JPH04160209A - Rectifying portion structure - Google Patents

Abstract

PURPOSE:To conduct good rectification in a compact structure by projecting inlet side end portions of a pair of narrow passage forming members in a wide passage, and forming a bypass by a rectifier upstream of the narrow passage forming members to form a vortex generating portion between the inlet end side portion and the rectifier. CONSTITUTION:A pair of narrow passage forming members 9 for forming a narrow passage L2 are projected to the wide passage 6 side, and the inlet sides thereof are covered with a rectifier 7 to form a central inflow passage L3 connected to a pair of bypasses and the narrow passage L2. The current which flows in from the bypasses L1 and flows through the central inflow passage L3 forms a pair of vortices which are currents, the tangential speed distributions of which are along the central inflow passage L3 in the vortex generating portions V on both sides of the central inflow passage L3 between the inlet end portions 9t of the narrow passage forming members 9 and the rectifier 7. The flowing direction of the current is regulated by the vortex formation to obtain rectification having only the components in the direction of flowing along the central inflow passage L3 and the narrow passage L2. Thus, a rectifying portion structure of simple constitution can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention rectifies and causes fluid to flow into a narrow channel formed between a pair of narrow channel forming bodies from a wide channel upstream thereof. The present invention relates to a rectifier structure including a rectifier.

[Prior Art] Conventionally, as a method for rectifying the flow of fluid flowing from a wide channel into a narrow channel at a portion near the narrow channel entrance of the wide channel on the inflow side, A wire mesh, punched metal, honeycomb, etc. is placed nearby as a rectifier, and the rectification effect is achieved by passing the fluid through multiple linear channels installed in parallel in these members. There is.

[Problem to be solved by the invention]

However, since the above-mentioned conventional technology forcibly rectifies the flow while utilizing solid walls arranged in parallel to form each flow path, the rectification effect on the fluid is greatly affected by the turbulence of the fluid flowing into the rectifier. In addition, in order to improve the rectification effect, it was necessary to increase the width of the rectifier in the flow path direction. This has prevented the device from becoming more compact and has made it difficult to obtain a rectifier structure with a high rectifying effect.

Therefore, an object of the present invention is to obtain a rectifier structure that is compact and capable of performing good rectification.

[Means to solve the problem]

In order to achieve this object, the characteristic configuration of the rectifier structure according to the present invention is as follows: Each of the inlet side ends of the pair of narrow channel forming bodies protrudes into the floor path, and on the upstream side of the narrow channel forming body, A flow rectifier is disposed facing the inlet of the narrow flow channel, and fluid is detoured from the wide flow channel to the central inflow channel for the narrow flow channel between a pair of end edges and a pair of inlet side ends, respectively. The pair of inlet side ends are configured by a shielding member that forms a detour to guide the flow, and the pair of inlet side ends are arranged so as to form vortex generating parts between the pair of inlet side ends and the rectifier, and on both sides of the central inflow path. The reason is that it is covered with a rectifier, and its functions and effects are as follows.

[For production]

That is, in the rectifier structure of the present invention, a pair of narrow flow path forming bodies forming a narrow flow path are provided so as to protrude toward the wide flow path side. The inlet side of this narrow channel forming body is covered with a rectifier. Here, in this rectifier structure, a pair of detour paths and a central inflow path where these paths merge and connect to a narrow flow path are formed.

The flow that flows in from these detours and flows through the central inflow path is generated between the inlet side ends of the pair of narrow flow path forming bodies and the rectifier by the vortex generator provided on both sides of the central inflow path. At this point, the tangential velocity distribution forms a pair of vortices that flow along the central inlet channel.

In this region, the flow direction is restricted by the formation of vortices, so in effect the flow has only a component in the flow direction along the central inlet channel and the narrow flow channel following it (
This results in a rectified flow.

〔Effect of the invention〕

Therefore, in the present application, a pair of vortices are formed on both sides of the desired flow direction, and the vortices perform a rectifying action, so that a stable flow rectifying effect can be obtained. Furthermore, since the detour is closer to the narrow flow path side, there is no need to extend the rectifier to the inlet side of the narrow flow path formation body as in the conventional case, and a relatively compact and simple rectifier structure can be obtained. There is.

Furthermore, if the narrow flow path in this rectifying section structure is the nozzle section of a fluid vibrating flowmeter, fluid is supplied to the fluid vibrating flowmeter downstream of the nozzle section in a good rectifying state. This allows stable fluid vibration to continue, making it possible to improve measurement accuracy.

〔Example〕

The flow measuring device (1) having the rectifier structure of the present application will be explained based on Fig. 1.2. Figure 1 shows a plan view of the flow rate measuring device (1), and Figure 2 shows this flow rate measuring device (1).
Details of the main parts of the fluid vibratory flow meter (2) incorporated in 1) are shown. First, this flow rate measuring device (1)
The general configuration of this will be explained. This device (1) is configured such that the inflow and outflow of the fluid (f) to be measured is such that the inflow direction (A) is 180 degrees opposite to the outflow direction (B). To explain in more detail, the fluid (f) such as gas or water flowing from the device inlet (3) passes through the abbreviated first bending path (4) and passes through the cutoff valve portion (5).
sent to. After passing through this shutoff valve part (5),
It flows into the reservoir (6) as a wide channel. This reservoir (
6) is provided with a rectifier (7) made of a shielding member. This rectifier (7) has a semicircular arc shape,
It is disposed opposite to the inlet of the nozzle part (8) of the fluid vibratory flowmeter (2) described above. Here, the inlet (8i) of this nozzle part (8) is formed by a pair of protruding parts (9) as narrow flow path forming bodies, which protrude into the above-mentioned storage part (6). .

From the arrangement relationship between the rectifier (7) and the pair of protrusions (6), the pair of end edges (lO) of the rectifier (7) are connected to the protrusions (
It is located on the downstream side in the flow path direction with respect to the pair of inlet side ends (9t) of 9). Therefore,
This pair of end edges (10) and the -pair of inlet side ends (9t)
A pair of detours (L1) are formed between them.

The fluid flows into the pair of detours (L1) facing each other, and at the upstream portion of the central flow path (L3) that connects to the straight flow path (L2) as a narrow flow path formed in the nozzle. They are formed to meet at the Here, the detour flow path (L
A pair of vortex regions (V) are formed sandwiched between 1) and the aforementioned pair of inlet side ends (9t) (this region is called a vortex generating section). Furthermore, the fluid (f) that has flowed into the nozzle part (8) is transferred to a flow passage enlarged part (12) provided downstream of the nozzle ejection surface (11) of the fluid vibrating flowmeter (2), and a throttle flow passage part. (13) and flows out from the device outlet (14).

The configuration of the fluid vibration flow meter (2) will be explained below based on FIG. 2. This fluid vibrating flowmeter (2) has the aforementioned nozzle part (8), a channel enlarged part (12), and a throttle channel part (13) that smoothly connects to the channel enlarged part (12). It is configured. Here, the nozzle part (8) has a 100-circle side wall part of the nozzle formed as a straight flow path parallel to the flow path, and has the nozzle ejection surface (11) perpendicular to the flow path direction. ing. Next, the enlarged channel part (12) will be explained. This enlarged channel part (12) has an enlarged channel inner wall surface (
15), and this inner wall surface (15) includes a main circular arc portion (16) in contact with the nozzle ejection surface (11), a straight wall portion (17) connected to this, and further this straight wall portion (17). It is composed of a sub-arc part (18) connected to. The rear end portion of this sub-circular portion (18) is connected to the aforementioned throttle channel portion (
13) by a similarly arcuate discharge arc portion (19). Furthermore, the flow path enlarged part (12)
A target (20) is provided at the center of the flow path to prevent the jet flow ejected from the ejection surface from moving straight. This target (20) has the effect of stably switching the flow direction of the jet flow in a microflow range.

Here, the convergence of the nozzle part (8) is w, the radius of the main arc part (16) is R1, the distance in the flow path direction from the jetting surface at the center of the sub arc part (18), and the radius of the main arc part (16) is R1. The distance in the flow path transverse direction from the nozzle axis at the center of is X, and the secondary arc part (18)
The radius of the target (20) is r, the width of the target (20) is Tw, the distance in the flow path direction from the jetting surface of the tip of the target (20) is TI, and the width of the throttle discharge part (14) is P. , R, LSx, r, Tw, TI, P are R/w=4.38, L/R=1.5, x/R=0.78, r/R'-0,5, Tw/w =1.75, TI/R=1, P/R=1. ．． There is a relationship of 18.

Further, the radius rl of the discharge arc portion (19) described above is approximately equal to r, and the maximum transverse dimension of the channel enlarged portion (12) is 2 (x
+r)/R=2.56, and furthermore, the nozzle ejection surface (1
The distance from 1) to the throttle channel section (14) is (L+r+
r1)/R=2.5. The rear end (2E) of the fluid vibration flowmeter (2) from the nozzle ejection surface (11) described above
The distance Z is Z=2. It is about 67R. Here, W
The actual dimension of R is 3゜2mm, and that of R is 14mm.
It is.

[Experiment example]

Experimental Example l Presence or absence of rectifier structure The measurement results of the flow rate-instrument difference characteristics in a fluid vibrating flowmeter with and without the above-described rectifier structure will be described below. Figure 3 (a) shows the flow rate-instrument difference characteristics when a rectifier is installed as in the example, and Figure 3 (b) shows the flow rate when a rectifier is not installed and the nozzle is directly connected. The flow rate-instrument difference characteristics when fluid is allowed to flow into the section from the storage section are shown. In the figure, ΔE is a value indicating Emax (maximum value on the plus side) - Emin (maximum value on the minus side) in the characteristic curve, and is a value that can determine the stability of the measurement.

Comparing FIGS. 3(A) and 3(B), the characteristic curves of the flowmeter show almost the same variation form over the small flow rate range to the large flow rate range. However, when looking at the width in the vertical axis direction, which indicates the magnitude of the error, the one that adopts the rectifier structure of the present application shown in (a) is about half or less than the one that does not use the rectifier structure shown in (b). It becomes. This shows that the change in error with respect to the change in measured flow rate has been significantly reduced compared to the conventional method. As a result, ΔE also decreased from 2.7 to 1.2.

The reason for this stability is that by adopting the rectifier structure of the present application, vortices are generated in a pair of vortex generating parts, and due to the action of these vortices, a sufficiently rectified flow is directed to the nozzle part of the fluid vibrating flowmeter. This is thought to be because it is flowing in.

Experimental Example 2 Dimensional relationship of each part in the rectifier structure Of the aforementioned protrusions, the first end (9L) near the fluid supply side where the shutoff valve of the reservoir is installed, and the first end of the rectifier adjacent to it The first distance from the edge (10L) is a,
The second end (9R) of the protruding part on the side far from the shutoff valve installation side of the storage part, and the second end (9R) of the rectifier adjacent thereto.
10R) is b, furthermore, the maximum separation distance in the nozzle flow path direction between the pair of inlet side ends (9t) of the protrusion and the rectifier (8) is C, and the convergence of the nozzle is w. FIG. 4 shows experimental results regarding changes in ΔE when these parameters are changed. In Figure 4, the horizontal axis shows a/(a + b), and the vertical axis shows ΔE
is shown.

Furthermore, C/W was selected as a variable parameter.

Here, the larger the value of the horizontal axis, the larger the first separation distance in the device, and the larger the variable parameter, the wider the distance between the tip of the protrusion and the rectifier.

For the result c/w, a range of 3.0 to 4.5 is the preferred result, and for a/(a + b), the range is 0.36 to 0.
．． A range of 54 has given favorable results. (ΔE is
Judgment was made based on the standard of 3% or less. ) Experimental Example 3 Dimensional Relationships of Each Part Having an Arc-shaped Entrance Side End FIG. 5 shows a configuration in which the tip end of the protrusion has a perfect circular arc shape. Furthermore, as a result of conducting an experiment similar to Experimental Example 2 using a device of this shape, the sixth
As shown in the figure.

As a result, almost the same results as shown in Experimental Example 2 were obtained.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings by the reference numerals.

[Brief explanation of the drawing]

The drawings show an embodiment of the rectifier structure according to the present invention, FIG. 1 is a diagram of a flow rate measuring device employing the rectifier structure, FIG. 2 is a diagram of a fluid vibrating flowmeter, FIG. 3 (A), (b) is a diagram of the flow rate vs. instrumental error characteristics when the rectifier structure is adopted and when it is not, and Figure 4 is Experimental Example 2.
5 is a diagram of the apparatus structure of Experimental Example 3, and FIG. 6 is the experimental result of Experimental Example 3. (2)...Fluid vibration type flowmeter, (6)...
... Wide flow path, (7) ... Rectifier, (8I) ...
Narrow channel inlet, (9)... Pair of narrow channel forming bodies, (9t)... Inlet side end, (9L)
...First end, (9R)...Second end,
(10)...Pair of edge parts, (10L)...
...First end edge, (10R)...' = Second end edge, (L1)...Detour, (L2)...-
・Narrow flow path, (L3)...Central inflow path, (V)・
...Vortex generation part, (a) ...First separation distance, (b) ...Second separation distance, (C) ...
・Maximum separation distance. -Acupuncture 1 411% -I

Claims (1)

[Claims] 1. A narrow channel formed between a pair of narrow channel forming bodies (9)
fluid (f) from the wide flow path (6) upstream of L2).
The rectifier structure is provided with a rectifier (7) that rectifies and flows into the wide flow path (6), and the pair of inlet side ends (9t) of the pair of narrow flow path forming bodies (9) are connected to the wide flow path (6). A rectifier (7) which is made to protrude inward and is disposed on the upstream side of the narrow channel forming body (9) and opposite to the inlet (8i) of the narrow channel is connected to a pair of end edges (10) thereof. The pair of entrance side ends (9t
) between the wide flow path (6) and the central inflow path (L3) for the narrow flow path (L2).
The pair of inlets are arranged such that a vortex generating part (V) is formed between the pair of inlet side ends (9t) and the rectifier (7) and on both sides of the central inflow path (L3). A rectifier structure in which the side end (9t) is covered with the rectifier (7). 2. The rectifier structure according to claim 1, wherein the narrow flow path (L2) is a nozzle part (8) of a fluid vibration type flowmeter (2). 3. With respect to the wide channel (6) to which fluid is supplied from the direction intersecting the longitudinal direction of the narrow channel (L2), the wide channel (L2) of the pair of narrow channel forming bodies (9) 6) The first separation distance (a) between the first end (9L) closer to the fluid supply side and the first end edge (10L) adjacent thereto is such that the pair of narrow flow paths are formed. a second spacing between a second end (9R) of the body (9) that is farther from the fluid supply side to the wide flow path (6) and the second end (10R) that is close thereto; The rectifier structure according to claim 1, wherein the rectifier structure is configured to be shorter than the distance (b). 4. With respect to the wide channel (6) to which fluid is supplied from a direction intersecting the longitudinal direction of the narrow channel (L2), the wide channel (L2) of the pair of narrow channel forming bodies (9) 6), the first separation distance between the first end (9L) closer to the fluid supply side and the first end edge (10L) adjacent thereto is a, and the pair of narrow flow path forming bodies ( 9), a second separation distance between the second end (9R) that is farther from the fluid supply side to the wide flow path (6) and the second end edge (10R) that is adjacent thereto; b
Further, the maximum separation distance in the longitudinal direction of the narrow flow path (L2) between the pair of inlet side ends (9t) and the rectifier (7) is defined as c, and the convergence of the nozzle portion (8) is defined as w. The rectifier structure according to claim 1, wherein the a, b, c, and w have the following relationships: c/w=3.0-4.5 a/(a+b)=0.36-0.54 .