is not necessary to manufacture the partition wall 8 as a separate component, which further reduces the number of components and reduces the assembly process. Thorough reduction can be promoted to promote cost reduction.

In the first embodiment described above, the flow meter 1
Focusing on the absorption of the pulsation 15 propagated from the downstream side, the bypass passage 7b is provided only in the case discharge passage 7. However, the deflecting means for promoting the branch flow to the bypass flow path 7b are provided near both ends of the partition wall 8, respectively, and the deflecting means 10b on the measuring section 5 side allows the fluid flowing from the measuring section 5 to the fluid case discharge passage 7 to flow. The effect is small because the flow is divided into the bypass flow path 7b and the pulsation at the downstream of the measurement unit 5 is reduced.
Even for the pulsation propagated from the upstream of the measuring unit 5, the effect of reducing the influence on the measuring unit 5 is exerted.

FIG. 3 shows a schematic structure of a second embodiment of the pulsation absorbing structure of the flowmeter according to the present invention. The pulsation absorbing structure of the second embodiment is applied to the flow meter 1A used as an electronic gas meter. This flow meter 1A is simply equipped with a partition wall 8 forming a bypass passage 7b in the in-case discharge passage 7 and deflection means 10a, 10b for stably flowing a part of the fluid into the bypass passage 7b. Without the bypass passage 6b even for the introduction passage 6 in the case.
Partition wall 17 that forms a flow path, and deflection means 10a, 10 for dividing the fluid into the main flow path 6a and the bypass flow path 6b.
It is equipped with b and. The bypass flow passage 6b has a flow passage length set so that the pressure wave flowing through the main flow passage 6a and the pressure wave flowing through the bypass flow passage 6b are out of phase with each other in the same manner as the bypass flow passage 7b described above. There is. The flowmeter 1A has the same structure as the flowmeter 1 shown in FIG. 1 except that the partition wall 17 and the deflecting means 10a and 10b are also provided in the in-case introducing passage 6, and therefore the same parts are the same. The reference numerals are given and the description is omitted.

The inlet 3 of the flow meter 1A is branched and connected to the main gas supply pipe 31 of the gas via a branched supply passage 32. The inlet 13a of the other flow meter 13 is connected to the main supply pipe 31 so as to be located upstream of the flow meter 1A. Further, at the outlet 4 of the flow meter 1A and the outlet 13b of the flow meter 13, as shown in the drawing, combustors 14A, 14 such as a gas heat pump (GHP) that burns and consumes gas.
B is connected.

As described above, when the bypass passages 6b and 7b are provided in both the case introduction path 6 and the case discharge path 7, the pulsation 15A propagating from the upstream side of the flow meter 1A is dealt with. The bypass flow passage 6b effectively exhibits the pulsation damping / absorption effect by the phase difference of the propagating pressure wave, and the bypass flow passage 7b is provided for the pulsation 15B propagating from the downstream side of the flowmeter 1A. Since the pulsation is effectively attenuated and absorbed by the phase difference of the pressure wave propagating, the influence of the pulsation from both the upstream side and the downstream side on the measurement unit 5 is reduced, and more accurate flow rate measurement is realized. be able to.

When only the influence of pulsation propagating from the upstream side needs to be reduced, although not shown, the bypass passage and the deflection means described above are provided only in the case introduction passage 6. It is also possible to Further, the structure of the partition wall that divides one flow passage into the bypass flow passage and the main flow passage is not limited to the airfoil shape shown in the above embodiment. For example, the partition wall 8A shown in FIG. 4 and the partition wall 8B shown in FIG. 5 are also effective. The partition wall 8A shown in FIG. 4 has a simple plate structure with both ends bent in the inflow direction of the fluid and has a substantially uniform thickness. The partition wall 8B shown in FIG. It is a plate structure.

Needless to say, the design of each of the above constituent elements can be appropriately changed without departing from the spirit of the present invention. For example, the electronic sensor used in the measuring unit 5 is not limited to an acoustic transducer or the like that transmits / receives ultrasonic waves, and for example, a fluidic type flow meter may be configured using a fluidic element. Is also possible.

[0035]

According to the pulsation absorbing structure of the flow meter of the present invention, for example, a partition wall that divides the flow passage into a main flow passage and a bypass flow passage, or a deflection for sending a part of the fluid to the bypass flow passage. When the means is installed in the case discharge path, the pulsation propagated into the case from the combustor connected to the outlet of the flowmeter, etc. Are distributed to the main flow path and the bypass flow path at a predetermined flow rate ratio, and are propagated separately in each flow path, and when merged, the phases of the main flow path are out of phase with each other. When the pressure wave propagating inside the pressure wave and the pressure wave propagating in the bypass flow channel are canceled each other, the pulsating pressure wave is attenuated and absorbed,
It is possible to reduce the influence of the pulsation propagated from the downstream of the flow meter on the measurement unit.

Similarly, when the partition wall forming the bypass flow passage and the deflecting means for adjusting the flow direction of the fluid so that a part of the fluid stably flows into the bypass flow passage are provided in the case introduction path. Is the pulsation that has propagated into the case from another flow meter that is branched and connected upstream of the fluid supply channel that is connected to the inlet of the flow meter, when it propagates through the introduction channel in the case. Propagation is divided into a path and a bypass flow path, and when they merge, the phases are out of phase with each other,
When the pressure wave propagating in the main flow channel and the pressure wave propagating in the bypass flow channel cancel each other out when they are combined, the pulsating pressure wave is attenuated and absorbed, and from the upstream of the flow meter. It is possible to reduce the influence of the propagated pulsation on the measurement unit.

Therefore, the partition wall forming the bypass flow passage and the deflecting means for stably flowing a part of the fluid into the bypass flow passage are provided in both the case introduction passage and the case discharge passage. By doing so, it is possible to reduce the influence of pulsation from both the upstream side and the downstream side of the measurement unit and realize more accurate flow rate measurement.

Further, since the partition wall and the deflecting means as a mechanism for reducing the propagation of pulsation do not require a movable part or the like and have an extremely simple structure, the structure and arrangement of the measuring part need not be specially devised. Both can be easily incorporated in the case of the flowmeter. That is, the case of the flow meter, the measuring unit in the case, and the like do not need to be remodeled, can be easily incorporated in the case, and accurate flow rate measurement can be realized easily and inexpensively.

[0039] In particular, since a configuration in which the curved outer surface which projects into the case of the threaded portion boss portion to be mounted on to case is used as a deflection means to the bypass flow path, the structure of the case itself is effectively utilized It is, use specially the deflection means of separate parts
Without need to agree, the reduction of the components, to thoroughly reduce the assembly process, it is possible to facilitate a reduction in cost.

Further, when the partition wall for dividing the case introduction path or the case discharge path into the main flow path and the bypass flow path is formed integrally with the case, the partition wall is also specially separated. There is no need to manufacture it as a part,
Furthermore, it is possible to promote cost reduction by thoroughly reducing the number of components and the number of assembly steps.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a pulsation absorbing structure for a flow meter according to the present invention.

FIG. 2 is a graph for explaining a pulsation damping action in a case discharge passage of the flow meter of FIG.

FIG. 3 is a schematic configuration diagram of a second embodiment of a pulsation absorbing structure for a flow meter according to the present invention.

FIG. 4 is a sectional view of a main part of a flow meter showing another embodiment of the partition wall used as the pulsation absorbing structure of the flow meter according to the present invention.

FIG. 5 is a sectional view of a main part of a flow meter showing still another embodiment of the partition wall used as the pulsation absorbing structure of the flow meter according to the present invention.

FIG. 6 is a schematic configuration diagram of an ultrasonic flowmeter used as an electronic gas meter or the like.

FIG. 7 is a schematic diagram showing a propagation action of pulsation generated from a combustor connected to a flow meter.

FIG. 8 is an explanatory diagram of a measurement error caused by the influence of pulsation when the flow rate is calculated from the detected value of the flow velocity.

[Explanation of symbols]

1 Flow meter 1A flow meter 2 cases 3 entrance 4 exit 5 Measuring section 5a Measuring line 5b, 5c Electronic sensor 5d entrance end 5e Exit end 6 Case introduction route 6a Main flow path 6b Bypass channel 7 Case discharge path 7a Main flow path 7b Bypass channel 8 partition walls Deflection means 10a, 10b 14A, 14B Combustor

Claims (2)

(57) [Claims] 1. An electronic sensor in which an inlet and an outlet of a fluid to be measured are provided on an outer surface of a case, and an appropriate physical quantity which changes according to a flow velocity of a fluid flowing in the passage is provided in the passage. A flow meter equipped with a measuring section for intermittently detecting by means of, an in-case introducing path connecting the inlet and the inlet end of the measuring section, and an in-case discharge path connecting the outlet end of the measuring section and the outlet. The pulsation absorbing structure of a flow meter for reducing pulsation acting on the flow of fluid in the measuring unit, wherein at least one of the case introduction passage and the case discharge passage makes the flow of the fluid the main flow path. configuration with a partition wall for partitioning into the bypass passage, and a deflection means for adjusting the flow direction of the fluid such that a portion of the fluid is equipped in the vicinity of the end portion of the partition wall flows smoothly the bypass channel and, and, the main flow passage As to the flow pressure wave and pressure wave flows through the bypass passage phase shifts during merging, setting the bypass flow path length further as the deflection means, it is mounted on the casing
A pulsation absorbing structure for a flow meter, characterized in that a curved outer surface of the boss portion for the bending portion that protrudes into the case is used . 2. The introduction path in the case or the discharge in the case
Before dividing the exit into the main flow path and the bypass flow path
The partition wall is formed integrally with the case.
A pulsation absorbing structure for a flow meter according to claim 1 .